Category HOMESTEADING SPACE

Joe Kerwin recalled: “Here’s the story about my first brush with Skylab: One day in January 1966, Al Shepard said, ‘Kerwin and Michel, I want you to go out to the Douglas plant in California. Marshall’s working on an idea of using the inside of an s-ivb fuel tank as an experimental space station.’ So we called out to Ellington for a T-38 jet and flew to Huntington Beach. At the plant they made us put on bunny suits and slippers, then showed us to the end hatch of a freshly manufactured s-ivb lying on its side. The hatch had been removed, leaving an opening about forty inches in diame­ter into the fuel tank.

“We noted that the hatch was secured with seventy-two large bolts. ‘How will the astronauts remove it in flight?’ we asked. ‘We’ll give you a wrench,’ they replied. We climbed into the tank. It was big enough, all right—about thirty feet long and twenty feet in diameter. It was empty except for a long metal tube along one side—the ‘propellant utilization probe’—and a cou­ple of basketball-sized helium tanks. There was a faint chemical smell com­ing from the fiberglass, which covered the interior. It felt like standing in the bare shell of what was going to be a home someday after the builders had finished with it.

“‘What would we do in here,’ we asked. ‘You can fly around in your suits.’ Perhaps you’ll test a rocket backpack. (That was prophetic.) And Marshall was even considering a plan to pressurize the tank with oxygen, so we could remove our spacesuits. That was a start!

“Curt had a conversation with the project rep about what experiments could and would be performed. After our return to Houston, he wrote Al a memo which likened the experiment selection process to ‘filtering sand through chicken wire.’ We were both inexperienced, glad to have some­thing to do, and skeptical. I did not dream that seven years later I’d spend a month inside that tank, in space.”

From a crew perspective, the development of the Skylab space station and the training of the astronauts who would live there are in many ways the same story. Usability is a primary concern in developing new space hard­ware. To ensure usability engineers would turn to the people who would be using that hardware. Throughout the development of Skylab, crewmem­bers would be brought in to give input on hardware as it was being designed and tested. So in many cases, they learned to use the equipment by helping its designers make it usable. Crew involvement began early in the develop­ment with the first Apollo Applications Program assignments being made in the astronaut office years before the first moon landing.

“Of course, those were early days for Skylab, and we’d looked at a tiny sample of ‘bottom-up’ planning, while the ‘top-down’ planning was tak­ing place elsewhere and would answer a lot of our questions,” Kerwin said. “ ‘Elsewhere’ was largely at the Marshall Space Flight Center. Not long after our trip to Huntington Beach, I was invited to observe a meeting between a visiting delegation from Marshall and msc managers. The Marshall peo­ple gave a briefing on their plans for the ‘Apollo Applications Program,’ as it was then called. They sketched several missions on an ambitious sched­ule and asked for operations and training participation. The msc managers

basically said, ‘That’s great, but we’re busy going to the moon.’ So the team from Marshall left, saying over their shoulders, ‘This is going to happen!’ And so it did. It was still seven years from launch, but activity got started, and astronauts began to participate. We all had various assignments then, supporting Gemini, Apollo, and Skylab, and they changed fairly often, but Skylab began to take more and more of my time and attention.”

Kerwin recalls standing around with a group of colleagues one evening in 1967 in the mockup building at msfc. Someone had drawn with chalk a big circle on the floor, twenty feet in diameter, representing a cross section of the s-ivb tank. In the circle the astronauts worked with Marshall engi­neers on deciding how best to arrange the sleeping, eating, bathroom, and experiment quarters. “Al Bean was our leader at that time, and Paul Weitz, Owen Garriott, Ed Gibson, and a few other astronauts were there too, with several engineers,” Kerwin said. “We had a great time and began to devel­op a friendly relationship with that s-ivb fuel tank.”

In the earliest days of the Apollo Applications Program, the astronauts working with the program were a loosely defined group, with members rotat­ing in and out as they began and completed projects for other programs. While the official flight crew rosters were not announced to the public until 18 January 1972, the group from which the assignments were made had been assembled about two years earlier.

“Pete Conrad had just come off his Apollo 12 flight, which was Novem­ber ’69, so this had to be around January or February of 1970 when Slayton came into a pilots’ meeting on a Monday morning,” Kerwin said in a NASA oral history interview. “He had a sheet of paper in his hand. He said, ‘The following people are now formally assigned to crew training and mission development for the Skylab program.’ He read the names of fifteen people. He didn’t say who was prime, who was backup, who was what mission or anything else. All he said was that Conrad was going to be ‘Sky King’; he was in charge, and he would tell us all what he wanted us to do.”

The list included not only the nine astronauts that would make up the Skylab prime crews—Conrad, Kerwin, Weitz, Bean, Garriott, Lousma, Carr, Gibson, and Pogue—but also the six astronauts who would form the back­up crews. “We had no idea what that list meant,” Kerwin said. “There was a lot of speculation going on about who was going to be on what mission. There were fifteen of us, which meant that there were three prime crews, but only two backup crews. So somebody was going to have double duty as a backup crew it looked like unless the first prime was going to be the last backup. Deke didn’t say. Deke was not a man of many words. He didn’t say more than he thought was necessary at the time. It turned out, again in ret­rospect, that the way he had read that list was first prime, first backup, sec­ond prime, second backup, third prime, exactly in order.”

In April 1971, “Sky King” Pete Conrad sent a memo to all of his “Skytroops” specifying who would be responsible for what. He made the assignments based on experience and on equalizing both the training and the in-flight workload.

The commander (cdr) would have overall responsibility for the flight plan and training; he’d also be responsible for the Apollo space­craft systems and spacewalks. Estimated training hours: 1,411.

The science pilot (spt) would be responsible for medical and atm hardware and experiments and would be the second spacewalk crewman (in the end all three crewmen trained to make space­walks). Estimated training hours: 1,500.

The pilot (plt) would be responsible for airlock, mda (Multiple Dock­ing Adapter), and workshop systems and for the Earth Resources Experiment Package (erep) hardware and experiments. Esti­mated training hours: 1,420.

Each of the fifteen men on the prime, backup, and support crews was also assigned specific experiments and hardware. This was as much for the benefit of the rest of the training, engineering, and flight operations world as for the astronauts themselves; it meant other organizations knew which astronaut to call to get an office position on a procedure or a hardware change. To keep those calls from becoming too much of a burden, train­ing managers were assigned to the crews to help organize their schedules. “Bob Kohler was our crew training manager, an energetic but calm man able to steer us through the months of competition for our precious time,” Kerwin recalls. “I think we burned him out; he left NASA after Skylab and became an optometrist.”

The activity planning guide Kohler put together for the first crew for April and May of 1973 was typically busy. “We’d already done our multiple-day on-orbit simulations and were now concentrating on launch, rendezvous, and entry integrated sims (‘integrated’ meant the simulations included full Mission Control participation),” Kerwin said. “Saturdays were full, but we had most Sundays for family, unless we were traveling. There were more and more medical entries: exams, blood drawing, and final preflight data runs of the various experiments. Saturday, April 24 was listed as ‘Crew Por­trait Day—flight gear?—check with Conrad.’ It was all a blur. Sometimes things happened on schedule, but often not. I have a handwritten sheet of paper from March of 1972 that says the following:

3/6/72: Joe—miff Interface Test has slipped to Saturday, per Dick Truly. Bob Kohler.

Joe— it slipped back to Friday—keep checking! Richard.

Friday it is—as of 3/7/72. Kohler.

Would you believe Monday the 13th—Kohler—3/8.

3/10: cancelled until further notice. ”

After the first crew launched, Kohler put together the sl-2 Crew Train­ing Summary, showing exactly how many hours each of the three astro­nauts had actually spent in trainers and simulators during the two years of “official” crew training. Conrad had the least, at 2,151 hours, but he’d been on three spaceflights already. Kerwin was next with 2,437 hours, and Weitz had the most at 2,506 hours. Those times don’t count the many hours they spent flying, in meetings, reviewing the checklists, and trying to memo­rize all the switch locations and functions—the “homework” that had to be done to prepare for the simulator work. (“This would explain why none of your children recognized you after the flight,” joked Kerwin’s daughter, Sharon.)

