Astronauts onboard the International Space Station (ISS) took refuge in a Soyuz escape capsule as a threatening piece of debris passed by without incident today, NASA announced. The 13-centimeter (five-inch) piece of debris, which made its closest approach at 12:39 P.M. (Eastern Daylight Time), originated from a 1993 launch and was not related to last month's satellite crash, says Gene Stansbery, orbital debris program manager at NASA's Johnson Space Center in Houston.

According to the NASA Web site, the precautionary measure was necessary because notice of the approach came too late to perform an evasive maneuver. The object's relatively small size and highly elliptical orbit made it difficult to track, Stansbery says. He could not provide a quantitative assessment of the level of risk faced by the ISS.

ISS crew members were given the all-clear at 12:45, and at 12:56, station commander Michael Fincke reconnected to Houston to announce that things were back to normal on the station. He also asked NASA to relay details on how close the object came to the ISS when they become known.

Photo of ISS as it appeared in June 2008 courtesy of NASA