Science on Skylab

Several books could be—and have been—written to summarize all of the scientific experiments performed on Skylab. Almost one hundred different pieces of experiment equipment were manifested for the original launch. Thousands of hours were spent on science. Tens of thousands of Earth obser­vation images were taken as well as over a hundred thousand solar astron­omy images.

The two fields that were Skylab’s greatest scientific legacy, as well as the ones requiring the largest time investments from its crews, were solar astronomy and life sciences in weightlessness. Research performed on Sky­lab would revolutionize both of these fields and would lay the groundwork for all that would come later.

Life Sciences

The Prologue: Early Spaceflight

Skylab was medicine’s first, best chance to unravel the mysteries of weight­lessness. Man’s ability to fly into space and to withstand the effects of being weightless had been matters of controversy since the very beginning of NASA. Opinions were all over the map. Some believed the experience would be pleasant and of no medical significance; the original astronauts were in this group. Others speculated that disruption would occur in many body sys­tems. Balance would go haywire without gravity to guide the inner ear; the heart would weaken; the passage of food “down” the digestive tract would suffer; urination might be impossible; and the isolation would induce a state of sensory deprivation, the “ breakoff phenomenon.” A lot of these hypothe­ses were published in medical journals, promoting the impression that space was dangerous and unknown.

The U. S. Air Force had begun to prepare itself to manage America’s manned space efforts, and this preparation included medical support. It was the unquestioned leader in the field of aerospace medicine with three

times the personnel and four times the budget of its closest competitor, the Navy. A distinguished German physician and physiologist, Hubertus Strug – hold, established in 1950 the first department of Space Medicine, at the U. S. Air Force School of Aviation Medicine. Other German scientists also did research for the Air Force.

NASA’s predecessor organization, the National Advisory Committee for Aeronautics, or naca, had no medical staff or expertise; all of its origi­nal experts were borrowed from the military. To provide medical support to Project Mercury, the Air Force contributed William Douglas, Stanley White, and Charles Berry; the Army, William Augerson; and the Navy, Robert Voas. These men brought with them the military method of qual­ifying humans for the stresses of flight. As aircraft flew faster and higher, pilot tolerance to and protection from acceleration, hypoxia, and disorien­tation had become major problems. The approach to solving them empha­sized testing and monitoring both in laboratories and in flight, an incre­mental increase in human exposure with healthy skilled test pilots, and very close liaison between medicine and engineering.

The academic community’s advice was quite different. It emphasized peer – reviewed scientific experiments by National Institutes of Health or univer­sity scientists and a great deal of animal research before exposing humans. The rationale was that the effects of spaceflight must be characterized and proven safe before people flew. Throughout the 1960s a continuous stream of criticism was heaped upon NASA by scientists: its programs were too ambi­tious, too rushed, not safe. One group insisted that NASA fly forty animals into space before committing to human flight.

Animals were the first to be sent into space. In December 1958 a squir­rel monkey named Old Reliable was launched in the nose cone of a Jupiter missile to an apogee of three hundred miles; it survived the launch, but the nose cone was lost upon reentry. In May 1959 a rhesus and a squirrel mon­key, Able and Baker, made the same trip and survived. Two chimpanzees, Ham and Enos, became the first animals to ride in Project Mercury cap­sules — Ham on a suborbital flight and Enos for two orbits. Both did fine. Mercury’s medical support group believed that these flights, plus the reports from the Soviet Union of a successful six-day Soviet flight of the dog Laika on Sputnik 2 in 1958 (though recent information indicates that Laika’s flight was far less successful that early reports would have had the world believe), showed that weightlessness was survivable, at least for short periods.

But biological scientists wanted still more. Led by Ames Research Cen­ter, they achieved NASA approval and funding for the Biosatellite project, which would launch and study various life forms on dedicated satellites. The first Biosatellite mission failed on launch. The second successfully flew plants and insects into space in September 1967. The third was to fly a ful­ly instrumented monkey, Bonnie, on a thirty-day mission to pave the way for the Skylab program.

Biosatellite 3 launched on 29 June 1969. The spacecraft was built by Gener­al Electric Reentry Systems Division at Philadelphia, weighed 1,550 pounds, and was launched on a Delta into a 240 nautical-mile circular orbit. Reen­try was commanded on the ninth day of the flight, on 7 July (just nine days before Apollo 11 launched to the moon). Bonnie was recovered but died less than half a day later.

Here is a letter on University of California, Los Angeles letterhead, to the editor of Science magazine, dated 14 August 1969. It’s a copy of a copy of the original. At top left someone has written, “This has been submitted to SCI­ENCE for publication although NASA objected to certain portions thereof.” And on the right the person wrote “slayton.”

