Category HOMESTEADING SPACE

On Skylab, for the very first time, life sciences were not just along for the ride—they were going to have top priority as a mission goal. And the NASA life sciences people—despite their organizational fragmentation, differenc­es of opinion, and constant criticism from outside—responded to the chal­lenge with a well-planned, ambitious set of experiments.

One group would test the cardiovascular system, studying heart function during exercise and simulated gravity (using lower body negative pressure). Another would be a very careful metabolic balance experiment with exact

44- Weitz assists Kerwin with a blood-pressure cuff.

measurement of all intake and output combined with pre-and postflight mea­surement of bone loss using gamma ray densitometry, more accurate than the x-rays used in Gemini. Yet another would measure the body’s respons­es to the stress of flight by measuring hormone levels in blood samples col­lected and frozen in flight—and observe whether the trend to a reduction in blood volume and red blood cell mass was continuing. And one would intensively evaluate the vestibular balance system in the inner ear, suspect­ed to be the culprit in space motion sickness. There were cleverly designed “scales” capable of measuring the “weight” (the mass actually) of the astro­nauts, of any food and drink they were supposed to eat but didn’t, and of their feces. There was even a special cap to measure and record brain waves during sleep, looking at duration and depth. The scientist members of the crews got to wear that one.

All these experiments would be carried out during flight, not just before and after, thanks to the ample size and weight of Skylab. But designing them to be carried out successfully was still an enormous challenge. The food sys­tem would have to accommodate the metabolic balance experiment. Feeding the crews was a pretty big part of getting ready for Skylab. Astronauts have to eat, and on this mission they’d have to eat for a long time. So there were a lot of requirements and considerations jostling each other for priority:

1. Learning how to package foods to be consumed in zero gravity.

2. Launching all the food for all three missions aboard the Skylab workshop because the Apollo spacecraft used as the crew’s taxicab wasn’t big enough to hold it. That meant selecting food treated and packaged to have a year-long shelf life in space—not the best setup for tasty meals.

3. Giving the crews food they’d like—making mealtime a positive experience on these long and isolated missions.

4. Keeping them well nourished, which is not the same thing as giving them food they’d like.

5. And last but definitely not least, discovering what happens to nutri­tional needs during long periods in weightless spaceflight. This would be one of the most important medical experiments.

Storage on orbit for up to a year at “pantry” temperatures was the most severe environment yet for space food. It ruled out fresh food, food that required refrigeration—any food you’d throw away at home if it hadn’t been eaten after a month or two. Both weight and spoilage considerations dictat­ed that the food should not be stowed mixed with water. If soup was want­ed, dried soup was stowed, and the water was added just before eating. So a lot of rehydratable food, from orange juice to spaghetti, was on the menu. Adding water doesn’t work for certain foods—for example, bread. The solu­tion here was to irradiate it for preservation, then vacuum-pack it. Unfor­tunately, vacuum-packing sucks most of the air out of bread, making it an unpalatable paste. Bread was not a hit. But the sugar cookies—food system specialist Rita Rapp’s own recipe—were delicious.

Foods that were to be served hot were packed in plastic bags, and the bags packed snugly in little flat round cans. The routine was as follows: open the can, add water to the food through a nozzle, smush it around to mix

the food and water, put it back in the can, put the can in a fitted receptacle in an airline-style tray, and turn on the electric strip heater. An hour or so later, the item would be hot. This system worked well. It was a little time­consuming; one crewman would usually prepare three meals an hour or so ahead of time. And it did generate a lot of trash. Hot coffee was achieved a different way; the crew just added hot water to the instant coffee and shook instead of smushing.

Once the Skylab food system, or galley, was developed, the big question was, how many different kinds of food would be provided, and how much of each? And that’s where the scientists came in. Their working hypothesis was that flying in space was like resting in bed, immobilized by illness or perhaps multiple fractures. You were in “negative metabolic balance.” You lost appetite and lost weight, and muscles not used began to atrophy. It was intuitively obvious that in space many muscles weren’t used much (those used for climbing stairs, for example). The energy needed for normal body activity must therefore decrease, and the need for food would decrease in proportion.

Along came Dr. G. Donald Whedon, an experienced and prestigious researcher, with a diet plan for Skylab. He proposed that all Skylab crewmen consume a diet of 2,400 calories per day, below their Earth-bound needs. The diet would contain precise amounts of calcium, phosphorus, and other electrolytes and specified amounts of protein and fat with very little variance allowed. Some additional carbohydrates—’’empty calories” such as lemon drops—were allowed if the men were still hungry. Menus would be made up with enough variety to provide a six-day cycle, which would then repeat.

The crews would eat this diet for eighteen days both before and after flight. And—here’s the key— both before, during, and after flight, every gram of matter that entered or left their bodies would be weighed and ana­lyzed. Thus, whether the men were gaining or losing calcium from the bones or nitrogen from the muscles would be known with precision. It was a love­ly experiment. But it gave rise to some practical problems.

First was standardizing the diet. The crew violently objected to the assump­tion that all of them would have to consume the same amount of food. Alan Bean weighed 150 pounds and had consumed less than 2,000 calories daily on his Apollo 12 flight. Jack Lousma weighed a fit 195 pounds and ate more than 3,000 calories a day on Earth. There was no way they could both be constrained to 2,400. The second problem was that the 2,400 number had been calculated based on the assumption that during spaceflight metabol­ic demands decreased and so did calorie consumption. This might hap­pen, the crew argued, but it was unproven; and even if it did happen, it was wrong to put the men on the in-flight diet for nearly three weeks before and after flight.

On і March 1971 Deke Slayton wrote a memo stating in part, “We are not raising goose livers, and it is unreasonable and unrealistic to force-feed astro­nauts.” Finally, the investigators agreed to tailor each crewman’s diet to his usual intake. A week-long test using prototype flight food was organized, and the results used to construct the in-flight diets. Instead of merging all nine men into one data set, each one would serve as his own control. Feed­ing the flight diet before launch was retained, however. Sure enough, eight of the nine crewmen lost weight during the eighteen days before launch.

Another problem was, how do you weigh things in weightlessness? It’s true; Justice’s scales are useless in space. The little weights would just float away. But objects in space still have mass—they just don’t have gravity pull­ing that mass against the scales. So Dr. Bill Thornton invented an ingenious device to measure the mass without using gravity. His theory was this: if you attach an object to the free end of a strip of spring steel, clamp the other end, and give the object a push, the steel will oscillate back and forth. And the heavier the object—or rather, the greater its mass—the more slowly will it oscillate. So you have only to attach whatever you want to measure, start it oscillating, and measure the time it takes to complete three back-and-forth movements—the “period” of the spring and mass. Skylab adopted Bill’s principle, and the Air Force built one large device for measuring the mass of the astronauts, and two small ones, for measuring food residue, feces, and other small amounts of substances and small items. Given the oppor­tunity, Dr. Whedon’s team wanted to measure the mass of everything to the greatest accuracy possible:

1. The bags used to capture feces came secured with green tape; the crews were instructed to “weigh” the tape, separately, each time they used a bag.

2. They were then asked to mass measure each used fecal bag “wet” before putting it into a vacuum oven, where it was dried for return to Earth.

3. Both large and small masses were requested to be “weighed” to six significant figures—less than a hundredth of a pound for people, and a thousandth of a gram for food residue. That called for averag­ing many repeated weighings.

Whedon’s team explored several methods for sampling sweat, but final­ly gave it up as impractical. They knew there would be considerable sweat­ing but estimated that only a small percentage of the controlled minerals would be lost by this route. “The problem with these procedures was that we’d be spending an inordinate amount of time in flight doing them,” Ker – win recalled. “With only three people aloft, eighty experiments to conduct, and a hotel to run, we needed everything streamlined and every nonessen­tial task deleted. We compromised. The investigators would use the aver­age weight of the green tape. We agreed to the many repetitions necessary to calibrate the mass-measurement devices in-flight to maximum accuracy, and they agreed not to require that accuracy in daily use.

“We also made another promise to ourselves. The rule was, if you didn’t eat all of a food item, you had to weigh the residue to keep accurate track of your intake. We vowed that if we started a food item, we’d finish it, and avoid having to weigh it.”

Many people in the medical field were involved in these issues, but the crew’s principal point of contact for the experiment was Dr. Paul C. Ram – baut, who functioned as the principal investigator’s principal coordinating scientist. Crewmembers argued, agreed, and compromised with Rambaut for several years. In January 1970 he wrote, “The proposed in-flight proce­dures do indeed involve excessive and unproductive use of crew time for manual manipulation of food, water and waste. This situation is unfortu­nate and its correction has so far eluded the most vigorous protests of the Medical Directorate.”

What Rambaut meant was that the Medical Directorate had fought hard for fully automated systems for collection and measurement of food and waste but had been spurned by the program manager because it would take too long, cost too much, and no one knew how to do it. The Medical Directorate was willing to make things as easy as possible for the crews. But they were absolutely not willing to compromise the validity of their exper­iments. In Apollo they had had to stand aside for operations. Skylab was their mission.

Progress was made during 1970. While the engineers were figuring out how to package soup in peel-top cans, NASA’s nutritionists were working on the menu. By August a list of seventy-two items was given to the crew for evaluation, and shortly thereafter their deletions and additions were tak­en into account. Out went the strawberry wafers, the lobster bisque, and the cheese soup; in went the German potato salad, peanut butter, and—in a move that would prove lucky later on—the Carnation Instant Breakfast. There were five soups, ten drinks, twenty-seven meat-and-fish items includ­ing chili with no beans, eight veggies, seventeen desserts and snacks, and five breakfast foods. The contract was issued (to Whirlpool, a washing machine manufacturer!) and food production planning began.

One of the new items accepted was frozen prime rib. Frozen? Yes! The program office had agreed to provide food freezers with enough capacity for about four hundred of the little food cans—almost enough to provide one frozen item per crewman per day. (The freezer, though, did not include a refrigerator, so fresh foods that would have to be kept cool were still not an option.) Besides prime rib the choices included filet mignon, buttered rolls, and coffee cake. The investigator objected to ice cream at first, fearing that its high fat content would make it too difficult to fit into the straitjacket of his dietary requirements. But the nutritionists showed that they could do the job, and ice cream was added to the list. This decision and these items were major contributors to crew satisfaction with the food, and the mission.

And then there was item number ten on the beverage list: “Wine (rose or sherry).” As the crewmembers discussed palatability and variety with the experimenters and attempted to make the diet as pleasant as practicable giv­en the constraints, someone said, “Wine is empty calories too! Let’s have some on the menu.” Surely, wine is empty calories by the standards of the experiment—it contains little or no protein or controlled electrolytes. But getting it by the doctors wasn’t so easy. Early in 1971 Deke Slayton wrote a memo requesting several changes to the food system. One of them was the addition of wine. This suggestion was indignantly rejected by the experi­menters. The reply stated, “We disagree with the assertion that the provi­sion of wine is mandatory to make the Skylab Food System flyable. Wine is not a necessary component of any nutritional regimen in any environment to which human beings are exposed. . . . The principal investigators of the MO71 and mho series of experiments are adamantly opposed to its use.”

The formal objection by the investigators’ representative, Dr. Leo Lutwak, stated, “Alcohol has effect on renal function via inhibition of anti-diuretic hormone. This introduces an additional variable even if consumed in the same amount daily by each man. Possible changes in retention and excre­tion of fluids and of hormones in flight (changes in kidney function with respect to water balance) are an important concern. . . .” But crew represen­tatives argued that if it were backed off to once a week, any effects would be transitory and self-correcting, and the investigators reluctantly concurred. This is how they put it:

Recomm endatio n:

1. Delete all alcoholic beverages from menu.

2. Will accept: a) No wine first two weeks in flight or in first 48 hours post flight. b) 4 oz. ofsherry (or equivalent stability wine) once per week thereafter. ”

The crew accepted this compromise philosophically. The nose of the cam­el was under the tent. Now they had only to select the wine. There were a few requirements. Dr. Lutwak was right; they needed to pick a sherry or other fortified wine that could tolerate storage in plastic for a year or more. Ordinary table wine, red or white, was likely to go bad. The other require­ment was to select an American wine.

A wine-tasting party was set up at Dr. Kerwin’s house on 20 November 1971. Wives were invited but didn’t get to vote. Kerwin had had the pleasure of narrowing down the list to six wines from Taylor, Paul Masson, Ingle – brook, Wente Brothers, Almaden, and Louis Martini. The evaluation sheet outlined the rating code (a modification of the Cooper-Harper scale used by military test pilots to describe the flying qualities of fighter planes) and added these comments:

There are six entries, three dry and three sweet. All are domestic. A couple of import­ed sherries are at the end ofthe table if you care to taste them for reference.

Recommend about У2 ounce for tasting purposes, as medical science cannot cure a wine hangover.

Plastic cups are provided to simulate flight hardware. It is permissible (though not mandatory) to re-use your cup. Rinsing facilities are not available—wipe with napkin or shirtsleeve if desired.

To help you fill out the "comment” line a list of adjectives follows: unpreten­tious, robust, dulcet, uncompromising, reminiscent, ethereal, insouciant, devil – may-care, cynical, Earthy. A more complete list is being compiled for the flight checklist.

The Taylor cream sherry was selected in a close contest, and Rita Rapp set about her packaging duties. But frustration lay ahead.

All of the crewmembers worked in a few public appearances during train­ing. One crewmember (“We won’t tell on you, Jerry,” Kerwin jokes) gave a talk in a southern state in which he mentioned that wine would be served on Skylab in the interest of gracious living and crew morale. Several of the listeners took umbrage at this, and letters began to arrive at NASA and con­gressional offices objecting to government-funded alcohol in space. NASA chose not to argue. Wine was quietly withdrawn from the menu, and the crews’ kidneys were spared.

Despite this setback, the food system came together nicely as launch day neared. Procedures were devised for stowing most of the food in large over­cans in the ring lockers in the upper workshop, each can carefully labeled with crewman, day, and meal. These would be brought down to the ward­room about a week’s worth at a time and arranged, ready for each meal. There was “overage” also stored—extra food in case of spills, substitutions (discouraged), or mission extensions. Much of the overage was devoted to items that wouldn’t affect mineral balance—lemon drops, butter cookies, black coffee. It was a little complicated in the days before bar codes, but everyone tried hard to make it work.

Also on the topic of mineral balance, there were the pills. It was very important to the investigators that the intake of protein, calcium, phos­phorus, and magnesium be held constant. Protein consumption had to be imbedded in the food items themselves, but the minerals could be consumed as supplements. So the following routine was devised: all items not eaten by each crewman were logged and reported to Houston during an evening sta­tus report. If an item was partially eaten, the residue was “weighed” and the weight reported. Overnight, the medical team calculated how much of these minerals had not been consumed, and in the morning a teleprinter message told each man how many calcium, phosphorus, or magnesium pills to take. Munching the morning pills quickly became routine.

As a final gesture of solidarity, the dieticians managed to squeeze a num­ber of fresh items into the crews’ diets during the pre-and postflight quar­antine periods. It was really nice to have a fresh salad with dinner amidst the cans and bags. The meals were pleasant and memorable and contribut­ed to a team spirit that made the hard work of experiment compliance in flight manageable.

The other major intersection between research and operations was exer­cise. It was a design challenge and battleground between the crews, the researchers and, often, the managers. When the Mercury astronauts were selected, there was an enormous emphasis on physical conditioning and toughness based on a complete ignorance of the effects of weightlessness on humans. So the Original Seven, having been exposed to every stress the doctors could think up, concluded that staying in shape was their respon­sibility, and nobody was going to tell them how to do it.

As Mercury and Gemini flights took place during the years 1961 through 1966, all in small capsules with little or no opportunity for exercise and for durations extending to Gemini 7’s fourteen days, a pattern began to emerge. Astronauts had eaten less during flight and returned having lost weight and (subjectively) some strength. There was evidence of a decrease in blood vol­ume and a suspicion that bone density might be decreasing. Normal bodi­ly functions were accomplished with no trouble, and the astronauts did not suffer psychologically — quite the reverse. They loved the weightlessness of space and declared their readiness to go to the moon.

More of the same was seen during Project Apollo. The crews accomplished their lunar surface excursions with enthusiasm and success, but they defi­nitely paid a price, coming home tired and needing several days to recover their preflight weight and strength. Space motion sickness, first reported in the Soviet space program, began to occur in the larger Apollo spacecraft; and there was a bit of a scare on Apollo 15 when the two lunar surface crew­men developed cardiac arrhythmias during the return flight. This was attrib­uted to a loss of fluid and electrolytes, especially potassium, during their extensive lunar surface activities. “No big deal,” said the astronauts, and the missions continued with potassium added to the orange juice. But a case could be made that their strength and endurance, and thus their ability to perform challenging physical tasks such as spacewalks, would be compro­mised on very long flights.

The doctors tried their best to organize an exercise program during Apol­lo. These efforts were rejected. Here is a quotation from a memo from Deke Slayton to Chuck Berry, dated 27 March 1968:

Your recent offer to assist in development of an in-flight exercise program for Apollo is appreciated. . . . I believe it is clearly understood that crew physical conditioning is the responsibility of this Directorate. . . . Our intention is to provide each crew with the means and protocol to maintain a reasonable level ofphysical well-being. We have no intention of complicating the procedure by keying to station passes, data collection points, or dictated work levels. You will be provided the crew’s best qualitative evaluation of their exercise program in the post-flight report.

That was the background for Skylab, which was to be the first opportu­nity for medical researchers to gain extensive in-flight data on human phys­iology in weightlessness. One of the centerpiece medical experiments was to be an exercise tolerance test. The astronauts would exercise on a bicycle ergometer to 75 percent of their maximum preflight capacity, while extensive measurements were made of heart rate, blood pressure, a twelve-lead elec­trocardiogram, oxygen consumption, and carbon dioxide production. The tests would be repeated every four days. The ergometer, without the mea­surements, would be available for exercise on the other days. It maintained good cardio-respiratory conditioning, but did little for strength.

Nobody raised any objection to the test. But there were several problems associated with the use of the ergometer for crew exercise. These ranged from whether and how a bicycle could be ridden in zero-G, and whether the data from zero-G would be comparable to that from pre-and postflight runs, to the question of how much daily exercise was the right amount, and wheth­er the ergometer alone was enough equipment. There was another device onboard, the Exergym—a small rope-and-capstan device that allowed a certain amount of “isokinetic” exercise—leg and arm pulling and push­ing at a constant velocity against a load. It was difficult to use and was used very little.

At the heart of the daily exercise debate was a fundamental issue. In order to understand the effects of long-duration spaceflight on humans, was it best to prescribe and constrain exercise or to let it vary freely and mea­sure and observe what happened? The research community was in favor of prescription. They argued that unless all possible variables could be con­trolled, the changes observed would be difficult, maybe impossible, to inter­pret. They had the science of statistical significance behind them.

The operations community (astronauts and most flight surgeons) was in favor of “measure and observe.” They argued that there was insufficient knowledge to write a good prescription; that there were too many variables whose control would have to be attempted—especially individual varia­tions in exercise tolerance and preflight conditioning; and that more would be learned by allowing the nine crewmembers to react to the environment. Having a spread of in-flight exercise intensity was good, they said; it would provide a chance to see whether a dose-response curve existed. And of course, the crew still had that strong distaste for being regimented.

The Skylab I crew worked out a compromise agreement. They would devise and document both a preflight and an in-flight exercise plan and would care­fully record all in-flight exercise. About six months before launch, the first crew performed their baseline exercise runs on the training version of the ergometer. The ergometer was a good aerobic device; it had been designed to accommodate loads of up to 300 watts for thirty minutes. But Bill Thornton had ridden the training version at 300 watts for nearly an hour and destroyed the motor; henceforth, it was “de-rated” to 250 watts. That turned out to be enough for the Skylab astronauts.

The baselines determined were the watts at which three minutes of ped­aling would stress each crewman to 25 percent, 50 percent and 75 percent of the maximum heart rate of which he was capable; that would be the in-flight protocol. Conrad’s baseline was 50, 80, and 120 watts; Kerwin’s, 50, 100, and 150 watts; Weitz’s, 100, 150, and 175. That’s when Conrad decided it was time to get in shape. He exercised his command authority to require a session of paddleball daily with one or the other of his crewmates. All three improved their conditioning noticeably. But the researchers decided it was too late to change the baseline; the crew ought to have an easy time of it on orbit.

How did it all turn out? All nine astronauts returned to Earth safely, and all but one are alive and well, over three decades later. The exception is Pete Conrad, who was healthy and vigorous until his tragic death in a motorcy­cle accident in 1999. But did the Skylab team accomplish their goals? Did they measure the right things and measure them accurately? Were they able to draw conclusions? And did they discover what’s needed to keep people well and effective in space?

First, all the equipment worked. Food was consumed, uneaten items logged, supplement pills taken. Urine was sampled and frozen; feces were proper­ly processed and dried; both were correctly returned. Exercise was accom­plished once it was learned how; oxygen consumption and vital signs were duly recorded. Lower body negative pressure and rotating chair devices did not fail. Nine men were measured as never before. And it’s a good thing they were because NASA remained conservative and skeptical till the end. Dur­ing the final flight, the NASA administrator required a weekly report—on Wednesdays, and in writing—that the crew was in good condition and cer­tified to go another week.

In spaceflight, the first symptom to show up is usually space motion sick­ness. The term was bowdlerized to “space adaptation syndrome” by some thoughtful researchers, but some irreverent crewmen called it dreaded space motion sickness, or “dsms” for short. It’s a lot like seasickness, and a severe case can make you miserable. A problem with treating motion sickness is that if you are already sick and take a pill, you’re likely just to throw it up. Shuttle crewmembers who get spacesick are now given injections to con­trol their symptoms. The drug, promethazine, is quite effective but makes you sleepy.

The odd thing is that a person’s susceptibility to motion sickness on Earth has no predictive value in space. You can be quite sensitive in boats or cars and never have a quiver while weightless, or the reverse. But repeated flights tend to diminish the severity of the illness. And after it goes away, usually in three or four days, zero-G is a lot of fun.

The Skylab I crew had no space adaptation syndrome during flight. Ker – win got seasick after splashdown and threw up in sickbay on the carrier, but seasickness was not unusual for him. The most surprising finding was that the rotating chair experiment showed that the crew was immune to motion sickness in flight once they had adapted. Kerwin said, “I think life on a rotating spacecraft will be easier than I thought.”

Once they learned how to ride the bicycle ergometer in zero-G, their per­formance matched their preflight levels. In between medical runs, Conrad exercised the most, Kerwin the least. In contrast with exercise, the lower body negative pressure experiment was much more stressful right from the

first run. Heart rates were higher, blood pressures dropped, and several runs were terminated early to make sure the subject didn’t pass out. Kerwin was the most susceptible. This was a concern early in the flight, but subsequent runs showed no further deterioration in performance.

Those three experiments were the main source of in-flight data on adap­tation — or deterioration—and the overall picture looked good. Also the crew ate well, slept well, and felt well. The physical work involved in their spacewalks gave them no trouble. Twenty-eight days in space seemed quite feasible. How would they react to gravity after landing?

Here are the basic findings. The crew had lost an average of 7.5 pounds of weight. They were unsteady and walked with feet wide apart. They were most comfortable lying down. Standing heart rate was 30 percent high­er than preflight. Ability to exercise on the treadmill was correspondingly lower; each of those heartbeats was moving less blood through their arter­ies. Treadmill performance on landing day did correlate with in-flight exer­cise; Conrad did best, while Kerwin was too tired to use the ergometer at all until the next morning. Response to the first lower body negative pres­sure test was just about the same as to the last in-flight test — worse than preflight. Blood tests showed that blood volume was down, and the num­ber of circulating red cells was smaller by 14 percent—the bone marrow was not producing them at all. Finally, postflight strength measurements on the arm and leg muscles showed big decrements.

Return to normal was relatively rapid. The crewmen ate and drank vig­orously after their first good night’s sleep, and much of the weight loss had been restored by the fifth day back. Performance on the lbnp and ergom­eter was close to normal preflight limits in a week, and completely normal in three weeks. Full leg strength returned more slowly, depending on what exercise the men chose to perform.

Some questions remained. Their bone marrow didn’t start to produce red cells again until about three weeks after landing. Imaging wasn’t sensi­tive enough to show visible bone loss, but examination of the returned urine and feces showed that they were losing calcium steadily with no sign of lev­eling off. The in-flight cardiovascular data from lbnp could be interpret­ed as “not yet steady state.” And the large losses in arm and especially leg strength were a sign that the crew hadn’t exercised enough. The next crew was strongly urged to do more.

Skylab 11, unlike their predecessors, faced space adaptation syndrome on Mission Day i. Lousma was most affected and vomited that evening. Bean and Garriott felt nausea; all three took Scop-Dex capsules on Day 2 to sup­press the symptoms, and Garriott and Lousma continued this medication on Day 3. Garriott and Bean tried making head movements to hasten their adaptation but decided they were not helpful. All were well enough for full duty by Day 4.

Initial adaptation issues aside, this crew’s in-flight experience was similar to that of the first crew. The big change was that they performed more exer­cise and did not allow exercise time to be preempted by other tasks as the first crew sometimes had. They launched with two additional exercise devic­es. After seeing the first crew’s strength losses, Bill Thornton got permission from Deke Slayton to add capability, with strict weight and volume limi­tations. (Exercise was still an operational responsibility.) Bill looked every­where for candidates, and found the Mini-Gym in John Rummel’s back room. He rebuilt it with help from center engineering and flight-qualified it. It was designed to produce “isotonic” loads on the back and legs, and was used faithfully by the crew during longer daily exercise periods. The other device was an “expander” from Sears, consisting of up to four springs with handles that could be used in various combinations. (The Russians cop­ied this device and used it in their Soyuz program for many years.) These devices largely solved the upper-body problem. The second crew also had a device to measure blood hemoglobin levels, to reassure the doctors that loss of red cells was not continuing.

Skylab II returned to Earth on 25 September 1973 at nineteen past one in the afternoon, and the Command Module was picked up by the uss New Orleans forty-four minutes later. Here’s some conversation between the crew­members and the crew Flight Surgeon, Dr. Paul Buchanan, as they pre­pared to egress:

Bean: “We’re going to have to be careful; as I said, I was dizzy. Better stick with me. But I feel like if I could move around, just sit up, and maybe the dizziness would go away.”

Garriott (who had already left his couch and taken the pulse of his crewmates): “I don’t think it will, Al. You ought to watch for it to increase slightly. It’s likely to increase, I think.”

Buchanan (to Garriott): “Are you doing all right standing?”

Garriott: “I’m doing fine, but I can tell that any sort of motion induces the sensation of pitching or rolling, a little dizziness.”

Bean: “That’s what I thought when I just leaned up. I thought that I didn’t feel like I was going to pass out, but I did feel like—that I would be unsta­ble. . . . Let’s not leave these guys standing out here too long.”

Bean (ten minutes later, in the medical lab): “I didn’t think we’d get back feeling this good.”

They did feel good, and they recovered rapidly from the effects of their flight—Garriott fastest. Their weight losses had been for Bean, 8.6 lbs. (5.5 percent); Garriott, 7.7 lbs. (5.7 percent); and Lousma, 9.25 lbs. (4.75 percent). By “r+5,” the fifth day after landing, their lower body negative pressure and exercise tolerance tests were “within normal limits”—that is, back with­in two standard deviations of their preflight results. That’s not 100 percent recovery, but it’s impressive. After R+9, Garriott and Lousma were returned to flight status in the T-38. Bean had strained his back on r+i (showing that muscles were a little more susceptible to injury after a long flight) and didn’t get back to flying for another week or so.

Loss of strength and endurance in the legs was virtually the same for this crew as for the first crew. That was a very encouraging finding and a worth­while payoff for the additional time this crew spent on exercise (about an hour a day each). But the decrements were still on the order of 20 percent, and Bean’s crew recommended to Carr’s that they increase exercise even more on their flight, then being extended to eighty-four days.

Although legs showed a decrement with their diminished use in weight­lessness, the arms were different. They were not only used for translation around the workshop, but there were two useful exercise machines available for heavy exercise. Jack was a consistent user of this hardware and his early postflight data show an average 15 percent increase in arm strength, while his two crewmates showed little change.