Another of the activities on the busy astronauts’ schedule was space­craft checkout. “In early June of 1972, we strapped into our T-38s and hus­tled to St. Louis, to the McDonnell Aircraft plant, where the flight Dock­ing Adapter had been mated to the flight Airlock Module and was waiting for final checkout [McDonnell had merged with Douglas Aircraft in April of 1967],” Kerwin said. “The next morning, June 6, we briefed, put on our bunny suits and slippers, and entered the flight unit. Outside was a large team of McDonnell engineers led by the test director. Every switch throw

was in the test plan, and its effects would be watched and measured.

“The test was scheduled for twelve hours, but we accomplished it in half that time, flying from panel to panel and reporting over the intercom, ‘Rog­er. . . in work. . . complete.’ The spacecraft was clean, beautiful, and com­pletely functional. We felt that industry had finally learned how to build them and test them, and we partied that night at the motel with our con­tractor teammates.”

There seemed to be no limit to the tasks requiring the crews’ attention during the period of the station’s development and their training, every­thing from the overseeing the functional requirements for the triangle shoes to fighting with the Public Affairs Office over television shows on Skylab. (The astronauts weren’t opposed to doing them, but they’d had no training and there was no time in the flight plan for them.) And of course an astro­naut wouldn’t want to find himself heading out for a spacewalk if, while on the ground, he hadn’t customized the fit and comfort of his ucta—the urine collection and transfer assembly worn under the spacesuits. One could change the location of the Velcro, add a snap, wear a suitably perforated ath­letic supporter, and wear the ucta over or under the liquid cooling garment. Then there was the task of designing, and redesigning, the crew clothing to be worn in-flight.

“Testing and modifying the clothing was fun, although it dragged out a bit because clothing was a matter of both requirements and personal tastes,” Kerwin said. The following excerpts from a series of internal memos exem­plify this:

To: cb/All Skylab Astronauts From: cb /Alan Bean Subject: Skylab Clothing

a) Would it not be better to remove the knitted cuffs completely from our Skylab flight suits, since it looks like the temperature will be warmer most of the time than we would desire? [That was a prescient guess by AH]

b) There seems to be a difference in philosophy as to what constitutes proper uni­form for the “cool Beta Angle" and the “warm Beta Angle" on the Skylab mis­sion. [Beta Angle was essentially the angle between Skylab s orbit and the sun; it varied with the season and determined how much ofeach orbit was spent in sun­light.] For the warm case our only option is to take off some of the cool weather garments. Taking off the jacket is all right because we end up with a cool polo shirt. However, if we wanted to take offour pants, we end up standing around in our underwear. I don’t personally have anything against running around in my underwear, I do it all the time at home; but it would be better to at least have something more military in appearance planned for the warm case.. ..

To: cb/Skylab Astronauts

From: cb /Joe Kerwin

Subject: Al Bean’s Clothing Memo

a) The knit cuffs are there to retain the sleeves and trouser legs under zero-g. They can be snipped offby a crewman at his option. Recommend they be retained, as a better military appearance will result.

b) The “warm weather uniform" question was a good one. . . . Unfortunately, all the clothing will be up there before we know the answer. We looked, briefly, at bermuda shorts last fall, and nobody thought they were needed…. Alterna­tively, we can ask Crew Systems Division to engineer the longiesfor easy cutting off. Pete, you decide. (Incidentally, AdmiralZumwaltsays we can wear frayed pants in the wardroom now.)

c) Lip buttons will be providedfor complainers.

To: cb /Skylab Astronauts From: GeraldP. Carr

Subject: Skylab Clothing (Another shot across Medinaut’s bow) (that’s Kerwin)

a) Agree that the cuffs make the suit a bit too warm, but Joe’s answer is fine. We can snip them out if they get too warm.

b) . . . I have no objection to making my own Bermuda shorts out of a “cold case" set ofclothing

c) Disagree with Joe’s proposal for lip buttons. Zippers or Velcro are much more appropriate in the space biz.

Eventually, the Skylab astronauts all agreed on a clothing set. It con­tained cotton T-shirts for warm-weather wear and provisioned a change of underwear every two days and of outerwear once a week. The outerwear was made of a fireproof cloth, polybenzemidazole (called pbi; “We couldn’t pronounce it either,” quipped Kerwin) that only came in a golden brown. But it was comfortable. Rejected were the proposed small-bore fiberglass (called “beta cloth”) items, which itched.

On the lighter side, the crewmembers all got to pick the music for tape cas­settes they would carry with them on the mission. Each would have a small tape player, with Velcro on it to attach to a handy wall so that they could accompany their various experiment chores with music. For example, on the first crew, Conrad was a huge fan of country; his cassettes featured the Statler Brothers, Lynn Anderson, and other favorites. Kerwin liked classical; some of his favorites were Rachmaninoff’s Rhapsody on a Theme of Paganini and Ravel’s Piano Concerto for the Left Hand. He also snuck in a few folk songs recorded by his brother, Ed. Weitz’s selections proved popular with his entire crew— Richard Rodgers’s Victory at Sea, the Mills Brothers, Glen Campbell, Andy Williams, and the Ink Spots. Selecting the music was one of those last-minute chores like completing the guest list for our launch,” Kerwin said. “It felt good; we were getting close.”

Of course, not all Skylab training took place in the relatively comfort­able confines of NASA centers and contractor locations. For example, as with Apollo, the Skylab crews went through training to prepare them for the contingency of an “off-nominal” reentry that could return them to Earth far from where they were supposed to land. “Although they never had to be used, the water egress, and desert and jungle training were lots of fun,” sec­ond crew science pilot Owen Garriott said.

The jungle training took place in Panama under the guidance of local Choco Indians. “They were expert trackers and, of course, knew the jungle as their own backyard,” Garriott said. “We were given an hour or so head start and told to evade capture and meet some twenty-four to forty-eight hours later on the beach some distance away.

“We all took off in groups of three—I was with Tony England and Karl Henize—at a fast trot, trying to get as far away as possible before darkness descended. The Chocos would set out after us and try to ‘grab our hats,’ equivalent to a capture.

“We succeeded almost too well,” Garriott said. “We didn’t get ‘captured,’ but we ran for so long that it got dark before we had properly made camp. We hurriedly gathered sticks to try to make a lean-to to be covered with a nylon sheet and to make a fire from small pieces of wood, but the every-day rains made a fire impossible. But darkness and more showers arrived before we had anything like a dry shelter. That night has been long remembered as the most uncomfortable, mosquito-plagued night of my life.

“Of course, we had to have a graduation celebration (after we were all finally recovered) on the banks of the Panama Canal,” he continued. “Scien­tist astronaut Story Musgrave, always the adventuresome explorer, thought it would be fun to swim across the canal—in pitch darkness. So he stripped down and paddled off into the night, with numerous warnings about avoid­ing the alligators. In an hour or so, back he came, none the worse for any animal encounters.”

Ed Gibson also had a memorable experience during his survival train­ing. Despite all the challenges of living in the wild, Gibson decided the big­gest threat to his own survival was one of his own teammates. “People ask me what is the most dangerous thing I’ve ever done in the space program,” Gibson said. “Well, we went on a jungle survival trip, and I was out in the forest with Jack [Lousma] and Vance Brand. And after a couple of days or so, Jack was getting pretty hungry, and he kind of came up and started feel­ing my flesh. And I realized my objective for that whole time was to find enough food to feed him so I wouldn’t get eaten.”

We kidded about, we may have a dry workshop on orbit, but you’re going to
go through a wet workshop in training, that being underwater.

Jim Splawn

Joe Kerwin recalled: “From, I’d guess, 1968 onward, we traveled ever more frequently to Huntsville—for engineering tests and design reviews, but more and more to do eva training in the new, bigger, and better water tank. I remember going there with Paul Weitz. We’d fly up together in a T-38. You’d take off from Ellington, point the nose to a heading of just a lit­tle north of east, climb to 17,500 feet, and go direct. We could make it in an hour if all went well. When we landed at Redstone Arsenal [the Army base in Huntsville on which Marshall is located], there’d be a rental car wait­ing, and we’d hustle off to the Tourway Motel; $7.50 with black and white TV, $ 8.50 with color.

