The six-person crew of the International Space Station was forced to take shelter this morning in a "lifeboat" when space debris came dangerously close to the orbiter.
NASA reported Tuesday that the crew sought shelter in the Russian Soyuz TMA-21 spacecraft, which is docked to the station's Poisk module, after learning that space junk was hurtling toward the space station. The crew entered the spacecraft at approximately 7:50 a.m. Eastern time and stayed inside for about 20 minutes.
If the space station had been hit by the space junk and badly damaged, the astronauts would have traveled home in the Soyuz spacecraft. However, the debris hurtled past, missing the orbiter by about 820 feet, NASA said. No one was injured, and there was no damage.
NASA reported that Mission Control did not find out that the space debris was approaching the station until it was too late to maneuver the orbiter out of the way.
Stephanie Schierholz, a NASA spokeswoman, called Tuesday's safety precautions a rare event, noting that astronauts have only been forced to seek shelter in the Russian spacecraft one other time.
"It's a combination of safety and being in a return vehicle, which is their emergency lifeboat," Schierholz told Compuerworld. "If for some reason they needed to return to Earth, they would already be in their vehicle."
Schierholz said NASA scientists still aren't sure what the debris was and haven't yet said how big it was.
The last time the space station crew had to move into the Soyuz capsule was March 2009, when a piece of an old rocket motor that was used to push a satellite higher into orbit came dangerously close to the space station.
That piece of space junk measured only about one-third of an inch in size, but NASA noted that an object the size of a grain of sand could cause serious damage to the space station because of the high velocity at which things travel in space.
Now that the space station has received an all-clear from Mission Control, the astronauts onboard have been able to get back to work preparing for the arrival of the crew of the space shuttle Atlantis in a few weeks.
Atlantis is expected to lift off on its final mission July 8. The Atlantis mission will be the last space shuttle flight, since that fleet is being retired after 30 years of service.
Sharon Gaudin covers the Internet and Web 2.0, emerging technologies, and desktop and laptop chips for Computerworld. Follow Sharon on Twitter at @sgaudin, or subscribe to Sharon's RSS feed . Her email address is email@example.com.