And that is when Dr. Bill Thornton, who was making the strength mea­surements, invented his “Thornton treadmill.” Faced with even more strin­gent limitations on what could be launched in the Command Module, Bill Thornton and engineering built the poor man’s treadmill from a strip of slippery Teflon, which could be fastened to the Skylab floor with fasten­ers already on board. The crew placed the Teflon near a side wall with a handrail to hold on to. Wearing cotton socks and the previously discarded

ergometer waist restraint, fastened to the floor with 180 pound-force bun­gees, they canted their bodies about thirty degrees forward and “ran,” feet slipping on the Teflon surface. It was much harder work than running, but it did the trick.

The Skylab ill crew lived longer in space than anyone had before—a lot longer—and spent more time and concentration thinking about the lack of gravity and its effect on their body and their performance. For the first month they felt rushed and behind and didn’t get enough sleep. After that they settled into a productive routine. How did they feel about it? Here is what they shared during the medical debrief:

Question: “When did you think you were in control of things and every­thing was ok?”

Ed: “Somewhere between four and six weeks. At four weeks we were over the hill and I think had started to settle down and by six weeks I felt locked in solid.”

Jerry: “If you drew a graph from launch day, you would have a fully steep slope and the graph would bottom out the day the three of us bombed out on M092 (for Jerry, that was on Mission Day 16, i December). And from then on, you can chart a gradual increase with a fairly reasonable slope until prob­ably Day 45, and then you could throw a gentle knee into it. Again there’s a positive slope, and we were on the increase all the way to the end.”

How stressful was the lower body negative pressure experiment? All three men came near to fainting on tests run during the tenth to sixteenth flight day. For these tests another astronaut was always assigned as an observer, able to watch the subject’s signs and terminate the tests if warranted. The test involved subjecting the subject’s lower body to a partial vacuum. There were three steps of increasing vacuum: minus thirty, forty, and fifty milli­meters of mercury, the latter estimated to pull blood into the legs about as much as standing quietly upright in normal gravity. These tests were ter­minated early, before the end of the minus fifty exposure—probably mak­ing both crew and experimenters a little doubtful that they’d go the whole three months. But things got better from there. Gibson had only one more test stopped, on Day 71; Carr and Pogue had none. Here are some of their comments:

Ed: “I would say that thirty up there was like fifty down here. . . the amount of sleep, amount of water intake and amount of salt intake were significant [variables] for me. If I felt dehydrated or overtired, I knew I would have a problem with lbnp. . . . I’ve always felt a craving for salt on this diet.”

Bill: “And related to that, perhaps equivalent, was the time of day. . . ear­lier in the day, you felt better.”

These men could feel the fluids shift within their bodies. During lbnp they would feel less fullness in the head as their legs became engorged—and sometimes that would be followed by cold sweat and faintness. Exercise also shifted fluid into muscles, but it felt much better. So did eva.

Jerry: “But the times when I could feel the fluid shifts the most were dur­ing exercise. As soon as you got on the bike and started pedaling, your head immediately began to clear up. And by the time you finished pedaling and the blood had shifted to your muscles, you felt great. Your nose was clear, the pressure was off your sinuses, and you felt good; tired from the work, but you felt clear.

Ed: “I recall that on the first eva it felt good to get outside and do some physical work for a long period of time. It was comfortable to have a heart rate above nominal for the duration of the eva.”

In contrast, they felt periods of dullness or sleepiness during times of less activity:

Jerry: “I think that during a period of adjustment my stamina, reserve, or whatever you want to call it, was gone. I found myself essentially living from meal to meal, what we call a lowering of blood sugar, when you’re get­ting really hungry and you start feeling fatigued and tired and dull. I don’t know what it is. I call it a lowering of the blood sugar. That’s what we felt up there, but as soon as we got a meal in us we would feel much better. You feel a little drowsy after the meal, but shortly after that you feel better. But then it only takes about two to three hours for you to become tired again. The old reserve and the stamina is gone and by 3:30 in the afternoon we were hungry again, feeling bad.”

Voice: “Did all three of you feel that?”

Bill: “I feel that way, but I would have liked to snack all the time I was up there; candy bars to eat periodically. I could have used those through­out the mission.”

Jerry: “I wish I could tell you where the calories go when you’re up there.”

Ed: “I felt the same effect as Jerry mentioned. I would have liked snacks. I would have liked three meals and then snacks in between, some high-ener­gy food like Bill mentioned.”

Question: “Listening to you, I get the impression that one might suggest shorter days or naps, recharging in that manner as well as eating.”

Ed: “A siesta right about noon time would have been great.”

Question: “Could you appreciate that your legs had diminished in size?

Ed: “You could see it and I think I could feel it in my calves, after I had worked the Thornton device, for example. That really was an excellent device. I’m glad we had it along. When did we start using it, around two weeks into the mission?”

Jerry: “Yes, somewhere between Day Ten and Fourteen is when we final­ly got time to set it up and start using it.”

Ed: “And from then on, we started to turn around.”

Jerry: “I felt pre-flight that the lbnp could be used. . . to maintain con­dition. I always hoped that you would take one of us as a control and put us in it every day as part of exercise. . . use it as an exercise tool and not require. . . all the instrumentation. Just get in it every day for five or ten minutes then see what you ended up with, compared to the other two guys.”

Question: “Which of you would have volunteered to be the no-exercise, no-LBNP control?”

Jerry: “Oh, I didn’t say no exercise (laughter). We had already decided that there would be no volunteers for no exercise.”

To summarize the crew’s opinion, the lbnp didn’t do much for them, but exercise was essential. And the postflight findings certainly bore them out.

They all adapted well to the topsy-turvy world ofweightlessness. As Carr related: “The first two-thirds of the mission, my dreams were one – G dreams, and I shifted to zero-G dreams about the last third. It really surprised me that I had some zero-G dreams.” They struggled a little bit to describe the feeling of carrying one’s personal “up” and “down” around in space:

Jerry: “Looking out the window at the Earth, sometimes the horizon would be upside-down. It was convenient just to flip (my own body) upside

down and look out the window. . . [but then] every once in a while you’d look inside at one of the other guys ‘upside-down with his feet locked in the ceiling’ and he looked funny that way. And the table was upside down. It was very strange.”

Jerry: “The normal mode of moving was just to go head first, whistling right down through the dome hatch all the way to the trash airlock. [But] if I ever decided to go through the other way, feet first, I had a very distinc­tive impression that I was very high and sure didn’t want to fall and hurt myself. It’s just because I had my feet out in front of me and all of a sudden there was a reference that connoted high.”

The following table compares data from the three Skylab crews.

Mission Duration	Food / Day (cal /kg.)	Exercise/Day (watt-min)	Weight Loss Percentage *	Leg Strength % decrease	Arm Strength % decrease
28 days	18.1	2,150	4.2% (1.7%)	20%	8%
59 days	19.7	4,686	5.3% (1.0%)	20%	0%
84 days	21.0	4,836	1.6% (0.0%)	14%	10%

Data Comparisons of Three Skylab Crews * Figure in parentheses is additional loss during prelaunch quarantine.

Those averages hide some sizeable individual variations. On Skylab I Con­rad exercised almost twice as much as Kerwin and munched many more cal­ories per kilogram than either of his crewmates. On Skylab II Lousma was a tiger for exercise, but Garriott ate the most. And on the final mission Carr set a record by losing essentially no weight (only two tenths of a pound) in nearly three months aloft. He was only the second astronaut ever not to lose weight in space. The first was Alan Shepard, not on his fifteen-minute Mer­cury flight but on his Apollo 14 journey to the moon.

But the averages do tell the story. The story is, “Feed them, exercise them hard, and they’ll do well in space.” Or, to quote Dr. Bill Thornton: “The conclusion is that muscle in space is no different from muscle on Earth; if it is properly nourished and exercised at reasonable load levels, it will main­tain its function.”

Based on the Skylab findings, here’s a combined narrative of what you could expect to happen to your body if you took a big “grand tour” flight to Mars.

When the rattle of the booster stops and you’re in orbit, that strange feel­ing of floating will occupy your attention fully. Your head feels full, as if you had a cold. You’ve been briefed to be very slow and careful with head and body movements. You will take this good advice and feel ok—but the per­son in the next seat will suddenly feel nauseated and reach for the sick bag. The flight attendant (all are trained nurses, as in the early days of commer­cial aviation) will give your neighbor an injection, and he’ll feel a little bet­ter in the morning and be back to normal in three days or so.

Your vestibular system adapts slowly to the absence of “down” — that constant acceleration of gravity. The same absence causes body fluids to migrate from the lower extremities up into your chest and abdomen; the body responds by decreasing thirst and effectively losing fluid. Your blood becomes a little more concentrated, with a higher red cell count. Your bone marrow notices this and stops producing new red cells.

You won’t get space motion sickness, but your appetite won’t be very good for the first several days, and learning to move, eat, go to the bath­room, and sleep while floating may seem hard. On the morning of day eight you’ll wake up thinking, “Wow! I feel great today!” But you’ll have lost six pounds since the day before launch. Your legs look ridiculously skinny. The chief flight attendant now puts you on a strict exercise program for the dura­tion of the flight.

Unused muscles atrophy; exercise is needed to keep them fit, and you have to keep doing it faithfully. A treadmill keeps your heart and lungs in order and provides some leg exercise; other devices simulate weight lift­ing and tone the other big muscle groups. The compression also helps your bone retain calcium, slowing the gradual thinning of bone structure that is another feature of zero-G.

Your flight goes on for several months. Your workload is light. The novelty of looking out the window at the stars slowly wears off; you become bored. Small habits and mannerisms of one of your fellow passengers, “Herb,” begin to irritate you. Psychological stress — “cabin fever”—is definitely a risk of long spaceflights as it is of any long isolation with a small group of people. Skylab didn’t experience much of that, because the crews had been so care­fully selected and extensively trained. We hope that your Mars flight has a compatible crew and good leadership. Talk to the flight surgeon about your problems with “Herb.”

You make it through the flight with flying colors. As reentry day gets clos­er, everyone becomes excited and upbeat. You and “Herb” exchange e-mail addresses. You’ve almost forgotten what gravity feels like. Now you are about to be reminded! You survive the parachute landing at the Space Recovery Field and are helped out of the spacecraft. You don’t feel very good. Every time you move your head the world moves too, a severe vertigo. You feel as if you weigh three hundred pounds, and you walk unsteadily, with feet wide apart. Your pulse races. You feel dizzy, tired, light-headed, and thirsty.

First your vestibular system needs to readapt to the long-absent gravity vector. Your weight is only a few pounds less than when you left, but you are low on body fluids and red cells in the blood—almost as though you had bled a pint or two from a wound. And your muscles, despite the exercise (did you slack off a little the last few weeks?) are weak. A very light landing day and a very long night’s sleep start you on the road to recovery. Next morning you feel like someone getting up after a bout with the flu—a little light-headed still, but good. A period of rehabilitation, with careful, supervised exercis­es, will be prescribed for three weeks to get you back to normal.

The red cell count will be normal in a month or so. Most of the calci­um lost from your bones will eventually return. You’ll have been exposed to radiation during your trip, including cosmic rays; the amount will deter­mine whether any future threats to health exist. The lifetime limit is prob­ably one Mars trip per person.

The Skylab medical data set rigorously quantified all these changes and allowed the causes of many of them to be understood. It demonstrated the safety of three-month spaceflights sufficiently to allow NASA to plan and build the International Space Station—and incidentally to allow the Soviet Union to plan and build Mir. Both the United States and Russia have built on this data and now routinely fly for up to six months. But the strict quan­titative metabolic balance study Skylab accomplished has never been repeat­ed. It did the job. And repeating it would drive the astronauts nuts.

If mankind is to travel from Earth to explore our universe, we will have to learn to live without the familiar experience of weight that is almost always with us on our home planet.

In the void between worlds, explorers will experience virtually total weight­lessness. It’s a strange environment without up or down, new to the body and with hidden threats, as big a step for us as was the classic emergence of life from the oceans onto dry land. They sputtered, we threw up, but apparently it won’t take us as long to adapt. The point is that the process of really understanding “weightlessness” and really adapting to it was started by nine men in 1973. This is the story of that adventure.

Skylab was America’s first step toward making space something other than a nice place to visit. Developed in the shadow of the Apollo moon missions and using hardware originally created for Apollo, the Skylab space station took the nation’s astronauts from being space explorers to being space res­idents. The program proved that human beings can successfully live and work in space.

For many members of the public, Skylab is perhaps best known for two things—its beginning and its end. During the May 1973 launch of the Sky­lab workshop, an unanticipated problem damaged the station on its way to orbit. And of course, Skylab captured the world’s attention with its fiery re-entry over the Indian Ocean and Australia in 1979.

But between those bookends lies a fantastic story of a pivotal period in spaceflight history. Skylab’s three crews lived there for a total of six months, setting — and breaking — a series of spaceflight duration records. While pre­vious U. S. spaceflights were focused on going places, Skylab was about being somewhere, not just passing through the phenomenal space environment, but mastering it. Everything that was to come afterward in U. S. spaceflight was made possible by this foundation—from scientific research in micro­

gravity on the space shuttle to the on-orbit assembly of the International Space Station.

Even the unanticipated challenges that arose during the Skylab program turned into opportunities. The damage that crippled the spacecraft during launch became a rallying point for NASA and led to a repair effort that was unplanned and unprecedented—and perhaps still unparalleled.

This book is the story not only of the nine men who lived aboard Skylab but of all those who made the program a reality. And, like Skylab itself, this book depended on the contributions of a variety of people who shared their stories.

One of the pleasant surprises encountered in writing our story came in late 2005 when we showed Alan Bean (commander of the second manned mis­sion) our draft of the second mission chapter. We had relied on the chron­ological account from Garriott’s in-flight diary to tie together the events and to develop the story of that mission.

Much to our surprise, Alan said that he, too, had kept an in-flight diary and offered it to us for inclusion in this book! Naturally we took him up on that offer and were then absolutely amazed to find the extent of his hand­written account—more than one hundred pages of carefully written—albeit very difficult to decipher—print and script.

It covered not only events on board but also interpersonal relationships, his thinking and action to promote team spirit and optimum performance, his thoughts of home and family, and even more. We then incorporated as much of the “Bean Diary” in the story of the second mission as we thought appropriate and then added his full diary as an appendix to assure that all of Alan’s thinking will be available to others.

Alan had kept the existence of the diary to himself for over three decades. Neither of his crewmates was aware that it had even been written. We are pleased and feel fortunate to include it here where others can better under­stand the thinking of arguably the most highly personally motivated crew­man to fly in space.

Each of the eight living members of the Skylab crews has shared their stories with us, providing fresh perspectives of this unique experience. We deeply regret that the program’s “Sky King”—first crew commander Pete Conrad—was not able to participate personally in this project. But his voice lives on in this book through previously recorded material.

You will also find portions of numerous interviews with Skylab engineers, scientists, managers, flight controllers, and other astronauts. We were struck by their unanimous view that Skylab was one of the most significant events in their professional careers—if not the most significant. Perhaps more to be expected, that is also true for all of the Skylab astronauts as well.

Yet, there has been very little written about the three missions themselves. Again almost all of our interviewees were most pleased to find that some of the crew were finally undertaking to report on these events from the per­spective of those involved and, hopefully, that the contributions coming from all of the Skylab team would not be lost. Unfortunately we will cer­tainly fall short of reaching the goal of recognizing even a modest part of their enormous contribution, but we do want to acknowledge their prime role in making the Skylab program the success we believe it came to be.

We hope that the dedication of this book reflects a little of that debt owed to the thousands of team members who really made it happen.

For all three of us, this book has been a true labor of love, and it is a story that we are very proud to be able to tell.

To start with, I was out in California
in Huntington Beach. And I got this call,
and it was the good Robert Crippen who was calling.

He said, “We had a drawing, and your name was drawn to be
a crewmember on smeat.” And I said, “What the hell is smeat?”

Bo Bobko

smeat, the Skylab Medical Experiment Altitude Test, was a full-length sim­ulation of a Skylab mission. The crew selected for the test would spend fif­ty-six days in a spacecraft mock-up without the benefits of actually being in space. Selection for the mission might seem a dubious honor, but for the commander of the chosen crew, things had been much, much worse.

“June io, 1969, was probably one of the low points in my life,” remem­bered astronaut Bob Crippen. On that date the future pilot of the first Space Shuttle flight learned that the project to which he had dedicated the past three years of his life was over. The U. S. Air Force had canceled its Manned Orbiting Laboratory program, leaving Crippen and his fellow members of the Air Force’s astronaut corps uncertain as to what the future held. Begin­ning almost four years earlier, a total of seventeen astronauts had been select­ed by the Air Force from the ranks of military pilots. During that time they had completed training on the NASA-developed Gemini spacecraft, which was to have been used in the Air Force program. They had also undergone training on the tasks they were to perform on the space-based laboratory.

At the time the program was canceled, the members of the corps were excited about the prospect of spaceflight, but now the Air Force would no longer have need for astronauts. The nation’s civilian space program, on the other hand, still had an astronaut corps, but that group had become overly

crowded as well. The last class of astronauts NASA had selected, a second group of scientist astronauts brought into the corps two years earlier in 1967, had dubbed themselves the “Excess Eleven” (or, in test-pilot terminology, xs-ii) when they realized just how low their odds were of being assigned to a spaceflight anytime in the near future.

Crippen said that after the program was canceled, “We sat around, and it seems like for a month afterward, we’d go to the bar every night at prob­ably about 2 o’clock in the afternoon and have a wake. One day, I remem­ber a crew meeting, and we were trying to figure out what we were going to do, and Bo [Bobko] said, ‘Why don’t we ask NASA if they could use any of us?’ And we said, ‘Bo, that’s the dumbest damn idea I ever heard. They’re canceling Apollo flights, and they’ve got more astronauts than they know what to do with.’

“But long story short, somebody asked. In fact, in some of my talks, especially with kids, I always remember Bo asked me that question, which I thought was dumb. It doesn’t hurt to ask, even if you think you know the answer. It really doesn’t.”

And, seemingly against the odds, the answer was “Yes.” The request for the mol astronauts to be accepted into NASA’s astronaut corps made its way to Office of Manned Space Flight associate administrator George Mueller, who was near the end of his tenure with the agency. The cancellation of the Manned Orbiting Laboratory marked the end of a period during which Con­gress had essentially forced NASA and the Air Force to compete with each other. Now NASA was beginning to make plans for its next crewed space­craft, the Space Shuttle. Mueller hoped to enlist the Air Force as an ally as it lobbied to make the Space Shuttle a reality. Although NASA already had more astronauts than it needed, Mueller believed it would be in the agen­cy’s best interest to try to curry favor with the Air Force by accepting its erst­while future spacemen into the NASA corps.

Director of Flight Crew Operations Deke Slayton, however, was unwilling to accept the entire group of Air Force astronauts into his already crowded corps. He invoked NASA’s requirement at the time that only candidates under the age of thirty-six be accepted, cutting the applicant field roughly in half. Seven mol astronauts were accepted into NASA’s corps as the seventh group of astronauts on 14 August 1969: Maj. Karol “Bo” Bobko, Lt. Cdr. Robert Crippen, Maj. C. Gordon Fullerton, Maj. Henry “Hank” Hartsfield Jr., Maj. Robert Overmyer, Maj. Donald Peterson, and Lt. Cdr. Richard Truly.

Even after NASA hired them, things weren’t settled for the former Manned Orbiting Laboratory corps. “We were fired twice the first year we were here,” Bobko explained. “They came and said, ‘You guys are fired. You’re going to have to leave.’ It wasn’t any joke; they were really serious. I don’t know if they called us in all at once or one at a time, but they told us we were fired. Twice.” However, each time the astronauts’ superiors in Houston gave the orders for the Group 7 astronauts to leave, their superiors’ superiors at NASA headquarters gave the orders for them to stay.

“At the time, I think, both Deke and Al were worried about the cancel­lation of flights,” Crippen said. “In fact, Deke was honest when he finally hired us the first time before the firings. He said, ‘I don’t have any flights for you until the Space Shuttle flies, and it’s not even an approved program.’ He said that’ll probably be around 1980 at the earliest, but he added, ‘I’ve got lots of work you can do.’”

Even though they were allowed to stay, the newest members of the corps sometimes felt like they were second-class additions. “I mean, we were not particularly loved and watered,” Bobko said. “When I got here, I was the last guy to ever study the Apollo. I’d go and say, ‘Can I get some manuals?’ And they’d say, ‘Yeah, but they’re all out of date.’ ‘What about classes?’ ‘No, those have been all canceled.’ Now it wasn’t that bad, because I’d go over to the simulator, and nobody cared about the simulator. So I’d be over there myself, and they’d let me stay almost as long as I wanted.

“There was a time I felt like I was a cosine wave in a sine-wave world,” he said. “We got on board, and they canceled [flights] before we got here; but after we got here, they canceled a lot more. There was supposed to be more than one Skylab, and I don’t think it was until after we were told we were coming that they canceled the last two Apollos. And then the Shuttle was supposed to be ready a lot faster.”

The ongoing cancellations were already having an effect on the corps when the mol astronauts arrived. “People were bailing out,” Bobko said. “Every crew meeting we went to, they talked about, ‘Well, they’ve canceled anoth­er thing.’ So the first year was pretty dismal, it really was.”

If Crippen and Bobko felt underutilized during their first years at NASA, that was to change in June 1971, when they were selected for a mission—of a sort. “[Pete] Conrad called me into his office, and said ‘ok, Crip, we’ve got this test that we want to run, and we want you and Bobko and [Bill]

io. (From left) Bo Bobko, Bill Thornton, and Bob Crippen.

Thornton working with it.’ So I said, ‘I learned never to volunteer, but it sounds like the best job available.’”

The third member of the group, Bill Thornton, had been selected to the corps on ii August 1967 as part of the second group of scientist astronauts. Though his path to NASA differed from that of his two colleagues, he had much in common with them. Like Crippen and Bobko, Thornton had come to NASA from the Air Force, where he had been a flight surgeon, among other things. Also like the other two, Thornton had been involved in the Manned Orbiting Laboratory program before coming to NASA, though in a very different capacity. At the Aerospace Medical Division at Brooks Air Force Base, Thornton had been involved in research and development for projects for NASA and decided to submit an application during the second round of scientist astronaut selections.

His qualifications were very good. He didn’t have the flight time Bo and Crip had, but he had over a thousand hours of testing (including flight test­ing) war weapons and missiles (during his first hitch in the usaf as a physi­cist) and then testing instruments designed for mol as a flight surgeon. He was awarded a Legion of Merit for this work and accumulated over twen­ty patents. (Today, his total of over thirty-five patents includes everything from military weapons systems to the first real-time computer electrocar­diogram analysis.)

The Skylab missions were intended to pave the way for the sort of long – duration spaceflights that would be needed to send humans beyond the moon and onward to other planets. For a trip to Mars to be possible, NASA would need experience with mission lengths far beyond the fourteen-day record that had been set during the Gemini program. Skylab would be the bridge between the two weeks that NASA had experience with to the months or years that would be needed to go to Mars. The plan was, with the first three Skylab flights, to quadruple the previous record, doubling it once with the twenty-eight-day first manned mission and then doubling that again with a fifty-six-day second mission. The plans called for the third crew to fur­ther demonstrate that a crew could successfully complete a mission of that length, rather than increasing the duration any more. (That plan changed, however, when the first two crews demonstrated just how well astronauts could function on long-duration missions, and the better part of month was added to the third crew’s stay on Skylab.)

However, the unprecedented length of the missions would mean that unprecedented preparations would need to be made. Attention was focused in two areas of concern: whether human physiology could withstand such long-term exposure to microgravity and whether everything developed and planned would actually work as intended.

Regarding the former concern, in 1967 the President’s Science Advisory Committee recommended an expansion of the Biosatellite program, which used animals to baseline the biomedical effects of spaceflight before longer- duration human missions were undertaken. The Biosatellite ill mission was carried out in the summer of 1969, sending a monkey, Bonnie, into orbit in a small capsule for what was intended to be a thirty-day mission.

On the ninth day of the mission, controllers were forced to abort the mis­sion and deorbit the capsule because of concerns about the monkey’s health. The recovery team successfully recovered it, but Bonnie died hours later. Fortunately any negative side effects of Biosatellite ill were minimal for Sky – lab. There was plenty of evidence that the monkey’s death was not directly due to microgravity exposure.

The experiment had at least one positive result for Skylab. Due to the con­cerns about Bonnie’s body mass loss, the microgravity mass-measurement device Bill Thornton had designed while with the Air Force became a high –

priority payload for the workshop so that any body mass loss by the Skylab crews could be tracked in flight lest they suffer similar problems.

Crippen, Bobko, and Thornton were selected to participate in a more down – to-Earth and ultimately more meaningful preparation for the Skylab mis­sions: the Skylab Medical Experiment Altitude Test, or smeat.

Rather than have the flight crews break away from their busy training schedule for full-length simulations, a surrogate crew was selected to com­plete a full-duration dry run of a Skylab mission. This smeat crew would test out various elements of the Skylab equipment and procedures in a series of trials, culminating in a full-scale simulation that was set at fifty-six days, at the time the longest planned duration of the Skylab missions and the length for which the second and third missions were scheduled.

The first part of the name came from the fact that trying out the medical experiments would be a major focus of the simulation, and the “altitude” referred to the fact it was conducted at the lower atmospheric pressure that would be used on Skylab.

In addition to the qualifying of the medical experiments, many other ele­ments of the Skylab program were to be tried out during the program. The crew was to eat a diet according to the guidelines that had been planned for the Skylab astronauts. Even the interpersonal relationships of the crew sealed in the chamber for almost two months, both with one other and with those they dealt with on the outside, would be a learning tool for the upcoming orbital missions.

Thornton, in particular, was excited about the possibilities smeat present­ed to do some hands-on testing of the Skylab equipment. He had already volunteered his services to the Marshall Space Flight Center in 1967 to help with the design and testing of Skylab equipment. He was determined that it should work on orbit and had expressed dissatisfaction with several of the designs. To him smeat was an opportunity to complete development and to test the flight gear as only he could test it—as he put it, “with a forced injection of operational reality.” His largest concerns going into the test were the urine collection and measuring system, the food system, and the bicycle ergometer.

The fifty-six days spent inside the altitude chamber would be only a frac­tion of the time that the three smeat crewmembers would devote to the test.

“It was about a year from the time we first started with all the planning and the engineering, and then the training and the preflight stuff, and then the actual test itself, and the writing reports,” Bobko said.

The training for smeat was an intensive endeavor in and of itself. For example, though they were to be safely on Earth the whole time just a short distance from help, the smeat crew went through the same medical train­ing as the Skylab members. Crippen said that the dental training, during which the astronauts learned to extract teeth, was a rather memorable expe­rience. “We’d each done a tooth and done the deadening with the Novo­cain and all that kind of stuff,” he said. “And they had this one kid that had a horrible looking mouth come in, and he needed to have a tooth out. They left Bo and I in there. The doctor said, ‘You guys pull teeth.’ We said, ‘We’ve pulled one.’ He said, ‘Go.’ He left, and I think I did the deadening, and Bo did the extraction.”

Bobko said that the youth was nervous about having the extraction done and was anxious about having to have a shot before the tooth was pulled. “And so ‘bedside manner Crippen’ here whips around with this needle that’s about that long,” he said, holding his fingers several inches apart. “But we went through with it,” Crippen said, “and he told us, ‘You’re the best den­tists I’ve ever had.’”

In another memorable incident during the medical training, Crippen broke his hand learning cpr. During training at Sheppard Air Force Base in Wichita Falls, Texas, the smeat crewmembers were taught cpr techniques with a “Resuscitation Annie” training dummy. “Back in those days, they always had you whack the person on the chest before you started,” Crip­pen said. “So I whacked the dummy.” When he did, the trainers told him he needed to hit the patient much harder than that. “And I did, and I broke my fifth metacarpal! So don’t have a heart attack around me.”

The smeat crew also spent time before the chamber test participating in the engineering design for the simulation. They played an important role in determining how the facility would be configured for the test. Bill Thornton was a stickler for good engineering in the chamber itself. The fire detection and “deluge system” sprinklers for putting out fires were of particular con­cern to Bill, who had been at Brooks Air Force Base when a serious cham­ber fire had taken place. The deluge system was tested successfully, but he followed up by tracing the power system to its source, supposedly a bank of

specially designed, long-life, high-reliability lead-acid batteries. But these batteries were corroded, and some had been replaced by ordinary automo­bile batteries. “He raised hell, and the batteries were replaced—with other automobile batteries,” Joe Kerwin recalls. “He raised hell again, and even­tually the correct batteries were obtained.”

