Japanese May Lose Hayabusa Spacecraft
Thursday, December 1, 2005
After successfully touching down on a tiny asteroid 180 million miles away and collecting a sample from its surface, Japan's Hayabusa probe was at risk of being lost in space yesterday unless engineers can solve an engine problem quickly and get the spacecraft started on its journey home.
"The deadline is loose, but we assumed early December," project manager Junichiro Kawaguchi said in an e-mail. "Efforts to revive the spacecraft have begun, but we are not sure we can finish in time. The situation is not too optimistic."
Cosmic geometry requires Hayabusa to begin its 1 1/2 -year return trip early this month or be trapped in space for eternity.
Hayabusa landed on the asteroid Itokawa on Saturday and fired two 10mm tantalum bullets into its surface, stirring a plume of dust that the spacecraft gathered in a horn-shaped collector. It was the first space mission to land on a celestial body other than the moon with the intent of picking up a sample and bringing it home.
But in withdrawing from the asteroid, Hayabusa sprang a leak in one of its sets of chemical thrusters, while a second set apparently froze. Kawaguchi said the two mishaps were apparently "distinct events," but "details are still under investigation."
Hayabusa's uncertain fate could turn out to be the final bitter irony for a spacecraft that has overcome remarkable hardships since the Japanese Aerospace Exploration Agency launched it in May 2003.
Solar flares damaged its electrical storage capacity, and after reaching Itokawa on Sept. 12, only one of Hayabusa's three variable-speed gyroscopes was functioning properly. The gyros are critical in maintaining the spacecraft's position in space.
An attempt to drop a tiny "hopping robot" called Minerva onto Itokawa went awry Nov. 4, with the lander ending up drifting away into space, and a Nov. 20 touchdown lasted 30 minutes but failed to collect a sample.
With time running out, engineers tried again last Saturday and confirmed success two days later. But the thruster problems arose four hours after liftoff, Kawaguchi said, and ground controllers lost radio contact with the probe until yesterday.
While Hayabusa struggled to complete its unprecedented journey, two sets of scientists announced results yesterday of European Space Agency missions to explore Saturn's largest moon, Titan, and to conduct the first subsurface radar probe of Mars.
In seven papers being published by the journal Nature, researchers detailed the 147-minute descent to Titan's surface in January by ESA's Huygens probe and the additional 69 minutes Huygens spent transmitting data before its mother ship, NASA's Cassini spacecraft, disappeared over the horizon.
"It's an extraordinary world which resembles the Earth in many respects," Huygens mission manager Jean-Pierre Lebreton said in a televised news conference from ESA's Paris headquarters. "There's a landscape with clear evidence of alluvial [river-related] activity."