“Bright and early the next morning we’d go to the neutral-buoyancy tank. That was always a professionally run organization and always a pleas­ant experience. We’d suit up in the dressing room, brief the test, and make our way up to ‘poolside’ and into quite a crowd—with divers, suit techni­cians, mockup engineers, and test personnel. Hook up the suit to commu­nications, air, and cooling water. Down the steps into the water. Then float passively while the divers ‘weighted us out.’ They did this by placing lead weights into various pockets to counteract the buoyancy of the air-filled spacesuit, until we were neither floating to the surface nor sinking to the bottom. I recall gazing idly up through the bubble-filled water to the bright lights above and imagining that I was a medieval knight, being hoisted on to my charger before the tournament.

“Then the two of us, each accompanied by a safety diver (ready to assist us instantly in case we lost air or developed a leak) would move over to the Skylab mockup, laid out full size in the forty-foot-deep water and practice film retrieval from the atm. We’d evaluate handrails and footholds, open­ing mechanisms and locks, how to manage the umbilicals, which trailed out behind us as we worked. After two or three hours we’d quit, return to the locker room, and debrief. It was wonderful training. By the time we launched, each of us could don and zip his own suit unassisted and move around in it with the same familiarity as a football player in his helmet and pads.”

The idea of neutral-buoyancy simulation of the microgravity environ­ment had arisen at the Manned Spacecraft Center in Houston before it was developed at Marshall, though neither center would implement the concept until the mid-1960s. Mercury astronaut Scott Carpenter had proposed using a water tank for astronaut training early in the space program, but manage­ment did not pursue the idea at the time.

A water tank was constructed for astronaut training at msc, but not ini­tially for neutral-buoyancy work. Rather it was used to prepare astronauts for the end of their missions. Since Mercury, Gemini, and Apollo flights all con­cluded with water landings, the msc tank was used to rehearse the procedures that would be performed in recovery of the astronaut and spacecraft.

When Ed White made the first U. S. spacewalk in 1965 on the Gemini 4 mis­sion, his experience seemed to belie the need for intense training; for White, the worst part of the spacewalk was that it had to end. When Gene Cernan made the second American spacewalk the following year, however, his expe­rience was quite different. He found it difficult to maneuver, his faceplate

fogged up, his pulse rate soared, and he got overheated. It was obvious that changes were needed in spacewalking technology and procedures, and that included training. The idea of neutral-buoyancy training was revisited and implemented in time to prepare Buzz Aldrin for his Gemini 12 spacewalk, five months after Cernan’s. With the changes that had been made and the intervening experience, things went far more smoothly for Aldrin’s attempt on the final Gemini flight. Underwater training continued during the Apol­lo program; spacesuits weighted past the point of neutral buoyancy allowed astronauts to simulate the one-sixth gravity of the lunar surface.

At Marshall neutral buoyancy development came about from a grass­roots initiative, at first as almost a hobby among some of the center’s young engineers in the mid-1960s. “Some of us young guys got to talking about, we really are going to be in space, and if you’re in space, you’re going to need to do work,” said Jim Splawn, who was the manager of space simulation at the Process Engineering Laboratory at Marshall. “And if you do work, how do you keep up with your tools? How do you train? So that started the discussion about how are you going to practice. How are you going to simulate the weightlessness of space? And we talked and talked for weeks, I guess, about that.

“And so one guy said, ‘Hey, have you ever watched your wife in the swim­ming pool?’ And we all giggled and said, ‘Yeah, you bet, we watch our wives and other wives too.’

“But he said, ‘No, no I’m serious. Have you ever looked at her hair while she’s underwater, how it floats?’ And that started a whole ’nother discussion, and so we said, ‘Well, why does it do that? It’s sort of neutrally buoyant—it doesn’t sink; it doesn’t necessarily float to the surface.’ So then we started talking about how we could do that. We started coming up with the idea then of going underwater. That was the first concept that we had, the first discussion about going underwater.”

The group thought the idea had potential and decided to use some of their free time to pursue it, and Marshall’s first neutral-buoyancy simula­tor was born. Of course official facilities and equipment require funding, so the first phases of their research relied on using whatever they had available. The first exercises were done in an abandoned explosive-forming pit. The pit had been used to create the rounded ends of Saturn I fuel tanks and was about six feet in diameter and about six feet deep. Initial dives were done in swimsuits until the group felt like they needed more duration underwater, at which point they began using scuba gear.

Their experiment was showing promise, and they were ready to graduate out of the six-foot-diameter tank. Once again, though, their almost non­existent budget forced them to make use of what was on hand, which was once again leftover Saturn hardware. The tank was based around an inter­stage for a Saturn rocket, the short, hollow cylinder that connects two boost­er stages together. “It was like a ring, probably twelve-feet vertical dimen­sion,” Splawn said. “So we had a backhoe, and dug a hole in the ground, and positioned the interstage and backfilled the dirt around it. And, guess what, we had a swimming pool now made out of excess Saturn hardware to become our next simulator for underwater work.”

The extra volume meant that they could take the next step in their under­water evaluation. Just as they had moved from swim trunks to scuba gear in the first tank, the second allowed them to move on to pressure suits, simu­lating the gear that astronauts would be wearing in orbital spacewalks.

“We had to go to Houston to try and get pressure suits,” Jim Splawn said. “Pressure suits in the mid – to late – 60s were few in number and of great demand and expensive and were very, very well protected by the Houston suit techs. So we took an alternate route; we contacted the Navy, and a cou­ple of us went to San Diego one Friday, worked with the Navy on Saturday, and they put us in high-altitude flying suits, and then they had huge over­size suitcases that they put these high-altitude pressure suits in, complete with gloves, helmet, everything, there. They trained us in a large swimming pool that they had; in fact, we had to jump off of diving boards into the water, and we took the helmets off, and we had to learn how to take a hoo­kah [breathing apparatus] for underwater diving, so they taught us how to get the helmet off and take the hookah and still survive. So anyway, they taught us how to do that, so then we flew home on Sunday afternoon; we brought back four pressure suits, just on commercial air. So that’s where we got our first pressure suits.”

The “hookah” is a rubber full-head covering that is used underwater, similar to scuba. Instead of coming from a tank, air is pumped down from the surface by a hose to maintain a certain airflow into the rubber “helmet,” regardless of the depth of the diver. It is particularly useful in tanks like Mar­shall’s neutral-buoyancy trainer because it allows voice communications to the surface. However, one must be careful to not turn upside down, as air goes out and water comes in.

Up until this point, Splawn said, Marshall and msc had not had any dis­cussions about the work each was doing on neutral buoyancy. “We had abso­lutely no interaction at all,” Splawn said. “We knew nothing at all about Houston and the type of simulations or training or anything else that they were doing. I really don’t know the timing between what Houston did and what we did. I just don’t have any data point there at all. Once it became known what we had and what we had done, there was competition, and some pretty heated discussions between Houston and us. But we ended up doing the crew training for Skylab.”

In fact the first astronauts came to check out the work when the team was still using the second tank. Alan Bean, at the time an unflown rookie, was one of the first astronauts to perform a pressure-suited dive in the interstage tank. It was also during the experimentation with the second tank that the team decided they could let the Marshall powers that be in on their work. Von Braun himself made a dive in a pressure suit to evaluate the potential of neutral-buoyancy simulation.

Bob Schwinghamer, who was the head of the Marshall materials lab,

recalled a nerve-wracking incident that occurred during one of Bean’s ear­ly visits. “I was safety diving, and I was floating around in front of him. He was in there unscrewing those bolts off of that hatch cover. And all at once, it said, ‘poof,’ and a big bubble came out from under his right arm, a stream of bubbles. I thought, ‘Oh my god, I’m going to drown this astro­naut.’” Schwinghamer said he attempted to cover the hole in Bean’s suit, but he could see the suit collapsing—first near Bean’s feet, then up to his knees, then his thighs. Since he didn’t have a communications system at that time, Schwinghamer left Bean and surfaced, and told the operators to give him more air.

