From the Ground Up

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

Almost immediately, he ran into problems.

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

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

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

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

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

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

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

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

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

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

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

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

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