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Fall 2011 Vol. 11 Number 2

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Taking Out the Space Trash

Computer-generated image of objects in Earth orbit, courtesy NASA Orbital Debris ProgramIn June of this year, the crew of the International Space Station was forced to take shelter in escape capsules because space junk passed dangerously close to the research outpost. An unidentified piece of debris came within 850 feet of the station, narrowly avoiding collision. A few months later, orbital debris again made headlines when the Upper Atmosphere Research Satellite, decommissioned in 2005, fell to Earth.

Abandoned space equipment, meteoroids, spent rocket bodies, and fragments from past collisions in space pose a substantial long-term threat to spacecraft and astronauts. Over the past 50 years NASA has been working to mitigate that risk and made significant progress. NASA’s meteoroid and orbital debris programs are respected national and internationally, and their models are now widely used. However, a recent report from the National Research Council warns the increasing complexity and severity of the orbital debris environment is outpacing NASA’s ability to address the threat posed by objects in orbit. Some scenarios generated by NASA models show that the debris currently in orbit has reached a point where it will continually collide and create even more debris, making space operations ever riskier.

The Research Council’s report found that the agency’s meteoroid and orbital debris programs have used their resources responsibly, but with new and more complex work, the agency must stretch those resources even further. The report proposes a strategic plan to help the agency prioritize and streamline its meteoroid and orbital debris-related operations — for example, establishing a single management office to coordinate and budget for all the agency’s orbital debris and meteoroid activities.

The agency recognizes that any long-term solution will involve removing debris from orbit, which introduces a new set of complexities. Developing and testing the technology to safely and effectively capture and/or return orbital debris to Earth will be a time-consuming and expensive undertaking. In addition, only about 30 percent of the objects can be attributed to the United States. According to international legal principle, no nation may salvage or otherwise collect other nations’ space objects; to do so could be considered an act of war. As NASA considers strategies for debris removal, diplomatic communication and political goodwill will be essential components.

Moving forward, the report says NASA should lead public discussion of the space debris problem and emphasize that debris is a long-term concern that must continue to be addressed. -- Lorin Hancock

Limiting Future Collision Risk to Spacecraft: An Assessment of NASA’s Meteoroid and Orbital Debris Programs. Committee for the Assessment of NASA’s Orbital Debris Programs, Aeronautics and Space Engineering Board, Division on Engineering and Physical Sciences (2011, 180 pp.; ISBN 0-309-21974-4; available from the National Academies Press, tel. 1-800-624-6242; $45.00 plus $5.00 shipping for single copies).

The committee was chaired by Donald J. Kessler, senior scientist for orbital debris research, NASA (retired), Asheville, N.C.; and vice chaired by George J. Gleghorn, vice president and chief engineer, TRW Space and Technology Group (retired), Rancho Palos Verdes, Calif. The study was funded by NASA.

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Copyright 2011 by the National Academy of Sciences