“He never lost his cool,” Schwinghamer recalled. “By then, he wasn’t neu­trally buoyant anymore; he was about sixty pounds too heavy. So he walked across [the tank], and he just climbed up the ladder and got out. That’s all there was. And I said, ‘Oh my goodness, what if we had drowned an astro­naut?’ But he was just cool.”

Working with pressure suits complicated the situation. The pressure suits, representing spacesuits, were basically balloons containing divers. That meant the air caused the suits to tend to float. In order to make the suits neutral­ly buoyant, weight had to be added to balance out the effect of the air. This had to be done very carefully. Putting too much weight in one area would cause that area to sink more than the rest of the body, invalidating the sim­ulation of weightlessness.

“After many, many stop-and-go kind of activities, we settled in on a low – profile harness of small pockets of lead strips, so that we could move the lead about depending on the mass of the human body that’s inside the suit and consequently what kind of volume of air you had inside that suit,” Splawn said. “We could move the lead weights around until we could put the test subject or flight crewman into any position underwater and turn him loose, and he would stay there.

“We started offjust in a room, so in order to get some data points, we put the guy in the pressure suit and then lay him flat on the floor and tried to get him to lift his arms—Is the weight distributed?—and lift his legs—Is the weight sort of distributed correctly?” Splawn said. “And so we said, ‘ok, get up,’ and he couldn’t get up, he had so much weight on him. That was in the very early days.” Typically, he said, about seventy to eighty pounds of lead weights were needed to achieve neutral buoyancy. To make sure the weighted,

pressured-suited divers didn’t encounter any problems, each one was accom­panied by two safety divers who could help out in an emergency.

Once the team had enough experience in the interstage tank, they were confident that neutral buoyancy could be used for weightlessness simula­tion. They were ready to move on to the next step. “From that we gradu­ated to what we called the big tank,” Splawn said. “The big tank is seven­ty-five feet diameter; it’s forty feet deep; 1.3 million gallons of water as best I remember. It was complete with underwater lighting, underwater audio system, umbilicals that would be very much like the flight crew would use to do an eva on orbit.”

This tank, Marshall’s Neutral Buoyancy Simulator, was designed to take the work to the next level. Unlike previous facilities, which were experiments designed to evaluate the efficacy of neutral buoyancy as a microgravity ana­log, the Neutral Buoyancy Simulator was a working facility. The theory had been proven and now was being put into practice. The facility was designed to be large enough to submerge mock-ups of spacecraft in order to test how easily they could be operated in a weightless environment.

“We sort of had the vision of building a facility large enough to accom­modate some pretty large mock-ups of hardware, and it really proved out to be very, very beneficial,” Splawn said. “Because once we had the difficulty at the launch of the Skylab itself headed towards orbit, it really proved its worth because of all the hardware we had to assemble underwater.”

The origin of the “big tank” was rather unconventional. In order to has­ten the process of building the tank, Marshall leadership found a way to circumvent the bureaucratic requirements of creating a new facility. “The facility was not a ‘c of F,’ or construction of facilities type project,” Splawn explained. “There is a small tool tag that is on the side of the tank, and it has a number stamped on that tag, and so that designates the seventy-five – foot diameter tank as a portable tool. There were a lot of eyebrows raised at that.” While the tank was not technically secured into place, saying it was portable was somewhat of a stretch.

“I don’t really remember how that happened,” Splawn said. “I know there was great interest in having a facility, and we thought we had the right idea of how to simulate weightlessness and how to train. We needed a facility, and the schedule of when we needed it just could not be supported through the official construction of facilities kind of red tape that you had to go through to get a facility approved, and then all of that kind of business that occurs to acquire a facility. So that’s why we went this alternate route.”

As a result of the way the Neutral Buoyancy Simulator was built, many people elsewhere in the agency did not know what Marshall was doing until it had been done (as was the case with associate administrator George Muel­ler, who was not aware of the tank until his “wet workshop” dive).

“The tank was built in-house,” Splawn said. “We used the construction crew out of a test lab because they were equipped and they were accustomed to doing construction work. So the steel segments of the tank, of course, were rolled steel. They were shipped in, and then the government employ­ees welded the tanks together, and we installed all the systems, electronic, mechanical, filtration, all of that was worked internally.”

The tank attracted some unusual visitors, Splawn recalled: “It was very interesting to have some of the caliber people come through our area that came through. Of course, starting with von Braun—back when we had just first started the thinking and the dream of going underwater to do evaluations in a weightless environment, we found out that von Braun was a scuba diver. So once we had been through the early stages and thought we could sort of reveal our thoughts a little bit, we contacted his secretary, Bonnie, and told her we’d like to have Dr. von Braun come and see what we were doing.

“I guess the first time he ever knew anything about it, we were on the twenty-foot tank. He didn’t know about it up until about then. Because us bunch of young guys, what we would do is work our regular kind of work through the day, and then we would go out in the late evenings and play, and I say ‘play’ in quotes. But we would try to figure out just exactly what we were trying to do. We didn’t know if we had a cat in the bag or not. But we finally revealed the cat to Dr. von Braun and got him to come down, and he thought it was wonderful. He said, ‘Ja, ja, keep going, keep going.’

“I remember one day that von Braun had been to the Cape for a launch, and we got a call from his secretary again. Bonnie said, ‘Dr. von Braun has just called me from the Cape, and he is bringing a guest on the NASA air­craft back with him from the Cape to Huntsville, and they want to go to the neutral-buoyancy facility this afternoon, and this guy’s name is Jacques Cousteau, and can you accommodate him?’ And I said, ‘Yes, ma’am, we sure can.’

“So von Braun dressed out in swim trunks, and Jacques Cousteau dressed

out in swim trunks, and they went for a dive in scuba gear, and von Braun showed Jacques Cousteau some of the things that we were doing underwater, put him through a few paces with some of the hardware that we had mount­ed in the tank at that point in time. So it was sort of interesting.”

As an additional safety precaution, the Marshall facility also included a decompression chamber, which could be used if a diver surfaced too quick­ly. The medical term is “dysbarism”—Greek for “pressure sickness” — but to divers it’s simply the “bends.” Bends has affected divers since humans began to dive for pearls centuries ago. It doesn’t just happen underwater; workers building the foundations of the Brooklyn Bridge a hundred feet beneath the surface of the East River developed the strange pains and dis­orientation of “caisson disease.” The doctor hired by the company to look into the problem noted with interest that the pains often went away when the men went back down to the diggings. But it was another twenty years before other doctors figured out what was happening.

When a diver descends in water, the water’s weight increases the pres­sure against the body; at thirty-three feet it’s double the pressure at the sur­face. In order to breathe, the pressure of the air the diver breathes also must increase. And that pressure drives nitrogen into the lungs, blood, and tis­sues. That’s not normally a problem; nitrogen is inert except at very high pressures, when it exerts a narcotic effect.

But if a diver ascends rapidly to the surface, the pressure suddenly dimin­ishes. Then the absorbed nitrogen reverses course and comes out of the tis­sues. The diver is able to breathe some of it out, but if the pressure was high, some of it forms bubbles in the blood and tissues, and these can have dan­gerous effects—bubbles compressing nerves in the joints cause bends, bub­bles blocking capillaries in the lungs cause chokes, bubbles in the blood ves­sels of the brain can mimic a stroke. To prevent these things, it’s essential to reduce the pressure on the body slowly enough to allow for “breathing out” the nitrogen without letting bubbles form.

The dives in Marshall’s tank never caused the astronauts to have any prob­lems. However, the recompression chamber was used once, Splawn said, for a Tennessee Valley Authority utility diver in the area who had been doing work underwater and surfaced too quickly and was rushed to Marshall. Splawn said that, while it was too late to prevent lasting harm, the cham­ber may have saved his life.