The tests took place in a vacuum chamber used to simulate atmospher­ic pressure at various altitudes, from ground-level value of 14.7 pounds per square inch (psi) down to a space vacuum. For the full-duration test, the pressure would be held at 5 pounds per square inch, which would replicate the atmosphere that would be present on Skylab (5 psi, with 70 percent of it oxygen). The cylindrical chamber had a twenty-foot diameter and was twen­ty feet high, which allowed for it to be configured with a Skylab-esque two floors. The chamber was outfitted with equipment to replicate the Skylab layout closely enough for a meaningful simulation, though it was far from an exact copy. Bunks in smeat, for example, obviously had to be placed par­allel to the floor rather than perpendicular as on Skylab. The chamber was outfitted with the medical experiments that were to be flown on Skylab, including the vestibular-adaptation-testing rotating chair, the lower body negative pressure device, the bicycle ergometer, and the body mass measure­ment device. The smeat crew was to use the same toilet facilities as were on Skylab (“Except ours wasn’t on the wall,” Bobko noted), and their waste output was to be measured as it would be on orbit.

“We had a second deck on the thing, and then we divided up the first deck into compartments,” Crippen said. “We had the one sleep compart­ment where Bo and I had a bunk, and another compartment for Bill, and we had a head compartment, and we had one where all the medical experi­ments were set up. It was similar but not exactly like the living deck on Sky­lab. It was comfortable living.”

The two bunk rooms were outside the main cylindrical area in a rectan­gular extension that led to the main airlock. The waste-management com­partment was an area partitioned off on the first floor of the cylindrical area. The large open volume of the main area housed the medical experi­ment equipment as well as the smeat equivalent of the Skylab wardroom, a food storage and preparation area with a table. The main room also fea­tured a small access hatch through which items could be passed to or from the outside world. This small airlock was about the only compromise made in smeat that was not available on orbit. The second level featured desks at which the three astronauts could work (an additional desk was located on the first level).

Before the full-length fifty-six-day run, the crew conducted shorter tests in the chamber to work out any problems before committing to being sealed in for the full duration. After a “paper simulation” in which the crewmem­bers went into the chamber and talked through a day’s activities, two run – throughs of two and three days were conducted. As with the full-length test, the shorter runs required that the crew go through the process of preparing to enter the lower-pressure environment in the chamber. “We ran a large number of tests where we’d only go in the chamber for a day or so and run these things to wring it out before we actually got in for the long duration,” Crippen said. “Otherwise we’d never [have been] able to do it.

“I remember one case where there was this one tech that worked in Build­ing 7,” he said. “He was normally one of their chamber guys that were trained to operate the chamber. He and I were doing one run one day. They’d always prebreathe you [require you breathe ioo percent oxygen for three hours to eliminate nitrogen from your tissues and thereby prevent the bends] before the pressure is reduced from sea level to 5 psi in the chamber. We were set­ting up in the prebreathe room, and only he and I were there, and he got up and took off his oxygen mask and made a phone call to his girlfriend. Sure enough, we got in there and he was on the bicycle, and I was oversee­ing him. And he started hurting, and they had to take him out and put him in the hyperbaric chamber, ’cause he almost ‘bent’ himself— well, he did get the bends.”

Just as the actual Skylab crews did, the smeat crew received small tattoos on their bodies to mark where sensors went for the medical tests in order to ensure the sensors were placed consistently and thus increase the accu­racy of the results. According to Bobko, “They came to me, and they said, ‘We’re going to tattoo you so you know where to put the electrodes.’ And I said, ‘OK, only after one of you guys shows us exactly how it’s gonna look.’” He acquiesced after one of the doctors had the tattoos placed on himself. “He said, ‘If I could figure out how to see [behind me], I would have put it on my ass.’” Well over thirty years later, smeat and Skylab crewmembers report that their tattoos are still visible.

As any good crew would, the smeat astronauts came up with an official crew patch for their mission. The patch, reflective of the crew’s plum assign­ment, depicts Snoopy the beagle from Charles Schultz’s Peanuts comic strip (a favorite icon of the astronaut office) with an aviator’s cap, goggles, and scarf and a rope tied around his neck. Their original idea was to use Snoopy and “put a fishhook in his mouth.” The crew contacted Schultz to see if he would be willing to draw Snoopy for their patch. He agreed, but with one change: Crippen said, “[H]e wouldn’t put a fishhook, so he did the little noose-around-the-neck thing for us.”

Another part of the smeat simulation that began before the crew actu­ally entered the chamber for the fifty-six-day test was the premission diet. Just as the actual Skylab crews did, the smeat astronauts ate beforehand a diet similar to what they would eat during the mission in order to establish some baseline information with which the metabolic data collected during the mission would be compared. According to Bobko, the “preflight” and “postflight” diets the crew ate were not exactly the same as what they ate in the chamber during the test but were carefully selected to have the same mineral count and nutritional value. The crewmembers had two refriger­ators brought to their homes before the chamber simulation: one stocked with the premission food that was all they were allowed to eat, the second was used for storage of waste output, which would be taken back to msc for analysis. As things worked out, the astronauts got plenty of opportunity to enjoy the preflight diet; the planned twenty-one-day period during which they were supposed to eat it stretched to twenty-eight days when the start date for the test slipped by a week.

Crippen said that he’d certainly had his fill of the prescribed diet after eating the twenty-eight-day preflight diet, the fifty-six-day mission diet and then the postflight diet. “That got to be a pretty long time,” he said. “I can remember after we got out that I wanted a hamburger something awful.” (Other astronauts had similar experiences. After weeks of preflight diet and almost sixty days of Skylab meals, Owen Garriott made arrangements to have a chocolate milkshake waiting for him on the recovery aircraft carrier when he landed after his mission.)

“We used to give them a hard time about the food,” Bobko said, “Like I’d ask them, ‘What’s your analysis technique?’ and I never got an answer. We’d have a meeting, and they’d hem and haw around it, but they never gave it.” The smeat crew’s persistence in challenging the experimenters’ dietary planning was to be a vital contribution during the actual test, which led to

її. The smeat mission patch.

an important change in the Skylab flight program. Thanks to Bill Thorn­ton’s persistence, a one-size-fits-all, relatively low approach to caloric intake planning was amended. “We tried very hard,” he said. “I tried to get infor­mation from them; we’d say, ‘How are you going to do this? We’re going to be eating this three months or so; how are you going to do the analysis?’ On the first day, obviously, we have outside influence, when does that wash out? You can’t average it over the fifty-six days, that doesn’t sound reason­able, etc. etc. And I never got an answer.”

“I don’t think they had an answer,” Crippen agreed.

“There were a number of things like that we had questions on that nobody really knew,” Bobko added.

Finally, on 26 July 1972, only ten months before the first crew would launch into space, the time came to enter the vacuum chamber. And so the fifty – six-day stay began, and the astronauts were faced with what seemed at the outset like one of the mission’s biggest challenges—keeping occupied for fifty-six days. Apart from its terrestrial location, one of the main differences between smeat and Skylab was the lack of much of the science package that would make up much of the actual work in orbit. While the smeat crew conducted most of the Skylab biomedical experiments, they were obviously unable to conduct the astronomy experiments and Earth resources observa­tions, which depended on Skylab’s location in Earth orbit, or the materials science research and microgravity experimentation, which depended on its constant state of free fall. Thus, they were given the full duration of a Sky­lab mission, without all of the Skylab activities that would fill that duration in orbit. In addition they were unable to share some of the favorite free-time activities of the orbital crews — viewing the Earth and enjoying the won­ders of weightlessness.

However, despite not having those Skylab activities to fill their time, the smeat crews managed to find ways to avoid becoming bored by their extend­ed isolation. “I think we all worried about that ahead of time,” Crippen said, “because it wouldn’t be like the guys flying where you had the atm and all that to do. We worked on trying to find stuff to do. They let us take things in. We built a model, or tried to build a model. We took Russian. We found enough activities where I think we were reasonably busy.” (Notes Kerwin: “I have a memo from Crip, April 1971, to ‘Skykingdom’ [Conrad, et al] ask­ing for things to do. We suggested bridge and ping-pong.”)

“We kept up the pretense: ‘ok, this is like a spaceflight,’ and we com­municated through Capcoms, and all that,” Crippen said (Capcoms being short for “capsule communicators,” the people in Mission Control assigned to talk to the astronauts on a flight). “They said ‘We’d like to make it as much like Skylab as possible,’ and we did that. We did things like only com­municating during aos schedule.” In orbit, a spacecraft could only contact the ground when it was within range of a relay station on Earth, periods known as acquisition of signal (aos). Using that schedule for smeat meant the crew had only the same limited opportunities to talk to Mission Con­trol as the orbital Skylab crews would. A closed-circuit television was used for training classes, and each of the crewmembers was able to use it for two videoconferences with their families during the test.

As would be the case during the orbital program, the smeat crew took on some extra work to fill some of the time. Crippen set up regular debrief­ing sessions during the weekend to help organize the crew’s efforts. Just as

would be the case on Skylab, housekeeping also filled some of the crew’s time. “They [once told] us that things coming out of there were stinking,” Crippen said. “And we were very sensitive because it didn’t smell bad to us. I can remember, especially after we got the complaint about things kind of smelling that were coming out of there, we’d take Neutrogena soap and rub it down and scrub things around, so we worked hard at trying to keep the place clean.”

And then there were the phone calls. As another way to pass the time, Crippen insisted before entering the chamber to begin the test that it be out­fitted to make phone calls to anywhere in the country. Bobko recalled the line being a wonderful luxury as his wife used the time that her husband was away to take a vacation through California, and he was able to keep in touch with her as she traveled.

Crippen had a slightly different experience when friend and fellow astro­naut Dick Truly arranged a little joke to remind the confined commander just what he was missing out on in the real world. “I remember somewhere around Day 40-something, I got this call from Dick Truly,” he said. “I got on the line, and there were two young ladies on the line, and it was the biggest sexy phone call I can remember. I almost came out the door right then.”

As it worked out, the premission concern about staying occupied proved to be unfounded. Between their primary smeat tasks and the supplemen­tal activities they had scheduled for themselves, the crew not only had no problems keeping occupied but found their schedule so full that they some­times had to skip some of the supplementary activities they had planned. Work days, six days a week, began at 7:00 a. m. and continued until 9:00 p. m. with breaks for meals.

In addition to managing to keep occupied, the crew also maintained good relationships with one other despite being confined together in a lim­ited space for almost two months. Bobko, though, noted that the question of how they got along after being “shut up” together is really somewhat mis­leading. “It wasn’t something that was a shut-up thing,” he said, “because we had worked with each other for damn near a year, for probably eight or nine months or something, before we ever got in there. So any of the crew dynamic had already been worked out. My feeling was that we each had our own little peculiarities, but we understood each other, and we knew what they were, and we accepted them, and we got along.”

The same, he said, was true of all of the spaceflight crews of which he was

и. The smeat altitude chamber.

a member. By the time the beginning of the actual mission arrived, the crew had worked together in training for so long that the various personalities had already meshed into a team, and any initial problems had been overcome. “I had a woman on one of my flights, Rhea Seddon,” Bobko said. “People would say, ‘What do you think about taking a woman on your flight?’ Well, hell, we’d trained with her for six or nine months. That had all been worked out; the dynamic had been established already.”

Despite the eventual monotony that set in by the end of the “postflight” diet period after months of restricted choices, the astronauts said that the Skylab food provided during the fifty-six-day chamber run was not bad at all. “After we got the menus, I don’t remember being unhappy with the food,” Crippen said.

Bobko, who later went on to command Space Shuttle missions, said that the unique hardware specifications of Skylab were a boon to the program’s

menu options. Unlike later spacecraft, Skylab had facilities to store frozen food, and unlike previous NASA spacecraft and the Space Shuttle, Skylab did not use fuel cells for power generation.

“Compared to Shuttle, I think Skylab menus were a lot better,” Bobko said. “They had the frozen steaks; they had ice cream; they had other fro­zen things. And, unfortunately, the Apollo having fuel cells, which made water, and the Shuttle having fuel cells, which made water, has kept their food all on a narrow track; they wanted it to be dehydrated to save weight on the Shuttle.” Skylab had plenty of lift capability to launch nondehydrat­ed food.

The biggest challenge was setting up the menus in such a way as to make sure that the demanding nutritional guidelines were all met. “The food sys­tem was a bit of a problem,” Bobko said, “because they wanted us to balance our intake of proteins and minerals every day, which just made selection and consumption and everything else more difficult. That was the difficul­ty with the minerals and [calories]. Because if you took peanuts, if I remem­ber right, it excluded a whole bunch of other selections because [they] had enough other things in [them] that it really restricted your choices.”

As would be the case with Skylab, the crews set up menus for six days, and then cycled through those selections for the duration of the menu, eating the same meals every six days. “The six-day cycle, at least for me, was interest­ing,” Bobko said. “The way certain activities repeated led to some unusual associations.” For example, he said, part of his exercise schedule was on the same six-day cycle as the meals; so the same meal—spaghetti—was being prepared every time he did the exercise. “So, it’s like, if you’re exercising, you know you’re going to have the spaghetti smell in the background.”

A few of the food items developed for the program, however, were less appealing than some of the others. “I can still remember finding out that Silly Putty and the little pudding that they gave us were in cans that were exactly the same size and looked exactly the same,” Bobko said. “So we tried to feed it to one of the experimenters before the test, but he didn’t show up to the meeting.”

Despite being designed to replicate the Skylab menu as closely as possible, the smeat menu did feature one perk that the orbital version did not. Once in every six-day cycle, the smeat astronauts were allowed to imbibe a serv­ing of sherry. The original plan had been for the Skylab menus to include a wine selection in each rotation, and a tasting had even been held for the crews to select what they wanted to carry into orbit with them. Medical

objections had been overcome, but serving wine on a government “ship” was too much of a break with precedent for the political sensitivities of 1972, and it was removed from the flight diet.

Fortunately for the smeat crew, however, by the time the decision was made to remove the sherry from the Skylab menus, the smeat menus had already been made out, and it was too late to go back through the process of completely rebalancing the various nutritional factors that would have to be changed if the sherry were removed. “We had it,” Crippen said, “and we really looked forward to it.”

A more significant disagreement over the menus, however, proved to be of great importance to the Skylab program. The intense scrutiny on diets was not just to make sure that the crews stayed healthy, it was also one of the major biomedical experiments. Since the crews would be setting new spaceflight duration records, scientists wanted to learn all they could about how the microgravity exposure affected their metabolisms. Their dietary intake would be closely monitored, as would their waste output and their body mass, in order to make sure there were no unknown issues that would be a limiting factor for future long-duration spaceflight.

In order to facilitate the close scrutiny of the astronauts’ intake, the deci­sion had been made to standardize the intake for all Skylab (and smeat) crewmembers so that all crewmembers would consume the same num­ber of nutritional calories each day. One set of dietary guidelines would be established, and all of the astronauts would adhere to it, making it easier to keep up with exactly how much everyone was eating. The astronauts and the investigators had been negotiating the diet since 1969, and when smeat took place it had changed from a standard 2,400 calories apiece to a base of 2,000 calories worth of real food (containing all the protein, calcium, and phosphorous allowed) plus up to 800 additional “snack” calories.

Bill Thornton, however, no stranger to medical concerns himself, dis­agreed with the decision and took it upon himself to prove that the standard­ized diet was a bad idea before it could be implemented on orbit, where there would be no way to change it. The tall and muscular Thornton, one of the corps’ most physically imposing members, believed that setting a uniform standard for all the crewmembers would be unhealthy, that each needed a nutritional plan custom tailored for his own body type and metabolism.

Bill decided to demonstrate the inadequacy of this diet (“2,000 calories

plus sugar for a 207-pound man with less than ten-percent body fat”) by con­suming it as directed. Pretest he maintained his usual extensive exercise reg­imen. In the chamber he estimated the difference between his usual routine and his chamber activities and made up the difference with cycle ergome – try. He gorged on sugar cookies and lemon drops to stay alive.

“Bill like to drove me nuts,” Crippen said. “He didn’t think the calor­ic intake they had assigned for the flights was adequate, and he was deter­mined to try to prove that so that they would up it. Bill was exercising on the ergometer. And he exercised on the ergometer, and he exercised. It’d be in the middle of the night and he’d be in there peddling on the thing.

“He finally got to be almost like a skeleton. He got to where I was wor­ried about him. I didn’t know how much weight he lost, but it was signifi­cant. Somewhere around the thirty-day point, I finally called outside and said either he’s coming out or you’ve got to send some food in. They boost­ed up what we ended up flying, and I thought it was around 2,500 calories a day. I got irritated at Bill a few times simply because I couldn’t get him off the damn bicycle. I thought he was going to starve himself to death. He’s a bulldog; but you know, he’s a great guy, and that was the only thing that he and I had an issue on—he wouldn’t get off that damn bicycle.”

And, indeed, the diet was insufficient for Thornton to maintain his body mass. “I was under the impression that a loss of twenty-eight pounds, most of it upper-body muscle, would be enough to convince anyone,” Thornton said. As it turned out, it wasn’t enough to convince the principal investiga­tor for the mineral balance experiment. Dr. Donald Whedon thought “He overexercised,” and his coinvestigator, Dr. Leo Lutwak felt “He only lost body fat.” But a lot of discussion resulted in extra food being stowed aboard Skylab for the flight crews. Specifically, the eight hundred calories of “snack” food was now allowed to contain significant amounts of protein, which put many more food items onto the snack list.

Just as the intake monitoring had issues that had to be worked out, so too did the output monitoring. A similar problem occurred in planning the urine-collection system as had with the nutrition-standard guidelines: the designers had taken a one-size-fits-all approach that while wonderful in the­ory proved to be less wonderful in practice.

The urine system was Thornton’s biggest hardware concern. It had to collect and measure twenty-four hours of output efficiently and reliably

with very small error, in weightlessness. The contractor had designed a two – chambered bag separated by a “hydrophilic” membrane to transfer the urine into the measurement chamber under enough pressure to activate a com­plex mechanical displacement indicator. It failed as soon as urine was used to test it instead of water.

“The urine collection burst on us,” Bobko said. “They had gone, I guess, into hospitals and figured out what the urine output would be, and it was too low. So two things happened, and one is that if you got up to take a leak at night, you may fill this thing up, so halfway through your evacuation, you had to cross your legs, and you had to [change] the bag.” The other thing that happened was that the bags occasionally became overfilled and burst.

Emergency meetings were held. A centrifuge was designed whose centrifu­gal force would generate enough pressure to transfer urine into new, filterless bags. Thornton was skeptical. He campaigned hard to get the system into smeat for test and was the only one of the three crewmen who used it.

There were multiple failures. Seven times the bag broke, usually near the end of a twenty-four hour cycle when it was nearly full. Thornton recalls, “I had only my dirty discarded underwear and a very limited amount of water and soap to sop up a couple of liters of urine into discarded bags and clean up the floor. Then I had to thrust my big hands into a maze of machined parts with sharp edges to dry them, lest they corrode and seize up. My hands looked like I had taken on a bobcat.” Crip and Bo joined Bill in tell­ing management it wouldn’t fly. A meeting was scheduled, and the three of them collaborated in preparing a rather blunt demonstration of the seri­ousness of the problem.

“They had the overcans for food, the big cans,” Crippen said. “I think it was Bill that was doing this, but we were all complicit. We took one of the big food cans and took a spring out of the tissue dispensers, turned one of the small food cans over and put it down in on the spring, and then took a urine-soaked rag and put it down in there, and sent it out there. So when they opened up, it popped out, to demonstrate that we had a problem in there.” The result was a complete system redesign with Dick Truly in charge. Bill suspects to this day that the food can was never opened; Truly just believed his fellow astronauts.

In addition to urine, stool was also sent out to be measured and analyzed. According to Bo Bobko: “We didn’t freeze-dry the feces; we didn’t have the vacuum as was available in space. We put them in little cans and sent them out. We sent the urine out, but we did the sample first; I think it was thir­ty milliliters per day.

“Then there was Thornton. I can remember them going to Thornton, and saying, ‘Bill, it’s Friday noon, and you haven’t given us a fecal sam­ple, and we’d like to let all the people go home for the weekend.’ And Bill would say, ‘Just a minute.’ So he turned around, and said, ‘You were talk­ing to the wrong end.’

“I can remember them giving us these little cups. I said, ‘These little cups, you know—how about something like four times larger?’ So they gave us something that looked like a mailing tube. I said, ‘You dummies, give us something that looks like an ice cream half-gallon container or something, that we don’t have a hard time hitting.’ So they did. But there were probably a lot of little things like that flight crews never knew about or cared about.

“They were complaining to us that we weren’t sending everything out. Like, they said we weren’t sending out all the feces. We said, ‘What are we doing with it? Storing it under the boards of the floor?’ I remember that time Bill got on the phone with our surgeon, kind of an excitable guy. Bill asked for a private consultation. He got on the phone, and he was saying, ‘I’ve been noticing some strange behavior.’ The flight surgeon said, ‘Oh, oh, tell us about it.’ He said ‘Well, you know, these people seem to be paranoid. It looks like we have some paranoid things,’ and we have this and that. The flight surgeon was assuming it was us, and he was getting more and more excited. The flight surgeon finally said ‘Who is this? Who is this?’ And Bill said, ‘It’s the management.’ You don’t think of him as a funny person. But when you have things like talking to the flight surgeon about this deviant behavior, you thought about it and laughed about it for days.”

In a similar vein, the crew noticed an unanticipated side effect of the low­er atmospheric pressure in the altitude chamber: “There was a lot of flatu­lence,” Crippen noted. “We tried to think maybe it was the diet, but I think it was just strictly the 5 psi. It was significant.” Common sense supports the latter theory: At the 5 psi of the smeat chamber, any given mass of a gas would have three times the volume that it would under sea-level atmospher­ic pressure. (Skylab crewmembers confirmed that the same phenomenon occurred during orbital operations as well.) Recalls Bobko: “We had a tim­er, and we were counting. I don’t remember how many times it was in a day, but it was a significant number.”

The 5 psi atmosphere had more mundane effects as well. The lower pres­sure reduced the transmission of sound so that during the first few days the crewmembers frequently found themselves shouting, and became hoarse as a result. (On Skylab, an intercom system addressed this problem.) They also found that they were unable to whistle in the lower pressure atmosphere and that sneezes were milder.

The most important part of smeat, of course, was the work the crew did in testing out the equipment and procedures designed for Skylab, making sure that everything would function as planned by the time the first crew arrived in orbit. While the problems the smeat crew had with the urine collection system were inconvenient for them, to say the least, their incon­venience served a greater good—the consequences of the urine collection problems would have been much greater had they first been discovered in the microgravity environment of Skylab.

One of the most immediate tasks for the smeat crew was to begin tak­ing the roughly delineated guidelines that had been developed for Skylab operations and turn them into the finely detailed procedures that would be needed for the astronauts in space. The efforts to refine the checklist were an ongoing process for the smeat crew, beginning long before the chamber test and continuing through the simulation.

“We did quite a bit of development on the checklist, because a lot of that was almost nonexistent when we started,” Bobko said. “It was in bad shape. So we had to do something; we had to make it operational. A lot of this stuff just wasn’t in an operational format.” Much of the early checklist, he said, was too short and vague for use in spaceflight. “It was ‘Don’t do this.’ It was all right for training, but it wasn’t really good enough to use. So we really worked on that quite a bit. That was part of the engineering and training that took place at the beginning.”

Working with the principal investigators for the medical experiments in developing the procedures, Bobko said, had an additional beneficial side effect. The opportunity to witness the smeat crew performing the experi­ments gave the investigators some idea of what they could expect in work­ing with the Skylab crews during orbital operations.

As was the case with the urine collection system, the smeat astronauts’ use of the Skylab hardware revealed problems with equipment destined for the orbital workshop. Their discoveries meant that the problems could be

addressed before the equipment was launched into orbit, where the sort of flaws uncovered during smeat would have been devastating for the program.

Bill Thornton’s dedicated use of the wheel-less bicycle ergometer, for exam­ple, did more than just reveal problems with the dietary guidelines imposed on the crew; it also contributed to breaking—and then fixing—the bicycle. (Though that problem was corrected, the ergometer would present other challenges during its use on orbit, though fortunately all of the crews were able to deal with it in situ.)

Thornton used the ergometer primarily to maintain his normal exercise level. But because he questioned its ruggedness and thought it had not been tested thoroughly, he wanted to put it to that test. He recalled, “After a rea­sonable break-in period I planned to take it to its 300 watt rating for an hour, but starvation was taking its toll, and I was relieved when it screeched to a stop at about forty-eight minutes. The airlock was used to exchange it for an old, indestructible model. A considerable time later the bike was returned, ‘fixed’ by restricting it to thirty minutes at 300 watts, now an ordeal with my continued malnutrition. But this time it took only twenty-nine min­utes and thirty seconds to destroy the bearings. I shall never forget the look of disgust on Crip’s face.”

This time, after independent engineering analysis, a different shaft and bearings were installed. The flight unit, however, was further restricted to 250 watts. Fortunately, this proved enough for the mere mortals who flew. Bill still remembers feeling hurt by the subsequent efforts of msec man­agement to separate him from his testing role. And he insists that he nev­er actually used it when Crip and Bo were asleep — “maybe when they were watching TV, but not after lights out.”

Here are some of the hardware redesigns accomplished as a result of the smeat tests:

In the lower body negative pressure device, a seal that was necessary for depressurizing the lower extremities developed a leak and had to be redesigned. In addition, the decision was made to car­ry a spare seal during the flight program.

The equipment used for measuring blood pressure was discovered to have been miscalibrated, causing it to produce inaccurate­ly high results.

Several problems were discovered in the metabolic analyzer unit. Some

ІЗ – Bill Thornton riding the cycle ergometer.

of the measurements it took were found to be substantially high­er than they should have been, and the oxygen consumption measurement of the device was discovered to be significantly greater in the 5 psi atmosphere in the chamber than at sea-level pressure. The unit was redesigned to provide accurate and con­sistent data for Skylab.

The electrode cement used for the vectorcardiogram test was found to cause skin irritation, and action was taken to prevent the sit­uation from recurring on Skylab.

Coagulation problems in samples were discovered to result from the blood sampling techniques used in smeat, and additional anti­coagulants were added.

The centrifuge used for blood separation was found to be prone to excessive vibration and had to be redesigned prior to the flight program.

Of course, not all the problems the crew experienced were the fault of the hardware. One of the less-coveted tasks for the smeat crew was wearing the electroencephalogram (eeg) cap that monitored sleep levels. Crippen initially had agreed to be the one to wear the cap but before the beginning of the chamber test discovered that the salve or jelly that had to be applied to wear the cap caused his head to break out in welts. When Crippen real­ized that he was going to have to pass on the eeg duties, Thornton volun­teered to take it over. But he too was unable to wear the cap. The task was then passed on to Bobko, who with no one left to pass it on to was stuck with it. Though no longer the one who would be wearing the cap, Crippen was still the one trained in its operation and thus had the responsibility of changing the tapes on which the device’s data was recorded. Unfortunate­ly due to an error in changing the tape, the data wasn’t recorded. No one realized, however, that there was a problem until after the test was over, and the experimenters went back to review the data. “So Bo went through [the test], and there was no damned data,” Crippen said. “I guess we got some from the first tape.” Even that experience presented new ideas for the Sky – lab program—for the orbital operations, some of the data was sent down in real time to prevent just that sort of problem.

The smeat experiences proved to be invaluable to the Skylab orbital pro­gram, and the three men were proud of their contributions to the success of Skylab. “The first mission would have been a lot more difficult for the med­ical experiments” without the lessons of smeat, Bobko said.

Crippen agreed that the breaking-in the smeat crew put the medical experiment equipment through on the ground was a key to how well things went when the equipment was used in orbit. “If we’d flown those without running them in some sort of operational situation, I think there would have been a problem,” he said.

Thornton praised Richard Johnston, then director of Life Sciences, for initiating a daily logging and review system for medical data which result­ed in good status monitoring during the flights—and eventually in a fine document capturing Skylab’s medical achievements, “Biomedical Results of Skylab.”

