By the beginning of the 1970s, sideburns and hair were growing steadily longer, but NASA’s ability to execute longer space missions had experienced stunted growth. None of the Apollo lunar voyages were expected to spend more than two weeks away from Earth and the longest single American flight – Gemini VII in December 1965 – had lasted a little under 14 days. With the Skylab space station, it was hoped to press the envelope by having three teams of astronauts spend between one and three months in orbit. The Soviets had gotten the long-duration ball rolling, with an 18-day Soyuz mission in June 1970 and a three-week flight to their Salyut 1 station in the summer of the following year. It was already known that spending months of isolation in the most hostile environment ever visited would demand intense physical and psychological preparedness…and NASA decided that the best way to achieve that preparedness was by running a space station on the ground.
Plans for such a mission were laid in August 1970 between Dale Myers, NASA’s associate administrator for manned spaceflight, and Bob Gilruth, the head of the Manned Spacecraft Center in Houston, later to become the Johnson Space Center. They were responding to concern from physicians that microbial populations might experience changes with three men confined in close quarters, which might cause flare-ups of bacterial infection. Within weeks, a test plan had been formulated. It focused on experiment procedures, a functional evaluation of Skylab equipment and providing baseline medical data.
Original hopes to use two full-size Skylab mock-ups were too expensive and it was decided to run the test in the Crew Systems Division’s altitude chamber, located in Building 7 at the Manned Spacecraft Center. Early plans called for a 28-day test in September 1971 and a 56-day run, beginning in November. Each one would feature the operation of Skylab experiments, primarily medical in nature, including lower-body negative pressure, blood volume and body mass, vestibular function, metabolic activity and mineral balance. Two teams of volunteers (not necessarily astronauts) would participate in the tests, which were designed to mimic conditions aboard Skylab as closely as possible. Following the extraction of the first ‘crew’ from the chamber, a 30-day debriefing was planned. Its results would help to prepare the second crew for their mission. These mock ‘flights’ would be known as the Skylab Medical Experiments Altitude Test (SMEAT).
The chamber itself had already been extensively man-rated. More than 20 feet in diameter and 20 feet high, it was a two-floored stainless steel structure with more than a dozen viewing ports, several penetration bulkheads and a pair of airlocks. It contained closed-circuit television equipment and a closed-loop system to heat or cool its oxygen-nitrogen atmosphere, together with channels for communications, lighting, oxygen supplies and fire suppression systems. For the purposes of SMEAT, only one floor would be used, although the other was available for relaxation. The wardroom and waste management facilities were partitioned, as they would be on Skylab, but the remainder of the chamber was modified to accomplish the medical objectives. Simulated lighting, caution-and-warning devices and communications (through a Capcom and, due to the limitations of tracking, available only 20 percent of the time) added to the sense of realism.
In December 1970, the 28-day test was dropped and it was decided to perform a single, 56-day evaluation. Original plans to use volunteers were dropped in favour of astronauts and Bob Crippen, Karol ‘Bo’ Bobko and physician Bill Thornton were selected in June 1971 for a scheduled start date in July of the following year. In fact, NASA’s formal report on SMEAT, published in October 1973, noted that the “use of astronauts was considered desirable, since this would [ensure] a general comparability of background, skills and motivation…[with] subsequent Skylab crews”. In a NASA oral history interview, Bobko recalled that the ‘selection’ actually came from a drawing of straws, whilst Crippen felt that SMEAT was “the best job available” to an astronaut who was years away from a real flight. For his part, Thornton had already worked on Skylab – he was one of the principal investigators for its small-mass measurement device, to be used for weighing specimens in flight – and his two comrades had previously worked on the Air Force’s Manned Orbiting Laboratory project before joining NASA. Consequently, all three had experience in the station design process.
During the year before the test, Crippen, Thornton and Bobko participated in the design and layout of the SMEAT chamber and began practicing with the medical equipment in the spring of 1972. In a very real sense, their training regime matched the actual training of a Skylab crew, with equipment and maintenance briefings, bench checks, crew compartment fit and function tests and summaries of emergency procedures. Field trips to Air Force medical installations and regional hospitals offered them a thorough understanding of diseases of the eyes, head, cardiovascular, pulmonary and musculoskeletal systems and even gave them the chance to practice treatments. During the course of that year, each man spent in excess of 500 hours training for SMEAT, more than a hundred more than scheduled.
Their preparation for ‘medical emergencies’ even included dental work. “The plan was…to make sure that the crews could deal with…minor medical emergencies,” recalled Crippen in his NASA oral history, “and part of that was to send us off to dentistry school. We ended up in San Antonio at the Air Force hospital.”
On one occasion, a young man in his late teens came to see them. His teeth were in terrible shape. Two needed to be extracted and Crippen and Bobko asked the dentist if he was going to remove them.
“No,” came the reply. “You guys can do it.”
The astronauts exchanged glances. The patient looked nervous.