Concerns over rapid decompression did affect the crews training in the tank in one way, though. “In our dives, we never went deep enough for long enough that we couldn’t safely return to the surface of the tank in a hurry,” Kerwin said. “But climbing into the cockpit of a T-38 and flying home at reduced cabin pressure was another story. Flying after diving sets pilots up for bends. So we did a study, and came up with rules for how long a diver had to loiter on the surface before launching for home. It varied from a few hours after one dive to an overnight stay after two days’ work underwater.”

Until Skylab, crewmen had worn biomedical sensors pretty much all the time during flight. On the early Mercury and Gemini flights, when ground sta­tions in the Manned Spaceflight Network (known by the time of Skylab as the Spacecraft Tracking and Data Network) were scattered around the world, the flight surgeon attached to each station crew would study those heartbeat and respiration traces intently as the spacecraft passed overhead, looking for signs of stress. Heart rates during spacewalks were useful as they were a pret­ty good indication of crew workload and oxygen consumption.

As the NASA doctors looked at the heart rates of astronauts under the stresses of launch acceleration, weightlessness, spacewalks, and just hang­ing around, they inevitably witnessed the occasional irregularity — usually a premature beat or a run of two or three of them. They came to accept these as within the limits of normal. But the arrhythmias they saw in the Apollo 15 crew on the way back from the moon were more marked and a cause of considerable anxiety on the ground. Future Apollo flights carried medica­tions for such arrhythmias.

With this background and the greatly increased duration of the planned Skylab flights, a medical desire for as much data as possible remained, as exemplified by the following excerpts from NASA memos:

To: EA/Manager, Apollo Applications Program October 3,1968 From: CA/Director of Flight Crew Operations [Deke Slayton]

Subject: Bioinstrumentation for Apollo Applications Program (aap) Missions

The long duration, large volume and required crew mobility of AAP core missions will require different guidelines for the transmission ofbiomedical data. Contin­uous-wear instrumentation will not be feasible. Numerous medical experiments will be performed which require instrumentation, and which will give medical monitors the information needed to assess crew status.

Therefore, the following guidelines are recommended: Bioinstrumentation will be worn for launch, entry, eva and medical experiments. It will not be worn at other times unless requiredfor diagnostic purposes. . . .

To: CA/Director of Flight Crew Operations Oct 16, ip68 From: DA/Deputy Director of Medical Research and Operations Subject: Bioinstrumentation Requirements in the Apollo Applications Program

. . . I feel it is inappropriate for you to propose guidelines for the acquisition of biomedical data without full coordination of these guidelines with our Direc­torate. The following comments regarding your memorandum are offered in a constructive vein in the hope that you may be persuaded to address future rec­ommendations to this Directorate….

It is our present hope that the principles enunciated in your two proposed guide­lines can be fully satisfied but we do not have sufficient technical or operation­al information to accept these guidelines as program constraints at the present time.

The doctors had a point; it was pretty early in the program. Deke withdrew the memo, and the problems were worked out amicably. Not without a glitch or two along the way, however.

To: cb/Pete Conrad From: CB /Joe Kerwin

Subject: Medical Operations Requirements

DA memo of5-15-70 (on file) presents instrumentation requirements and guide­lines for Skylab…. Wearing of bio-harness during sleep is a new requirement, is not feasible or useful, and should be discouraged!

At about this time, the question of dental treatment on Skylab surfaced. The astronauts’ dentist, Dr. Bill Frome, recommended putting a dental kit onboard and training two men on each crew to use it, in light of his experience with astronaut patients. He argued that palliative treatment, even up to extracting an abscessed and painful tooth, was preferable to terminating a mission. Deke asked Kerwin to review it.

A one percent chance ofa serious dental problem on a 28-day mission is not sur­prising. That’s (28x 3 =) 84 man-days, which is onepercent of 8,400 man-days or 23 man-years. If we have 46 astronauts, one ofthem will need emergency den­tal care every six months — which matches Dr. Frome’s experience.

I have asked Dr. Frome to set up his proposed 1.5-day training program and run me through it as a guinea pig….

I believe that the right thing to do is to let them put the hardware on board, agree to train one of three crewmen (which cuts the risk but does not eliminate it) and reevaluate after the first mission.

“Management decided to go ahead and train two members of each crew, and we had a ball,” Kerwin said. “We traveled with Dr. Frome to San Anto­nio, to the U. S. Air Force Dental Clinic at Brooks afb. Bill and the den­tal staff had recruited a number of volunteers who needed to have a tooth extracted. (One of the first lessons was that you didn’t pull teeth, you extract­ed them.) So there we were, six of us, wielding syringes filled with xylocaine and wicked-looking dental forceps (and much more nervous than the patients were), getting those jaws numb and those molars out under the watchful eye of our dentist instructors.

“Paul Weitz drew a retired Air Force general. My patient’s molar broke in two during the procedure and had to come out in pieces. We were very glad when it was over. But I believe we could have done the deed in flight had we needed to. (We didn’t, and no dental emergencies arose during any mission.)

The dental kit became part of a medical kit for taking care of illness and injury aboard the Skylab space station. It was called the In-Flight Medical Support System. In retrospect, it looks like supplies for a pretty modest doc­tor’s office, but at the time it was quite a leap forward. It contained minor surgical instruments, a laryngoscope and tracheostomy kit, intravenous fluids, and lots of medications including injectables. Diagnostic equipment included equipment to make and examine blood smears and do cultures and antibiotic sensitivity tests on various body fluids. Kerwin, the doctor of the group who was quite familiar with the tools, was very much in favor of car­rying the equipment to Skylab. Some of the others, familiar with medical equipment primarily from being on the receiving end, were less so.

To: CA/Donald K. Slayton

From: CB/Joseph P. Kerwin

Subject: In-Flight Medical Support System (imss)

It’s clear from glancing through the list that this is mostly a doctor’s bag, not a first-aid kit. The document doesn’t say that, and it even proposes to train pilots to use all the equipment, which I find unrealistic. (Medschool was easy, but not that easy!) It’s also apparent that to justify the more elaborate equipment opera­tionally —from the standpoint of mission success— is darn near impossible. Major medical catastrophes just aren’t that much more likely to happen in eight weeks than they were in two. Minor illnesses are, but not heart attacks, etc… .

But that’s not the only point of view. Let me give, from my point of view, some reasons for carrying a doctor’s bag:

1. Up to now, the medical program has been unbalanced in the direction of pure research instead of treating illness and injury in space. This is a capa­bility we don’t need today, but we certainly will need it in space station times —for economic reasons at the least. It seems prudent to start using Skylab to develop equipment andprocedures to meet this need, just as we used Gemini to develop a rendezvous capability.

2. It’s true that a doctor isn’t mandatory on any Skylab flight. But if you do happen to have one along, you ought to allow him to do a little goodfor the program in his spare time by providing him with some of the tools of his trade. He could do an occasional physical exam on his buddies, and try out the simple laboratory tests on himself, by way of proving that they work. It would sure beat looking out the window.

In retrospect Kerwin found that last statement to be really dumb — noth­ing in Skylab beat looking out the window. But the In-Flight Medical Sup­port System was approved, and the same two crewmen who wielded the dental forceps were taught to use an otoscope and an ophthalmoscope, pal­pate and percuss, and report their findings to a doctor in Mission Control. “It was a wild experience for the pilots and a valuable refresher for me,” Ker­win said. “We were even taken to the trauma unit at Ben Taub Hospital in

Houston on a Friday night, where under the skilled tutelage of Dr. Pedro Rubio, the chief resident, we watched one of the best emergency medicine teams in America deal with life-threatening trauma and illness.”

Trauma training at Ben Taub Hospital proved a memorable experience for the astronauts. It was always scheduled on a Friday or Saturday evening when the probability of gunshot or knife wounds was apparently the high­est. Sure enough the crew saw their share but usually kept their distance from the emergency team engaged in what was a life-or-death procedure for some incoming patients. More relevant to their Skylab situation, they also had personal discussion and training with the experts in ear, nose, and throat; gastrointestinal tract; and eye and other specialties about how to handle in-flight emergencies. Even in these early days, they could expect to have experts in prompt voice contact and even with TV downlink to pro­vide images to the ground. So they ended up with reasonable confidence that most emergencies could be handled if they should arise.

