NASA exec suggests some ways to build a better shuttle
X-34 and X-37 prototypes showcased at the National Space Symposium
COLORADO SPRINGS, Colorado (CNN) -- The next generation of space shuttles may utilize such futuristic technologies as magnetic levitation launchers, self-healing thermal parts and solar powered propulsion systems, the director of NASA's Marshall Space Flight Center said Thursday.
In his keynote address to space industry leaders at the National Space Symposium, the man most responsible for getting present-day space shuttles into orbit seemed eager for the future to arrive.
But don't get Art Stephenson wrong. He thinks the space shuttle has performed well during almost 20 years of service. He praised the spacecraft for its dependability and versatility.
"What other vehicle can make house calls to the Hubble (observatory) and map the world?" he asked, alluding to recent shuttle success stories.
'Shuttle hugging' not worth its weight in gold
The aging workhorses are expected to remain the sole U.S. manned launch vehicles for years to come, thanks to some $100 million in planned upgrades over the next five years.
But "shuttle hugging" comes at a price, Stephenson said. A liftoff costs about $400 million, meaning the payload cost runs about $10,000 a pound.
"If we took the shuttle up, loaded the bay with gold, it wouldn't be worth the trip," he said. "The high cost of launch is holding up the exploration of space."
Stephenson, whose Huntsville, Alabama-based office manages the propulsion systems for the shuttle, wants manned a launch vehicles 10 times as cheap as the shuttle.
Spacecraft parts that could heal themselves
NASA's Art Stephenson doesn't want to be a 'shuttle hugger'
Toward that end, Marshall center engineers are working feverishly to develop cutting-edge technologies, such as magnetic levitating sleds that could be used to launch the next generation of manned orbiters.
Another NASA facility researches self-healing thermal systems. "If it's damaged, it foams up and replaces material that is lost," he said.
Marshall engineers also are working to develop so-called "air-breathing" rocket engines that inhale oxygen from the air during liftoff. That reduces the vehicle's fuel weight at launch, resulting in significant cost savings.
Other futuristic technologies on the Marshall drawing board include a solar propulsion system and pulse detonation engines.
Working to reduce disaster odds
Besides cost savings, new shuttle technologies must offer improved space travel safety, said Stephenson, who wants the next generation of "human-rigged" launch vehicles to reduce the risk of catastrophic launches by a factor of 10.
Every time a shuttle goes up, there is a one in 450 chance of disaster, Stephenson said. The upgrades should cut that risk in half. Still, flying the shuttle will remain a risky business, in particular because of the awesome power of the launch rockets.
"The speed of gas out of solid rocket booster is three times the speed of a bullet," Stephenson said. "And the temperatures are hot enough to melt solid steel."
Stephenson frets that today's shuttle crews lack a means of escape from the shuttle in the event something goes wrong during a launch.
"The solid rocket boosters can't stop. You can't think of turning around. One strike and you're out."
The next generation of spacecraft should allow astronauts to abort a takeoff, like airline pilots, he said. And they should give the crew a "more robust re-entry system" in case emergencies arise.
NASA has suffered numerous technological pitfalls in developing the X-series vehicles, a fleet of prototype shuttle replacements. And Stephenson acknowledges that some advances could take 40 years to come to fruition, if ever. But he hopes NASA can start using some of them within a decade's time.
The mag-lev sled, for example, "is a technology we think can be demonstrated in five years, if we get the funding we are talking about, and be operational in ten years."
Stephenson, the former president of Houston-based Oceaneering Advanced Technologies, was named director of the Marshall Space Flight Center in 1998.
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NASA's Marshall Space Flight Center
U.S. Space Foundation
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