The International Space Station could one day get armed with a laser to shoot down orbiting debris, researchers say.
This concept could eventually lead to a laser-firing satellite that could get rid of a large percentage of the most troublesome space junk orbiting Earth, scientists added.
NASA researchers suggest that nearly 3,000 tons of space debris reside in low-Earth orbit, including derelict satellites, rocket bodies and parts and tiny bits of wreckage produced by collisions involving larger objects. Impacts from pieces of junk that are only the size of screws can still inflict catastrophic damage on satellites, since these projectiles can travel at speeds on the order of 22,370 mph (36,000 km/h).
The problem of space debris is growing as more satellites and spacecraft get sent into space. Moreover, large pieces of junk can generate lots of small fragments if they get hit, and those fragments can then go on to strike other objects in orbit for a chain reaction of destruction.
Most spacecraft, including the International Space Station, can withstand impacts from debris smaller than about 0.4 inches (1 centimeter) with adequate shielding. However, ground-based radar and computer models suggest that more than 700,000 pieces of debris larger than 0.4 inches now orbit Earth. Although items larger than 4 inches (10 cm) are big enough for astronomers to spot, debris between 0.4 and 4 inches (1 to 10 cm) in size is significantly more difficult to identify and dodge.
Now researchers suggest the Extreme Universe Space Observatory (EUSO), scheduled to be installed on Japan’s module on the space station in 2017, could help the orbiting complex detect dangerous debris. They add that a powerful laser under development could then help shoot down this space garbage.
“The EUSO telescope, which was originally designed to detect cosmic rays, could also be put to use for this useful project,” study lead author Toshikazu Ebisuzaki, an astrophysicist and chief scientist at the RIKEN (Rikagaku Kenky?sho) Computational Astrophysics Laboratory in Wako, Japan, told Space.com.
EUSO was originally developed to detect ultraviolet light produced by ultrahigh-energy cosmic rays as they enter the atmosphere at night. The scientists reasoned that its wide range of view and powerful optics could also help it detect high-speed debris near the International Space Station.
Once EUSO detects incoming space junk, the researchers suggest, a Coherent Amplification Network (CAN) laser can then blast the debris. The CAN laser consists of many small lasers working together to generate a single powerful beam. This device is currently under development to drive particles at high speeds in atom smashers.
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SOURCE: Discovery News, Space.com | Charles Q. Choi