Finally, though, the time came to bring the test to a close. Crippen said he was never entirely sure if the test was going to run exactly the full fifty – six days for which the second two Skylab missions were planned. First, he said, he believed that the simulation might be brought to an early close and the crew released from the chamber. But then as the test drew nearer to its conclusion, he wasn’t sure if the mission planners might not decide to extend it to continue the experiments.

Bobko said he also wondered whether the crew might have to spend addi­tional time in the chamber. “Near the end, I can remember thinking we may not get everything done, because we just have a lot to do,” he said. “Fifty- six days was the target, and they said, ‘If anything goes wrong, we can take you out.’ But there was a feeling of, we had a purpose, and we had to get to it done. I can remember having some concerns that we weren’t going to get all the results that we really wanted to get. And it all turned out; I think that we did. And like I said, I’m not sure that if anybody said, ‘You want to go for another fifty-six days,’ I would have been ready for that.”

Crippen agreed: “I know I wouldn’t have. If it were one or two more days to get some stuff done we would have been able to do that.”

The smeat crew would eventually get their chance to move up from sim­ulated space missions to the real thing. As Slayton had predicted when the mol astronauts were brought into the NASA corps, their chance to fly did not come until the Shuttle was ready to launch, twelve years after they were brought in. Even before that happened, though, after almost a decade of being on the lower rungs of the astronaut corps ladder, the mol astronauts saw their situation change in 1978 with the selection of the eighth class of candidates, chosen specifically for the Shuttle program. “We were start­ing to get into Shuttle before I felt like I wasn’t a new guy,” Crippen said. By that time, many of the veteran astronauts from the earlier groups had left the corps, and the mol class played a vital role in the early Shuttle pro­gram. Crippen said that he was told that some of the same managers who had opposed bringing in the Air Force astronauts originally went on to feel lucky to have them when the Shuttle began flying.

Ironically, and sadly, though each did get to fly and command Shut­tle missions, Crippen and Bobko’s careers as flight-status astronauts ended much as they began: waiting on a space launch from Vandenberg Air Force Base that was never to come.

The Air Force had modified Space Launch Complex 6 (slc-6, pronounced “Slick Six”) at Vandenberg Air Force Base in California, once destined to serve as the launch pad for the mol program, for use with the Space Shuttle. Missions were planned for launch from the “new” Shuttle pad, and crew­members were selected for those missions, including Crippen and Bobko.

“One of the sad things was, [in mol] we were supposed to fly from Van­denberg on Slick Six, Space Launch Complex Number 6,” Crippen said. “And sure enough, I was up to command 62-A, which was going to launch out of Vandenberg out of Slick Six.”

Bobko recalled: “I can remember going out there during mol and stay­ing in the crew quarters. And then they redid the crew quarters out there to make them a command center. And then they changed it back to crew quarters. I can remember being out there the second time, same place, I don’t know how many years later, when they were getting ready to do the Shuttle flights.”

The 62-A mission that Crippen was assigned to command was to be the first Shuttle launch from the Vandenberg complex and would have been the first launch of a manned spaceflight into a polar orbit. The flight was sched­uled for mid-1986, but it was never to be. On 28 January 1986, the Space Shut­tle Challenger was lost during launch from Florida, destroying the vehicle and killing the seven members of its crew. As a result of that tragedy, the decision was made not to launch the Shuttle from Slick Six.

Just as it took a team of thousands working together to make the Skylab program, telling its tale would not have been possible without the gener­ous contributions of many people. While the three of us struggled over the past several years to put everything in place and to make this story of Sky – lab both accurate and interesting for all readers, we have found that abso­lutely key elements required the personal contribution of additional mem­bers of the Skylab team.

Alan Bean’s substantial contribution to this book, for which we are im­mensely grateful, was discussed in the preface.

And then there is Ed Gibson, the scientist pilot of mission three, who makes clear the major contributions made on the longest Skylab mission of all and who sets the record straight about some of the common misconcep­tions surrounding the mission. He is the principal author of most of chap­ter io, “Sprinting a Marathon.” He attacked the challenge passionately and went above and beyond our expectations.

Gibson’s insight can also be found elsewhere in the book, particularly in his in-depth explanation of solar astronomy on Skylab. Gibson’s knowl­edge of our sun, and observation thereof, is vast, and his expertise made for an invaluable addition to the book.

In addition, we would like to give particular thanks to the following people.

Vance Brand and Bo Bobko, who shared not only their personal ex­periences but also a wealth of resources they had saved over the years.

Chris Kraft, who provided us with unpublished Skylab material he had written for his memoir, Flight: My Life in Mission Control.

Lee Belew, Jerry Carr, Phil Chapman, Bob Crippen, George Hardy,

Charlie Harlan, Hans Kennel, Jack Kinzier, Don Lind, Gratia Lousma, Jack Lousma, Bob MacQueen, Joe McMann, George Mueller, Bill Pogue, Chuck Ross, Bob Schwinghamer, Phil Shaf­fer, Ed Smylie, Jim Splawn, J. R. Thompson, Bill Thornton, Stan Thornton, Jack Waite, and Paul Weitz, all of whom shared their experiences with us, either during in-person interviews or through written correspondence. (Some of these also extended and enhanced material from their interviews with the jsc Oral History Project for this book, particularly in chapter io.)

Colin Burgess, our series editor, who got us started on this adventure and shepherded us along the way. Colin also contributed the story about Stan Thornton’s experience finding a piece of Sky – lab; and he occasionally provided feedback on our manuscript when not too busy working on countless of his own.

The jsc Oral History Project, an incredible historical archive. Inter­views from the project served as the foundation for the crew bios and the Skylab III chapter of this book and added additional in­sight to other areas.

Francis French, Gregg Maryniak, and Rob Pearlman, who looked through our in-progress manuscript and provided expert feedback.

Gary Dunham, who supported us graciously during this process.

Homer Hickam, who captured what we were trying to do in his ex­cellent foreword.

Richard Allen of Space Center Houston, for letting us in at odd hours to review the Skylab trainer.

Genie Bopp; Sandra Brooks; Susanna Brooks; Eve Garriott; Bill and Leah Hitt; Lain Hughes; and Lee and Sharon Kerwin, who were kind enough to read through our developing book and point us in the right direction.

Many, many others who answered questions for us as they arose.

David Hitt would also like to thank his father, Bill Hitt, for setting his first­born in front of the television on 12 April 1981 and fanning the flames ever since; Jim Abbott, for being the best mentor a young reporter could have hoped for; Nicole, for going along on an amazing experience; Jesse Hol­land; and last, but certainly not least, the good Drs. Garriott and Kerwin, for giving me the greatest adventure of my life by letting me share in one of the greatest of theirs, for being my patrons through Olympus, and, most of all, for their friendship.

Joe Kerwin would like to thank his wife, Lee; his daughters, Sharon, Joanna, and Kristina, for letting him be a part-time dad before the flight and for providing his main motive for coming back to Earth; and his grandsons, Christopher, Joel, Anthony, Brendan, and Joshua, for giving him a reason to help write this book—that they might be encouraged to go on adven­tures of their own.

Owen Garriott is most appreciative of the support provided by his family and children in his life both as a “flyer” and as a writer as he prepared this book. It is not an insignificant source of personal satisfaction to find that some of his enthusiasm for space adventure has carried over to his children.

Perhaps the best way to begin a tour of Skylab is to begin where its crews did—on the outside, with a look at the station’s exterior.

If a crew in an Apollo Command Module were to approach Skylab with its docking port before them, the nearest module would be the Multiple Dock­ing Adapter (mda) . From the exterior, the mda was basically a nondescript cylinder, marked primarily by its two docking ports. One of the docking ports, the one used by the crews docking with Skylab, was located on the end of the cylinder. The second, the radial docking port, was at a ninety – degree angle from the first, on the circumference of the mda.

The other notable feature of the Multiple Docking Adapter was the truss structure that surrounded it and connected it to the Apollo Telescope Mount (atm), on the side of Skylab opposite the radial docking port. The atm is easily recognized by its four solar arrays, which had a very distinctive wind­mill appearance. Between the four rectangular arrays was a cylinder that housed the atm’s eight solar astronomy instruments. Covers over the instru­ment apertures rotated back and forth, revealing the instruments when they were in use and protecting them from possible contamination when they were not.

Continuing from mda, the crew would next come to the Airlock Mod­ule (am), a smaller cylinder partially tucked into the end of the exterior hull of the larger workshop cylinder. The Airlock Module was most nota­ble, as the name suggests, for its airlock featuring an exterior door allow­ing the crew to egress to conduct spacewalks outside the station. While the program that spawned Skylab had been dubbed “Apollo Applications” for its extensive use of Apollo hardware and technology, the Airlock Module was actually a “Gemini Application” — the door used for evas was a Gem­ini spacecraft hatch.

The airlock and all the spacewalk equipment on Skylab were designed for one purpose — to allow the crew to retrieve and replace film from the solar

telescope cameras on the Apollo Telescope Mount. “There was no thought of the crews doing repairs or maintenance on other things,” Kerwin said. “Little did we know!”

The airlock was partly covered by the Fixed Airlock Shroud, a stout alu­minum cylinder that was a forward extension of the skin of the workshop. The aft struts from which the Apollo Telescope Mount was suspended were mounted here. The truss structure included a path, complete with handholds that spacewalking astronauts could use to move from the airlock hatch to the atm so that they could change out the film.

Finally moving farther past the Airlock Module, the crew would reach the largest segment of Skylab, the cylindrical Orbital Workshop. This was the portion that consisted of the modified s-ivb stage. As it was originally con­structed, the most distinctive features of the station were the two solar array wings, which stretched out to either side and which were to be the primary source of electrical power for the workshop. Prior to launch the photovolta­ic cells that made up the arrays folded up flat against the beam that would hold them out from the sides of the workshop. These beams, in turn, fold­ed down against the outside of the s-ivb stage in its launch configuration, making the wings much more aerodynamic for the flight into orbit.

After completing their fly around, a crew would return to the top of the Multiple Docking Adapter and dock their spacecraft to the station. A com­plete tour of the interior of Skylab should begin right there on their cap­sule. After docking, the Command and Service Module became a part of the cluster. While there were occasions when things needed to be done in the Command Module, they were few. Perhaps its primary use while docked with Skylab was essentially as a telephone booth; crewmembers could float up to the Command Module to find a little privacy for conducting space – to-ground communications with their loved ones at home on a back-up fre­quency that was not available in the workshop.

Upon opening the hatch and entering Skylab, the crew would first find themselves inside the mda. Originally planned to have a total of four dock­ing ports around its circumference, the mda lost three as a result of the switch from the wet workshop to the dry. When the wet workshop cluster, which had to be assembled individually on orbit, was replaced with a facil­ity launched all at once as a dry workshop, the additional ports at which to dock separately launched modules were not needed. Eliminating the three

14- A cutaway view of the Skylab space station.

extra docking ports freed up a large amount of wall space around the mda’s circumference, space that was utilized to turn the module into essentially an additional science annex.

The design of the interior of the Multiple Docking Adapter was itself one of Skylab’s experiments. The argument had been made that in the micro­gravity environment in orbit there was no need to follow the same design paradigms that were unavoidable on the ground. There was no need to leave a floor empty to walk on. The ceilings were no more out of reach than walls, and equipment could be placed on them just as easily as on a wall. The mda was an experiment in designing for that environment, with no up or down. Equipment was located all the way around the wall of the cylin­der, allowing more complete use of the available space than would be prac­tical on Earth.

Foremost among the scientific equipment located in the module was the operator’s station for the Apollo Telescope Mount, a large flat panel featur­ing the controls and displays for the atm with a narrow table in front of it.

The atm console was arguably evidence of the extent to which the module’s designers were influenced by Earthbound thinking. Though care was tak­en to design the mda as an ideal microgravity work environment, the atm console was furnished with a chair for the astronauts to sit in while oper­ating the controls. “We called it the ‘Commander’s Chair,’ because it was Pete’s idea,” notes first crew science pilot Joe Kerwin. “It didn’t survive lon­ger than about the first two weeks of our mission; we then put it away some­where, and I don’t think anyone retrieved it.”

Also located in the mda was the Materials Processing Facility. Included in this experiment was a furnace used to study flammability and melting of solid materials in microgravity. The adapter also housed the Earth resourc­es experiment equipment.

Leaving the Multiple Docking Adapter and heading farther down into Skylab, one would next come into the Airlock Module, the function of which was very aptly described by its name. Joining the mda and the Air­lock Module together was the Structural Transition Section, which con­nected the larger diameter of the Docking Adapter on one end to that of the smaller Airlock Module on the other. The Structural Transition Sec­tion housed extensive systems operation equipment. The Airlock Module provided a way for astronauts to egress the station for spacewalks. Before they could go outside, the Airlock Module would have to be shut off from the rest of the station and then depressurized. Once the atmosphere had been removed, the airlock hatch could be opened, and the eva crewmem­bers could go outside.

To prepare for an eva, all three crewmembers would put on their space- suits in the larger open area of the Orbital Workshop, where the equipment was stored. The astronaut who would be staying inside stopped short of don­ning his helmet and gloves but suited up the rest of the way in case a prob­lem occurred. The eva umbilicals were stored in the Airlock Module, and the ends of these were pulled down into the workshop during this time and connected to the suits of the two eva crewmen. These provided oxygen, cooling, and communications for the two astronauts who would be going outside as well as tethering them to the station.

Once all three were suited up, the non-EVA crewman would precede the others, move through the airlock and into the MDA/Structural Transition Section. There he would attach himself to a shorter umbilical. With his

helmet off, he would be breathing the atmosphere in the mda, but in the bulky spacesuit, he needed the umbilical for cooling as well as for communi­cations. The eva crewmen would move to the airlock and close both hatches (helped on the mda side by the third crewmember). Once the hatches were closed, the Airlock Module would be depressurized by venting its atmo­sphere into space. The outside hatch would be opened, and the two space – walkers could venture outside.

Once the eva was completed, the two astronauts would return to the Airlock Module and close the outside hatch. The am would be repressur­ized, and they would open equalization valves in both end hatches to assure equal pressure with the rest of the station. Finally, they’d open both hatch­es, return to the workshop and doff their suits. The normal pressure regu­lation system would add gas to the workshop as needed.

The Airlock Module’s location in the middle of Skylab meant that a prob­lem with repressurization could mean the end of the mission. If for some reason the module were unable to hold an atmosphere, the third crewman would put on his helmet and gloves and depressurize the Multiple Docking Adapter. The other two would disconnect their umbilicals from the Air­lock Module and rely on a reserve oxygen supply in their suits while they opened the hatch between the two modules, and moved into the docking adapter. Once there, they would reconnect their umbilicals in the mda, and then seal it off from the Airlock Module and repressurize it. If they and the ground were then unable to figure out a way to fix the problem with the Air­lock Module, the mission would be aborted. They would leave the mda for the Command Module and return home.

Continuing deeper into the station, one would next reach the large Orbit­al Workshop volume. This section was divided into two “stories,” with a hole in the middle of the floor of the top story that allowed the crew to move between them.

Like the Multiple Docking Adapter, the workshop was part of the exper­iment in designing for microgravity. Whereas the mda was designed with­out consideration for the direction of gravitational force on the ground, the approach to the workshop design had been to keep in mind that it would be used by men whose brains had long been wired for the one-G environment in which they had lived their entire lives. The “bottom” story of the work­shop was arranged with a very definite up and down. Furnishings and large

equipment sat on the floor like they would on Earth (with a few exceptions), and the walls functioned more or less the way walls normally do. The upper compartment was more of a hybrid, with variations from the one-G—based design of the lower section.

The area at the top of the workshop was very unusual by spacecraft stan­dards. Traditionally spacecraft design is a field in which mass, and by exten­sion volume, are at a premium, reflecting the challenge of moving anything from the surface of the Earth into orbit. As a result spacecraft tend to be rel­atively cramped with every inch utilized as much as possible. While mod­ern spacecraft like the Space Shuttle and the International Space Station are roomy compared to early vehicles like the Mercury and Gemini cap­sules, their designs still reflect the basic limitations in putting any mass into orbit. Skylab had a couple of advantages that made it exceptional in that respect. The availability of the Saturn v as the launch vehicle and the deci­sion to use an s-ivb for the Orbital Workshop meant that it was much less constrained by the traditional mass and volume limitations. Nowhere was that more apparent than at the top of the workshop, which featured an open volume that by spacecraft standards was incredibly large. While the low­er floor was divided into separate “rooms,” the upper floor, the larger of the two, was not divided. An astronaut could float freely in the middle of this volume without bumping into the walls.

In fact Skylab’s designers were concerned that this could present a real problem. They feared that an astronaut could get stranded in the middle of this open volume; without anything nearby to push off, he would have to rely on air currents or his crewmates to push him back toward a solid sur­face. To eliminate this danger and to provide for easier movement through Skylab, they provided a “fireman’s pole” in the middle of the workshop, running from one end to the other. The idea was that the astronauts would hold on to the pole to move “up” and “down” the workshop. The pole, how­ever, proved unnecessary, and the crews found that it just got in the way. It turned out to be quite easy to push off from a surface and glide to one’s des­tination —no pole required. The first crew took it down for the duration of their stay, but at the end, politely restored Skylab to factory specs, reinstall­ing the pole for the second crew. They in turn did the same—promptly tak­ing it out of their way but putting it back before they left so that the third crew could remove it one last time.

The upper portion of the workshop dome volume was left almost vacant for experiments requiring a lot of volume for checkout, like a Manned Maneu­vering Unit prototype. Just below this was a ring of white storage lock­ers, which the first crew found provided an excellent “track” to enable easy shirt-sleeve jogging and tumbling around the inside circumference of the workshop. Also located in the upper deck were storage of food supplies for all three missions, a refrigerator and a very heavy (on Earth, at least) steel vault for film storage.

A few experiments were also located in this area, including Skylab’s equiv­alent of bathroom scales, the body mass measurement device, which the astronauts used to keep track of how much “weight” they had lost or gained. The upper dome volume was also where the two astronaut maneuvering units were kept. One was a backpack device that was the forerunner of the Manned Maneuvering Unit later used on some Space Shuttle missions and of safer, the Simplified Aid for eva Rescue, used on the Internation­al Space Station. (Ironically, a member of the one Skylab crew that did not get to test the maneuvering unit, Joe Kerwin, was a co-inventor of the saf­er unit, while working at Lockheed Martin years later.) The other device was a maneuvering aid that astronauts operated with their feet, rather than their hands.

The upper story of the workshop also featured a pair of airlocks. Too small for a person to go through—only about ten inches square—the two Scientific Airlocks (sals) were designed for solar physics, astronomy, Earth photography, and space exposure experiments, allowing astronauts to pass materials samples through to see how they weathered the harsh environs outside. The two airlocks were on opposite sides of the compartment from each other; a solar airlock pointed in the same direction as the Apollo Tele­scope Mount, while the antisolar sal faced in the opposite direction. (This solar-looking airlock would be an important part of addressing problems that occurred during launch.)

Also located at the top of the dome was Skylab’s unofficial “Lost and Found.” “Most of us have enough trouble keeping up with our pencils, notes, paper clips, and other small items here on Earth in a largely ‘two dimension­al’ world,” Garriott explained. “By two dimensions, we mean that an object may get pushed around horizontally, but it seldom floats away vertically in a third dimension, like a feather might do. But space is different—everything floats away unless it is tethered or tied down. But our eyes and our minds

have been trained for years to look only on the tops of surfaces to find lost articles. We may not ‘see’ a small floating object in space, or may not look in all the more obscure places a lost article may have become lodged.

“But serendipity came to the rescue here,” he said. “The very slow air cir­culation from the lower decks up to the single air intake duct in the top of the dome volume slowly urged all drifting objects to come to it. We found that each morning when we arose, we could find many of our small, lost articles on the screen on the intake duct!”

At the bottom of each of the workshop’s two “stories” were floors with an open-grid construction that was a fortunate relic of Skylab’s development. During the wet-workshop phase of Skylab’s history, engineers looked at whether any of the station’s infrastructure could be included in the s-ivb stage while it was being used as a fuel tank up to, and during, the launch. Anything that could be built into the tank would mean mass that would not have to be carried up later, and installation work that the crew would be spared. The catch of course was that it would also have to be something that could withstand the environment of an s-ivb filled with cryogenic pro­pellants, that it could not pose a risk of igniting the propellants, and that it must not interfere with the function of the rocket stage. One item that the engineers decided they could include was the floors of the workshop. How­ever, solid floors could not be used, since they would impede the flow of fuel through the tank. As a result, special floors were designed with a grid pattern that would allow fuel to flow through them.

When the switch was made from the wet workshop to the dry, the grid – pattern floors were no longer needed for their original purpose. However, the design was kept for the dry workshop because it was realized that the grid could serve another purpose as well, solving one of the challenges of life in microgravity. The Skylab astronauts were given special sneakers that had triangular fittings attached to their soles. These pieces would fit into the tri­angles that made up the floor’s grid pattern and lock in place with a small rotation of one’s foot. This allowed the crewmembers to stand in place on the floor without the help of gravity.

Finally, one would reach the farthest point from the Command Module, the bottom “story” of the Orbital Workshop. This was the primary living area of the space station and included its bedrooms, bathroom, kitchen, and gym. This area was divided into four major areas: the sleep compartments, the waste-management compartment, the wardroom, and the experiment volume.

Skylab had three sleep compartments, one for each of the astronauts aboard at any time. To make the most of the available space, the beds were arranged vertically in the quarters. Without gravity to keep a sleeper in place, the beds were essentially sleeping bags with extra slits and a vent to make them more comfortable. These were mounted on an aluminum frame with a firm sheet of plastic stretched within it to serve as a “mattress.” A privacy curtain took the place of a door at the entrance to each “bedroom.” Also in each sleep compartment were storage lockers, in which crewmembers could keep their personal items, and an intercom for communications.

The intercoms in the sleep quarters were among several located around the station, which served a dual purpose—they allowed communication both with the ground and throughout the station. Because of the low air pressure on Skylab, sound did not carry far, which could make it difficult to be heard in other parts of the station.

Voice communications with the ground were carried out in two major ways. The primary means of communication was the A Channel, which was used for real-time conversations with Mission Control. The other was в Channel, which was recorded on an onboard tape recorder and periodi­cally “dumped” to the ground and transcribed. This allowed the astronauts to pass along their thoughts about such things as habitability issues on Sky­lab, things that were not urgent but were needed for future reference. The crews were given questionnaires about aspects of life aboard the station and would dictate their answers into the intercom on в Channel.

For Project Mercury, NASA had to quickly develop a worldwide satellite­tracking network so that voice communications, data from spacecraft sys­tems, and commands from the ground could be sent and received. Stations were placed in exotic locations such as Zanzibar and Kano, Nigeria — often with help from the State Department — and were staffed by small teams of NASA employees and contractors. There was no real-time communication between Mission Control and most of these stations; data was relayed via leased commercial phone lines, undersea cables, and radios.

Capability of the system was continuously upgraded during the Gemini program. By the time Apollo 7 flew in late 1968, satellite relay of voice and data permitted Houston to communicate directly with the spacecraft; the remote-site teams were called home, and a unique travel experience disap­peared. But communication was still only via the transmitters and receiv­ers at the tracking stations.

The system inherited by Skylab was called the “Spacecraft Tracking and Data System.” It consisted of twelve stations: Bermuda, Grand Canary island, Ascension Island, St. Johns (Newfoundland), Madrid, Carnarvon and Hon­eysuckle Creek (Australia), Guam, Hawaii, Goldstone (California), Cor­pus Christi (Texas), Merritt Island (Florida), plus the ship Vanguard off the east coast of South America, and sometimes an aircraft (call sign aria) used to fill gaps during launch and reentry. As a result, communication between Skylab and Houston took place only in the brief passes over these stations, often interspersed by an hour or more of silence. The crew could tell where they were around the world by Houston’s calls — “Skylab, Houston, with you at Guam for eight minutes.”

To the left of the sleep compartments was the waste-management com­partment. This room featured a water dispenser that was the microgravity equivalent of a sink, a mirror for personal hygiene, and, of course, the space toilet. The Skylab mission required a level of innovation in this area not achieved in previous spaceflights. While the bag-based system used on pre­vious spaceflights for defecation had not been particularly pleasant, there was not really room on the smaller vehicles for a better means of dealing with the issue. For the comparatively short durations of those missions, it was something that astronauts simply had to bear.

Skylab, however, involved both a long-enough duration to merit finding a better solution as well as the space needed to provide one. For urination, the crewman stood in front of the collection facility with his feet beneath straps to hold himself in place. He urinated directly into a funnel with modest air­flow drawing urine into individual collection bags, one for each crewman. For defecation, he rotated about 180 degrees and seated himself on a small chair on the wall, rather like a child’s potty chair. But here a plastic bag had been placed beneath the seat for each use, which maintained a simple and hygienic “interface” with the astronaut. A lap belt and handholds were pro­vided to allow the user to stay in one place. As with the urine system, air­flow took on some of the role that gravity would play on Earth. An innova­tive feature of the fecal collection system allowed these bags to be placed in a heating unit after mass measurement, then exposed to the vacuum, which dried their contents completely. It was then much lighter and quite hygienic. The dried feces and samples of the urine were saved and returned to Earth for post-mission analysis.

To the left of the waste-management compartment was the wardroom, the station’s combination kitchen, dining, and meeting room. (Explained Kerwin: “Why was it called the wardroom? Because the first crew was all­Navy, and they got to name stuff. The wardroom is the officers’ dining and meeting room in a Navy ship.”) In the center of the room was Skylab’s high-tech kitchen table. Its round center was surrounded by three leaves, one for each crewmember. The flat surface of each of the leaves was actu­ally a lid, which could be released with the push of a button. Underneath the lids were six holes in which food containers could be placed, three of which could be heated to warm food. The trays had magnets for holding utensils in place. The table also featured water dispensers, which could pro­vide diners with both hot and cold water. Both thigh constraints and foot loops on the deck provided means for the astronauts to keep themselves in place while eating.

The walls of the wardroom were lined with stowage lockers and with a small refrigerator-freezer for food storage. The wardroom was one of the most popular places on Skylab for spending time—partially because it had the largest window on Skylab, which could be used for Earth – or star-gazing.

The largest portion of the bottom floor was the experiment area, which was home to several of the major medical experiments. The Lower Body Negative Pressure experiment was a cylindrical device, which an astronaut would enter, legs first, until the lower half of his body was inside. After a pressure seal was made around his waist, suction would then decrease the pressure against his lower body relative to the atmospheric pressure around his upper torso. The pressure difference would cause more blood to pool in his lower extremities, simulating the conditions he would experience when he returned to Earth and gravity caused a similar effect.

Also in the experiment volume was the ergometer, essentially a wheelless exercise bicycle modified for use in microgravity. Like its Earthbound equiv­alents, the ergometer featured pedals, a seat, and handlebars, but it was also equipped with electronics equipment for biomedical monitoring.

The Metabolic Analyzer was used with the ergometer to monitor the crew’s respiration. The device itself was a rectangular box with a hose connected to a mouthpiece. The user would put on a nose clip and then breathe in and out through the mouthpiece. The analyzer could not only measure respira­tion rate and breath volume but also, via a mass spectrometer, the composi­tion of the air he exhaled and thus oxygen consumption and carbon diox­ide production.

Another experiment in that area of the workshop was the Human Vestib­ular Function device, which was basically a rotating chair. With an astro­naut sitting in it, the chair could be rotated about the axis of the subject’s spine at speeds up to thirty revolutions per minute, either clockwise or coun­terclockwise. The purpose of the experiment was to test how their vestibu­lar systems (responsible for balance and detection of rotation and gravity) adapted to the microgravity environment. The experiment had been per­formed with the astronauts on the ground to provide a baseline and was per­formed again in orbit for comparative results.

Another major item located in the experiment room was only an experi­ment in the broadest sense—that life on Skylab was all part of research into long-duration spaceflight habitability factors. Because of the way the low­er deck was divided and because the shower was a later addition to the sta­tion’s equipment, the shower was instead located in the larger, open experi­ment area instead of being located in the waste-management facility, which in other respects was Skylab’s bathroom.

Water posed a potential hazard in Skylab. In weightlessness water would coalesce into spheres, which could float around the spacecraft. If they weren’t collected, they presented the risk that they could get into electronic devic­es or other equipment and cause damage. Small amounts of water could be easily managed, but large amounts were generally avoided in spaceflight. To wash their hands, for example, astronauts would squirt water into a cloth and then clean their hands with it rather than putting the water directly on their hands.

