Space debris has passed the "tipping point," said a report released Thursday by the National Research Council, which called on NASA to find ways to better monitor and clean up the orbiting junk threatening active satellites and manned spacecraft. "We're going to have a lot more [debris] collisions, and at an increasingly frequent rate," said Don Kessler, a former NASA scientist who chaired the committee that prepared the report. The orbiting objects include ejected rockets and broken satellites.
Kessler predicted in 1978 that the number and size of objects in Earth's orbit would eventually become so large that they would collide with one another and create even more debris -- a chain reaction known as a "collision cascade." Recent data underscore the growing problem: Two collisions since January 2007 helped at least double the number of trackable debris fragments that are in Earth's orbit, the NRC report said.
U.S. Strategic Command, a military unit able to track man-made objects 10 centimeters and larger, says there are now more than 22,000 such pieces in orbit. NASA estimates there could be hundreds of thousands -- or even millions -- of smaller, non-trackable pieces of debris in space.
Active satellites are at risk of damage and "as the amount of debris increases, there will be increases in the cost of operating" satellites, said Brian Weeden, a technical adviser with the Secure World Foundation.
Manned spacecraft are also in danger. The International Space Station had a close call in late June when an unidentified object came within 1,100 feet but caused no damage.
The report does not offer many specifics for strategy, but it emphasizes the need for NASA to come up with a plan that centralizes staff and better utilizes the agency's limited resources. The NRC also recommended engaging the State Department on the international front. Less than one third of space debris can be attributed to the United States, and it will be important to have Russia, China and other players in space pursue cleanup as well, Weeden said.
Weeden said that space debris will be a major concern within 10 or 20 years -- and that's a relatively short lead time given the scope of the issue. "You can't fix the problem quickly," he said. "We've had 50-plus years of activity in space bring us to this point, so the answers are not going to be easy."
WASHINGTON POST
