FEBRUARY 27 2012 22:25h

Active removal of space debris urged

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HOUSTON, Feb. 27 (UPI) -- Space junk around the Earth could be managed by removing a few large pieces every year from the debris cloud surrounding the planet, U.S. experts say.

Researchers said such cleanup measures combined with more passive solutions like draining fuel from defunct satellites would probably keep the levels of space debris in orbit constant for the next 200 years or so, SPACE.com reported.

"Orbital debris is a serious issue, but at the same time, the sky is not falling," J.C. Liou of NASA's Orbital Debris Program Office in Houston said.

"I think we can continue to manage the current environment for some time -- maybe 10 years or 20 years -- before we have to consider debris removal to better preserve the environment for future generations," Liou said.

About 22,000 pieces as large as a softball and hundreds of thousand of smaller pieces of spent rocket bodies, decommissioned satellites and fragments of ongoing orbital collisions surround the Earth, NASA estimates.

All of this space junk is a threat to the operational satellites in orbit and to the International Space Station and other crew-carrying craft, scientists said.

"The typical impact velocity in low-Earth orbit is about 10 kilometers per second [22,300 mph], and because of that, even a sub-millimeter debris could be a problem for human spaceflight and for robotic missions," Liou said.

"The time has come for us to consider active debris removal," he said.

Liou says a modeling study suggests if five large objects were removed out of low-Earth orbit every year starting in 2020, debris levels in 2210 would be roughly the same as they are today.