NASA monitors space junk threat to station

A piece of approaching space junk is not expected to endanger two crew members aboard the International Space Station early this afternoon, but NASA continues to monitor the debris and a technical problem that could become relevant.

The latest tracking data shows a four-inch diameter piece of a Russian Cosmos satellite could fly within three-quarters of a mile of the station at 1:19 p.m. EST.

But the chance of a collision is not yet high enough to force astronaut Jeff Williams and cosmonaut Max Suraev to take shelter in their Soyuz spacecraft, which would serve as a lifeboat during an emergency evacuation.

Early today, flight directors told the crew members they would be awakened at 10 a.m. if probabilities warranted a move to the Soyuz.

So far, the crew has not been awakened.

However, NASA is also troubleshooting a problem with an improperly latched assembly that allows a solar array wing on the left side of the station to rotate.

The two pairs of solar array wings on the port side have been locked in place to limit the damaging effects that too much shadow could have on the wing structure.

That in turn could affect steering gyroscopes' ability to maintain the outpost's trajectory as the debris approaches. Thrusters on the station's Russian segment could fire to adjust the attitude, complicating the tracking calculations.

We'll update the status of the debris threat as new information is provided.

IMAGE: This is one of a series of images featuring the International Space Station photographed soon after the space shuttle Atlantis and the station began their post-undocking relative separation. Undocking of the two spacecraft occurred Nov. 25, 2009. Some scenes in the series show parts of the Mediterranean Sea and Africa and Spain in the background. Credit: NASA.

ISS022-S-002B (7 July 2009) --- NASA astronaut Jeffrey Williams (left), Expedition 22 commander; and Russian cosmonaut Maxim Suraev, flight engineer, take a break from training at NASA's Johnson Space Center to pose for a portrait.