It’s a lengthy letter. Here are a few excerpts:

The recent flight of Biosatellite iii with a male macaque monkey (Macaca nem – estrina) was the culmination of more than five years’ intense collaborative sci­entific effort. . . . The flight lasted only 8y ofa planned 30 days. . . . The phys­iologic deterioration of the monkey. . . is mainly attributed to the effects of weightlessness. . . .

The monkey was in excellent physical condition at the time oflaunch…. All physiological sensors functioned perfectly throughout the flight and after recov­ery. There were 33 channels of physiological information…. The range of these measurements in different body systems and their detailed character are with­out parallel in any single previous experiment on Earth or in space.

The last sentence had been underlined, and in Deke’s unmistakable hand was the comment, “That’s what killed him.” (Garriott joked that if the surgical preparations the monkey underwent, among the least violative of which included incisor tooth extraction and tail amputation, had been required for potential Skylab astronauts, NASA would have lost nine out of nine crewmembers.)

The letter goes on to describe the monkey’s gradual loss of responsiveness to tests; the drop in body temperature, heart rate, and blood pressure; the emergency reentry, and the death in Hawaii from a sudden heart arrhyth­mia after hours of emergency treatment. Now the investigators sum up:

The well-documented sequence of events leading to collapse in this monkey sug­gest the need for a guarded approach to design of missions for man that might involve extreme effort after a considerable exposure to weightlessness. . . the important findings listed above characterize this mission as highly successful. They also indicate the great value of carefully designed animal experiments… especially where the physiological sensors and required experimental control are difficult or impossible to secure in mannedflight. Sincerely, five scientists.

In the q&a session at a press conference, held 22 October 1969, Dr. W. Ross Adey, the principal investigator, was asked, “Why believe one bad result in a monkey instead of seventeen good ones in astronauts?” He replied that the astronauts didn’t do all that well, really—Dick Gordon never did get the tether attached (on Gemini 11), and he sweated profusely. Then the fol­lowing exchange occurred.

Question: To follow up Bill Hines’s question: might your experiments with this monkey indicate that monkeys are less adapted to spaceflight than men are?

Adey: Well, I think the question of individual susceptibility cannot be ruled out. After all, this is one monkey, and there are seventeen men. And here I would like to take off my hat as an experimenter and put on anoth­er one, as a member of the President’s Science Advisory Committee, which has had a medical group looking into the question of the biomedical foun­dations of manned spaceflight. And their advisory document to the Presi­dent has been released and is in the course of being published. And I would submit that the best considered opinion is that we do not now have the bio­medical basis for going ahead with the very elaborate programs proposed in the way of space platforms and space stations which involve major new engineering developments, and that the biomedical competence—or rather, the body of knowledge, as the report says—and I think I quote it correctly; it says that the necessary biomedical basis does not exist in NASA nor in the scientific community generally, and that it is not realistic to go ahead with the planning of major new space systems and exclude from almost any con­sideration the question of the biomedical capability of man to not merely

survive in space, which has been his requirement to this point, in essence, but to perform at a high level on a continuing basis.”

Kerwin recalled, “Well. That truly threw down the gauntlet to us Skylab types. None of us were thrilled to hear that the Apollo 11 mission had dem­onstrated mere survival. But clearly it was up to us to show that we could perform at a high level—on a continuing basis—while floating around. That we could brush our teeth, go to the bathroom, take spacewalks, yes, even (gasp) do science—just like Bonnie had.

“Chuck Berry’s response to the Biosatellite business was courageous and correct. He publicly and accurately identified the differences between the monkey’s circumstances and ours and judged Skylab to be safe. Given a lot of bedside hovering, of course. He’d put himself on the spot, and when things didn’t go perfectly early on in our mission, some medical pessimism returned.”

Meanwhile, those seventeen astronauts had flown into space for dura­tions that ranged from four and a half hours to fourteen days, and they’d all performed well and recovered quickly from any effects of the flights. There had been changes. There was weight loss, ranging upwards of ten pounds. There was loss of appetite and in some cases motion sickness. There was some muscle weakness after flight. Blood volume decreased, and a few astro­nauts had a tendency to be light-headed immediately after recovery. On one flight (Apollo 15, well after Biosatellite) there were disturbing heartbeat patterns in two crew members. Calcium excretion increased, and there was just a hint that bones might be losing structural strength. These gave rise to questions about the feasibility of long-duration spaceflight. Skylab was the place to answer them.