They're the ones thinking outside the space capsule.
- By James Oberg
- Air & Space magazine, November 2003
NASA Langley Research Center
(Page 2 of 5)
Early tests were encouraging. “I was amazed that a paraglider with a flexible canopy could fly so well at supersonic speeds,” Kinard recalls. “We did wind tunnel tests, and the [wing] fabric was like a piece of metal—no flutter, perfectly stable.” Flying at up to Mach 8 would generate heat from friction with air molecules, so the glider got a thin coating of silicone over its flexible Fiberglas fabric.
The actual flight of the IMP, on an Aerobee-150 sounding rocket in 1964, had mixed results. The paraglider inflated properly and collected meteoroid data. But the attached rocket nose cone failed to separate before reentry, so the glider began its descent through the atmosphere dragging an anchor. Amazingly, it righted itself and flew briefly, until the aerodynamic pressure got too high. At that point, one inflatable boom burst, probably from the stress of dragging the nose cone, and the IMP dropped to the desert like a wounded duck. It took days to find all the meteoroid collection panels that were torn off the wing as it fell.
So much for IMP. Scientists soon found another way to get micrometeoroid detectors into space—on test flights of Saturn boosters. But the idea of inflatable reentry vehicles had caught the imagination of engineers, including some outside NASA, who started musing about light craft that could make the return trip all the way from Earth orbit. “We did nothing intentional to inspire it,” Kinard says, “but we got lots of attention.”
One of those engineers was Robert Brodsky, who at the time was in charge of bringing in work to Aerojet-General’s Space General division, which had built the Aerobee rocket. Aerojet had designed the electronics and other systems for IMP, while B.F. Goodrich had built the structure. Even before IMP’s test flight, both companies started pushing the concept of inflatable reentry with their customers, primarily the Department of Defense. In the early 1960s, the Pentagon was flirting with developing its own astronaut program (see “A Sudden Loss of Altitude,” June/July 1998) and was interested in proposals for a small, storable craft that could return a person from orbit in a hurry.
“I got the idea that we could alter the IMP design sufficiently to turn it into a space lifeboat,” Brodsky says. He saw it as an option for dire emergencies only, like a life raft on an oceanliner.
“There were only two reactions,” Brodsky recalls. “Initially, sheer incredulity.
Then—seeing the challenge—great enthusiasm.” In 1962 the Air Force materials lab gave his company $250,000 to look into the concept; the funding later grew to $1 million. “In those days, that was a lot of money,” he says.
The project lead was Jesse (“Bud”) Keville, a 37-year-old engineer who set to work designing the lifeboat and building and testing components. Space General called it Project FIRST, for “Fabrication of Inflatable Reentry Structures for Test.” Keville’s team kept the basic IMP paraglider with its three inflatable struts, and placed a prone astronaut in the center strut. The lifeboat weighed a mere 850 pounds. Stowed on a spacecraft, it could fit in a threefoot by 10-foot cylinder; inflated, it was 23 feet long, with a wingspan of 28 feet. The engineers even came up with a deluxe three-person version, and a six-person model that weighed a ton.