“But I did the novocaine with the needle,” Crippen recalled, “and Bo flipped the tooth out, because it wasn’t in very firmly.”
The response from their patient?
“You guys are the best dentists I’ve ever been to!”
Crippen and Bobko kept quiet. The last thing they wanted to announce was that they were both military test pilots will absolutely no background in dentistry…
Other practice was less satisfying, including CPR on a ‘Resuscitation Annie’ dummy. When Crippen’s turn came, he thumped the palm of his hand hard onto the dummy’s chest…so hard, in fact, that he broke his fifth metacarpal! “Everybody concluded they didn’t want to have a heart attack with me around,” he mused later.
On the morning of the SMEAT start date, 26 July 1972, Crippen, Thornton and Bobko underwent a medical examination and pre-breathing to purge nitrogen from their bloodstreams. (Crippen later recalled that these preparations were actually worse than the test itself.) Inside the chamber, one of their earliest observations was that the reduced-pressure atmosphere caused sound to appear further away and somewhat softer, requiring them to shout and becoming hoarse in the first few days. Also connected to the pressure was an inability to whistle, a temporary increase in abdominal gas and severe flatulence and a noticeable mildness of sneezing. Typical daily routines involved reveille at seven in the morning, work from nine until one in the afternoon, followed by a second work period from two until seven, after which they ate dinner. A review of their activities and 30 minutes of housekeeping capped off each day and after two hours of ‘personal recreation’ they bedded down at eleven each evening.
For recreation, Crippen and Bobko – who were, by now, also preparing to serve as support crew members on the Apollo-Soyuz mission – brushed up their Russian language skills. They also completed a training course on the Apollo command and service module, via a closed-circuit television link, and even did electronics courses, solar physics courses and commercial pilots’ study courses. It was their choice before entering the SMEAT chamber that they would fill their spare time in a ‘useful’ way…
Not all went to plan and problems with the bicycle ergometer caused it to quickly break down, prompting the crew to pass it out through the main airlock for repair. The urine system also leaked. “Most of us, and probably most of the Skylab guys, drank a lot of liquids,” Bobko said later, “and so produced more urine than they had anticipated and…[so they] collected the urine in a bag and homogenised that and took a sample off and froze it. Well, what would happen is that at two o’clock in the morning, you get up and the bag would be full…and so, here you are, just kind of groggy out of bed and have to change it out and the bags were not very strong. There was an occasion when we dropped one and it broke. You know how messy it is to drop a half-gallon of milk on the floor. You can imagine!” Humour aside, with the ‘real’ Skylab launch scheduled for May 1973, cleaning the urine spills took the men at least an hour. This was unacceptable, not least because hand-washing facilities and the availability of disinfectants aboard the workshop would be insufficient.
Life aboard SMEAT was by no means luxurious – the astronauts’ main comfort came from a set of sun-loungers, which they assembled each evening – and they found themselves surrendering much time to cleaning the toilet, the work area and the floors. A simulated Skylab shower was “delightful” to use, once every week, with all three men showering on the same day. Meals were typical Skylab fare: small cans which fitted into food trays with built-in heating elements. Strict recording of body intakes and wastes and blood samples were religiously kept for the medical experiments.
Yet, psychologically, they managed to maintain good relationships with each other and with the support staff, through a system of ‘gotchas’. One dastardly plan involved a handful of meat-free chicken bones, smuggled into the chamber…and a few collected hairballs of lint from their suits. The three men had become tired of the strict protocol associated with the medical experiments and felt that a few laughs would be triggered by creating the impression that they were not alone inside SMEAT. Their plan was to leave the chicken bones and a few hairballs on a used meal tray, pass it through the airlock, with a note telling the doctor how much the ‘cat’ had enjoyed the fresh meat…
Unfortunately, time constraints meant they could not execute the plan, but had the gotcha taken place the look of sheer horror on the test conductors’ faces, as several weeks of intense medical protocol were seemingly ruined, would certainly have been golden.
Leaving the chamber on 20 September 1972 – with Crippen and Bobko both sporting full beards – the men were full of praise for SMEAT. The mission had been an essential test of the requirements for long-duration missions – missions which continue to be performed aboard today’s International Space Station. Yet the medical experiments were the bane of the three men’s daily lives. Crippen, Thornton and Bobko actually produced a comical mission patch, with the dog Snoopy as its centrepiece, restrained by a particularly nasty leash to signify their torment. Their uncomfortable two months in the SMEAT chamber was dirty, smelly and frequently unglamorous…but provided crucial data to make the future Skylab missions infinitely more bearable.
This is part of a series of History articles which will appear each weekend, barring any major news stories. Tomorrow’s article will focus upon the C-Prime Decision: the audacious plan, in August 1968, to send the first men to the Moon.
Great article! You didn’t mention that Bill Thornton also worked on MOL while he was in the Air Force, before he was selected by NASA. I don’t know whether he crossed paths with Crippen and Bobko then. But his MOL work included developing the body mass measurement device and the specimen mass measurement device that flew on Skylab.