The spiderlike Dante II robot explorer toppled after breaking one of its eight legs and must be airlifted out of a volcanic crater strewn with boulders.
NASA scientists considered abandoning the $1.7 million robot but instead decided Saturday to try to have a helicopter lift it out of Mount Spurr, where it lay on its side, its camera still panning the terrain."Dante is still alive," said John Bares, a robotics expert from Carnegie Mellon University.
The remote-controlled robot had been sent into the 11,000-foot mountain July 29 to test its ability to survive harsh environments. Scientists hope to one day use robots similar to Dante to explore other planets.
Dante lost its footing Friday night when one of its legs malfunctioned as it was climbing up the crater's steep slope, Bares said.
Scientists were moving the robot through the rugged boulder field when one of the front legs didn't respond to the commands about 400 feet from the crater rim.
"It pushed down too hard - we really don't know why," Bares said.
Dante might have been able to get up on its own, but the scientists decided instead to end the mission and fold up Dante's legs to make it as small as possible for the airlift.
"We've run a week longer than we intended - and the mission accomplished more than we really hoped," Bares said.
On Monday, they plan to pluck the 1,700-pound machine off Mount Spurr, 80 miles west of Anchorage, and try to find out exactly what went wrong. Scientists plan to watch the airlift from the volcano rim.
"I don't know if we'll ever know what actually caused it to go down," Bares said. "The machine was right at the limit of its capability. In those conditions, any normally tiny event can trigger a collapse."
The command center, which has been operating out of a trailer in an Anchorage parking lot, will be shut down by Saturday night, he said.
Bares said Dante had performed successfully, getting to the bottom of the crater, taking readings on gases and transmitting video images of the landscape for seven days.