The shower provided means for a true spaceflight luxury. In it, astronauts could clean themselves in a manner that, while not quite the same as the way they would shower on Earth, was much closer. They would pull a cylindri­cal curtain up around themselves and then squirt warm water directly on their bodies using a handheld spray nozzle. Confined within the curtain, the water posed no risk to the spacecraft and after the shower could be cleaned up with towels or a suction device. The crews found the suction it provided inadequate for drying off completely and so used lots of towels. Nevertheless,

15- Lousma demonstrates Skylab’s shower.

at least one crewmember thought this “luxury” was both unnecessary and a gross waste of time.

At the center of this lowest floor of Skylab, the very opposite point from where the tour began, was the Trash Airlock. The s-ivb stage from which Skylab was modified had two tanks that originally would have been used to store the propellant: a larger tank for the fuel, liquid hydrogen, and a small­er tank for the oxidizer, liquid oxygen. The entire manned volume of the workshop was inside the stage’s liquid hydrogen tank. The liquid oxygen tank, which was exposed to vacuum, was used for trash storage. Between the two was an airlock that was used to transfer trash into the storage area. The oxygen tank was vented to space, creating a vacuum that helped pull the trash through, but it had a screen to prevent any trash from escaping. The arrangement meant that the waste generated on Skylab was stored safe­ly instead of becoming orbital debris.

The task of turning a spent rocket stage into a livable space station was prov­ing more difficult than anticipated. The man in the spacesuit was attempt­ing to carry out the tasks that would convert the used, empty fuel tank into an orbital workshop. It was a daunting challenge. If the series of steps could be carried out, it would provide an expedient path to homesteading space. If not the station as designed would be worthless, an unusable husk. For the plan to work, when it came to these tasks, one of the agency’s great truisms definitely applied—failure was not an option.

Almost immediately, he ran into problems.

Loosening the bolts before him was a simple enough task on the ground. Here though it was substantially more difficult. When he turned his wrench, instead of the bolts rotating, he did. The bolts were held in place, and since he was floating, there was nothing to keep him still. The gloves he had to wear only made things worse. Their bulkiness made it difficult to perform precise tasks. The fact that his suit was pressurized meant that it took effort to move the fingers of the glove. After a while, his hands would become sore from the effort. It was too much to ask, he realized. It couldn’t be done. Reluctantly, he signaled to the safety divers to bring him to the surface.

That revelation was to be a turning point in the development of Skylab, America’s first space station, and may well have saved the program. The man in the spacesuit was Dr. George Mueller, the National Aeronautics and Space Administration’s (nasa’s) associate administrator of Manned Space Flight, and the event took place in a water tank at nasa’s Marshall Space Flight Center (msfc) in Huntsville, Alabama. Mueller had been trying to find the best solution to the latest in a string of difficult decisions involv­ing the orbital workshop. His quest for answers had led him to get hands – on experience himself with a simulated space station.

i. George Mueller (left) and Wernher von Braun prepare for dives.

The agency had already decided that a Saturn ivb rocket stage would be converted for use as the workshop. (Its name is a relic from early nomencla­ture for the Saturn rocket series.) Because launching more weight into space requires more fuel, every effort is made to reduce weight on a spacecraft. Dividing rockets into stages is one way that can be accomplished—when the fuel in one section is gone, that section separates, and the rest of the rock­et continues. That way the rocket doesn’t have to haul the weight of empty fuel tanks the entire trip.

Though there was agreement that the s-ivb stage should be used for the workshop, there were two schools of thought as to how that should be done. The initial idea was to launch the workshop as part of a Saturn IB rocket, the smaller of the two Saturn boosters. That rocket was not powerful enough to deliver a completed workshop to space, but it could place its s-ivb upper

stage in orbit. Once the s-ivb was there, a crew of astronauts could convert the spent stage into a space station. Because this plan involved the station being launched full of fuel, it was known as the “wet workshop.”

The other option was to use the larger and far more powerful Saturn v. That booster also used an s-ivb as its third stage. The workshop could be readied for use on the ground, and stacked on the Saturn v in place of the third stage. The first two stages would carry the heavy payload into orbit. This latter option was the “dry workshop.”

As NASA’s supply of Saturn v boosters was dedicated to the upcoming mis­sions to carry men to the moon, the wet workshop option would allow the orbital workshop program to proceed simultaneously with the Apollo moon­landing program, using the more readily available Saturn IB rockets.

The plan, though, depended on the ability of astronauts to convert a fuel tank, which had just expended its supply of volatile liquid hydrogen and oxygen, into a home where they could safely live during the months to come. The crew would have to dock with the spent stage and then, working in bulky pressure suits, remove several bolts to gain access to its large liq­uid hydrogen tank. Then the astronauts would “passivate” the tank, mak­ing sure all of the propellant was gone and filling it with breathable gasses. The passivated stage would then have to be fitted with the equipment that would turn it into a laboratory and home. Those opposed to the wet work­shop option argued that the required tasks would be too difficult for the astronauts to carry out while wearing spacesuits and working in a vacuum and in weightlessness.

Mueller, who initially supported the wet workshop, joined its detractors in 1969 following his visit to the Marshall Space Flight Center. He had been invited by the center’s director, Dr. Wernher von Braun, who had been the leader of a team of German rocket scientists who were brought to the United States at the end ofWorld War II. As happened more than once during their tenures as center directors, von Braun was in disagreement with Bob Gilruth, his counterpart at the Houston, Texas, Manned Spacecraft Center (msc), later renamed Johnson Space Center (jsc ). George Mueller recalled: “The resolution of the question of a wet workshop versus a dry workshop occurred when I was met at the Marshall Space Flight Center airport by Eberhard Rees. He said that Wernher had asked him to show me the newest facility at [Marshall]. He took me to an old hangar, which was most unremarkable.

And then he took me inside, and here was a gigantic tank.

“As we climbed up, he explained that they had decided that they need­ed a neutral-buoyancy facility to establish the feasibility of carrying out the refurbishment of the wet workshop. There were a number of technicians and several spacesuited divers working in the tank.

“Eberhard did not know what my reaction would be. This was an unauthor­ized capital expenditure and broke most of the rules for facility mods—typi­cal Wernher. I guess to Eberhard’s surprise, my first reaction was that I want­ed to try out the tasks that the astronauts were being asked to do myself. So that’s where I learned how to scuba dive. Once I tried even the simple task of closing the valves between the tanks, it convinced me that we couldn’t rebuild and refurbish the tank in orbit, so that led me to the decision to go with the dry workshop.”

After the dive Mueller began the process of making his decision a real­ity. “Bob Gilruth took a little more convincing, and Bob Thompson [the Skylab program director at msc] was dead set against it. I really had to just say, we’re going to do it, because I couldn’t convince them,” he said. “What they were trying to do, connecting all those things up, never would have happened.”

It’s interesting when you stop and think about it,
how you get thrust very unexpectedly into an environment that
a few years later is the apex of your career.

You were doing stuff that had never been done before,
and you were successful.

Jim Splawn

“Eighteen days before launch—let’s see, that would be April 26—the Sky – lab 2 crew entered quarantine and started eating our carefully measured flight-type diets,” Joe Kerwin recalled. “That meant saying goodbye to our wives and families and moving into a couple of trailers on jsc property. Yes, we missed our families, but the arrangement was efficient, and we were in peak concentration mode. Nobody could come near us without a brief physical exam and a surgical mask. Launch readiness was everything. One of us recalled Coach Vince Lombardi’s famous and often misinterpreted quote about football: ‘Winning isn’t everything. It’s the only thing.’ He did not mean that football was more important than God, country, or fami­ly, just that on Sunday afternoon, you should not be thinking of that oth­er stuff. That’s where we were. It was a good, team feeling; I remember all six of us [the prime crew of Conrad, Kerwin, and Weitz and their backups, Rusty Schweikart, Story Musgrave, and Bruce McCandless] standing out­side the trailer each evening at bedtime, joking as we filled our urine spec­imen bottles for science.”

By launch morning the uncertainties of the Skylab program had practically vanished. All the battles that had been fought to improve the hardware and

procedures were over. Chris Kraft, jsc director, had called the first crew in to his office about a month earlier to tell them to knock off trying to change the medical experiments and start working to accomplish them; and Com­mander Pete Conrad had been able to say that they were already there. Train­ing was over. They felt confident of their abilities and trusted the team. The crew and NASA were ready to fly and had no premonition of disaster. “You could say Fate had us right where she wanted us,” Kerwin said.

With only one day left on the countdown for their own launch, the crew watched from the roof of the Manned Spaceflight Operations Building the Skylab station launch on a beautiful May morning. The Saturn v rose slowly and majestically from the pad and disappeared into the eastern sky. The launch looked good. They went back down the stairs to the crew quar­ters conference room, where the flight director voice loop from Houston’s Mission Control was set up so that they could listen to the activation activ­ities as they lunched and did a last-minute review of the next day—their launch day.

According to Owen Garriott, “May 14, 1973, was a beautiful day at the Cape. All of the three planned Skylab crews, along with tens of thousands of space enthusiasts, were in attendance to watch what would be the final launch of NASA’s most powerful launch vehicle. It all appeared from the ground to go perfectly with a long, smoky trail headed into the blue sky.

“Jack [Lousma] and I headed back to our usual motel—Holiday Inn, Cocoa Beach—to change into flight suits and head for Patrick Air Force Base where our NASA T-38 was ready for a quick flight back to Ellington Air Force Base, near the Manned Spacecraft Center. We wanted to be home as soon as pos­sible to observe the Skylab telemetry and verify that our home to be was in good shape for human visitation and also to watch the launch of Pete, Joe, and Paul scheduled for the next morning from Mission Control.

“As we were walking out to our rental car for the short drive to Patrick, we noticed the recently appointed director of the Marshall Space Flight Cen­ter, Dr. Rocco Petrone, walking along the porch in front of his second sto­ry room. ‘Looked like a great launch,’ we shouted. ‘Yes, but don’t get your expectations too high. There were some telemetry glitches observed.’

“With no more time for discussion, we headed for our aircraft, hoping that the telemetry issues would be resolved by the time of our arrival in Houston. We could only speculate about what these ‘glitches’ were, never imagining

16. Skylab was launched as the third stage of a modified Saturn v rocket.

the problems to be encountered and then solved in the next ten days.” That apparently beautiful launch was when things started to fall apart. The problems didn’t surface all at once. There had been a “g spike” — a sud­den, brief shock to the vehicle—about forty-five seconds after launch as the Saturn booster was accelerating through the speed of sound. Around a min­ute after liftoff, and very near the time of “max-Q” when the atmospheric pressure on the speeding vehicle is at the maximum, telemetry received in Houston indicated the micrometeoroid shield had deployed prematurely,

an anomaly not fully appreciated as the Saturn kept going and deposited Skylab in the correct orbit.

Once the s-ivb stage was in orbit, a planned sequence began to reconfig­ure it from its launch mode to its operational arrangement. The first deploy­ment action was to jettison the “sla Panels,” four large panels that protect­ed the docking adapter and atm during launch. That action went well. The next sign that something was wrong began to surface as workshop temper­atures started to climb above normal, but the full extent of the problem was still not apparent, and the deployment appeared to be going well. Mission Control proceeded with the next scheduled step: rotating the atm ninety degrees to face the sun and opening its four solar panels into their “wind­mill” configuration. That too went smoothly.

Then it was the turn of the Solar Array System, the main solar panels on the workshop itself. First the Solar Array System beams, the solar panel housings, would be deployed to ninety-degree angles from the workshop; then the panels themselves would unfold accordion-style. Fully open they would provide two-thirds of Skylab’s electrical power. And after they were open, the thermal/meteoroid shield over which they’d been folded (the “heat shield”) could itself be popped up away from the workshop’s exterior sur­face to assume its function of reflecting the sun’s heat and breaking up small meteoroids. The beams did not deploy. And the workshop surface and inter­nal temperatures continued to climb. Something was wrong with the heat shield, which should have kept the workshop cool even before deployment. Mission Control went into troubleshooting mode.

By late afternoon they finally realized the truth: the heat shield was gone. That G spike during launch had been the shield departing the vehicle. The anomalous telemetry had been completely accurate. Further there was no response at all from Solar Panel 2, indicating that it was probably gone as well. Solar Panel 1 was showing just a trickle of current, leading controllers to believe it was still present but stuck shut. NASA was soliciting high-reso­lution photography from other satellites and ground-based telescopes.

While the full import of what had taken place would take some time to pin down exactly, it became very apparent very quickly that something very bad had happened. For those involved in the program, 14 May would be an unforgettable day; many can still recall what they were doing when they learned that what had looked like a perfect launch had in fact been anything but and that years’ worth of work was in real danger of being lost. Mar­shall Skylab program director Lee Belew remembers that he was at Kenne­dy Space Center that day, having traveled down there to watch the launch. One particular memory that has stuck with him over the years since was being grilled by the national media for answers that were still unknown. “I was interviewed by Walter Cronkite at the Cape, and of course, he asked pretty tough questions.”

Phil Shaffer was in Mission Control at Johnson Space Center. He was not actually on duty; he was scheduled for a shift as flight director for launch and rendezvous the following day, overseeing the launch of the first crew. “Don Puddy was the flight director for the workshop launch,” he said. “Because I was going to sit down to launch sl-2 [with the first crew] the next day, I was there, more than willing to be a ‘gofer’ for him. When the telemetry just went nuts and those pieces started coming off, we didn’t know what had happened except that a lot of things we were seeing from telemetry didn’t make any sense. We certainly hadn’t seen anything like that in any of the simulations. We got to orbit, and Don started trying to get the post-insertion sequence to work. Many of the actions he was trying to get done involved equipment that was missing now. It wasn’t working, and the instrumentation was so screwed up we really couldn’t tell what was going on. Then additional unex­pected things began to happen on orbit, began to not work. Probably the best thing I did for anybody that day was start a malfunction list. Puddy didn’t have time for it. Two or three hours into the business, Gene Kranz leaned over the console and said, ‘You guys better start a malfunction list.’ I told him, ‘Here it is; it’s got forty-seven items on it, or some number like that, things that need to be pursued.’ So at that point we were stalled out on the post-insertion activation sequence. And stuff just kept failing, and we could see it was beginning to get hot inside Skylab.”

Though things looked grim, Shaffer had a moment that night of being able to view the Skylab in a more positive light. “I remember distinctly, the night of the day of Skylab i launch, I knew it was going to come over Hous­ton,” he said. “And I went out to look for the ‘string of pearls’ as it had been advertised—the [booster’s second stage] stage, the sla panels, the refrigera­tor cover, and the Skylab itself. There it was, a big ol’ string of pearls, going across the sky. Outstanding. Beautiful. It was really spectacular. It was a crystal-clear night in Houston, and I watched it for a very long time, almost from horizon to horizon.”

As controllers began to determine what the problems meant for the work­shop, the first crew realized what it meant for them: they weren’t going to Skylab the next morning. Instead they were going back to Houston. Ken – win recalls that his family and friends were having a prelaunch party at the Patrick Air Force Base Officers’ Club in Melbourne. “I called my wife and told her the news. ‘No launch tomorrow. But might as well keep partying!’” The next morning the crew manned their T-38 jets at Patrick and flew back to Houston. They joined a full-scale battle in progress: the NASA/contrac – tor engineering workforce versus Skylab’s problems.

As it happened, the high atmospheric forces near “max-Q” had caused the shield to be torn off the Workshop and drop into the Atlantic Ocean, all unseen from the ground. “Max-Q is a very dangerous, peculiar place, and the pressures are really peculiar at that point and shock waves all over the place,” Shaffer said. “If something is going to come undone, that’s where everybody says it’s going to come undone.” And to make matters worse the meteoroid shield also tore one of the workshop solar arrays completely off, dropping it into the ocean as well. The second workshop solar array had a different story. In this case the departing shield caused a metal strap to wrap across the array, which turned out to likely have been a blessing in disguise. On the one hand the strap caught the array and prevented it from deploy­ing properly, leading to severe power limitations after launch. On the other hand, the strap held the array in place during the launch so that it couldn’t be ripped off too, a life-saving event for the Skylab science program, which needed the power the array would later be able to generate.

“We knew quickly something was wrong, that’s for sure,” said Marshall’s George Hardy, who had gone down to Houston to monitor the launch and ended up staying there for much of the time before the first crew launched, serving essentially as a liaison between the operations team in Houston and the engineering team at msfc. “We knew there’d been a failure of the heat shield to deploy, or to properly deploy. We weren’t quite sure about that. Because there weren’t any extensive strain gauges and instrumentation and things like that on it that, we couldn’t pinpoint a structural problem of some kind exactly. But we knew that it wasn’t functioning properly. We weren’t getting thermal protection. It was a battle for the first days.”

That battle was fought on several fronts. First was keeping the vehicle in shape for the crew’s arrival, whenever that would be. (The orbit of Skylab

yj. The exterior of the Orbital Workshop, stripped of its heat shield, began to bake in the solar radiation.

passed directly over the Kennedy Space Center every five days, so launch opportunities would be at five-day intervals after the original 15 May launch date.)

Skylab’s only source of power was the atm solar panels, and every watt was needed, which meant keeping the atm pointed straight at the sun. But with the heat shield gone, pointing at the sun was the worst direction for work­shop temperatures. It was 130 degrees Fahrenheit inside the workshop. The results of the high temperature could be disastrous: food might spoil; nox­ious chemicals might outgas from the walls; batteries and other equipment might be degraded. The materials lab at Marshall had conducted a tempera­ture overtest on the substances used inside the workshop to make sure there wouldn’t be an outgassing problem if temperature exceeded nominal levels but had only run the test up to over 100 degrees. After the loss of the heat shield, they resumed their testing, this time at higher temperatures.

The flight controllers battled this dilemma for ten days. With no pana­cea for the conflicting problems of heat and attitude available, those days were filled with constant compromise between the dual concerns. They’d roll Skylab away from the sun, to keep the temperatures from increasing. Power would drop, battery charge decrease, and a roll back toward the sun would have to happen.

The question of controlling the station’s attitude was further complicat­ed by its means of attitude control. Skylab had the three large momentum wheels, like large gyroscopes, called “Control Moment Gyros.” By order­ing the cmg’s electrical system to push against the gimbals of one or more of these cmg momentum wheels, it was possible to move the direction in space in which Skylab was pointed, thanks to the principle of conservation of angular momentum. So it was easy enough to change the station’s direc­tion. But when this was done, other small forces were encountered (techni­cally called “gravity gradient forces”) that tended to drive Skylab’s attitude in another direction, perhaps opposite of the one desired. This problem was not so easily solved and required firing the cold gas jets in space to hold the desired attitude. Further complicating the matter, the amount of cold nitro­gen gas was strictly limited, and if this procedure were to continue for too many days, perhaps twenty or thirty, all the gas would be expended and attitude control would be lost. So a fix was needed in rather short order to save the Skylab missions.

For ten days mission controllers worked constantly to preserve the del­icate balances needed to keep the station fit for when its first crew arrived. Over half the supply of the nitrogen gas for the entire mission was used in these ten days. “It was ironic,” Hardy said. “There was a preferred orienta­tion for generating electric power. However, it turns out that most of the time that was the most adverse orientation for the workshop overheating and for drag.

“It was management of the orientation of the workshop on a continual basis, going to one particular attitude knowing that it was penalizing you in some areas. But you had to do that, and you figure out how long you have to stay there and then get back in the other attitude. It was a real balanc­ing act between those three things. The operations people did a fantastic job in that, and of course we loved the great engineering team. There were real questions about whether the batteries would actually survive that kind of cycling. We just started cycling, and I guess we learned a lot of things.” But they kept Skylab alive.

The second front of the battle to save Skylab was finding a way to erect a substitute for the heat shield. The spacecraft, its contents, and any crew just could not tolerate those temperatures. And whatever NASA came up with, they had to be quick about it. The longer launch was postponed, the less likely it was that Skylab would remain salvageable.

Engineering teams were formed at NASA centers across the country and told to forget the paperwork for a while. “It was an opportunity for some imagination,” Shaffer said. “It was an environment where if you had a good idea, it was really easy to get it executed, ’cause all of the energy was there to do that.” The astronauts from the later Skylab missions and the back­up crews were sent out to the centers to provide an operations viewpoint for the efforts.

“I remember leaving the launch site and coming back to the Holiday Inn,” Jack Lousma said. “I met Ed Gibson and Julie, and they had more word than I did. They were somewhat disappointed and discouraged. I was thinking, at least the Skylab is up there, and even though it’s not perfect, there’s proba­bly something we can do about it; at least it’s up there. I had no other knowl­edge, and no one else did either. I didn’t know what the extent of the dam­age was, or if I should feel confident that something could be salvaged. But I knew at least it was up there. And that was somewhat heartening.

“I went on to Houston because they hadn’t figured out what the problem was for a short period of time. I wasn’t there long, because we had to find out what was wrong with the Skylab and figure out what to do about it. I remember coming to work one morning, and Al Shepard said ‘I want you to go to Langley and help them develop one of the fixes for the thermal shield.’ I didn’t go home, I didn’t get any clothes, I didn’t do anything, I just got in a T-38 and flew there directly. I spent about three days there and worked all day and all night with those guys at Langley to develop one of the concepts that was being proposed. This was an inflatable structure [inspired by an ear­lier communications satellite design], where it was a very lightweight mate­rial that would be shaped in the form of a covering, and it would be inflat­ed when it got up there. It was all this silvery material.

“I think we [would have] extended it out the airlock, but I could be cor­rected on that. I don’t remember there being any external tie downs, or anything like that, that we developed. But anyway they had fabricated one of those very quickly, and started the inflation, and tried to deal with those engineering difficulties, and finally made it work. I introduced my crew comments on it as we went along on how to make sure the crew could actu­ally do it and be able to get it to operate.

“But my conclusion after being there for two or three days was that it was not going to be a satisfactory fix. It was too vulnerable to losing its inflation; the dynamics of its inflation and spreading over the workshop were mar­ginal in my estimation. So all of us rendezvoused down at the Cape direct­ly after that. All of us went to the Cape and met with Pete’s crew. I sat and listened to all of the presentations of the fixes that were available, and then I told them that I didn’t think that the one I was working on had top prior­ity. They could make up their own minds, but here’s what I thought about it. It wasn’t one of the ones that went through.”

After all the work was done and all the ideas were brought together and reviewed, three solutions seemed feasible. All three ended up being launched, and two were used.

From the Manned Spacecraft Center in Houston, a cloth sunshade that would be deployed by flying the Command and Service Module from point to point around the workshop, while the crew would unfold it and secure it to structure. Installation would be feasible but tricky. This one was not used.

From the Marshall Space Flight Center in Huntsville, the “Marshall Sail” (also known as the Twin-Pole Sunshade), designed to be deployed by a pair of astronauts during a spacewalk after docking with and activating Skylab, using the Skylab airlock. A solid and elegant solution, it was deployed over the original parasol a few months later by the second crew to extend the life of the parasol’s delicate aluminized Mylar reflective covering material.

From Houston, a “Solar Parasol” (or “jsc Parasol” or just “the para­sol”) — a large square of thin nylon cloth attached to four spring-loaded fish­ing poles and packed in a long metal canister. As luck would have it, there was the Scientific Airlock built into the wall of the workshop on the sun­pointing side. It was designed to allow astronomy and materials experiments in pressure-tight canisters to be pushed right out into vacuum to take their observations. The parasol made some investigators unhappy by monopoliz­ing that airlock for the entire mission. But it played an essential role in sav­ing Skylab, being a quick, safe solution to the heat problem. It was invent­ed by Jack Kinzler.

i8. Jack Kinzier (secondfrom right) explains his parasol concept.

Jack Kinzier graduated from South Hills High School in Pittsburgh in 1938. He was hired at the National Advisory Committee for Aeronautics’ Lan­gley Research Center in 1941 as a journeyman toolmaker. His skills earned him multiple promotions, and in 1961 he was assigned to the Manned Space­craft Center in Houston as chief of the Technical Services Division. He nev­er got a college degree, but his “equivalent in experience” was worth at least a master’s in mechanical engineering.

“Different groups were working on sun shields deployed on spacewalks,” Kinzler recalled. “When I realized nobody thought about going inside and doing it the simple way, I thought, ‘Well, I’m going to look around some.’”

He found the experiment airlock on the sunny side of the station—he called it a “Sally Port”—in the trainer in Building 8. “So I had one of my techs go down to Houston and buy four fiberglass extendable fishing poles,” he said. “I drew up a hub with springs attached to the bottom of each pole. Then I had the sheet-metal shop roll up a tube about eight inches in diame­ter. I called up my parachute shop and said, ‘Get me a twenty-four-foot sec­tion of parachute cloth.’

“The machine shop fastened the four fishing rods to my base. I fastened

that base to the floor of our big high-bay shop area. We fastened the cloth to the rods and long lines to the tips of each rod. I lowered the big overhead crane to floor level and swung my four lines over the crane hook. Then I called Gilruth, and everybody came over for a demonstration. I said, ‘I think I’ve got something you’ll like.’

“So they were standing around thinking, ‘What’s Kinzler up to now?’ I raised the crane back up, letting out excess line ’til I had enough clearance, then let the crane pull all four lines simultaneously. It looked like a magi­cian’s act because out came these fishing rods, getting longer and longer. They’re dragging with them fabric. They get all the way to where they’re fully out, and all I did was let go and it went ‘sshum!’ So the springs were on each corner (and each spring pulled a pole outward and downward), and they came down and laid out right on the floor just perfectly. And everybody was impressed, I’ll tell you. They were impressed! So that concept—my con­cept —was chosen for the real thing.”

Kinzler and his techs gladly paid the price for success, working day and night for six days building the flight version (substituting thin nylon for the parachute cloth) and testing it. Afterward he got a lot of fan letters — and from NASA its highest decoration, the Distinguished Service Medal.

Many others were working on the problem at jsc. Ed Smylie, then chief of the Crew Systems Division, remembered: “We constructed an umbrella that would deploy like a flower petal, rather than like a traditional umbrel­la. We covered the assembly with a test canopy filled with holes to reduce air resistance during our deployment tests. On the initial test it worked perfectly. I invited NASA management to review our design. Most of senior management from Johnson, Marshall, and headquarters joined us. Upon deployment the frame twisted itself out of shape and failed completely. The managers shook their heads and went away. When I asked my crew what happened, they said they thought the spring was too weak and installed a stronger spring.

“Shortly after, I had a call; I should abandon our design and support Max Faget [director of engineering at Johnson] in the design of the chosen approach. As I recall, the frame was constructed in the jsc fabrication shop under the direction of Jack Kinzler and Dr. Faget. I can remember work­ing with Max laying out the frame on the floor of the shop in the middle of the night. Max turned to me and said, “Isn’t this fun?” I had not thought of it that way, but he was right. There was intense pressure, but it was a fun kind of pressure.”

Ed shared the fun and the pressure with his key engineers — Jim Correale, Larry Bell, Harley Stutesman, Joe McMann, and others. He set up a clear­inghouse called “Action Central.” All elements of the center used it for get­ting things done quickly. One of his branch chiefs took it upon himself to charter a Learjet to move supplies as needed around the country.

“Everybody was working horrendous hours, and towards the end of those ten days one of my branch chiefs was leaving Building 7A one evening, and as he walked out the back door he simply collapsed,” Smylie recalls. “He was not injured, but his system had simply shut down.

“The briefing of the Skylab 1 crew was held in the ninth-floor confer­ence room [of the main building at Johnson, then called Building 2] after the crew had been quarantined. Everybody had to wear those little paint­er’s masks over their mouths and noses. It was quite a sight to see the astro­nauts, senior management, engineers, and industry types—over a hundred of them—crowded together in that room around the huge table, all wearing those little white masks. After an hour or so everyone’s masks were getting damp and hard to breathe through, so people started moving the masks a little bit and sneaking breaths. Then Pete Conrad stuck a cigar out the side of his mouth and commenced to smoke it—still keeping the mask on his face. Soon everyone was moving the masks away from their mouths so they could breathe. They started wearing them over their ears, on top of their heads, anywhere—but no one took off their mask!”

