Wednesday, May 13, 2009

Live In Orbit: Space Junk Flies By Atlantis

A small piece of debris from a Chinese communications satellite destroyed in an anti-satellite test whizzed near shuttle Atlantis and the Hubble Space Telescope tonight but it wasn't close enough to require evasive action.

The 10-centimeter chunk was following an orbital path that took it about 2.8 kilometers out in front of Atlantis and 150 meters below the shuttle and Hubble. Its orbital plane, however, was 3.9 kilometers from the shuttle's.

NASA's Mission Control Center informed the crew of the debris pass a few hours ago and told the astronauts that it wasn't anything to be concerned about. The debris flew by without incident.

The Hubble telescope is in an orbit 350 miles above Earth, one that is more littered with debris than the lower, 220-mile orbit of the International Space Station. The risk from micrometeorite or orbital debris strikes is elevated slightly as a result. NASA said before the flight the mean chance of a strike during the course of the Hubble servicing mission was about 1 in 221.

NASA deputy shuttle program manager LeRoy Cain said today that the agency is keenly aware of the dangers presented by micrometeorite and orbital debris and has put in place a strong program to identify and react to any threats.

"We just have to watch it. And we'll take action if action is necessary," Cain said.

NASA Mission Control, meanwhile, just told the astronauts that no focused inspection will be required during the mission -- a big relief in two ways.

First, it means the shuttle's heat shield did not sustain critical damage during ascent or early in flight.

And second, the astronauts don't have to worry about shoehorning a time-consuming inspection of the shuttle's heat shield into an already jammed-packed mission that includes spacewalking work on five consecutive days.

The crew will take a second look at 16 heat shield tiles on the port side of the shuttle's nose. Engineers said there was not sufficient coverage of that area during initial inspections, so the astronauts will use the camera on the end of the shuttle's robot arm to take another quick look.

The sensor-laden inspection boom used on Flight Day 2 inspections will not be required for the job, which is only expected to take about an hour.

Flight controllers are still determining exactly when that work will be done.

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