Astronauts on Tuesday retrieved a 2,000-pound satellite they set free from space shuttle Endeavour to test a huge inflatable antenna.
The spacecraft, released by the six-man crew Monday, served as a platform for the experimental antenna, which expanded to the size of a tennis court when it was pumped with nitrogen gas.Tiny explosives set off by a timer severed the silvery antenna from the satellite about an hour later. Depending on your point of view, the antenna looked like a flat parachute or a round trampoline on an upside-down tripod.
The giant orbiting balloon was expected to plummet through the atmosphere and burn up Tuesday afternoon.
Canadian astronaut Marc Gar-neau used the shuttle robot arm to grab the satellite 176 miles above Earth. The satellite contains all the data from the $14 million antenna experiment.
"Congratulations, Marc. Nice job," Mission Control told Gar-neau.
Whether the thin, Mylar antenna inflated properly won't be known for certain until the shuttle returns to Earth with the satellite next week. The balloon appeared to extend to its full size of nearly 50 feet in diameter and struts 92 feet long.
The antenna, which had noticeable rippling across its surface, rotated more than expected and even began to tumble.
"But I'd say even in the worst case from what we've seen, it was very close to a full success," said project manager Steven Bard of NASA's Jet Propulsion Laboratory in Pasadena, Calif.
The antenna did not broadcast any signals. NASA simply wanted to demonstrate the technology of using inflatables - lighter and cheaper than traditional mechanical systems - to place large objects such as antennas, sun shades and solar collectors in space.
"We really think we took a giant step," Bard said. "We really showed that you can inflate such a large structure like this."
More tests are needed, however, before equipping spacecraft with inflatable parts. Erratic motion like tumbling and rippling, for instance, would make any antenna pretty useless.