Live in Orbit: Undocking ahead; debris no threat

NASA has again determined that the International Space Station won't need to dodge out of the way of approaching space junk.

A piece of a Chinese satellite will miss the outpost by a safe distance early Wednesday, officials said this morning, without specifying the "miss distance."

Last Friday, a piece of a European rocket stage whizzed by within a mile from the joined station and shuttle Discovery. Analysts had calculated that there was no chance of a collision.

Discovery's crew will awake around 11 a.m., then get ready to leave the station this afternoon after a stay of more than eight days.

The seven shuttle astronauts bid goodbye to the station's six crew members last night and hatches between the two spacecraft were sealed.

Prior to undocking, a new autopilot procedure will be used to fire Discovery's primary thrusters to reposition the station-shuttle stack so that the shuttle is flying in front.

Discovery is flying without the aid of six small steering jets in its nose and tail that would normally be used during the undocking procedure.

After firing the larger jets, as usual, around 3:30 p.m. to separate from the station to about 75 feet, the jets will shut down as the orbiter glide backwards to about 400 feet.

From there, pilot Kevin Ford will guide the orbiter through a flyaround of the outpost that will allow crew members to take photographs cataloguing its condition.

After that, Discovery will fire its engines again to start the journey home.

The crew today will do a final inspection to make sure heat shields have not been damaged while docked at the station and are safe for re-entry through Earth's atmosphere.

Landing is planned at 7:05 p.m. Thursday at Kennedy Space Center.