Space junk S.O.S: Experts say it's past tipping point

WASHINGTON - Experts say there is so much junk in space that some thought must finally be given to cleaning it up.

That may mean vacuuming up space debris with cosmic versions of nets, magnets and giant umbrellas. A new report says the situation got worse because of two recent events - a Chinese weapon test and the crash of two satellites.

Space junk can cause fatal leaks in spaceships or destroy valuable satellites. The International Space Station sometimes has to move out of the way of debris.

Since the space age began, the area just above Earth's atmosphere has been littered with leftover boosters and old satellites. There are now agreements to limit space junk but the report says the two recent events doubled the amount of fragments.

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In late June, an unidentified object came within 1,100 feet of the International Space Station but caused no damage. However, the close call forced the astronauts on board to evacuate to emergency spacecraft as a preemptive measure.

The proliferation of space debris has also increased the chances of collision between pieces of space flotsam, which then break apart into smaller pieces. Such was the case in 2009 when a U.S. Iridium communications satellite smashed into a broken Russian spacecraft. A 2007 Chinese anti satellite test also added an estimated 3,000 pieces of space junk now circling the Earth. At the time, scientists said that China's destruction of one of its weather satellites resulted in one of the most severe instances of space fragmentation ever recorded.

"Those two single events doubled the amount of fragments in Earth orbit and completely wiped out what we had done in the last 25 years,"said retired NASA senior scientist Donald Kessler, who headed the National Academy of Sciences report.

All that junk that means something has to be done, "which means you have to look at cleaning space," said Kessler.

The study only briefly mentions the cleanup possibility, raising technical, legal and diplomatic hurdles. But it refers to a report earlier this year by a Defense Department science think-tank that outlines all sorts of unusual techniques. The report by the Defense Advanced Research Projects Agency is called "Catcher's Mitt" and it mentions harpoons, nets, tethers, magnets and even a giant dish or umbrella-shaped device that would sweep up tiny pieces of debris.

While the new report does not recommend using the technology, Kessler said it is needed. He likes one company's idea of a satellite that is armed with nets that could be sprung on wayward junk. Attached to the net is an electromagnetic tether that could either pull the junk down to a point where it would burn up harmlessly or boost it to safer orbit.

NASA officials said they are examining the study.

The report is from the National Research Council, a branch of the National Academy of Sciences, which is an independent organization chartered by Congress to advise the government on science.