for National Geographic News
International Space Station crew members put the station on autopilot and evacuated to a space "life raft" briefly on Thursday to escape bombardment by a shower of debris.
In the end, the debris passed the space station without incident. But the evacuation provided a rare test of one of the plans to get the crew to safety if the station is struck.
"The worst-case scenario would be that the debris would cause damage to the space station and the crew would come back to Earth," NASA spokesperson Michael Curie said from Kennedy Space Center in Florida.
The threat was not related to the recent in-orbit satellite crash but came from 0.3-inch (0.9-centimeter) pieces broken off of a motor that NASA has cataloged as Object 25090 PAM-D.
"This [debris] is from a motor that would have been used to boost a satellite at some point," Curie said.
Initially, the debris was classified as posing a low threat of collision with the space station. But the possibility was upgraded to a more dangerous "red" threat on Thursday morning.
Just after 12:30 p.m. ET, the station's crew of three retreated to a Russian Soyuz spacecraft attached to the station for about ten minutes.
The tiny Soyuz craft has 141 cubic feet (4 cubic meters) of living space.
The crew could undock if necessary and fly around the station, or the module could leave orbit and return to Earth. The Soyuz craft contains life-support supplies and batteries generally used during descent as well as primary and backup parachutes and landing rockets.
Astronauts have evacuated to Soyuz for similar threats in the past, but normally the ISS can maneuver out of the path of debris.
"Typically, when you get advanced notice, you can perform a maneuver," Curie said. "But with notification late Wednesday and the erratic nature of this debris, it was too late to do that."
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