While the crews trained and studied, their orbital station began to evolve slowly from concept to actual hardware. The project borrowed whatever ideas, equipment, and manpower it could from NASA (Congress more than once directed the two agencies not to duplicate efforts) and invented when necessary. McDonnell, for example, had to figure out how to move the crew from the Gemini capsule to the lab module after MOL reached orbit. The engineers tried various ideas—spacewalks, an inflatable crew transfer tunnel connecting the Gemini and module hatches, rotating the capsule to stick its nose into the module, like a bee’s into a flower, and cutting a 26-inch-diameter circular hatch in the Gemini capsule’s heatshield that the crew could float through. The last idea was selected provisionally, pending flight tests to determine whether a hatch in the heatshield would stay sealed during reentry.
The Gemini-B required other changes form the NASA version, which had first carried astronauts into orbit in March 1965. Retro-rockets and other equipment stuffed into a bay behind the shield were modified to accommodate the transfer hatch and MOL’s higher orbit. The capsule also had to be capable of restarting after its month-long sleep at the tip of the lab module.
At the time, the MOL lab module was the most spacious of any American spacecraft—about 400 cubic feet per astronaut. The arrangement was simple: two men in a can, with beds at one end, stores at the other, one wall for food and hygiene, one wall for work. Unlike the later Skylab, MOL had no shower. It would have felt roomy (“Zero-G really opens up the usable volume,” notes Fullerton) but spartan.
One of MOL’s main purposes was to solve the problems of living in space for extended periods—problems that had not been addressed by the short Mercury and Gemini flights. “There were a lot of people when the program first started that didn’t think man could survive for 30 days in space,” recalls Macleay. “They thought you’d come back jelly.”
The laboratory had to be self-sustaining for as long as 30 days at a time, and had to carry enough food, water, and other expendables to sustain two pilots. Early on, the MOL designers began favoring a two-gas atmosphere instead of pure oxygen for the crew to breathe, and they considered both nitrogen and helium as the second gas. Macleay remembers one of the more peculiar results of the oxygen-helium tests. If it had ended up as MOL’s atmosphere, he says, “your voice was going to sound like a duck’s.”
In the spring of 1966, the Army Corps of Engineers acquired almost 15,000 acres of ranch land abutting Vandenberg Air Force Base for its new Space Launch Complex 6. From SLC-6, the Air Force said, Titans could put into polar orbit vehicles weighing 15 tons—the weight of the MOL station.
And there was good news, for a change, from the defense department. McNamara told the House Armed Services Committee that MOL would get $159 million in fiscal year 1967, enough to keep things on track for a 1968 launch. Air Force pilots would be up there before NASA got to the moon.
The engineering side was looking up as well. On November 3, 1966, a Titan IIIC lifted off from Cape Kennedy carrying a modified Gemini capsule atop a mock MOL canister made from a Titan rocket stage. When the Gemini’s hatch was examined after an ocean recovery, concerns about a deadly hole in the heatshield vanished. In fact, the heat of reentry had welded he customized hatch shut. MOL seemed to be well in hand.
But in January 1967, a harbinger of trouble appeared. During ground tests at Cape Kennedy, a fire broke out inside the sealed Apollo 1 capsule, killing all three NASA astronauts on board. This meant a redesign for Apollo, but it also meant a costly reconfiguring of the Gemini-derived capsule used in MOL.
“The Apollo fire forced a review of all materials,” for fire resistance, says Lawyer. “There was a noncompetitive redesign of the vehicle. It cost a huge amount. Indirectly, the fire on the pad had one hell of an impact.”