William Atkins
Saturday, 14 March 2009 04:13
Science -
Space
Page 1 of 2
On Thursday, March 12, 2009, NASA ordered International Space Station crewmembers to abandon the Station and hole up in the Soyuz capsule that was docked to the Station for just these types of emergency situations. Several pieces of space debris (junk) were heading toward them, and a collision was possible.
The
“Red Alert” threat came from several pieces of space junk with a size of about 0.3-inch (0.9-centimeter).
The pieces, called micrometeoroid orbital debris (MMOD), came off of a motor that has been cataloged by NASA as "Object 25090 PAM-D."
The motor from this
PAM-D was part of a Delta PAM (Payload Assist Module)-D upper stage, which had been used to launch the Global Positioning System 37 (GPS-37) satellite in 1993.
Tracking of the small piece of debris called MM/OD (MicroMeteoroid/Orbital Debris) was at first thought to be a “Low” threat to the safety of the ISS crewmembers.
However, later telemetry/tracking data showed that it was a much larger threat, and NASA issued a “Red Alert” and told the ISS Expedition 18 crewmembers to evacuate into the Russian Soyuz space capsule.
In most such circumstances, NASA is given plenty of time to move the Space Station into a different orbit, but this time the notice was not given with sufficient time to move the Station away from the flight path of the space debris.
In addition, the orbit of the space debris was uncertain because they were entering and exiting the Earth's atmosphere, which made it move haphazardly in its orbit.
The three crewmembers of the Space Station—ISS commander and U.S. astronaut Mike Fincke, ISS flight engineer and Russian cosmonaut Yury Lonchakovy, and ISS flight engineer and U.S. astronaut Sandra Magnus—only had enough time to rush to the Soyuz spacecraft that was parked outside of the ISS.
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