Space Junk



"Space debris has passed the “tipping point,” according to 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 first predicted in 1978 that the number and size of objects in Earth’s orbit would become so large that they would continually 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, according to the NRC report.

U.S. Strategic Command, a military unit able to track man-made objects 10 centimeters and larger, says there are 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 also in space.

The NRC also recommends engaging the State Department for work 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, Weeden said.

The report provides no timeline for NASA to implement changes in its debris programs, but given the tipping point we have passed, Kessler said, “The earlier we [deal with the problem], the cheaper it’s going to be in the long run.”
Weeden said space debris won’t be a major concern in the next couple of years, but it will be within 10 or 20 years — and that’s a relatively short lead time given the scope of the issue, he said.

“You can’t fix the problem quickly,” Weeden 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.