NASA - National Aeronautics and Space Administration

Space Debris Being Tracked; ATV-3 Remains Docked

NASA and Russian managers decided Wednesday to make preparations for a possible debris avoidance maneuver Thursday to steer the International Space Station clear of a piece of Russian COSMOS satellite debris and a fragment of an Indian rocket body. By deciding to prepare for a possible avoidance maneuver, station managers delayed until at least Friday a second attempt to undock the European Space Agency’s “Edoardo Amaldi” Automated Transfer Vehicle (ATV) Transfer Vehicle.

The three-person Expedition 33 crew is in no danger and continues its work on scientific research and routine maintenance.

If the maneuver is required -- and it could be called off any time -- it would occur at 8:12 a.m. EDT Thursday, using the engines on the ATV, which is still docked to the aft port of the Zvezda Service Module on the Russian segment of the complex. The decision followed a discussion involving the International Space Station Mission Management Team, with representatives from all five international partner agencies represented.

The decision to proceed with maneuver planning was made after tracking data showed the piece of debris edging just inside the so-called “red zone” of miss distance to the station with a time of closest approach calculated to occur Thursday at 10:42 a.m. Eastern time. It is not known how large the object is.

Tuesday’s initial attempt to undock the European cargo ship was called off due to a communications error between the Zvezda module’s proximity communications equipment and computers on the ATV. Russian engineers told mission managers that they fully understand the nature of the error and are prepared to proceed to a second undocking attempt.

Once it is undocked, the ATV will move to a safe distance away from the station for a pair of engine firings that will send the cargo ship back into the Earth’s atmosphere to burn up over the Pacific Ocean.

For more information about orbital debris and how Mission Control manages the space station operations when faced with possible collisions, visit:

› www.nasa.gov/mission_pages/station/news/orbital_debris.html

› Read more about Expedition 33