The astronauts were also introduced to a fine team of consultants from the Houston medical community—specialists who would be on call dur­ing all the Skylab missions to advise the NASA flight surgeons should trou­ble arise in flight. Drs. Page Nelson, Hiram Warshaw, Everett Price, Kamal Sheena, and Jules Borger gave freely of their time and talent. Knowing they were there provided the crew with a feeling of security.

One of the best things to come out of the In-Flight Medical Support System, Kerwin said, was the checklist. Stimulated by the need to explain medical equipment and procedures to a bunch of pilots, the medical team linked up with the training team to produce a fine, very graphic, and explic­it manual showing with simple line drawings what everything looked like and what to do.

“We had one more treat in store,” Kerwin said. “Drunk with enthusiasm by the opportunity to experiment in space, the medical research team pushed for one final capability—to take and return blood samples. Not a big deal, you say; but it was, first because it had never been done before and second because it posed some hardware challenges in weightlessness.”

It was done. The crews agreed to give blood weekly; one member of each crew was trained to be the “vampire”; and an assortment of air-evacuat­ed tubes, a centrifuge to separate cells from plasma, and arrangements to freeze and return the samples were designed and flown. It all worked quite well. “I drew my own blood, not wanting to put Pete or Paul to the trouble of learning (and perhaps forgetting) how,” Kerwin said. “Pete hated being stuck and on the ground tended to become light-headed. But the blood couldn’t rush from your head in zero-G, so Pete was fine. He just looked away from the needle.”

The first crew, by benefit of being first and of having the physician of the group among its number, bore much of the hard work in planning for crew participation in the medical experiments (with a lot of help from Bill Thorn­ton, also a medical doctor and a Skylab guinea pig himself during simula­tions) . Therefore the training activity for the second and third crews fol­lowed much the same protocol as developed for the first flight team.

“Of course there were always some personal differences in practice,” Gar – riott said. “Whereas the first mission would have a doctor on board who knew the medical objectives and protocol in detail, as he had helped devise them, plus the fact that some of his other crewmembers were apparently not too enthusiastic about some of the procedures (e. g., blood draws), the sec­ond flight team all started substantially at the same level in terms of med­ical experience.”

Garriott described his crew with respect to the medical procedures as being all novices but with a keen interest in the protocol and personal results. No deference was provided to the scientist astronaut in this area, he said; everyone wanted to know about and participate in all that they could. They were all trained to draw blood and planned to do it in flight. They started with practice puncturing the skins of oranges or grapefruit with a hypoder­mic needle to simulate that of a human arm. Next came human volunteers, usually from life-science workers in the msc laboratories. As it turns out, there were more female than male volunteers (“Perhaps tougher constitu­tion, or more highly motivated?” Garriott remarked), and this often made the task more difficult—perhaps having less visible and accessible veins to attack. But all three of the crewmen successfully accomplished the blood draws a number of times, finally even drawing their fellow crewmen’s blood at least once. “It was good practice and we actually enjoyed the training,” Garriott said.

During flight all three crewmembers put their training into practice. Gar­riott routinely drew the blood of Bean and Lousma, while one or the oth­er would draw his blood on the desired schedule, every week or so. On one occasion in the middle of the crew’s two-month stay, the ground asked to have a video of the actual procedure. Lousma was scheduled to draw Gar – riott’s blood.

“We got all the cameras placed properly and the video recorder running for later dump to the ground,” Garriott said. “With all the paraphernalia in place, I bared my left arm, got the tourniquet tight, Jack made an excellent ‘stick,’ and the blood flowed freely just as desired. When finished, we with­drew the needle and blood promptly squirted all over the place! I had for­gotten to remove the tourniquet first and all the blood pressure trapped in the lower part of the arm took the path of least resistance into space. So we cleaned up the mess I had made, rewound the tape recorder and did it all over again using my right arm. The physicians on the ground seemed hap­py with the demonstration.”

The book that follows is a riveting, insightful account of the Skylab mis­sions flown by the United States in 1973 and 1974. It is also simply a great yarn. Skylab began as an underdog, was nearly knocked out several times, staggered back to its feet, and fought on against overwhelming odds until it became a champion. In a lot of ways, it was the Rocky of space, and just like the story in that great film, it is an inspiration for all who know it. The difference is the remarkable saga of Skylab is all true.

For those of us who are old hands at NASA and in the space business, it is sometimes easy to forget what a great adventure it was and still is. Ulti­mately when all the layered explanations of why we go into space are peeled away, adventure remains at its core. But adventure aside, there are many quite practical reasons to go off our home planet. For one, the solar system is awash in energy resources such as microwaves and solar energy, and even the helium-3 isotopes that cover our moon seem perfect for futuristic fusion reactors. For another, the absence of gravity might ultimately produce won­derful new products, even life-saving medicines. And where else but space can we go to get above our light and radio-wave-polluted Earth and gain unobstructed views of our sun, the solar system, and the universe? Space is a scientific gold mine, and I believe some day it will be an economic one as well. But to be successful in the cosmos, we have to first figure out how to get there and stay. In other words, we have to learn to homestead space. This book tells how we first began to understand how to do that, through the program known as Skylab. Although often neglected by spaceflight historians, Skylab provided the key to all human space activities that fol­lowed. Quite simply, it was the series of flights that proved to the world that humans could live and work for long periods in space.

I grew up in the golden era of science fiction where all the spacemen (and spacewomen, though often scantily clad) were stalwart and brave. They were sort of ingenious, techno-savvy Davy and Polly Crocketts conquer­ing the wild frontier while riding rockets. The robots in those tales were usually built only to help their humans through some difficulty (“Danger, Will Robinson!”), and the mightiest computer was the one every human had between his ears. If people were to explore space, they’d just have to go there themselves and have a look around. There was no other way. Not many of my favorite old-time writers guessed that by the time we were actu­ally able to go into space, there would be a revolution in robotics combined with minimizing the size and maximizing the capabilities of computers. The reality of early spaceflight (and that’s where we are now—very, very early) is that it is far easier, cheaper, and faster to send a robot than a human into space to explore and send back information on anything we please. But does that satisfy us? No indeed, and it shouldn’t. For instance, we are also perfectly capable of purchasing a video travelogue of Paris. From the com­fort of our living rooms, we can see the traffic passing beneath the Arc de Triomphe and the strollers along the Champs Elysees. But can we experi­ence Paris with a video? No. We can only get a sense of what it is like. We can’t look around a corner to see where some interesting alley might lead, or sit on a park bench and smell the aroma of fresh bread, or discover a new artist in the Louvre. It is the same for space. Ultimately to experience it, to gain from it all the riches it holds, the old sci-fi writers were correct. We humans must climb into pressurized containers and boldly rocket into the cosmic vacuum and there wrest from it with our own two hands all that it holds. In other words we still need spacefaring Meriwether Lewises and William Clarks off on bold adventures while accomplishing important sci­entific and economic work for the nation. The men and women who built and operated Skylab understood this and were determined to make such space accomplishments possible.

Skylab was designed to gain scientific knowledge in Earth orbit by utiliz­ing equipment originally designed to carry men to the moon and back. It could be fairly said that Skylab was built from the spare parts of the Apollo program. Accordingly it was often neglected while the moon shots got all the energy and money, but eventually its time in the sun came, and what a grand time it was! Looking back now it’s astonishing what we learned

from it. During its three crewed missions, a trove of scientific knowledge was harvested that is yet unmatched by any other space facility, including the International Space Station. Skylab’s huge volume, its well-constructed and considered scientific packages, its ability to generate more than ade­quate electrical power (after some emergency repairs!), and its focused crews made it, in my opinion, the finest comprehensive science and technological platform any country has ever sent into space. But I have to confess what I really, really like about Skylab is this: When it got into trouble, spacemen armed with wrenches, screwdrivers, and tin snips were sent up to fix it. No robots, no computers, no remotely controlled manipulating arms, just guys in suits carrying tools. The old sci-fi writers would have loved it!