While the Houston-designed parasol had the advantage of being easy to deploy and thus providing a quick fix to the heating problem, Bob Schwing – hamer, who was the head of the Marshall materials lab, had concerns about its long-term durability. “I was afraid of that because I had run these tests about building the flag, and I knew the nylon wouldn’t stand up very long.” Schwinghamer was also concerned that the station’s TACS thrusters would damage the thin material when they fired. “What if it rips or comes apart totally?”

“For the Marshall Sail, I had used that same rip-stock nylon material, and I had a material called S-13G, which was a thermal-control material, real nice white stuff, very highly reflective,” he said. “When you sprayed it on that sail parachute material, it still had high flexibility. It wouldn’t flake

19. Seamstresses prepare the Marshall Sail sunshade.

off or anything. So we sprayed it with that, and I ran some ten-sun tests in the lab to see how long it would stand up, and we knew it would last for the Skylab mission.

“Then we had some Navy seals in; they packed it. We didn’t have a para­chute packer; they packed it. That thing was pretty big, it was like thirty by forty, I think. We got some seamstresses in from New Jersey to do the sew­ing. I remember that stuff was laying all over the floor, and they were just sewing away, and pulling that big sail through there. And we got that stuff all done in ten days, in time to fly.”

The failure of the micrometeoroid shield had come as a complete surprise to the Skylab engineering team, which had not foreseen even the possibility of its failure. “The meteoroid shield went through design reviews like all the other hardware did,” Hardy said. “There were known design requirements; there were some tests that were done. You couldn’t do a test that exposed it

directly to aerial loading and things like that, obviously. Nobody predict­ing a failure or anything like that. But like a lot of other things, after it hap­pened, you go back and look and see where you were deficient in your anal­ysis and some of your designs, but not prior to launch.

“McDonnell Douglas Huntington Beach was the prime contractor for the Orbital Workshop, which included the heat shield. But other contrac­tors were involved in design reviews and things like that. I don’t know, there could have been somebody out there that was expressing some concern that wasn’t taken into account. But if there was, it was almost after the fact, because I had no knowledge of that.”

While the rescue effort was underway, an investigation was started into the causes of the failure. The board of investigation was chaired by Bruce T. Lundin, director of NASA’s Lewis (now Glenn) Research Center and pre­sented its findings on 30 July. The board determined that the most proba­ble cause of the failure was pressurized air under the shield forcing the for­ward end of the shield away from the workshop and into the supersonic air stream, which tore the meteoroid shield from the workshop. The report stat­ed that this was likely due to flaws in the way the shield was attached to the workshop, which allowed in air.

The failure to recognize these issues during six years of development was attributed to a decision to treat the shield as a subsystem of the s-ivb, based on the presumption that it would be structurally integral to the tank. As a result, the shield was not assigned its own project engineer, who could have provided greater project leadership. In addition, testing focused on deploy­ment, rather than performance during launch. The board found no evidence that limitation of funds or schedule pressure were factors and that engineer­ing and management personnel on Skylab, both contractor and government, were highly experienced and adequate in number.

Resolving one final issue was absolutely essential to Skylab’s long-term success. It was to answer the questions “Is one of the solar array wings still there; what’s wrong with it; and how can we get it deployed?” Related to these were the further questions of how much the crew could do with atm power alone and how they would do it. Even if it were possible to deploy the remaining solar array wing, living off the atm power would be nec­essary when they arrived and until (and if) they got the solar panel open. The crew spent a lot of time with the flight planners, going through all the checklists, and marking them up for low-power operations. General con­clusions were:

With care and frugality, the crew could live in the workshop and do some of the experiments.

They should use lights sparingly and turn them off when they moved and not make coffee or heat food.

The solar physics and Earth resources work should be minimized. (The medical experiments were pretty low power users and ok.)

And so forth.

There was serious doubt that Skylab could go three missions like that or that it would be worth doing. One or two failures would put it out of busi­ness. The science return would be badly hurt. They had to get that solar panel out to save Skylab.

Some images had been obtained. They were blurry but showed that the solar panel was there. What was holding it shut would have to await inspec­tion after crew arrival. But the holdup must have to do with the ripped – off heat shield. Freeing the array would require a spacewalk. And the team had to select a suite of tools for the job right then without waiting for the inspection. Engineering did a superb job of outlining possible situations they might meet and finding a collection of tubes, ropes, and cutters to make up their tool kit.

And soon the decision was made that NASA couldn’t possibly be ready to launch on 20 May. The flight controllers said they could hold on another five days. So they aimed for 25 May, the next fifth-day opportunity to launch.

“I was in the flight operations management room at jsc at the launch on May 14 and spent about the first week down there,” George Hardy remembered. “After the first ten-twelve hours of meetings and looking at data, everybody was walking around with their heads down. I’d just come out of a meeting with Gene Kranz. I felt we’d bought the farm; we’d lost the mission. And Kranz said, ‘No, no, we’ll figure it out. We’ll figure out some way to get this thing done.’ That’s the sort of guy he was, still optimistic.

“The next seven to ten days was remarkable. I stayed down there with the first-line Marshall engineering support group. And, of course, we stayed in touch with what was going on at Marshall. But I got to see firsthand what the jsc folks were doing too. It was quite remarkable.

“We were getting all kinds of suggestions from the public. I still have, tucked away somewhere in shoeboxes or somewhere, letters that I got from people all over the world that had suggestions about what we might do.

“The other thing I remember, Chris Kraft had a meeting every morning in his conference room, and he accepted me in that conference room just like I was one of the jsc guys. We had the best working relationship you can imagine. There was no ‘invented here or there.’ Both centers worked aggres­sively to get their sun shield out, and both of them worked; both of them served their purpose. Those were good days, great days.

“That was something, the first seven days. It was actually ten days, but there was a movie about that time called ‘Seven Days in May,’ and Jim Kings­ley and I joked later about that. It turns out at that point in time we’d worked on Skylab about seven years, and we almost lost it, so we decided we were going to write a book called Seven Years in May.”

About a week after the launch, Hardy left jsc to return to Marshall and oversee his team there. He recalled that Rocco Petrone, who in January of that year had been brought to the center to serve as its new director, was very involved in the discussions about the status of Skylab. “Dr. Petrone would come by every morning and get a briefing on what was going on,” Hardy said. “He’d usually call sometime during the day. And he’d come by every after­noon. And every afternoon we’d have a briefing for him on every problem, all the plans for the next day and everything. He’d come by like six o’clock in the afternoon, and sometimes those briefings would last until midnight. You had to stay on top of it. At that particular time, initially, he hadn’t been [at msfc] but a very short time, and his wife wasn’t here, and he was living in an apartment, so he had a lot of time. He’d come over there and eat Ken­tucky Fried Chicken, or whatever it was we’d ordered for that night, and stay with us. A lot of times he’d stay five or six hours.”

Lee Belew had a similar recollection: “We worked day and night. I mean, absolutely day and night. With Rocco whipping us all the time. He was something else.”

Bob Schwinghamer was also at Kennedy Space Center for the launch. “I was down there on the fourteenth,” he said. “I had the family along for that launch. That was a big deal, Skylab. Right away we started hearing that the temperature was not the way it should be; and they concluded that some­thing had happened with the micrometeoroid shield and everything.

“I hung around the control room as long as I could down there. I final­ly went back to the motel and told everybody, ‘We’ve got to get out of here, and we’re going to leave very early, about three o’clock in the morning,’ and it was about nine or ten then. We drove all the way back, nonstop. And I got in sometime the next day—I don’t know exactly when—went over to Hose, which is where our control center was, and for the most part stayed around there. We started trying to figure out what might have happened, and what should we do.”

Like most at NASA’s manned spaceflight program at that time, Schwing- hamer has memories of long hours of hard work, and as with most at Mar­shall then, Rocco Petrone features prominently in those memories. “It was ten days and ten nights,” Schwinghamer said. “I didn’t go home the first three days. And then after that, Rocco would come in about ten o’clock at night all the time, eleven o’clock, ‘What kind of progress are we making?’ After we started building the sail, I had three teams for around-the-clock coverage on the sail, and I had a big chart in my office, and I had a guy that his responsibility was to log in the results: When did you paint? Have you inspected? All the steps were there, and they were logging them in as they occurred.

“And Rocco would come in at ten or eleven o’clock at night, and he’d say, ‘I’ll be back later.’ Well, hell, you didn’t know if later was in an hour, or two hours, or tomorrow morning. So the first three days, my deputy Gene Allen and I stayed all night. Finally on the third day, we looked at each other, with dark circles under our eyes, and I said, ‘Gene, I can’t keep this up.’ He said, ‘I can’t either.’ I said, ‘I’ll tell you what let’s do, let’s go on two twelves, and a little bit extra if it takes it, fifteen, maybe, or whatever. But nominally two twelve-hour shifts.’ Well, we did that after the first three days, and it worked out pretty good. Somebody was always there when Rocco showed up. Oh, he was tough on us. Oh, he was tough. But that’s what it took.”

Schwinghamer recalled that during the preparation of the sail, the process laboratory at Marshall insisted that they should be responsible for spraying the protective coat on it. He warned them that it would probably be more difficult to apply than they were anticipating and said that his materials lab could do it. “They said, ‘Ah, we can do anything,’ And I said, ‘All right go ahead, spray it.’ So I went over there, and it was about six o’clock, seven o’clock in the evening, and I was standing there, and it was the damnedest mess you ever saw. All of a sudden, somebody behind me says, ‘Did you guys ever make any flight hardware in this place?!’ It was Rocco, and he was mad­der than a hornet. It was a mess. He said, ‘Bob, you get everybody that has anything to do with this sail into your office; at eight o’clock tonight we’re going to decide how this gets done.’

“So I called Matt Sebile, the lab director in the process engineering depart­ment. I call him on the phone and he said, ‘Well, I’m cutting the grass, I’d like to get finished.’ I said, ‘I tell you what, I can’t tell you what to do; I’m just a division chief. But if I were you, I’d get my butt over here just as fast as I could.’ And he did, and he had ratty old Bermuda shorts on and dirty ten­nis shoes. At that eight o’clock meeting, Rocco says, ‘All right Schwingham – er, the sail’s your responsibility. J. R. [Thompson, head of crew systems at Marshall], you’re responsible for the deployment and how it gets used. Now get out of here, and get it done.’ Of all things, my dad came down to visit us from Indiana right in the middle of that. I said, ‘Dad, no fishing this time.’ He always used to come down, and I’d take him fishing one time.”

Despite the busy schedule, Schwinghamer did get to talk to his father, once, during the visit, while he “was home shaving one morning, and tak­ing a shower.” His father questioned why his son was spending so much time at work. “He said, ‘Are just you doing that?’ And I said, ‘No, everybody’s doing that.’ He said, ‘I can’t understand that.’ He was the superintendent of a chair factory up there in Indiana. He said ‘You know what, I couldn’t get my people to do that.’ I said, ‘Everybody’s doing that, not just me.’”

While Petrone loomed large in Marshall’s efforts during those ten days, he made at least one contribution of which he was utterly unaware. One eve­ning Schwinghamer found himself in need of some material used in the sail, which was only produced at the Illinois Institute of Technology in Chicago. Obviously simply ordering the material would have taken far too long; he had to have it right away. As happened often during the around-the-clock work, it was already into the evening when Schwinghamer discovered he needed the material.

“I wanted to get [the center’s] Gulfstream to go up and get that stuff so we’d be there at seven o’clock the next morning and could bring it home by noon the next day,” he said. “Of course, everybody was gone, and you couldn’t get the normal approvals. I tried to call some people at home to get approval to use the Gulfstream. I finally conned somebody — I don’t remember who,

I don’t wanna know—who would give me enough paper that I could go out there and say I need to take the Gulfstream. And we did that.

“And I kept thinking, ‘Rocco Petrone’s the director, if I get caught doing this, I’m done for.’ That would have been a little too far. But since it was at night, there was no call or request or requirement for the airplane, and we got by with it all right. Boy oh boy, that would have been very bad. I can tell you some center directors we had that I could have talked my way out of it, but I couldn’t have done it with him.”

The only-semi-authorized use of the center’s Gulfstream was practically by the book though, compared to another vehicle use Schwinghamer was involved in during that ten-day period. When he ran out of another materi­al he needed one evening, Schwinghamer called Tom McElmurry in Hous­ton for more at around 9:00 or 10:00 p. m. “I called him; I said, ‘Tom, I’ve got to have some of that damn material. Can you bring me some?’ And he said, ‘I think I can.’ He got here at midnight, I’ll never forget. He said, ‘Bob, I’m not flying back to Houston tonight. I’m going to get a hotel room. Can you get me a car?’

“I thought, ‘How am I going to get a car now?’ And then I thought, ‘Oh, the lab director’s got a car, and I know where they keep the key.’ The secretary always left the key under the desk. I said, ‘I’ll get you the lab director’s car.’ My thought was, he’s going to take off at six in the morning, and Heinberg wouldn’t come in until seven thirty, and I could get that car back, and he’d never know it was gone. But I worked all night, and I was getting pretty woozy. By that time in the morning, I didn’t think about the damn car any more. The car was sitting out at the Redstone strip.

“Heinberg comes in—the secretary told me this story—he looked through the Venetian blinds, and said, ‘Where the hell is my car?’ She said, ‘Mr. Heinberg, it’s in your parking place.’ He said, ‘You just come over here and look, and the car was gone.’

“So then they called all around, and they had the mps running around looking for the car with the license number and all that crap. And they finally found the car out there at the Redstone airstrip, and somebody out there, said ‘Yeah, Schwinghamer did that.’ So he called me up about ten o’clock that morning, I’ll never forget. And he said, ‘Schwinghamer, you know what, you’re totally irresponsible.” And he hung up. And I thought, ‘Oh, I’m fired.’”

There were several other occasions when the exigencies of the situation meant that protocol was waived in favor of expediency. “We had very strict rules about handling flight hardware,” Schwinghamer said. “You couldn’t just put that in the trunk of your car and drive off. This guy that worked for me had this big Ford van with just two seats in the front. I got so tired calling transportation and then having them show up four or five hours, or the next day, later. And I thought, ‘The hell with it.’ So every time we had to move [something], I’d get him and we’d put it all in the back of that big Ford van and move it.”

On one occasion, though, he had “unofficially” transported some flight hardware for a qualification check, and someone came back and told him it wasn’t working. “And I said, ‘What are you talking about? We checked that thing out ourselves here and it was working fine.’ So I went up there and said, ‘Nothing happened here, did it? I mean, when we moved it?’

“I looked around real carefully, and one corner of that cube was scrunched, and it had green tile in it. And they had green tile on the floor up there. I said, All right, this metal got yielded. I suspect it fell on that corner.’ Finally one guy broke down, and he started crying. He said, ‘I did it, I didn’t mean to.’ I’ll never forget, he was one of the best techs we had. I really hated that. I said, ‘Just forget about it. You get this thing going again, fix it, and I won’t say anything.’ I felt so bad, ’cause he was one of the best techs we had and that would have gotten him in a lot of trouble. And I had a little personal interest too: I thought, next thing you know, they’re going to start inquir­ing about how this stuff gets moved around. We were in it together, I do believe. He fixed everything up, and it worked fine.

“One night I needed something in that same building, and I got in before they closed everything, but I stayed too long, and then I couldn’t get out,” Schwinghamer recalled. “I had what I needed; it was two small parts. And I couldn’t get out. I thought, ‘If I call these damn security guys, they’ll be here in two hours or something. I’ll climb the fence.’ It was one of these fenc­es with that overhanging barbwire. I didn’t think about what the hell I’m going to do when I get up to the barbwire. I cut a big gash in my butt, and I fell off the fence and fell on the ground. It was about eight feet high. And just when I hit the ground, two headlights came on. These darned securi­ty guys drove up and slammed up the brakes and jumped out. One of their names was Miller; I knew him well, ’cause he had nailed me for speeding four or five times. He walked up there, and I’m lying on the ground, saying ‘Oh, my. . And he said, ‘Hell, I should have known it’d be you, Schwing – hamer.’ He didn’t do anything; he let me go. Boogered my butt too.”

“We didn’t let anything deter us in those days,” Schwinghamer said of the construction of the sail. “A lot of funny stuff happened on our way to the Skylab. We did all kinds of stuff in those days. I can remember I was getting in hot water all the time. And it was day and night, I’m telling you what. It was really something. Oh, we did all kinds of stuff like that at that time, but we got her built. And they got it deployed, and the temperature came down real nice.”

A total of seven of the sails were built; two of which were set aside as flight hardware, and the others were designated for testing. “I even had one left and gave it to the Space and Rocket Center out here,” he said.

During the ten days they were grounded, the astronauts of the first crew were still under quarantine and continued to eat their flight diet so as not to ruin the metabolic balance experiment regardless of when they launched. But a trip to Huntsville was necessary, to inspect hardware and discuss repairs with Skylab engineers and to try out the Marshall Sail twin-pole sunshade in their water tank.

“That spacesuited water tank run was a memorable experience,” Joe Ker – win said. “There was an air of quiet intensity. We were all old hands at this, donning the suits, checkout, entry into the water were quick and easy. A pre­liminary version of the sail was ready, and tools were available. We worked our way through the deployment process, noting omissions and improve­ments. We liked what we saw. It was late in the evening when we emerged, and we didn’t know that reporters had gotten wind of the exercise and were clamoring to get in and take pictures. Word came to us, we’d done enough, go back to the motel and home tomorrow; let the backup crew take over. So we returned to the motel, and who should show up but Deke Slayton, carrying a couple of large pizzas and a bottle of wine. Best pizza and wine I ever tasted. Morale was good. Deke knew how to lead. And the metabol­ic balance experiment didn’t suffer. That was the only time we broke the meal regimen.”

Marshall’s Neutral Buoyancy Simulator, large enough to hold full-scale replicas of space hardware underwater, had already played a vital role in the Skylab program in the wet workshop versus dry workshop decision. Now it would make yet another key contribution. “It really proved out to be very,

20. Jim Splawn (left) shows Rocco Petrone (center) and Bill Lucas the mount of the sunshade poles.

very beneficial,” said Jim Splawn, who was the neutral-buoyancy tank manag­er at Marshall at the time. “Because once we had the difficulty at the launch of the Skylab itself heading toward orbit, it really proved its worth because of all the hardware we had to assemble underwater.”

Like so many others involved in the effort to save Skylab, Splawn had been at the sl-i launch and was already putting plans in motion even before boarding the NASA plane for the return flight to Marshall. “Once we knew we had a problem, I got on the phone with the crew back here in Huntsville and said, ‘Hey guys, we’ve got to start thinking about how we may help with the repair — design of tools, the mechanics of the procedures we go through. We need to start thinking about that, not tomorrow, but right now. And just ‘think outside the box,’ as we say today.”

The two biggest tasks were to contribute any ideas as to how the prob­lems with the orbital facility could be fixed and to begin thinking about how they would train the flight crews on the procedures and the tools that would be needed to make the repairs. “And that started within probably an hour or so of knowing we had a problem,” he said.

Once development of the Marshall twin-pole sunshade began, the water

tank played an important role in qualifying the design. Test hardware would be fabricated and tested in the tank, problems would be identified and cor­rected, and the cycle would begin again. “With us being there right next door to the shop areas, we had the run of the entire shop to make whatev­er we needed,” Splawn said. “There were times when the shop would make a welded piece, and we’d grab it and run to the water, and when we would put it in the water, it would sizzle because, luckily, with the close proximity we were just working that fast.”

During that period the tank essentially operated as a twenty-four-hour – a-day facility. “Our wives, our families brought changes of clothes to us; they brought hot meals to us. I have no idea how many hours we went with­out sleep. I think at one point I personally went about thirty-four, thirty-six hours. But it was simply because the adrenaline was flowing; you had a mis­sion, and you felt that it was just absolutely your job to do everything you could to make it happen. And we were no different from dozens and doz­ens of other people at Marshall that were pursuing an answer to the problem that we had. So it was very rewarding to see it all come together eventually and put us in business.” Other key members of the msfc neutral-buoyancy team included Charlie Cooper and Dick Heckman, and astronaut Rusty Schweickart spent a large amount of time working with the team to pro­vide crew operations input.

For Splawn his work on Skylab, and particularly the effort to save the sta­tion, was the highlight of his career. “When we were doing flight crew train­ing, we never dreamed that we would end up doing an exercise like this, to have a salvaging kind of ‘Let’s fix the Skylab for the crew so that they can go and spend their days on orbit and do the things they had been trained to do.’ We never dreamed we’d end up in that kind of posture. But the way it worked out, that really is a highlight of my career, even beyond the flight crew training, which for us was probably what we thought would be the apex of our careers. But that ten days, obviously, topped it.

“For the launch of the last crew, we took all of our staff— all the divers, secretary, everybody—to the Cape and got to see the last launch,” he said.

At the same time that the work was going on to figure out how to erect some sort of sunshade on Skylab, another effort was underway to work out how to free the station’s remaining solar array so that it could deploy and provide power. With an attitude that was typical of people involved in the

2i. When the first crew arrived at Skylab, they discovered that debris had prevented the solar array (white beam at top) from deploying from the workshop (black cylinder at bottom).

project, the engineers took a task that was considered impossible and prompt­ly began working to figure out how to make it happen.

“Six weeks or so prior to that, maybe it was a little longer, we had done a failure modes and effects analysis, which is kind of typical,” said Chuck Lewis, a man-systems engineer at Marshall at the time (not the same as the Chuck Lewis at Mission Control in Houston). “And one of the things that we and jsc did together was a study of what sort of contingency plans were feasible. One of the issues, believe it or not, was if one of the solar arrays mal­functioned. And the answer to that was, ‘It’s not possible [to do anything]. Can’t get there. Don’t even need to worry about doing any analysis on that.’ The message was, ‘You’re not going down the side of the s-ivb. It’s not pos­sible to get down there, because there are no handrails.’ That was the killer in the notion of whether you could do anything about this.”

Just weeks after the task had been deemed impossible, J. R. Thomp­son, who went on to become the director of the Marshall center, and later nasa’s associate administrator, called in Lewis and others after the Skylab had arrived in orbit and controllers had learned that the unfixable problem had occurred. “J. R. Thompson called three or four of us up to the confer­ence room up there,” Lewis said. “He had the whole vehicle on one drawing spread out on a table. And he said, ‘ok, guys, I know we’ve said we aren’t going to do this. But we’re going to do it. We’re going to figure out how to get down there and see what’s going on.’”

Work on solving the task began even before the initial imagery revealed what exactly had happened. “J. R. was jumping the gun a little bit, not knowing what the details were. Essentially telling us, ‘Start thinking hard about this. We don’t know what’s going on yet, but start thinking about it.’” A “war room” was set up to deal with the situation, with communica­tion lines established with other NASA centers and with the contractors who would be able to provide expertise on the equipment either involved in the problem or needed to fix it.

“We were sitting in that office,” Chuck Lewis said, “and at that point we were basically going on a thirty-hours-on and eight-hours-off schedule; you worked till you dropped—which was about thirty hours—and then went home. I spent the first or second night under the conference table in the room under the one-G mock-up in 4619. My wife brought up a sleeping bag, and I sacked out the first night under the conference table, and J. R. Thompson went and slept in that advanced concepts module, which later turned out to be the precursor to Spacelab. And we were all growing beards and had sunken eyeballs and everything else.

“We were all in contact with an awful lot of people. Because at this point the environment had changed from ‘Who are you, what’s your need to know, who do you work for, and why should I give you this information?’ to ‘What can I get for you?’ Managers were walking around asking what we need­ed — money, people, airplanes, whatever—which was a 180-degree reversal from the typical NASA mindset.

“It seemed like everybody in the world had ideas for solutions. And every­body was working on something. So we had the MacDac [McDonnell Douglas] contractors and our NASA guys sitting in the same room across the aisle from one another. Everybody was keeping track of what was going on. It was the day after launch because everybody was working—Boeing and MacDac and Martin and a bunch of people were working overnight to put concepts together.

“We were being called constantly. The phone was ringing off the wall; everybody had an idea. Every now and then Thompson would come in, and he’d have some reporter calling him on the line, and the typical question was, ‘What are you guys doing?’ And Bob’s answer typically was, ‘It’s what we’re not doing that’s easier to answer. Ask us what we’re not doing, and that’s an easy answer. We’re doing everything.”

Relatively early in the discussions, the idea had arisen of conducting a “stand-up eva,” in which the first crew would fly their Command Module around to the stuck solar wing, open the spacecraft’s hatch, and one crew­member would stand up through the open hatch and attempt to free the array. They got in touch with their counterparts at Johnson Space Center, who said they had been thinking the same thing. “We’d been sitting there with a mock-up on the table, playing around with toothpicks and strings,” Lewis said. “We kinda brainstormed that together and thought what we need to do is figure out something to take up there that will let you poke and prod and maybe pull on something.”

By the morning after the sl-i launch, someone had found a lead on just such a tool. “About nine o’clock in the morning, one of the MacDac guys poked me on the shoulder and said, ‘Chuck, we just learned about a com­pany in Centralia, Missouri, called A. B. Chance Company,’” Lewis said. “They made what they called hot poles for linemen to use from the ground to reach up and activate breakers and stuff like that. They were fiberglass collapsing poles.

“[The Mcdonnell Douglas engineer] said, ‘We found out they also have a number of detachable tools that go on the end of these poles. It might be that if you call these guys, there might be something useful there.’ Anyway, the MacDac guy gave me the phone number for this A. B. Chance Compa­ny, and I said, ‘Sure, I’ll give them a call.’

“So I gave the guys a call, and I talked to the first person who answered and kind of explained the situation. I said, ‘This is Chuck Lewis, and I work for Marshall, and you probably know that we’re having a little trouble with the last launch, and we think you guys might have a tool with some end effectors on the end that we might be able to use.’ The answer I got back was, ‘Well yes, we do, we have a lot of those, and I can send you a catalog right out.’”

Of course, with the crew launch at that point scheduled just days later on 20 May, a mail-order catalog wasn’t going to be anywhere near fast enough. Lewis explained the situation and was directed to the next person up the ladder at the company, who told him that the same – or next-day delivery he needed just wouldn’t be possible because of an airline strike.

“I said, ‘That’s ok, no problem, no problem. Let me talk to the next guy up,’” Lewis said. “He said, ‘ok, I’ll let you speak to the product manager.’ So a guy came on the phone, and his name was Cliff Bosch.”

Bosch told him that A. B. Chance did carry the sort of tools that it sound­ed like NASA needed, took his phone number, and promised to call back in fifteen minutes with an inventory of possible solutions.

“So I let him go, and about that time, the same guy that had original­ly clued me about the A. B. Chance company bumped me on the shoul­der again and said MacDac had been working on an automatic, pneumat­ically operated nibbling tool that you could pull the trigger, and it would nibble through,” Lewis said. “They’d been working on that all night, and [the president of McDonnell Douglas] wanted to bring it out, and he was headed to Huntsville, flying his Aerocommander, and if the guy from A. B. Chance really came up with anything, he’d land at the airport in Cen – tralia and pick it up.

“So when Cliff called back, I asked him how things went, and he said, ‘Oh I haven’t had so much fun in a long time. It’s the first time I’ve ever done this; I walked through the stock room with a box in my hands, and I just picked up stuff off the shelves—now how do I get it to you?’

“And I said, ‘Well, do you have a little airport there in Centralia?’ And he said, ‘Yeah.’ I said, ‘Well, the president of MacDac is going to pick it up in his Aerocommander and bring it to Huntsville.’ And he said, ‘Hell no, you guys don’t know how to use this stuff; you need somebody there to tell you how to use it. Has he got an extra seat?’ So we negotiated back and forth, but the upshot was that Cliff came to Huntsville.”

By the time Bosch arrived at Marshall, first-crew backup astronauts Sto­ry Musgrave and Rusty Schweickart had joined Lewis’s team in working on the solution to the stuck solar array. When Bosch arrived in the high-bay room with the full-size Skylab mock-up, he and the team all sat in a circle on the concrete floor, and he began showing them everything he had brought in his box. “We all sat down cross-legged on the floor, and it was kinda like opening presents at Christmas time,” Lewis said. “He had all kinds of stuff. He must have had thirty or forty pounds worth of end effectors, and two of the extendable poles.”

