Mission control tells the space station astronauts tell they would have had only 10 minutes of reserves left if the debris had hit the station.
Astronauts aboard the International Space Station hunkered down this week while waiting to find out if a piece of space junk would hit their temporary abode at about 20,000 mph.
The crew took cover in the Soyuz TMA-13 capsule briefly Thursday morning, while waiting for the object to pass after ground control alerted them that it could hit the station. NASA estimated the piece of space junk to be about 5 inches in diameter, according to a brief online report about the incident.
"With the uncertainty of it, we are wanting to take a conservative approach," a NASA mission control employee at Johnson Space Center in Houston explained to those aboard the space station. "It's a low probability of hit. However, the object is rather large, from what we can track, and if it does happen to hit the ISS, we're talking only about a 10-minute reserve time."
She advised the crew to prepare to close the U.S. segment and hatches.
Crew members asked her to clarify whether they were supposed to board the Soyuz "right now." They were and they did. Within minutes, the crew was alerted that the object had passed.
Then ISS Cmdr. Michael Fincke urged ground crews to do what they could to ensure that the day's activities, including ham radio transmissions to schools, could proceed.
Moments after that, Russian ground control indicated the object had passed, and their U.S. counterparts confirmed the information.
"We are all very happy that [it] has passed with no impact," the NASA employee said. "That's great news."
Earlier this week, NASA announced that people on Earth could now watch the ISS through video showing the outside during some times of day. The live cam was not available as the astronauts hunkered down, but an audio recording of the communications between the astronauts and ground crews is available on NASA's Web site.
It's unclear exactly how close the debris came. If it had hit, the ISS would likely have been crippled. It's likely the crew would have tried to undock from the station and re-enter the Earth's atmosphere aboard the Soyuz.