Of course, with any space mission there is far more to the story than the spacecraft itself, or the crews. There must first be the visionaries who conceive the mission, then the politicians who must back it, followed by the armies of engineers, managers, accountants, and myriad other profes­sionals who make it all work on the ground before the first rocket engine is lit on the pad. As this book informs us, one of Skylab’s visionaries was a favorite of mine, none other than Dr. Wernher von Braun. In my mem­oir, Rocket Boys/October Sky, I told how when I was a teenager, more than anything in the world, I wanted to work for Dr. von Braun. In fact his bril­liance was the distant, flickering flame for all the rocket boys and girls of that era and the reason a lot of us became engineers and scientists. Part of the fun of this book is reading how Dr. von Braun just went ahead and did things, including building the giant Neutral Buoyancy Simulator (nbs) at Marshall Space Flight Center in Huntsville, Alabama. The nbs was a big tank of water that allowed astronauts and engineers to simulate the weight­less conditions of space. I am very appreciative that Dr. von Braun cut a few bureaucratic corners and built the nbs. Not only did his tank ultimately save Skylab, it also saved me when I suffered a bout of decompression sick­ness and had to be treated in its chamber. It was a great facility, although now sadly abandoned and fallen into disrepair. People ask me these days if I miss working for NASA. I do, sometimes, but mostly because I can’t dive in the grand old nbs.

Although Skylab was accomplished before I became a NASA engineer, I did work on similar space missions, including training astronauts to repair the Hubble Space Telescope. That was an intricate, difficult mission but we

knew we could do it because we had the example of Skylab’s repair. I also worked on Spacelab, which was a science laboratory carried in the Space Shuttle’s cargo bay. The Spacelab program, which proved to be a wonderful set of science missions, was profoundly affected by Skylab. Many times while working on a Spacelab situation, I heard, “Well, when I worked on Skylab, something like this happened and we. . .” Invariably the information given solved the problem we were working. One might suspect we Spacelabbers resented help from the old Skylab hands but not so. When there’s work to be done in the space business, listening to veterans who’ve already done it is a smart thing to do. I’m proud to say that’s what we did, at least on Spacelab and the Hubble Space Telescope repair missions.

I count as a good friend one of the authors of this book, astronaut Owen Garriott. With our friends and family, he and I have explored the Galapa­gos Islands and also hunted in Montana for dinosaur bones. It is fascinat­ing to read this book and see a somewhat younger Owen aboard Skylab. Actually, from this account, he hasn’t changed much. He’s still a detailed observer of his surroundings and an amazing fount of scientific knowledge. He is also quite competitive and intensely focused. In other words he’s chal­lenging to be around and, therefore, the kind of friend we should all culti­vate. Over the years I’ve also met all the other astronauts who flew on Sky­lab, plus backup Rusty Schweickart and Capcom (and future first Shuttle pilot) Bob Crippen. When October Sky the movie came out, I invited Pete Conrad to attend. I was gratified when he showed up for the premiere, and it didn’t take long before we were deep in conversation, mostly about Sky – lab and our mutual experiences in the nbs. While my agent kept tugging at my elbow (“Homer, Steven Spielberg wants to say hello!”), I kept fending him off. Finally, I turned and barked, “Look, don’t you understand? I’m talking to Pete Conrad!" My agent slunk off, and Pete and I finished our talk, one I still savor. I also once had Dr. Joe Kerwin turn up in one of my book-signing lines. I was astonished, though supremely pleased to see him there. I knew then I’d written a pretty good book.

The scientific and technological brilliance and love of adventure of all the Skylab astronauts were remarkable. This was also true of nearly all the people who worked on Skylab, such as Chuck Lewis, my former (and great, not to mention indulgent) boss at NASA, and Bob Schwinghamer who let me work in the nbs. Perhaps it was luck, or good fortune, but somehow the program got the people it needed and deserved. As a result, nearly every American-crewed mission since Skylab has been profoundly affected by the experiences gained by its nine crewmembers and the thousands of men and women who conceived, promoted, designed, constructed, rescued, and then made operational that magnificent facility. Just as the title of this book indi­cates, Skylab ultimately taught us how to make space our home. For a facil­ity partially built from spare parts, I think that’s prodigious!

The astronauts assigned to the flight crews were not the only ones having to train for the mission. In February 1972, over a year before the launch of the Skylab station, the Mission Control Center team began running their first simulations for the missions.

The long-duration aspect of the Skylab program presented new chal­lenges for the mcc team that would require advance preparation. On the ground every moment that the crews were in space, a team of people would be supporting them around the clock in Mission Control. In fact the control team would be operating Skylab even when the astronauts were not aboard it. And for the Mission Control team as much as for the astronauts, Skylab was a new spacecraft, completely unlike anything flown before, with its own unique parameters and requirements. In addition, the work the crews would be doing on Skylab would be unlike anything done in space before, so new procedures would have to be learned in order to support them.

According to Phil Shaffer, the lead flight director, operations control for Skylab was a mixture of old and new for the flight directors, with some elements being very similar to those in Apollo, and others being different from anything flown before. “The part that is similar to prior programs is that there was a trajectory function and there were the systems functions,” Shaffer said. “There was an electrical guy, a communications guy, there was an environmental guy, you know, each with their support staff and in that sense was all very similar. The manning level or the expertise requirement was the same as if we were doing a lunar mission.

“The teams, if you stood away a little ways, looked like Apollo teams or Gemini teams in the way they were structured because there was a flight director who literally was responsible for everything, there was a capsule communicator for air-to-ground voice, there was a surgeon, and there was a networks guy,” Shaffer said. “And all of those positions, you know some of them had slightly different names. Like gnc [guidance, navigation, and con­trol] for the csm was called gns [guidance navigation system] for the Sky – lab to distinguish different positions. Different names were required when both the csm and Skylab were up and active at the same time. There was a limited on-orbit team for when the csm was powered down. There were five on-orbit teams that did planning, preparation, and support execution for the experiments, evas, maintenance and repair, or whatever else was going on. These teams were led by [Phil] Shaffer, Don Puddy, Neil Hutchinson, Chuck Lewis, and Milt Windler. There was also a trajectory team led by Shaffer that was decidedly different from the on-orbit teams. It supported launch and rendezvous, and deorbit and entry, and maintaining orbital life­time by raising the vehicle orbital altitude. They did all those calculations. So, there were six teams: five on-orbit teams and one trajectory team, basi­cally, for the year of the program.”

Differences began with the launch. The crews flew into space on one space­craft that was essentially a taxi carrying them to another spacecraft where they would spend the bulk of their mission. “Another thing that was dif­ferent was having two very dissimilar vehicles, with some of the time both being active, so that you had two com guys and two environmental guys and two electrical guys on occasion,” Shaffer said. “Certainly until you got the Skylab powered-down for leaving or the Command Service Module pow­ered-down for the habitation period. The situation on Apollo was similar during the lunar-landing sequence with the Lunar Module and csm being involved. It was a bit of a zoo keeping all of that business straight.”

The attitude control systems for the massive Skylab space station were also very different from both a conceptual and an operational standpoint than any of their predecessors. “The new for Skylab was not new in name but new in type and that was an attitude control system with Control Moment Gyros [cmgs] ,” he said. “That was a whole new business in place of small rock­ets, reaction control thrusters, to control the attitude. You had these giant cmgs that were wonderful. The cmg system was assisted by a cold gas sys­tem called TACS [Thruster Attitude Control System].”

Attitude control—which basically amounts to which way the spacecraft is pointing—on Apollo was pretty straightforward, a basic application of Newton’s law that states for every action there is an equal and opposite reac­tion. That law is what allows rockets to travel through space, even though there is nothing there to push against. A rocket engine burns fuel to gener­ate thrust, and the action of the engine spewing flame backwards leads to the opposite reaction of the rocket moving forward. The same principle that pushes a large rocket through space also, on a much smaller scale, allowed the Apollo spacecraft to control its attitude. Rocket engines burned fuel, and the spacecraft turned in the opposite direction. The Skylab Thruster Attitude Control System took that simple concept and applied it in an even simpler way. Rather than burning fuel, the TACS simply vented cold gas into space. The action of the gas being vented produced the opposite reaction needed to control attitude.

