SPACE, as the late Douglas Adams pointed out, is very big. But the bit near Earth is also very crowded. Half a century of rocket launches has turned the high frontier into a junkyard. Around 3,000 tonnes of empty rocket stages, defunct satellites, astronauts’ toothbrushes and flecks of paint are thought to be in orbit.
Besides being messy, such debris can be dangerous. Anything circling Earth is moving pretty quickly, so collisions between space junk and satellites can happen at closing velocities of 10km a second or more. Large bits of junk are routinely tracked by radar. The International Space Station (ISS), for instance, regularly tweaks its orbit to avoid a particularly menacing piece of litter. But at such high speeds, even a small, hard-to-follow object can do tremendous damage.
Rocket scientists have been pondering how to deal with this problem for years. But a paper just published in Acta Astronautica by Toshikazu Ebisuzaki and his colleagues at RIKEN, a big Japanese research institute, has gone further and proposed actually building a test device.
Like all the best ideas, Dr Ebisuzaki’s plan involves zapping things with lasers. He proposes to point these lasers in the right direction using a telescope intended for a different job entirely. This is the Extreme Universe Space Observatory (EUSO). It is designed to...
from The Economist: Science and technology http://ift.tt/1OKI7vy
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