Pod People

They’re the ones thinking outside the space capsule.

Air & Space Magazine | Subscribe

(Continued from page 3)

But as days passed without an actual recovery, Russian launch officials were forced to fess up: The 540-pound probe was lost. Accident investigators later determined that Demonstrator 2 had detached from its rocket too early, at around the time Volna’s second stage separated. “Because of the uncontrolled detachment,” their report concluded, “no conclusions can be drawn on its further behavior and on any performance aspects.”

That leaves the IRDT hardware still unvalidated after three tests. Project engineers have made a few minor fixes to their design and plan to try again next spring. So far, they’ve seen nothing that tells them the basic concept won’t work. Astrium (now part of European aerospace giant EADS) and Babakin have even formed a joint stock company, Return and Rescue Space Systems, to produce and sell inflatable reentry systems. But after the loss of Demonstrator 2, Helmut Hoffman, head of the company’s Russian office, told the Russian magazine ITOGI: “The question of the project’s future financing will depend on the test results.”

The IRDT’s designers have a range of applications and spinoffs in mind for the new vehicle, if it can be made to work. Besides returning cargo from the space station, it could be used for jumping out of burning skyscrapers. And Dieter Kassing, ESA’s IRDT program manager, has raised even more interesting possibilities: Talking to reporters following the failed 2002 test, he said, “I can imagine that this technology also could possibly be used for some sort of emergency and rescue mission for humans” in space.

In recent years, the notion of jumping from an orbiting spacecraft has been discussed only as an extreme sport. Rick Tumlinson, president of the California-based Space Frontier Foundation, calls it “orbital surfing.” Bevin McKinney, an engineer who worked on the privately funded (and now-abandoned) Rotary Rocket concept in the 1990s, has also tinkered with designs for an orbital escape system. His proposal involves a large parachute-shaped aerobrake made of ceramic fibers, plus an inflated heat shield in front of the astronaut’s body. “The trick is to come down very slowly from high altitude,” he told a reporter for a skydiving newsletter in 2001.

Among those pushing for a space bailout capability is Robert Kendall Jr., son of the Douglas engineer who worked on Paracone in the 1960s. Together with his father, who retired in 1976, Kendall Jr. has patented several designs for inflatable air-drop systems. Department of Defense contracts on unrelated technologies kept the father-son team busy in the 1990s, but they continued to publish scientific papers advocating the use of inflatables for orbital reentry. Several years ago, says Kendall Sr., “we submitted a proposal [to the Air Force] to recover satellites, astronauts, microgravity experiments, and reusable launch vehicle components.” They even proposed a test flight to return an instrument-equipped mannequin from orbit to a designated site on the ground. No one was interested enough to fund it.

Some aficionados of personal bailout systems still hold out hope that NASA will one day look in their direction. But so far, the agency’s plans for a rescue vehicle for space station crews appear not to include one-person lifeboats.

FIRST designer Robert Brodsky still talks up the idea to pretty much anyone who will listen. He accuses NASA of being close-minded on the subject of inflatable reentry vehicles. “Lack of a mission need stopped the program in the ’60s,” he says. “But ‘not invented here’ in NASA is stopping it these days.” Several years ago, he proposed that the agency update the old FIRST concept as a crew return vehicle, or CRV, for the space station. “They patted me gently on the head, because their idea of a space lifeboat is radically and very expensively different from mine,” he says.

John Muratore, who until recently managed NASA’s CRV program at Houston’s Johnson Space Center, denies that the agency turned a blind eye to inflatables. “It’s an interesting technology, and we have looked at it,” he says. The problem, he says, is that “you chase a weight curve. You add weight to [withstand stress], so the heating goes up, and the vehicle gets bigger and heavier.” His team studied a dozen designs and did a deep literature search. They heard from the inflatable backers. They just weren’t convinced.

All of which leaves Brodsky, Kendall, and the other pioneers of inflatable concepts where they’ve always been. Despite the technology’s interesting past and its promise for the future, it still doesn’t have a great present.

Stephan Walther, the managing director of Return and Rescue Space Systems in Bremen, Germany, hopes that will begin to change with next year’s test of the IRDT, and that a string of successes will eventually persuade ESA to pay for a full-up cargo system. As for inflatable lifeboats, “I’m personally convinced it’s possible,” he says, but adds that it will take a lot more research and engineering development before people are willing, literally, to climb on board.

Comment on this Story

comments powered by Disqus