Raumfahrt - Hazardous space junk is piling up. Can this satellite help?



Space is vast. But around our planet, it is getting a bit crowded — with space junk.

More than a half million chunks of decommissioned, human-made satellites, lost tools, broken parts and trash the size of a pea or larger whiz at more than 17,000 miles per hour around the planet. Space junk threatens the lives of astronauts on the International Space Station and the functionality of satellites scattered across low Earth orbit.

That is why space enthusiasts are excited about RemoveDEBRIS, the first-ever satellite capable of actively collecting space debris. On Sept. 16, this junk collector deployed a net that snared a piece of space garbage mid-flight in a one-time, groundbreaking demonstration.

Within the next two or three months, the kevlar net and its trapped cargo will fall back toward Earth and burn up in re-entry. But the maneuver required more than just slinging a net to catch a piece of metallic prey.

RemoveDEBRIS represents one of many endeavors geared toward the important task of snatching space projectiles out of the sky. Each project calls for tricky calculations — imagine trying to clean up your room in the middle of a tornado. But one math problem remains unsolved: Who will pay for space trash collection?

A growing—and shrinking—problem

Humans have a tendency to build up piles of discarded material on Earth, said Bill Ailor, an aerospace engineer at The Aerospace Corporation. “We dump it into the ocean or whatever, and assume the Earth absorbs it. We’ve done the same in space.”

Approximately 1,800 active satellites already orbit the planet, and companies like SpaceX, OneWeb and Boeing have proposed launching new satellite constellations in the coming years — on the order of hundreds or tens of thousands.

Those satellites could expand internet access to rural areas, improving the lives of millions around the globe. But once they’ve served their purpose, they, too, might become part of the orbiting trash field.

A piece of space junk will meet one of two fates. It will either slow down enough to fall back toward Earth, burning up in the atmosphere. Or it will smash into another piece of space trash, producing more, smaller projectiles with orbits of their own.

In 1978, NASA scientist Donald J. Kessler proposed a catastrophic scenario where colliding space junk creates a cascade that breeds an impenetrable cloud of fragments in lower Earth orbit. This “Kessler Syndrome” could make space travel and satellite communications impossible for years at a time. In other words, say so long to Skype, weather forecasts, GPS and military surveillance.


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