Removal of space debris -- a collection of defunct parts of old satellites, rockets and spacecraft -- has been a major headache for space agencies. According to current estimates, there are up to 500,000 pieces of debris the size of a marble, or larger, orbiting Earth. This orbital junk can travel at speeds of up to 17,500 miles per hour -- fast enough to cause serious damage to satellites and even the International Space Station (ISS).
Now, a team of scientists from Japan’s Riken research institute have come up with an ambitious plan to eliminate the debris. In a paper published in the latest issue of the journal Acta Astronautica, the researchers proposed a method that basically involves blasting an estimated 3,000 tons of debris through a fiber optic laser mounted on the ISS.
This, the researchers claimed, would be a two-step process. Firstly, the researchers plan to use the existing infrared telescope of the European Space Agency’s Extreme Universe Space Observatory (EUSO) -- originally built to detect high-energy cosmic rays bombarding Earth -- to track the space junk. The second part of their proposed plan involves using a fiber-based laser system to shoot the objects until they are knocked out of their orbit and destroyed during re-entry into Earth’s atmosphere.
“The new method combining these two instruments will be capable of tracking down and deorbiting the most dangerous space debris, around the size of one centimeter. The intense laser beam focused on the debris will produce high-velocity plasma ablation, and the reaction force will reduce its orbital velocity, leading to its reentry into the earth's atmosphere,” the researchers said in a statement on Friday.
The group now plans to deploy a small proof-of-concept experiment on the ISS using a small, 20 centimeter version of the EUSO telescope and a laser with 100 fibers.
“If that goes well, we plan to install a full-scale version on the ISS, incorporating a three-meter telescope and a laser with 10,000 fibers,” Toshikazu Ebisuzaki, the lead author of the paper, said in the statement. “Looking further to the future, we could create a free-flyer mission and put it into a polar orbit at an altitude near 800 kilometers, where the greatest concentration of debris is found.”