International Space Station I 20th Anniversary
DESIGN AND ASSEMBLY OF THE INTERNATIONAL SPACE STATION
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ometime around 1985, just after the Reagan administration had given the green light for NASA to build a space station in low-Earth orbit, in Building 15 at the Johnson Space Center, engineers were assembling a mockup of one of the station’s modules. The model, built specifically to fit into the payload bay of a Space Shuttle orbiter, looked a lot like the reusable Spacelab modules supplied by the European Space Agency, with lots of systems packed into the floor and equipment racks along the walls. “The module was around 47 feet long,” said Gary Kitmacher, who was then an architectural manager for the Man-Systems Division of NASA’s Life Sciences Directorate, “and there were hatches on either end and four hatches around the outer part on one of the ends. We called that the Common Module. Most people thought that was the best way to build a module, and that’s what we started out with.” As it turned out, the model being put together in Houston wasn’t quite the best NASA could do, but it was an improvement over the living/working quarters aboard Skylab, the only American space station to date. Skylab astronauts, including Gerald Carr, Bill Pogue, and Ed Gibson, had consulted on the design of habitable spaces for a new station. Skylab, whose Orbital Workshop compartment had been built inside a repurposed Saturn V rocket stage, was relatively roomy, at approximately 21 feet across and 48 feet long, a habitable volume of about 10,664 cubic feet. With the Multiple Docking Adapter and Airlock Module included, habitable volume grew to
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12,417 cubic feet. Overall length with the Apollo Command/Service Module docked was a little over 118 feet. Inside, the workshop was divided into two stories, stacked along the tube’s longer axis. The ceiling of the “upper” deck opened into an airlock module, which connected to a docking adapter, which in turn connected to the vehicle the astronauts had used to travel to the station: the Apollo Command/Service Module (CSM). “We learned some surprising things from the Skylab astronauts,” said Kitmacher, who is now manager of International Space Station Education and Communications. “One was that they were fine with being weightless, with floating around in zero g, but they really wanted a constant up-and-down orientation – and they wanted ‘down’ to be toward the Earth, by the way.” Many NASA engineers, who didn’t see the point of the concept of an up or down in space, were surprised. The Skylab workshop had an up-down orientation, but the docking adapter didn’t, and was completely disorienting to the astronauts. The CSM – whose interior, when docked at the station, was clearly visible – had a vertical orientation completely opposite that of the workshop. Aerospace engineers in general tended to dismiss such concerns as irrelevant. Early space programs, such as Mercury and Gemini, had focused on the significant challenges of safety and survivability. But the long-term occupation of a space environment by a “microsociety” of people living and working together in confined quarters raised important psychosocial issues. NASA project leaders had
NASA image
BY CRAIG COLLINS