One of Bosch’s tools, in particular, struck the team at Marshall as having potential. “The one thing they had that was really neat was this scissorslike

22. Ed Gibson (from left), Rusty Schweickart, and Pete Conrad participate in discussions about saving Skylab.

cutter that they used to clip electrical cables, that was kinda like the tree trimmer,” Lewis said. “The guys at Marshall re-engineered that in about a day and a half to provide some extra mechanical advantage because they did the analysis on the strap—we’d figured out the material by that time—and we knew what sort of load it was going to take for those jaws to get through that and whether they were going to be able to pull on it. So they put a dou­ble-pulley arrangement in there that was not there originally.”

Of course modifying a tool for spaceflight and actually being able to fly it are two different things. “They had to get that through stress test and every­thing else,” Lewis said. “And how it usually goes is it takes forever. Well, in

this case what they had done was to set up stations, just like college regis­tration. Station one, there was a desk out in front of the office, and some­body would be there with a rubber stamp. Put your drawing down, stamp it, take it over to station two, stamp it. And of course, while all of this was going on, we still had managers going through, saying, ‘What can we do to help? What do you need, money?’ So we had a lot of support.”

(That support wasn’t just limited to people within NASA, either, as Steve Marks, who was working at the time as a NASA aerospace education special­ist, recalls. Marks was involved in an effort to explore the untapped poten­tial of television for NASA education and was transporting some equipment for that project to Marshall. Driving late at night, he was pulled over by a police officer for speeding. However, when the officer saw the NASA logo on the van, and Marks explained that he was delivering equipment to Marshall, the officer promptly sent him on his way—without a ticket.)

While the team at Marshall was going through the goodies that Bosch brought, another team took the poles to look into how they could be stored in the equipment bay of the Command Module. (Ultimately, the collapsible A. B. Chance poles would not be used, and NASA would instead re-create a modified version consisting of segments that could be assembled.) By that afternoon, the group working that issue at Kennedy said that they believed they had figured out how to store poles in the Command Module, but they wanted to actually see what they were working with to be sure.

“And J. R. came striding in; he strode into our meeting circle on the floor,” Lewis said. “We were still sitting cross-legged on the floor of the high-bay area, and he said, ‘Where’s this guy from Centralia, the guy with the tools? ’ Cliff raised his hand. J. R. said, ‘Your plane leaves for the Cape in forty-five minutes, can you be ready?’ And he said, ‘Yeah, give me a chance to call my wife.’ He hadn’t talked to her since he left that morning for work. He’d had a glass of orange juice, that was it. So he called his wife, and he said—at least, this is what he reported back—he said, ‘I asked her to pack me a bag, and send it on a plane to Florida. I tried to explain what was going on, and I promised I’d explain it when I had a chance.’ I think it was the Gulfstream that he got on and took his tools, with the exception of the flight items that our guys were still running through the machine shops.

“My recollection is, it was about a week and a half before he got home,” he said. “To me, that’s just a wonderful story, and it’s such a wonderful exam­ple of what was going on around the world.”

During the ten-day period between the troubled launch of the Skylab on 14 May 1973, and the launch of the first crew on 25 May, three completely independent repair methods had been conceived and built by the NASA team and tested and practiced by the flight crews who would deploy them.

“I consider these ten days the crowning achievement of NASA’s real-time performance in their near half-century of existence—only matched in the recovery of the Apollo 13 crew a few years before,” Owen Garriott said. “With Skylab, however, all NASA centers and thousands of civil servants and space contractors were involved in saving the program.

The foundations that would eventually lead to the launch of Skylab in May 1973 had been laid much earlier. The idea of building a space station was noth­ing new. Not only did it predate Skylab, it predated manned spaceflight.

The first serious proposal for a manned space station was published in 1923 by German rocketry pioneer Hermann Oberth in his work, The Rocket into Interplanetary Space. In that work Oberth wrote, “Such a station could serve as a basis for Earth observations, as a weather forecasting satellite, as a communications satellite, and as a refueling station for extraterrestrial vehi­cles launched from orbit.”

A few decades later the concept of the space station was familiar not only in the spaceflight community but also to the public at large. It hit the main­stream in a major way when it was explained by Wernher von Braun and others in a series of Walt Disney-produced television specials in the latter half of the 1950 s. In a series of three Tomorrowland specials, the space sta­tion was presented not only as a place where humans would live and work in Earth orbit but also as a way station to other worlds. As a special-effects – laden enactment demonstrated, an orbital space station would be a key ele­ment in sending humans to the moon. The specials were based on concepts von Braun had presented at the First Symposium on Space Flight in October 1951, selected papers from which were published in Collier’s Magazine under the title “Man Will Conquer Space Soon.” Von Braun laid out what he saw as a logical progression for space exploration, beginning with simple orbit­al missions, moving on to the construction of a space station, which in turn would be used to support missions to the moon in the year 2000.

It was not to be. Two decisions sealed the fate of the idea of the space sta­tion as a steppingstone to the moon. Even before an American had been in orbit, the nation’s space program was focused on a single goal. On 25 May 1961, less than three weeks after Alan Shepard became the first American in space, President John F. Kennedy issued the challenge to Congress that was to define the nascent human spaceflight programs of two nations for years to come: “I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the Earth. No single space project in this period will be more impressive to mankind or more important for the long-range exploration of space; and none will be so difficult or expensive to accomplish.” Billions of dollars, and more than eight years, were to go into making the dream a reality. Every spaceflight made during that time was dedicated to bringing the goal another step closer.

That decision effectively made any thoughts of a space station for its own merits a much lower priority and created a major stumbling block to the idea of using a space station to get to the moon. Von Braun’s logical progression of infrastructure development required time that was a luxury that NASA could not afford in trying to meet Kennedy’s deadline.

The second shoe dropped the next year with the decision to use the lunar – orbit rendezvous mission profile for the moon landings rather than the Earth-orbit rendezvous profile von Braun had outlined in the Disney spe­cials. Lunar-orbit rendezvous involved sending two spacecraft to the moon instead of just one. While one descended to the lunar surface, the other remained in lunar orbit with the fuel that would be necessary to return to Earth. This technique made it possible for less mass to be sent to the moon. A lander that had to carry its Earth-return fuel to the surface would require even more fuel to lift that fuel back into space. Leaving the fuel for return

to Earth on an orbiting spacecraft eliminated that need. As a result, both lunar-rendezvous spacecraft together were smaller than the one craft that would have been sent to the moon on an Earth-rendezvous mission. That meant they both could be launched on one Saturn v, unlike the larger craft that would have been launched on separate boosters and assembled in orbit. The lunar-rendezvous technique gave NASA a quick path to the moon but at the cost of a space station.

Kennedy’s decision to pursue a bold fast-tracked lunar-landing program resulted in the most ambitious period in the history of space exploration and accelerated the achievement of the first human footsteps on another world. However, Mueller believes that in the long term human spaceflight would have been better served without that deadline. While it sped up the accom­plishments of Apollo, he argues that haste was possible only by sacrificing the development of an infrastructure that would have supported continued exploration. “It’s sort of unfortunate that the decision was made to go to the moon ‘in this decade,’ because that precluded the development of a real transportation system,” Mueller said. “It never really got the sort of atten­tion that it should have gotten, because it really, in my view, was the point in time when we had the opportunity to begin a true space civilization, a space evolution. In retrospect we would have been better off if we’d concen­trated on a transportation system.”

In an ideal situation, Mueller said, a combination of lunar orbit rendez­vous and Earth orbit rendezvous would have been used for moon landing missions, creating a system in which the bulk of the spacecraft used to fly crews from the Earth to the moon and back would have remained travel­ing in a loop between the two, while smaller transfer vehicles carried astro­nauts to and from the surfaces of the two worlds. Such a system not only would have supported ongoing exploration of the moon, but it also would have helped develop techniques and infrastructure that later could have been used for human missions to Mars.

Though development of a space station had been placed on the back burn­er following the decisions of 1961 and 1962, it had not been abandoned, and several NASA centers continued to work on ideas for space stations. Langley Research Center in Hampton, Virginia, was working on the Manned Orbit­al Research Laboratory, which would support a crew of four to six astronauts for up to a year. The Manned Spacecraft Center in Houston was developing plans for Project Olympus, a large station that would remain in orbit for five years, where twelve to twenty-four crewmembers could live. Marshall, of course, was the home of von Braun, who had been outspoken about his own ideas for a space station. “There were a lot of concepts,” Mueller said of the early space station discussions in NASA in the early-to mid-1960 s. “Everybody was working on one. I’m afraid that a lot of them were just ideas.”

“Launch day arrived, ready or not, as days do,” Joe Kerwin said. “It was a beautiful, quiet morning at the Cape. We went through our checks and soon were standing on the platform at Pad 39B, waiting for ingress and looking out over the peaceful ocean, with sea birds flying below us. The Cape was practically deserted; all the guests had long since gone home. The families would see this launch on television.

“I was the last crewmember to be inserted into the Command Module because I had the center couch and would be in the way of the others. There was plenty of help strapping in and making the oxygen and communica­tions connections. And a friendly handshake and pat on the shoulder, and the hatch was closed. Communications check. Countdown continues; here’s the right place in the checklist. Pete’s on the left, in charge; he has the abort handle. Paul’s on the right, the Command Service Module systems expert. I’m in the middle, computer backup and navigation. We’ve done all this a million times (two million for Pete), and it’s all going well.

“About ten minutes before launch, Pete said on the intercom, ‘Guys, Mis­sion Control needs something to cheer them up. What can we say at liftoff that’ll do the trick?’ We discussed it a little bit and Pete made up his mind. Liftoff came, and amidst the noise and shaking, as the tail of the Saturn IB rose above the level of the launch gantry, Pete made his first voice call: ‘Lift­off. And the clock is running.’ And his second: ‘Clear the tower. And Hous­ton, Skylab Two, We Fix Anything, got a pitch and a roll program.’

“One of the longest, busiest days of our lives was underway.”

Mission Control had reason for needing cheering up on the first crew’s launch day, 25 May 1973. The team felt the clear need to get the astronauts to Skylab before it was too late to save it. There were launch constraints: one was that calling a hold too late in the count required detanking then refueling the booster, making a launch the next day impossible. And a new

23. The “milkstool” used to raise the Saturn ib boosters for launch on the Saturn v—fitted launch pad is visible in this photo of the sl-2 launch.

problem had cropped up. The mission operations computer began experi­encing overload problems. When that happened it needed to be taken offline and reinitialized. It must not be offline during launch. And the cause of the overloads was unknown.

The launch flight director, Phil Shaffer, had several intense conversations with his computer supervisor, who assured him that he could bring the com­puter online for liftoff and that it would stay online throughout launch. Phil had a decision to make. He recalled: “At T minus six minutes the launch

director at the Cape came to me for a ‘Go for Launch.’ At that time the mis­sion operations computer was down and being brought up. The last status check was at T minus three, and if we went down, then it would preclude a next-day launch. I gave a ‘Go’ to the Cape. And then the computer did come online, and it performed nominally ’til the end of the first stage burn. At staging the computer overload problem just disappeared.”

A similar problem would occur at the end of the last mission when because of memory problems the mission operations computer was dropping out every ten to twenty minutes. Mission Control found that they could rein­itialize between station passes and keep coverage seamless that way, and it worked. It provided a pair of bookends for Skylab: two problems assessed and overcome by the flight control team.

Despite having been through the launch procedure countless times in simulation, the two astronauts making their first spaceflight found the real thing rather exciting. “The liftoff and ascent were of course quite an expe­rience for us newbies,” Paul Weitz said. “There is a programmed activity with the booster’s first stage called ‘Propellant Utilization Shift.’ When we got the pu Shift, the thrust dropped off dramatically as far as I was con­cerned — my first thought was that we had lost an engine. Pete, of course, said something to the effect ‘Cool it, rookie.’”

They reached orbit without incident, and gloves and helmets came off. Kerwin, who had “average” susceptibility to seasickness, took a planned sco – polamine/Dexedrine capsule before leaving his couch; Conrad and Weitz pressed ahead with rendezvous. They were due to arrive at Skylab in about eight hours, and there was a lot to do. The space beneath the crew couches was a sight to behold, a sea of brown cloth and rope securing all the strange equipment that made up the Skylab repair kit. That under-the-couch vol­ume was normally kept clear for launch. In case of a very early abort, the Command Module would be pulled away from the booster by its Launch Escape Tower, and the parachutes would deploy and land the spacecraft off­shore. If the winds were unfavorable, a landing on the beach was possible, a hard landing, which would cause the couches to “stroke”; that is, to crush compressible aluminum material inside their struts and move down a foot or so, cushioning the shock to the crew. But that space was needed for the three sunshades and all the poles and cutters that were selected for repair. So NASA just made sure the east wind at altitude was not strong enough to blow the vehicle back onto the beach.

Upon reaching orbit, Kerwin disconnected his center couch and slid it underneath Conrad’s. Then he spent much of the eight hours before ren­dezvous untying and rearranging all the gear to check it out and have at hand what might be needed on Mission Day 1. After a series of maneuvers, Conrad spotted Skylab out the window and expertly executed the braking maneuvers that brought the Command Module beside it.

Once in place, Pete flew the Apollo spacecraft slowly around Skylab. It all looked pretty much as expected, but the sight of all that gold-colored Mylar where the heat shield was supposed to be—already turning a dis­colored brown in spots from the intense ultraviolet sunlight—was a little alarming. It looked hot.

“After orbital insertion, we started our catch-up with the ows [Orbital Workshop],” Paul Weitz said. “Joe got the first look at it through the tele­scope. After rendezvous we did an inspection fly around. The atm and its solar array had deployed normally. One solar wing on the ows was miss­ing —it was cleanly gone, with no apparent damage to the ows. Broken wires, cables, and mechanical attachments protruded from the base of the array like tendons on a broken turkey wing. The other array was partially deployed but was held close to the ows’s surface by a piece of debris from the missing meteoroid/heat shield that had wrapped itself up over the top of the solar array wing. All the rest of the meteoroid shield was gone. We took photos and downlinked TV to the ground.

“It was a frustrating time for me because my job was to take the pho­tos with a thirty-five millimeter camera with a telephoto lens, and to get the TV imagery. Well, both of these devices had relatively long lenses, and there was not much clearance between the window and the couch support structure. It was difficult in zero-G to get a good stable picture, but I guess it turned out ok.”

After completing the fly around, Pete maneuvered to the Multiple Dock­ing Adapter’s centerline docking port and performed a trouble-free soft dock. The Apollo docking system had two parts. The Command Module had a probe, a device that looked like a diamond-shaped metal-frame skel­eton of a box standing on one corner with a cluster of small latches at the opposite corner—the capture latches. The four corners in the middle of this box were hinged and motorized. Commanding the motors to straight­en those corners, would make the probe get longer and skinnier—it would

extend—and commanding the motors to bend the corners would retract the probe, pulling the capture latches in. In the Multiple Docking Adapt­er’s docking port was the other half of the mechanism, the drogue—a con­cave metal cone with a hole at its apex just big enough to allow the three capture latches to push in, then snap out like door latches. The procedure was to extend the probe, then drive the vehicles together until the capture latches engaged the hole in the drogue, retract the probe, pulling the two spacecraft together until the twelve big main latches touched, engaged, and made an airtight seal.

For this interlude Pete engaged the capture latches but didn’t retract the probe; the Command Service Module just swung lazily in place by the end of the probe while the crew had a bite to eat and planned the evening’s activ­ities with Houston. A full hard dock wasn’t desirable at this point because of the likelihood that they’d undock again shortly. The docking system need­ed to be dismantled and reset after a hard dock.

The team agreed that an eva would be done that day. It looked as though there was a chance that if the crew pulled on the stuck solar panel cover, it might come free. They had a tool in their kit with which to make the attempt—a curved metal “shepherd’s crook,” which they could attach to a five-foot aluminum pole. Everyone felt fine, no motion sickness; and NASA had not yet passed the mission rule prohibiting evas (except in an emergen­cy) until the fourth day of a mission to allow time to adjust to weightless­ness —just to make sure astronauts don’t vomit into their helmets. So they prepared the shepherd’s crook, put their helmets and gloves back on, and Pete retracted the capture latches and undocked.

The next step was to let the air out of the Command Module. Pete suf­fered an ear block during that depressurization but insisted the crew keep going. He flew back around to the offending solar panel cover, and Paul opened the side hatch. Paul got to be the shepherd; he glided halfway out the hatch, crook in hand. Joe’s job was to hang on to his legs to keep him from going out all the way. He maneuvered the crook into the gap between the solar panel cover and the side of the Orbital Workshop and pulled with all his strength.

“I positioned the crook under the end of the wing and gave a mighty heave.” Weitz recalled. “The wing did not move, but it pulled the csm toward the ows. Now, the hatch opened to the left, which blocked half of Pete’s field of view. So I am yanking on the pole; the csm is being pulled in; and much to my amazement, in zero-g I was even moving the one-hundred-ton lab. I could see the cold gas thrusters on the ows firing to maintain attitude, and Pete is mumbling and cursing in his attempts to maintain some semblance of station-keeping.

“Pete decided to give up on the shepherd’s crook and to try the branch loppers. Joe changed out the end equipment, and I tried to cut through the material that was holding the wing down. We could not get a satisfactory grip on the debris that would allow me to cut through it, so we in exasper­ation decided to call it a day.”

After the unsuccessful attempt, Kerwin helped Weitz get the pole and himself back into the spacecraft. They closed the hatch and headed back to the station’s axial docking port to dock with Skylab again, this time for the long haul.

Joe Kerwin recalled the docking: “Fate had another bear trap to fling in our path. When Pete approached the docking port to soft dock, the cap­ture latches would not engage. He tried it again, with a slower approach. Then he tried it with a faster approach. He tried the first backup docking procedure in the checklist. No joy. Then the second backup docking pro­cedure. Still no joy. Suddenly there was a grimmer problem than the solar panel. If we couldn’t dock, we would have to come home. With nothing accomplished.

“Pete backed off and kept station with Skylab and talked it over with Hous­ton. It was close to midnight back home, and the crew had been awake for twenty-one hours, but Pete’s flying was as smooth as ever. And there was one more procedure in the book, labeled laconically: final docking attempt. It required what amounted to a second spacewalk. Could we do it?

“Back up three months. We’re in the Command Module trainer, going over a few procedures with our instructor, Jake Smith. We’d finished every­thing on the list and were ready to go home. Jake said, ‘Guys, there’s this third backup docking procedure we’ve never gone through. It’s never been used. Why don’t I just talk you through it once, so you can see which wires to cut.’ We were ok with that, and fifteen minutes later we had filled that training square. God bless you, Jake!”

Gloves and helmets went back on. Once more they brought the Com­mand Module down to vacuum. Pete’s ear was still blocked but was not too painful. This time they removed the hatch to the docking tunnel. Joe made the changes to the docking probe per the checklist, put the hatch back in place, and they repressurized. Paul then did the rewiring in the right – hand equipment bay. The idea of this procedure was to remove the elec­trical interlock that prevented the main latches from actuating unless the capture latches were secure. Pete would drive the csm into the drogue and just keep thrusting while he commanded the probe to retract. Then if the crew were lucky, the main latches would close on contact with the Skylab half of the tunnel.

Everything was checked. Pete stood in for the last attempt. The check­list said it would work in ten seconds or never. He closed in and made con­tact and kept the forward thrusters firing. Probe to “Retract.” “We counted, ten, nine, eight, seven, six, five, four, three, two—and a machine gun went off in our faces,” Kerwin said. “That explosive rattle was the main latches engaging. We were staying!”

As he checked the tunnel between the two spacecraft, Weitz discovered that eleven of the twelve latches had captured during the hard dock. The last one engaged manually with no problem. “There was a great collective sigh of relief onboard and in Mission Control,” Kerwin said. “We equalized pressure, opened the tunnel hatch, snacked again, used the waste manage­ment system, and so to bed. And we slept like babies. No one had time to even think about space motion sickness.”

Reflecting concerns that the equipment issues that had caused problems for docking could also cause further complications later, Pete’s final com­ment as the crew went to sleep in the Command Module at 1:30 a. m. had been, “Now that we’re docked, I’m not sure how we get ««docked.”

On Day 2, Houston’s first call came at eight minutes after nine. The first words from Skylab were, “We’re all healthy, Houston.” Whether they were likely to stay healthy would be determined by a couple of tests scheduled after breakfast. The issue was whether the atmosphere in Skylab was safe to breathe.

The walls of the workshop, originally built to contain liquid hydrogen, were insulated with a thick layer of polyurethane foam covered with fiber­glass. The foam was manufactured with toluene diisocyanate, a toxic mate­rial. Testing showed that the polyurethane would begin to break down from heat at a temperature of about 390 degrees, releasing toluene and other nasty products into the air. Had that happened? The estimated temperature the foam had reached was 350 degrees on the skin side and 160 degrees on the interior. But that was just an estimate.

Dr. Chuck Ross, the Skylab 1 crew surgeon, recalled: “This was one of our biggest concerns about Skylab’s condition—that breakdown of the insu­lation would release a ‘toxic soup’ of poisonous gases into the atmosphere. We worked the problem hard under the leadership of our chief toxicologist, Elliott Harris. We identified and procured gas-sampling tubes which would measure the levels of toluene and adapted them to suck gas through Skylab’s hatch equalization valves. That was so that we could do a ‘sniff test’ before anyone entered Skylab. We procured two activated-charcoal [filter] masks for the crew to use while first entering the ows. And we prevailed upon the control team to evacuate all the gas out of Skylab and refill it—I think they did that twice before the crew arrived.”

Now was the time to conduct those tests. First the crew verified that pres­sure had held steady in the short tunnel between the Command Module and the Multiple Docking Adapter. Then the Command Module hatch was opened, and the docking probe removed and carefully set aside for future investigation. Next Paul Weitz broke out a sniff-test sampling tube and drew a sample of air from the Multiple Docking Adapter to test for toluene. The test was negative as was a previously planned test for carbon monox­ide (a routine precaution that would be repeated periodically throughout the Skylab missions). At about 11:30 a. m. Paul removed the second hatch and moved into the Multiple Docking Adapter, eagerly followed by the rest of the crew. This was the crew’s first exposure to moving around in a large volume—and about ten minutes after entry Pete said to the Capcom, “Tell the docs we didn’t need our motion sickness pills.”

Pete did a thorough inspection of the docking probe and drogue. Hous­ton made several suggestions about what to look for. Pete replied, “All right. And what’s your opinion on if we had to undock, how’d we go about doing it? Do you think we could get the capture latches to cock?” Houston said they were thinking about that.

Removal of the probe showed that two of the three capture latches had opened but the third was stuck down. Pete also noted a scrape along the side of the drogue, probably due to one of his more forceful docking attempts. After cycling the latches several times and noting that the same one hung up repeatedly, Pete stowed the probe for the time being.

While Joe started activating Apollo Telescope Mount systems, Pete and Paul worked on starting up power and ventilation to the workshop. Paul had the first fans turned on by 1:30 p. m. Wearing a charcoal mask, he made a quick trip into the workshop to check the airflow gauges and general con­dition and turn on the rest of the fans. The air recirculation system con­tained charcoal filters that would absorb toluene if it was present. Return­ing to the Multiple Docking Adapter, he told Houston, “Okay, on our fairly quick inspection the ows appears to be in good shape. It feels a little bit warm, as you might expect. From the three to five minutes I spent in there I would say subjectively it’s about—it’s a dry heat. I guess it feels like 90 to 100 degrees in the desert. Hank, I could feel heat radiating from all around me. . . . I had the soft shoes and the gloves on, and nothing I touched felt hot to me.”

Power was a major consideration (and would remain so for the next two weeks).

Houston: “. . . and to help our power situation, I guess we’d like to get the ows entry lights turned off there while we’re eating lunch—after you complete the sniff.”

Paul: “I thought I turned them off when I came out, Hank.”

Houston: “Okay, you may have.”

Pete: “Yes, he did.”

Paul: “You think I’m not power conscious?”

The toluene sniff test was now repeated for the workshop and was neg­ative. The crew floated back into the Command Module to eat lunch, and at about a quarter past four Pete and Paul entered the workshop again, this time without masks, to prepare to deploy the parasol.

Pete: “How do you read, Houston?”

Capcom: “I’m reading you loud and clear, Pete.”

Pete: “Okay; I got you on the speaker box—ow. Yes, I got my hot gloves back on again. The speaker box is about 130 degrees.”

The parasol had been packed in a rectangular aluminum experiment con­tainer about one foot square and five feet long. Now Pete and Paul carried it from the Command Module down to the Scientific Airlock on the sun­ny side of the workshop, the same side of the cluster as the Apollo Telescope Mount and so normally always pointed at the sun. This location was a lucky

24- The parasol deployment mechanism fitted to the solar airlock.

one for it was centered on the side of the workshop that needed to be shad­ed. (It wasn’t so lucky for a couple of experiments designed to use it.)

One end of the container was inserted and locked into the airlock to make an airtight seal. Then the metal Scientific Airlock outer door was cranked open, exposing the parasol to vacuum. At this point, Pete and Paul retreat­ed to the Multiple Docking Adapter for a cooling-off break and a drink of water. Meanwhile Joe was in the Command Module setting up a TV camera to catch a glimpse of the deployment looking aft through a window down the length of the cluster.

Now a series of seven metal rods were inserted one at a time through a seal in the free end of the container and slowly pushed, carrying the apex of the folded-up parasol out into space. To the parasol’s apex were connected four fishing rods to which in turn the nylon parasol material was fastened. The rods had been telescoped; as they extended fully, each section locked in place. Then the crew released a brake holding springs designed to push the fishing rods out and down until they opened fully and locked into place, covering the workshop.

Considering the haste in which this rig had been designed, built, tested, and loaded into the Command Module for flight, it’s a wonder it worked at all. It did work, but it required a lot of sweat and some ingenuity to get it laid out flat.

Pete (at four minutes after 8:oo p. m.): “ok, Houston, we had a clean deployment as far as rods clearing and everything, but it’s not laid out the way it’s supposed to be. . . . The problem seems to be that the folds in the material have taken too much of a set. . . . We’re open for suggestions.”

Capcom: “Roger. First off, we’d like to get Joe to tell us what he saw out the window. We’d like to know if all the rods are approximately the same plane.”

Joe: “Well, we don’t think so, Houston. . . . The front legs, that is the for­ward ones closest to the Command Module, came out smartly. . . . It looks as if they actually went over center a little bit, then bounced back. The back ones did not come out, it looked like, all the way—didn’t come to ninety degrees. They went slowly, and they just kind of drifted to a stop.”

Capcom: “Okay. What kind of an angle do you think they made with the plane of the first two rods?”

Joe: “It’s your guess, but I guess thirty degrees, something like that.”

Capcom: “ok. We would like for the cdr and plt to go back in the work­shop and pull her in, and we want you to complete the procedure down to Step 43 so you’ve done a full retraction.”

Paul and Pete got the parasol pulled in, and noted that the rods that had been exposed to vacuum were nice and cool as they came back in.

Paul: “Rod B is gathering frost as it lays here in the fiery workshop.”

Finally, they pushed it out a couple of feet and immediately pulled it in again. That straightened out the aft rods pretty well.

Houston: “We’re looking at two flight plans tomorrow. We’re taking a tentative look at one that doesn’t consider anything in the Workshop. The alternative is going as planned. We’d like to get your opinion on this. . . .”

Pete: “. . . we spent the better part of two or three hours down there; and every time we’d get hot, we’d come up and take a rest. Now, if the temper­atures are coming down, I would like to stick with our original flight plan, and we’ll start activating it down there.”

Houston: “Okay. Our best estimate, Pete, is we’ll be below ioo degrees in there by tomorrow morning.”

2$. The sun-shield parasol, as deployed by the first crew of Skylab.

Pete: “Well, what do you think it was in there today?”

Houston: “We guess about 125.”

It was going to be pretty hot work. But the Multiple Docking Adapter was about sixty degrees — jacket weather. And the crew knew they’d be eat­ing, sleeping, and cooling off “upstairs” for the next several days.

Now Houston’s priority was to get Skylab back into solar inertial atti­tude —with the Apollo Telescope Mount pointing directly at the sun. This was both the coolest attitude, assuming the parasol worked, and by far the best for generating electricity from the Apollo Telescope Mount’s solar pan­els. Skylab had a very accurate system for pointing directly at the sun. It had a cluster of Fine Sun Sensors, which could measure the difference between Skylab’s attitude and the sun line within a tenth of a degree. But the error had to be less than ten degrees to start with; outside of that, the sun sensors themselves couldn’t find the sun. Houston was struggling now to get the cluster pointed within that ten-degree cone.

