Retro Rocketeers

If a capsule was good enough to get a crew to the moon, these old-timers say, it’s good enough to get a crew back to Earth.

Lockheed Martin has considered both lifting bodies and ballistic capsules for the proposed Crew Exploration Vehicle. The rounded capsule is shown attached to a service module, which provides propulsion. (Lockheed Martin)
Air & Space Magazine | Subscribe

(Continued from page 1)

The first task was to assess the Apollo command module as a possible lifeboat, or crew rescue vehicle, for the space station. That remains NASA’s most immediate need, since without it the station crew is limited to three people, the seating capacity of the Russian Soyuz craft. The second question was whether an Apollo capsule could serve as the proposed crew transfer vehicle, which was envisioned to launch from Earth on an expendable rocket, visit the space station, and return to Earth, possibly many times.

The team began by ticking off the Apollo design’s advantages. In their formal report, the members called the Apollo command and service module—the cramped three-person capsule plus the cylindrical module that provided propulsion and stored critical items like oxygen and fuel—a “highly successful, rugged, and robust system.” Compared with a vehicle like the shuttle, it was simple and well understood, which meant reduced risk. And only six weeks after the Columbia accident, risk was very much on the team members’ minds. “Everybody reacted that you’ve got to do everything you can to make the thing safe,” says Myers.

The idea of ransacking museums for actual leftover Apollo hardware was quickly discarded. None of it was thought to be usable, due to age, obsolescence, lack of traceability of the parts, or water immersion—the capsules had come down in the ocean. But the team just as quickly concluded that a rebuilt command module would work well for the first, and simpler, of the two roles—the space station lifeboat. Even without the service module, the command module could accommodate at least four astronauts and enough air and other supplies for a bailout mission.

The vehicle could even grow slightly larger than the 1960s model. “If the CM were scaled up by 5–8%,” said the group in its report, “a crew of 6-7 might be accommodated in a self-contained vehicle.” The only things that would have to be built new were a propulsion module for leaving orbit and a docking adapter for the station.

But there was a limit to scaling up, says Szalai. You didn’t want to make the capsule so big that you strayed from the design that had been so thoroughly tested during the Apollo program. Remaining within that envelope also enabled you to keep the parachute and launch pad escape systems used for the lunar missions.

Whatever data the team members needed for their analysis, they mostly had in their heads. Brand brought along “some stuff about the Skylab rescue mission,” and Cohen had “a few thought-joggers, like Apollo dimensions and weights.” But, recalls Szalai, “the amazing thing is, nobody referred to notes. The things that are most important to you are burned into your brain.”

To keep the stretched Apollo capsule from getting too heavy, the group counted on 40 years of progress in lightweight composite materials. And even though upgrading to a station-compatible cabin air pressure of 15 pounds per square inch, three times Apollo’s pressure, would add weight, that wasn’t considered to be an insurmountable problem.

This was only the basic vessel, though. Inside the roomier command module, practically nothing would remain the same. “Virtually every system would have to be redesigned, even if it were decided to be replicated,” the group concluded in its report. “Entirely new electronics systems and displays will be required.”

Szalai recalls wondering, “Could you use any of the [old] hardware? We spent a few hours, system by system. None of it was supportable; vendors were long out of business. Could we even use the seat? No, we knew how to build better ones now.” One item did survive, though. The Apollo hand controller, used for pilot inputs, could “probably be replicated,” the report stated, although the software that ran it would have to be rewritten from scratch.

“By the end of the first day,” Szalai recalls, “we knew where we were going.” The team disbanded for the evening, some heading to the homes of relatives, some to dinner (and further discussions) at their hotel. The next morning, they turned to Apollo’s landing method, the classic splashdown. Here the group departed from tradition: They agreed that there is an advantage in coming down on dry land: After all, the Russians had been doing this for years with Soyuz capsules (see “Aiming for Arkalyk,” Aug./Sept. 1998). Dry landings would eliminate the expense of rescue ships but would require the engineering of new descent hardware.

Comment on this Story

comments powered by Disqus