EDWARDS AIR FORCE BASE — The prototype of the world's first space ambulance, designed to provide emergency escapes for the crews of the International Space Station after it goes into Earth orbit, made its debut flight Thursday morning.
The X-38--a whale-shaped, wingless vehicle with fins that look as if they were inspired by a 1956 Cadillac--is the first new spacecraft to reach the flight testing stage since the space shuttle was developed more than two decades ago.
The craft is meant to bring the space station's crew safely back to Earth in any emergency in which there is not enough time to launch a shuttle to collect them.
The windowless, pilotless craft is designed to be fully automated, so that even badly injured crew members could climb in, separate from the station, and the vehicle would then serve as an ambulance, using satellite-based navigation aids to carry them back to one of several designated landing fields on Earth with no further effort on their part.
Thursday's unmanned X-38 mission, during which a fiberglass prototype 80% the size of the spacecraft was dropped from under the wing of a B-52 bomber 23,000 feet above Edwards Air Force Base, featured only about four seconds of free flight.
NASA officials said the mission was aimed primarily at testing the parachute system, steering mechanisms and landing apparatus.
Although the seven-minute flight was not free of glitches--a twist in the main parachute's lines caused several anxious seconds among onlookers before the chute fully unfurled--the X-38 landed relatively softly in the desert northeast of Lancaster and less than 1,000 feet off target.
"This is a 10," exulted mission director John Muratore after the flight.
Muratore, who works at Johnson Space Center in Houston, is credited with the idea of combining two aviation technologies--lifting bodies and advanced parachute design--to come up with an emergency vehicle that can be built at a cost far below original estimates of $2 billion.
At this point, NASA has spent about $10 million on the X-38. The budget for completion of the project, including building four of the fully outfitted spacecraft, is about $500 million.
In an emergency, the craft would leave orbit and use the lifting body technology as it entered the upper atmosphere. The flat under-surface of the X-38 would serve as a heat shield during reentry and then generate lift for an unpowered glide through the upper atmosphere, like an airplane wing--much as the bottom of the space shuttle does. At 50,000 feet, the chutes would be deployed.
Muratore said this first flight, after three years of development, "was not quite as clean as we would have liked . . . but that's the purpose of testing--to refine everything more and more as we go along."
Besides being elated, he was obviously relieved.
"Parachute testing is tough," he said, "because when things go bad, it's pretty spectacular."
About 20 more tests of X-38 prototypes will be conducted at Edwards Air Force over the next several years. If all goes according to plan, an X-38 with the capacity to carry the entire seven-person crew of the space station will be fully operational in 2003. It will be transported to the space station by a space shuttle.
The space station will be inhabited before then by construction crews, who will be provided with a Russian Soyuz escape capsule for emergencies until the X-38 is ready. A Soyuz is routinely parked on the troubled Russian Mir space station for that purpose.
For the Thursday test, the prototype was attached to the bottom right wing of the B-52. Moments before takeoff, veteran astronaut John Young--who walked on the moon during the Apollo program and was command pilot in 1981 of the first shuttle flight in space--purposefully strode out onto the dirt edges of the runway. A NASA official quickly retrieved him and brought him back to the VIP viewing area.
"I was just checking out the runway," an unrepentant Young explained, knocking the desert soil off his shoes. "They did a good job packing it down."
Almost exactly on schedule about 7:30 a.m., the B-52 took off. About an hour later, the X-38 was released.
The last of three chutes, making its appearance about 1 1/2 minutes into the test, was a brightly colored, rectangular parafoil--a highly maneuverable parachute--capable of making pinpoint, soft landings.
Shortly after it was deployed, NASA personnel watching on large video screens at Dryden Flight Research Center--the NASA facility at Edwards--began expressing concern. "That doesn't look right," said one.
The twisted lines had prevented it from reaching full wingspan.
"Not good, not good," repeated another NASA worker, softly, several times.
"I think we all had a little adrenaline going," Muratore said later.
Muratore could have deployed a backup parafoil at that point, but decided instead to give the X-38 the chance to resolve the situation on its own.
Apparently it did just that, because suddenly the parafoil blossomed to its full, 7,350 square foot size.