The cmgs worked on a more arcane principle of physics—angular momen­tum. Tilting the spinning rotor of a Control Moment Gyroscope resulted in a torque that would rotate the entire station. Attitude control via cmg had the additional benefit for a long-duration mission of requiring no fuel, rely­ing instead on the power produced by Skylab’s solar panels.

In addition to the new attitude-control techniques, Shaffer said, new Mis­sion Control responsibilities were added to provide support for the science operations on Skylab. “And then there were the experiments,” he said. “We had a control function for Earth sensing. We had a control function for the celestial viewing. One looked up, the other one looked down. We had a con­trol function—a control position—for all the biomedical activity, a control function for materials science.”

While Mission Control had been involved in science support before, nota­bly during the lunar research during Apollo, Shaffer said that the support needed to coordinate the Skylab research was substantially more complex. For example, both Skylab and Apollo missions included making surface observations from orbit. Skylab had its Earth resources observation pack­age and Apollo carried equipment in the Service Module’s sim [Scientific Instrument Module] Bay that imaged the lunar surface. Although there was a general similarity in function, they were very different in operation. “The

Earth resources guy [in Mission Control], for instance, had a huge coordi­nation activity he did with the aircraft overflight, and with the ground truth people, and with the weather service going on with his planning. This was dramatically different from the equivalent function on Apollo. The guy in the Command Service Module was not running the sim Bay.”

Another change for Skylab that was worked out before flight was the real­time mission planning that would have to take place while the crews were in orbit. On prior missions extremely detailed plans were laid out ahead of time. On Skylab more activities were scheduled on a day-to-day basis dur­ing the mission. Every day the flight control teams would plan out what the crew would do the next day. “The evening shift did the detail preparation for the next workday’s activities,” Shaffer said. “The midnight shift did the overall plan for two days hence. And in part I think that was done to provide shelf life for both the support data that was going to go to the crew for the upcoming day and to give negotiation and preparation time for the struc­ture of the plan two days hence.”

That’s not to say no planning was done further ahead. Rough outlines of activities were put together for a week in advance, structured around such things as astronomical or Earth resources observations that were to be made. Since those had to take place at a very precise particular time, they were placed on the schedule first, and other activities that were more flexi­ble were filled in around them.

“All of that was all done by the time we entered the upcoming twenty – four-hour thing; then the remaining pieces were put in,” he said. “The sur­geons would have to get their requirements in. Life sciences was a really big deal, so significant effort was needed to get all of their activities in within their constraints. Vehicle maintenance had to be done, including servicing the atm and the associated eva activity. All of that got dropped into the plan. All of that happened on the evening shift. And that was new. The nearest thing to it may have been the lunar excursion planning activity while crews were on the lunar surface for two or three days. It evolved, and we all got really comfortable with it.”

There was some concern about why there had to be so many levels of advanced planning, but the system proved effective. Among its strengths was that getting a good bit of the planning done early freed up more time to react to any unexpected situations or to finish any previous scheduling that needed adjustment. “If we needed more time to get the detail flight plan support stuff ready for the crew, you had it,” Shaffer said. “There was basi­cally another whole shift available to finish up that work. And if something was wrong with your big plan for the day, then you had time to renegotiate whatever problems that created.”

Of course, no matter how much planning was done in advance, there were always times the plan had to be changed as new circumstances arose. “The classic case, to me, happened on one of my watches,” said Shaffer, “and it comes up under my title of‘surgeon’s rigidity and the bologna sandwich.’ A volcano in Central America decided serendipitously to start a major erup­tion while we were on orbit with all of our wonderful erep equipment. Of course the geologists and geophysicists were going nuts because it was an opportunity to use much of the erep sensor equipment we had to really get new and significant information about an erupting volcano that they had never had the opportunity to get before. It would be like looking ‘down the gun barrel’ right through clouds. They really wanted to do this.

“The conflict was that the orbit track that was going to go over the vol­cano happened during an already scheduled meal. The surgeon, because of his dietary scheduling requirements rigor declared that they were critical, and he couldn’t change the mealtime. That might change the digestive pro­cesses results, and there was no compromise for it. And I had a lot of sym­pathy for both parties, but here was a one-time event and we were going to be up there for many, many meals.

“Finally after much debate, I resurrected mission rule one dash whatev­er it is that says the flight director is in charge in real time. It means he can do whatever he needs to. So I decided to do it, and I told the surgeon on the loop that we are going to do the data take over the volcano, that his dietary concerns are not equal in terms of return. Plus, everybody knows ya’ll have the wrong diet. Everybody knows the best diet for in-flight work is a bolo­gna sandwich.

“The surgeon kind of imploded. I think he thought I had impugned him, and so he stopped objecting. We did the data take, and it was wonder­ful. Lunch was about a half-hour late. It was no big deal. I believed that. I believed it didn’t make any difference. We got all of that done.

“A curious thing happened the next day. When I came on shift there on my console was a bologna sandwich, which honest to goodness was a foot and a half long and six inches wide and had at least an inch of bologna in it. Nobody ever ’fessed up to where it came from. So I don’t know whether the surgeons did it or somebody who had heard the conversations. I always hoped that the surgeon did it. But it changed the dynamic. We got along better after that. Not a lot, but. . .”

During flight, this issue was greatly alleviated by the addition of another level of coordination within the science community. The initial structure in which the various disciplines each advocated their own concerns to Mis­sion Control was putting substantial strain on the flight directors, who had to weigh and balance those concerns. “So what we did was invent a tsar—a ‘science tsar,’” Shaffer explained. The first science tsar was Robert Park­er, a member of the second group of scientist astronauts. “At that point we refused to listen to all those people any more; we only listened to Robert. He brought the finished product into the planning shift, which we then imple­mented. That all worked well in the planning cycle, though it didn’t help a lot if you ran into something happening in a real-time conflict, because Robert wasn’t always available to us.”

At one point during Skylab mission preparations, Shaffer said, the ulti­mate authority of the flight director for dealing with real-time situations as they occurred was challenged by a visitor from NASA headquarters. “This is another one of those stories people don’t know anything about,” he said. “During the Skylab 2 sims [simulations], this guy showed up, badged and everything, and walked into the control center. Because I was launch flight director, I was running the sims.

“And he said, ‘Where’s my console?’” Shaffer said. “And I said, ‘Who are you?’ He said ‘I’m the mission management representative from Washing­ton.’ I said, ‘What do you do?’ And he says, ‘I am from NASA headquarters, and I have the final say in all of the decisions we’ll make in this program.’ And I said, ‘Well, I find that pretty interesting. I’ve never heard of you before, and there’s really no place in my flight control team for you to do that, par­ticularly during a dynamic phase. Frankly, you’ll be a lot more trouble than you’re worth no matter how good you are.’ And he says, ‘Be that as it may, I am here to stay.’ And I said, ‘Very well.’”

Shaffer said that he considered calling director for flight operations—and NASA’s first flight director—Chris Kraft to come deal with the situation, con­fident that the original “Flight” would back him up. However, he decided to try and handle the problem himself before resorting to calling for help. “I went back to my console and got on one of my secondary voice loops to the simulations supervisor, and said ‘I want you to give me the “Apollo tape case,”’” Shaffer said. “So Sim Sup says, ‘Why am I doing that?’ I said, ‘Because I’m asking you to.’ And he said, ‘I got it.’

“So he gave us that case and things really went to hell in a hand basket. The tape was the source for all the csm systems failure descriptions and data used for training simulations for the flight controllers and flight crews. We couldn’t tell where we were in orbit after the launch phase, communi­cation was really ratty, and there were electrical problems, computer prob­lems, etc. I unplugged and ran up to his console and said, ‘Tell me quick. . . what do I do now?’

“The guy looked at me, reached up, unplugged his communications set, got up, and walked out. We never saw him again during a dynamic flight phase.” On orbit however, his group was very active via an ad hoc organiza­tion called the Mission Management Team.

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]

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

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

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

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

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,

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.