Where can I get information about orbiting space junk?

The Air Force Space Command NORAD radar system tracks about 7,000 objects larger than 10 centimeters, but this is only the tip of the iceberg. The Arecibo radio telescope conducted a limited survey, and from the number of radar returns from objects larger than one centimeter identified over 150,000 objects in orbit. NORAD tracks a total of 100,000 individual objects from the size of a glove or larger. The Arecibo data suggest there are about one million objects larger than 2 millimeters. When you include things like paint chips and other sub-millimeter objects that are untrackable, the numbers may be as large as one hundred billion.

The Space Shuttle collided with a paint fleck from a previous mission or rocket launch and this chipped the front window leaving a crater several millimeters across. A 1-centimeter object moving with a relative speed of 17,000 kilometers/hour would deliver as much energy as a small hand grenade. The International Space Station has a front bumper that will try to protect its most vulnerable parts from the numerous objects of millimeter-size, but larger objects will be a rare, but ever-present problem capable of producing breaches in the pressurized parts of the station.

For more information try the European Space Agency debris site. There is a Space Debris resource page at the Aerospace Corporation site. Also, there were over 1000 matches to 'space debris' found on Alta Vista. There are also articles in the print media:

Eberhart, J. "Tallying Orbital Trash." Science News 138, 29, July 14, 1990. 

Goldstein, R. M. and Goldstein, S. J. Jr. "Flux of Millimetric Space Debris." Astron. J. 110, 1392-1396, 1995. 

Goldstein, S. J. Jr. and Goldstein, R. M. "Some Properties of Millimetric Space Debris." Astron. J. 107, 367-371,

Copyright 1997 Dr. Sten Odenwald

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