Monday, May 10, 2010

The travels and travails of Galaxy 15

Don't look now, Zombiesat may be gaining on you


About 22,000 miles out in space, in the precincts of geostationary orbit, a satellite has lost its ability to communicate with its ground controllers. The satellite, Galaxy 15, is now adrift. While the chance of a collision with another satellite is remote (hah!), it's still doing its communications satellite job, and when it drifts into the zone of another commsat, it could intercept communications intended for that satellite. Collisions are unlikely because the other working sats can see it coming, and get out of the way. Galaxy 15 is now, according to reports, going to drift over to a libration point, a "gravity well", 105 degrees west and 75 degrees east) that apparently is the location of a few other of these undead satellites.


My question: what are the chances of this zombiesat colliding with another zombiesat, and generating more space junk in geostationary orbit? (Of course, there is more space up that high in space.) Maybe the libration point would be a good place to send our next-generation astronauts for practice before an asteroid rendesvous, and they could practive rendezvousing with these zombiesats and attaching boosters to get them OUT of the geostationary orbit libration points.

Articles about zombiesat Galaxy 15

Zombiesat attack: Solar storm fries satellite's brain

Zombiesat: Out-of-control satellite

Out-of-control satellite threatens others (an angry zombiesat is not to be trifled with)


"But it is a problem that satellite operators know how to deal with. Industry experts say there are several dozen spacecraft, sometimes called "zombiesats," that for various reasons were not removed from the geostationary highway before failing completely.

Depending on their position at the time of failure, these satellites tend to migrate toward one of two libration points, at 105 degrees west and 75 degrees east. Figures compiled by XL Insurance of New York, an underwriter of space risks, say that more than 160 satellites are gathered at these two points, which Bednarek described as the orbital equivalent of valleys."

160 satellites? I wonder what these look like in a telescope?

In a more general sense, and speaking more about the threat to low-Earth orbits, here's another article about space junk (also called ODDs, Orbital Detritus Dangers):

How much junk is in space?



About 500,000 known pieces of space junk – down to items about 0.5 inches (1.27 centimeters) wide – are constantly tracked by the Department of Defense's U.S. Space Surveillance Network. Of those, about 21,000 objects are larger than 4 inches (10.1 cm) in diameter. These are items like spent rocket stages and broken satellites such as Galaxy 15.


Zombiesat! What's next for the out-of-control Galaxy 15 satellite

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Galaxy 15 drifts onward

They couldn't shut it down (try a big-a** laser next time, maybe), so now Galaxy 15 is poised to intercept signals intended for other geostationary satellites as it drifts merrily towards its eventual libration point destination.

Attempt to shut down zombiesat Galaxy 15 fails

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