Houston, at 9:40 p. m.: “We’re going to take a look at the temperatures, and we think they’re coming down. We’re prepared to command solar iner­tial here over Hawaii.”

At 9:45 p. m., Houston: “Skylab, Houston. You’re on your way to solar inertial now.”

At 11:15, Paul: “We’re not in solar inertial, you know.”

Houston: “Roger. We assumed that we should be close to solar inertial attitude. We’re not solar inertial mode; we’ll be working that ourselves.”

Paul: “Well, you’re not even very close. . . . Do you know where to go?”

Houston (laughter): “Probably not.”

Pete: “Well. I’m looking out the window, and it looks as if you need a plus rotation about Y and a plus about x. And I’m not sure of the magnitude, but about 10 degrees or more.”

Houston: “Okay, what we’re going to do is put in a plus Y rotation of for­ty degrees, and a plus x rotation of fifteen degrees. If we don’t hack it this time, we’ll probably suggest turning it over to you. . . .”

Kerwin recalled: “Well, to make a long story short, they did turn it over to us, and we got it done. Pete and Paul looked out the sun-side window in the aft portion of the Multiple Docking Adapter, and when they agreed on an attitude correction, I’d put half of it in the Apollo Telescope Mount’s computer, and it would execute the maneuver. That way we got closer and closer without overshooting. When we all agreed we were well within ten degrees, we switched the mode to solar inertial. The atm said, in comput­er language, ‘Oh, there you are, sun!’ and finished the job. When all was steady, we built our final ‘how to find the sun again’ tool. When we were pointed precisely at the sun, the sun-facing window threw a bright oblong spot of sunlight on the opposite wall. We just carefully surrounded that spot with gray duct tape and went to bed. To my knowledge, no one ever had to use it again. But it was there if they did!”

On Mission Day 3, bedtime having been three hours late, wake-up was an hour and a half behind the preflight schedule—still behind and with a lot of activation challenges ahead, but getting closer.

7:24 a. m., Pete: “Hey, what time would we’ve gotten up this morning, if it was a normal wakeup?”

Houston: “Okay, we had you scheduled for about 1500 Zulu” [11:00 a. m. Houston time].

Pete: “I meant—we should have gotten up at 1100, right?”

Houston: “Roger, that’s the nominal time, Pete. But we were going to let you sleep late, since you didn’t get to bed until late last night.”

Pete: “Okay. Well, we’re slowly trying to work our way back to the nor­mal schedule. . . . Say, what’s your cooling look like?”

Houston: “Looks like we’ve been dropping about a degree an hour. We’ve got a lot of our measurements back on scale now. We’re showing some duct temperatures around ninety-five, ninety-eight degrees. . . .”

Breakfast was in the Command Module again. The wardroom hadn’t been activated yet, and it was too hot anyway. But they were eating well and enjoying it.

Pete: “I’m feeling pretty spunky. Got a good night’s sleep, just had a lit­tle sausage, a little scrambled eggs, and I’m working on my jam and bread, with a little coffee, goes pretty well this morning.”

Houston: “That sounds good to me. I haven’t had my breakfast yet.” Pete: “Sorry about that.”

As the crew began to get serious about workshop activation, little prob­lems and confusions popped up. The crew had their heads down trying to get the tasks done, and Houston was starved for information about where they were on the timeline—and in the vehicle. And all this was complicat­ed by the sporadic nature of communications.

Houston: “Skylab, Houston through Honeysuckle for six minutes. cdr, are you in the Command Module now?”

Pete: “No, sir. I’m in the wardroom.”

Houston: “Okay. . . .”

Pete: “What do you need?”

Houston: “Well, we’ve got a couple of things we’d like to get done up there, if it’s convenient for you to take a break.”

Pete: “Yes, I’m on my way. I’ll be there in a flash.”

And here’s Pete later in the day:

Pete: “The other thing we just finished spending a little time on was—we thought we had the urine system all rigged up and it wouldn’t work. I was the test subject and I had a big failure. And we went back and regrouped on it and we’ve concluded that you have to have a fecal bag in the thing. You have to have the fecal bag in a certain way or you just don’t get enough vac­uum through the urine system, enough flow, to pull urine down the urine tube. But the other two guys have been working on that down there for a while. They say it works ok.”

Houston: “Roger. Copy.”

And later.

Houston: “Skylab, Houston. We’ve got a dump maneuver starting now. You’re going to have to wait on that star tracker procedure. Wait until next daylight.”

Pete: “Okay, Henry. Nobody was quite sure who was supposed to do it, so it didn’t get done.”

Houston: “No sweat, don’t worry about it.”

Temperature reports were frequent throughout the day.

Pete (at 11:00 a. m.): “Hey, Houston. The biggest thing I can notice is the grid floor is beginning to cool compared to yesterday. Some of those oth­er lockers are bigger heat sources, but everything generally seems cooler in here, although still reading off scale high on the ows temp gauge.”

Paul: “Henry, as Pete mentioned this morning, it’s hot over by water tank one on that side of the Scientific Airlock. And just for information, there’s a lot of the metal-to-metal fittings that don’t fit too well at 130 degrees, like they did at 70. Had a pretty tough time getting the wardroom hose on water tank one, which is still hotter than a two-dollar pistol. . . .”

Paul (at 1:00 a. m., just before bedtime): “Tonight we dug out the per­sonal hygiene kit spares container and found that every tube of Keri hand cream in there had ruptured. I don’t know why. . . . Also, about two-thirds of the toothpaste has burst. And some of it has been cooked to the point where it is very, very thick and unusable any more. . . .”

But not everything was troublesome. As Pete had implied the previous evening, getting around the huge Skylab cluster was proving to be a joy.

Pete (at 11:17): “Hey, I’ll tell you there is no problem adapting, and you can go anywhere you want. You may get out of control a little bit en route, but you don’t bang into anything hard. And if you just take your time push­ing off, you can go anywhere you want in the vehicle. Just super fast!”

A few days later, Pete dislocated a finger while doing acrobatics around the ring lockers, but it slipped back into place easily. Dr. Kerwin applied a tongue depressor splint for the day, but Pete removed it after a couple of hours, and all was well. They mentioned it to Dr. Ross as a nonevent.

Pete’s evening report, delivered at about 9:00 p. m., showed that they were making progress toward blessed routine but were still behind the plan. Here’s a sample:

Pete: “. . . Today, Day 3, let me give you the urine volumes—cdr 210 ml, spt 160, plt 200. [Those volumes were for a partial day.] Today, we have no body mass for you. We have no exercise to give you. We’ll cover item Echo [medical status] on the private comm. tonight—although there isn’t anything to report. We’re in good health. And let me read you today’s food log. ‘The cdr ate everything today except corn. The reason for that was that the bag failed when inflating with water, and I got corn all over every­where. Now for yesterday, Joe calculated that I should have taken—and I did take—two calcium pills.’”

He repeated the food items skipped and supplements taken for Paul and Joe.

Houston: “Okay. We’d like to talk about the Flight Plan. How we saw things was perhaps—the first thing tomorrow is to just pick up where we left off and work on through, with a couple of exceptions. There will be a press conference tomorrow. . . and there will be a trim burn at about 01:07 [Greenwich Mean Time] — about a twenty-nine second burn time.”

Pete: “Okay, twenty-nine seconds, roughly.”

Houston: “That’s affirmative.”

Pete: “I figured I pushed so hard trying to dock the other night I almost deorbited the thing.”

Houston (laughter in background): “It’s still there.”

And so began the tradition of evening status report, always friendly, relaxed, and informative, just keeping everybody floating in the same direc­tion. The food and water data allowed the doctors to calculate supplement pill needs and have the information to the crew in the morning; the crew had a glance at tomorrow’s plans; and Houston could appraise where the crew was and how they felt about it.

So ended the third day.

Mission Day 4, 28 May, was a day of firsts:

First time the men were up on schedule—at 6:oo a. m. Houston time.

First breakfast in the wardroom.

First time for Joe to draw blood (theirs and his own), centrifuge it and freeze it for return.

First runs of the major medical experiments, lower body negative pressure (experiment number M092) and exercise tolerance on the bicycle ergometer (number M171).

Last, and maybe least, the first mention by Houston of the India­napolis 500 to Pete, a racecar driver himself and a big fan.

Houston: “Skylab, Houston. We’ve got you stateside for 16V2 minutes. Good morning.”

Paul: “Hi there. Our hands are full of bloody medical equipment, but we’ll recover, I think.”

Pete: “Hey, Bill. Joe just drew all three of us. That went very smoothly. . . cdr just finished shaving. Breakfast is cooking, and I think with a little luck at all, we might get on to a good routine. This is our first real crack at the post-sleep checklist, so we’ll get a good chance to see how long it takes us. . . . If it weren’t for the fact that we have such a spectacular view out the wardroom window, which we didn’t open until yesterday evening, late, I’d think we were back in Houston simming.”

Back on Earth, Rusty Schweickart and his backup crew were working on a spacewalk to pry loose Solar Panel 1. For several days they were still gath­ering information and comparing notes and opinions; a firm plan hadn’t yet taken shape. On the evening of Day 3, Paul had made a lengthy record­ing on Skylab’s tape recorder answering questions about the standup space­walk he’d done on Day 1. Rusty and the engineers wanted to get a very clear idea of how the strap was dug into the Solar Array System (sas) beam fair­ing so they could duplicate it on the underwater mockup and come up with a solution.

Later that day Rusty had a lengthy air-to-ground conversation with the crew. Pete opined that if a guy “had a crowbar he could pry with his feet against the Solar Array System beam and pry it right off of there. . . . Paul got that claw under it, but he couldn’t provide enough leverage. The claw is so short and the pole was so whippy that he couldn’t provide enough lever­age to pry it off of there. . .”

Rusty: “Roger. Copy. Do you think that you could have gotten the cut­ter (the limb lopper) around that strap down at the base, or did you try to get it around the strap?”

Pete: “No. I don’t think that cutter would have done it. . . . I’ll tell you what’s in the back of my mind right now. We have a pry bar in one of these tools, and I’m going to figure out a way to tether a crewman so when we go out and do our thing on Day 26, it’s worth our while to see if we can’t whin­ny around there.”

At this point, Conrad was still planning on attempting to free the stuck solar panel during the film-retrieval spacewalk scheduled at the end of the crew’s mission.

Rusty: “Roger, Pete. For your information we’re already working in the water tank trying to see what we can do along those lines. We’ve looked at the pictures—and we have determined that the tool we have on board will cut that strap. And we’re trying to determine if there is a place that you can get at the strap with the cutting tool. . . . If the strap is cut loose, do you believe that there’s anything else holding the beam down?”

Pete: “Not from the outside, Rusty, but. . . .”

A lengthy technical discussion followed. In summary, the answer was “maybe.”

Another item that would probably hold the solar panel cover (the Solar Array System beam) down even if the strap were cut was an internal damp­er, part of the hinge mechanism designed to prevent the sas beam from deploying too quickly. The wing’s designers were pretty sure that the cold temperatures aloft would have frozen the damper, and that somehow con­siderable pulling force was going to have to be exerted on the Solar Array System to break it free. Rusty’s team went away for four days after that talk and worked hard on a procedure. The crew would start working it again when the ground had a proposed solution. In the meantime, life had to con­tinue on the injured space station.

Living in Skylab was already generating a lot of trash. But Skylab had a very convenient place to put the trash and an elegant way of getting it there. At the bottom of the lower deck of the workshop was the Trash Airlock (tal), which was used to put trash into the s-ivb stage’s large liquid oxygen tank. To use it, a crewman opened the upper door and inserted a filled trash bag.

Then he closed and locked the upper door and opened the lower door into the liquid oxygen tank. Air in the Trash Airlock escaped immediately, but the bag had to be pushed out with a plunger. Once that was done, the lower

door could be closed and the Trash Airlock refilled with air, ready for reuse. Jamming of the Trash Airlock would be a huge problem: there just wasn’t any other place to put all the food waste, packaging, used urine bags, and so forth. It couldn’t happen. But it nearly happened.

Pete: “We almost thought we’d jammed the trash airlock yesterday. The bag that had the uctas [worn under the spacesuits on launch day] in it real­ly expanded. And we were just flat lucky to get that one out of there.”

Houston: “Don’t scare us like that.”

Pete: “Listen, don’t scare you: it scared us worse than it scared anybody else. So we’re taping our plastic urine bags. Just as a rule, I think we’ll tape things, and we’re only going to use about half the volume of the TAL, just to be on the safe side.”

At ten minutes before 2:00 p. m., Houston called.

Houston: “Skylab, Houston for the cdr.”

Joe: “Go ahead, Houston. He’s listening.”

Houston: “Thought he might be interested to know that the Indy race is in a hold for rain. However, the sun has come out and it looks like they might get a race off about fifteen past the hour. We show you’ll be going pretty close to Indy in about seven minutes. Why don’t you take a look at the clouds? If it looks good, drop the flag on them.”

Pete: “If I don’t get a chance to see it, then you all pass my word up there that I wish them all the best of luck—to all my friends that are driving.”

Temperatures in the workshop were still about ninety-five degrees as the crew prepared for the first major medical runs. And Lower Body Negative Pressure was expected to be a bit stressful. It was a clever simulation of gravi­ty’s effect on blood distribution and thus on how hard the heart had to work to maintain blood pressure. Here’s how it worked: the subject inserted him­self feet first into a metal cylinder (think of a slender garbage can) up to the waist, wrapping an airtight rubberized cloth seal around his waist. Then air was pulled out of the can, reducing the pressure around the legs and low­er abdomen. This would cause blood to pool in the lower half of the body, as though the subject were standing erect in gravity. (A familiar example of the effect would be “parade ground faint.”) Blood pressure and heart rate would be monitored to see how the heart responded to this loss of available blood. This would be an indirect test of whether the astronaut subject was going to have trouble after return to Earth at the end of the mission. Since the amount of blood in circulation was known to decrease in space, it was thought that a gradual decrease in tolerance might be seen.

Kerwin, in view of the high temperatures, recommended that on the first run only the smallest increment of pressure be tested—30 millimeters of mercury, about V2 pound per square inch, and that the exercise experiment likewise be restricted only to the first and second levels. Houston concurred with restricting Lower Body Negative Pressure but asked that Paul Weitz, the first subject, try to go the full protocol on the ergometer. At 7:00 p. m. Kerwin reported how things had gone.

Joe: “Okay. [Lower Body Negative Pressure] was interesting. We ran the whole run, 30, 40, 50, because the numbers looked okay as we went. He had at least twice the increase in leg volume that I’ve ever seen before, but his figures [blood pressure and heart rate] were normal.

“Then we went to [the exercise experiment], and as a lot of us had suspect­ed, we’ve got a significant mechanical efficiency problem in riding the bike.

. . . We terminated the run with a little under three minutes to go, both for that reason and because of an obvious thermal problem. It’s just too hot in there to go 200 watts on the bicycle. And while we will run M17K, pending resolution of the. . . problems, I’m going to strongly recommend against running at the top step.”

The design of the ergometer had received a lot of attention. How did one ride a bicycle in zero-G? Your feet wouldn’t stay on the pedals, and your behind wouldn’t stay on the seat. Without restraints of some kind, you’d float away whenever you pushed. The first insight was to use special shoes to attach the feet to the pedals. And since Skylab’s triangular grid pattern was already being used for foot restraints, that design was adopted for the pedals. It worked well.

To restrain the rest of the body called for a more complex device. The astro­nauts had asked Dr. Story Musgrave, Kerwin’s backup as Skylab 1 science pilot, to tackle the problem. Story had worked with the ergometer designers at Marshall and come up with a sophisticated answer: a padded waist belt with adjustable straps to attach it to the floor and a shoulder harness with adjustable straps as well. There were also adjustments available for the han­dlebar, the seat height, and the seat’s fore and aft position—like the driver’s seat on a modern car. All the crewmen had worked out with this harness and found their favorite adjustments, and a large cue card was created with each person’s numbers. What could possibly go wrong?

A lot. At the lowest workload things went pretty well. But when Paul increased the resistance and pushed harder, the waist belt’s straps began to dig into his thighs, cutting off circulation to the legs. Restrained by the har­ness, he couldn’t rise up off the seat like you do on Earth when you’re ped­aling rapidly. His legs hurt too much to finish the run.

At day’s end, Pete reported to Mission Control that they were still not caught up.

Pete (8:18 p. m.) : “We’ve been running pretty full blower. And all these extra goodies have been coming up. . . . So we need to do some catching up. . . . And it looks like, one of these days, we are going to have to halt for about a couple of hours anyway to gi the place if we’re going to keep it clean.” [“gi” was slang for soldier.]

A little later, he asked Houston to set up a private communication the next day between himself, the flight director, Chris Kraft, and Deke Slay­ton. He said, “It’s not anything other than I want to just talk to them. It’s no emergency or anything like that.” And it wasn’t. Pete just liked direct con­tact with the bosses to make sure they knew we were ok and to give them his slant on the mission. He was a great communicator.

He was good at relaxing too—better in this case than the somewhat har­ried science pilot:

Pete (8:30 p. m.): “Hey, Joe, do you know where the binoculars are?”

Joe: “They were in A-9 last time I looked.”

Pete: “We’re catching up with some satellite down here. You ought to come down and look out the window at it.”

Joe: “I’m busy.”

Pete: “ok.”

Mission Day 5 was the day the Apollo Telescope Mount experiments got

powered up for the first time. Kerwin saw the first beautiful, sharp images from the н-alpha camera, the extreme ultraviolet camera, and the camera that showed continuously what humans had before seen only during rare total eclipses—the solar corona. Still to come were x-ray images. He record­ed video, used the TV downlink to show the ground real-time images, and began the slow process of learning how to use the views to recognize and interpret active regions, to spot flares early in their brief violent lifetimes, and to watch for other solar phenomena. The real solar physicists on Earth envied him this visual feast.

Pete at lunchtime: “Hey, we’re all congregated in the head, all for differ­ent reasons. Why don’t you go ahead and slip us the news?”

Houston did—mostly who was making what speeches on Memorial Day.

This afternoon both Conrad and Kerwin got to tackle the bike and the Lower Body Negative Pressure. Pete tried the hardest—he was determined to come back from this mission in good shape—and his heart rate exceed­ed 180 as he tried to ride his three minutes at 75 percent of maximum. He couldn’t do it, and he experienced a couple of irregular heartbeats—prema­ture ventricular contractions—while he was trying. Kerwin couldn’t do it either. The harness problem was not going to go away; it was time for an onboard campaign to solve it. As to the Lower Body Negative Pressure, the heart rates, and symptoms on both Pete and Joe didn’t look all that differ­ent from preflight—yet.

While the crew was pondering the harness problem, the doctors in Hous­ton were seriously concerned. They had committed to twenty-eight days in orbit—despite the Biosatellite monkey’s fate and the disconcerting death of the cosmonauts — on the basis that exercise tolerance and Lower Body Neg­ative Pressure testing on orbit would show that the crew remained fit and able to deal with reentry and landing. But already the crew seemed unable to reach the desired exercise levels. Conferences were held. The medical peo­ple didn’t see Pete’s irregular heartbeats until Day 8, due to the complexities of getting experiment data sent to the ground and distributed. When they did, their concerns went up another notch.

Meanwhile the crew pressed on. Power conservation still came first.

Pete (7:30 p. m.): “Hey Joe, did you say we can’t use the event timer [on the Apollo Telescope Mount]?”

Joe: “That’s right.”

Pete: “Is that for power considerations only, or is there something wrong with it?”

Joe: “The power.”

Pete: “ok.”

Joe (9:00 p. m.): “Weitz, you left your blower on.” [In the waste manage­ment compartment.]

Paul: “How could I?”

Joe: “Well. . . .”

Paul: “What can I say, dear? I’ll try harder. . . .”

They increased their skill in zero-G operations:

Pete (9:05 p. m.): “We have put to bed, once and for all, the question of ‘Can you run around the water ring lockers?’ I have just made ten trips around the water ring lockers, and the spt has made five; which means he owes Ed Gibson a steak dinner, and Dr. Faget was right.” [Max Faget, the brilliant engineer who had designed the blunt reentry shape of the Com­mand Module, had bet the crew could do it.]

And they began to get personal with the onboard voice recorder:

Joe (10:18 p. m.): “Hey, sweet, lovely в Channel. Your lonely spt, who is hungering for human companionship, would like to report the serial num­bers of the—damn!—tubes for tomorrow’s blood letting.”

Pete and Joe: (Laughter)

At evening status report, Houston gave the crew a thermal forecast.

Houston: “The average internal temperature has shown a 5-degree drop over the last 24 hours. The magnitude of the drop per day is slowing down. . . . There may be a small portion—less than 10% of the parasol that is not doing its job as a radiator. We will probably stabilize out in the neighbor­hood of 80 degrees. . . .”

Pete: “Okay. I know where that 10% is. You can run your hands around the wall and find it real easy.”

Houston: “Be advised—Indianapolis—you guys are going to be overhead at 12:36 Zulu, almost right overhead. That’s 7:36 in the morning local, so if the weather’s clear you ought to be able to look straight down and watch the cars warming up.”

Mission Day 6 began following the first night all three slept in their sleep compartments. They said it was still a little warm, but they slept well and felt spunky. Houston read up the news, including these bits:

And the Texas legislature has voted to restore the death penalty in certain cases

The engagement of Princess Anne, daughter of Queen Elizabeth II, was announced today in England. The Princess will marry a commoner, Cavalry officer Lieutenant Martin Phillips….

Again the Indianapolis yoo was postponed until hopefully this morning.. ..

People in nearby Dallas are concerned with a mysterious ooze called ‘the blob ’ which first appeared about two weeks ago, up through a suburban back yard.

There was going to be good news and some more trouble for Skylab this day. The good news came with the first run of the M131 Vestibular Function experiment at 9:30 a. m.

M131 was not a crew favorite. It was a complex medical experiment designed to explore the function of the balance system in weightlessness. The princi­pal investigator was Dr. Ashton Graybiel of the Navy’s School of Aerospace Medicine in Pensacola, Florida—a distinguished, experienced scientist and a wonderfully gracious gentleman. A couple of times, he even lent his red convertible to crewmembers who’d come to Pensacola for testing.

Several tests were part of M131, and most of them were easy and interest­ing. But one of the tests was designed to find out what happened to people’s susceptibility to motion sickness in space. And to do that, he had to — well, make them sick. The subject would strap himself into a rotating chair and put on a tiny blindfold consisting of two small eye cups on an elastic band (the crew called it “Minnie’s Bra,” referring to Minnie Mouse). Then the observer would start the chair rotating at a rate selected before flight, and the subject would begin to move his head slowly forward and back and side to side at a steady pace. On the ground, this action would result in unpleas­ant symptoms after about seventy head movements. Graybiel had defined a symptom complex called “Malaise ill” — which meant you usually threw up. The crew objected violently to this, and he backed off to “Malaise iia,” which meant pallor, sweating, stomach awareness, then nausea. If you stopped right away you wouldn’t throw up, but it was not fun. Minnie’s bra had to be small so that the observer could detect the subject turning pale.

It was agreed that this was an important test. There’d been quite a bit of motion sickness reported in the Russian space program. (Second crew sci­ence pilot Owen Garriott recalled: “We were told that the Russians were beginning to wonder why only they experienced space sickness, when Amer­icans were apparently immune! There are several reasons, probably related to the volume available for crew mobility, but that’s another story.”) There were also several suspected cases in NASA’s Apollo program, including most notably Apollo 9’s Rusty Schweickart.

The Space Shuttle was already being debated in Congress; it called for an astronaut to land the orbiter manually, a task involving considerable skill; no one wanted to trust it to a motion-sick pilot. NASA was even slightly averse to using the term. The researchers had begun to call it “Space Adaptation Syndrome.” The crew still called it dsms for “Dreaded Space Motion Sick­ness.” And the Skylab crew didn’t want to compromise their safety either. For the first mission, they requested that the commander, Pete Conrad, be excused from the Motion Sickness Susceptibility test. That way he’d always be ready to fly home if an emergency took place aboard Skylab. Management readily agreed, and so did the ever-cooperative Dr. Graybiel.

Today would be the first test. Paul Weitz, the lucky one, was scheduled to be the subject, Kerwin the observer. Paul had not had motion sickness in the first days of the flight, and he didn’t relish getting it now — even though the first series of head movements would be made with no rotation. He passed with flying colors. He made 150 head movements, the maximum allowed, with none of the symptoms of motion sickness. He had some sensation of rotation, “as if my gyros were being tumbled,” but felt fine.

What was going on? On Day 7, Kerwin underwent the test with rotation, (seven and one-half revolutions per minute was his number), and went 150 head movements with no symptoms. It was decided to increase the revolu­tions in steps. On Days 12, 16, 20, and 24, Joe and Paul were tested, until they were spinning at the maximum safe value of thirty revolutions per minute. No symptoms occurred. Both the crew and investigators were amazed. Pete had been let off the hook for nothing. It seemed that in zero-G, once you were adapted, you were immune to space motion sickness. This was pretty good news for the Shuttle program.

The other big Day 6 event was the first “erep Pass.” erep stood for “Earth Resources Experiment Package,” Skylab’s complex of cameras designed to take multispectral, high-resolution, three-dimensional photographs of ground

and ocean locations of scientific interest. The crew would call them “tar­gets,” but some NASA folks thought that sounded too military.

Skylab normally pointed its upper side, and the Apollo Telescope Mount solar experiments, directly at the sun. It retained this attitude on both the day and night sides of the orbit for two reasons: it required minimum fuel, and it also kept the solar panels perpendicular to the sun whenever the spacecraft was in sunlight—for maximum electrical power. Since at that point Skylab had only the Apollo Telescope Mount solar panels, energy was marginal.

What did this have to do with Earth Resources? In order to point those Earth cameras directly at the planet, Skylab had to maneuver out of solar inertial attitude into local vertical. In local vertical mode, the side of Skylab opposite the atm was pointed straight down at the Earth at dawn. Then a gentle pitch rate was begun, which rotated Skylab gently nose down, keep­ing the cameras pointed directly at the Earth for most of one day-side half orbit.

As the locations of interest passed beneath the spacecraft, the various cam­eras would be operated, often in conjunction with low-altitude photography by aircraft and sometimes observations by scientists on the surface. That done, Skylab would rotate back to solar inertial attitude.

The pass was scheduled for between 3:00 and 4:00 p. m. — daylight over the United States. The local vertical maneuver was initiated a little after three, and by 3:30 Pete and Paul were busily photographing sites.

Pete: “Ready—do mode auto.”

Paul: “I found it. How about that? Looking through a little hole in the clouds.”

Pete: “What did you find?”

Paul: “I found the site. . . . Okay. On White Sands and Tracking.”

Skylab sliced rapidly across the United States from northwest to south­east at four miles a second. With a lot of good film in the can, they shut the cameras down and returned to solar inertial attitude about 4:00 p. m. As they did, the crew noticed a battery charge light that shouldn’t have been on. The bad news was about to happen.

Houston (5:40 p. m.): “cdr, Houston. . . Could you do a little favor for us? We’d like to get regulators 6, 7, 8 and 16 off the line.”

Pete: “Okay.”

Houston: “Roger, copy. And also, for information, we’re going to be pow­ering down the epc [the atm’s Experiment Pointing Control system] to con­serve power. And we’ll also be turning down the airlock module’s second­ary coolant loop.”

Pete: “Okay. What’d we do, run lots more [power] than you thought?”

Houston: “Negative. . . but a few of the batteries went down. . . .”

Houston (5:45 p. m.): “Skylab, Houston, we’d like to hold up on the M131 run ’til we get into daylight.”

Paul: “What for, Hank? We’re halfway through the ogi [Oculogyral Illu­sion, one of the vestibular system tests] Mode now.”

Houston: “Well, we’ve got—we’ve got a power problem here.”

They sure did. What had happened was that several batteries reached a state of charge of less than 45 percent during the Earth Resources pass, and their controllers took them off the line—they weren’t recharging. The next hour was spent turning things off and trying to get the batteries to recharge. By 6:50 Houston was able to report, “As we go over the hill here, it looks like the electrical power system is at least stable now. The batter­ies are coming up. So we’ll see you at Vanguard. . . . And Pete, the Indy’s over now. It got stopped by rain in 130 something laps, and Gordy John – cock was the winner.”