Since 1957, humans have been polluting the Earth’s orbit with bits of debris, known as space junk. There are currently around 20,000 fragments of space junk orbiting the Earth. Pieces of old satellites, used rocket stages and fragments from collision, erosion and disintegration are all floating up there, reaching speeds of up to 17,500 miles an hour.
Ideas for getting rid of this dangerous junk range from gathering it with giant nets to sending it out of Earth’s orbit using magnets.
But there’s a new proposal for how we could get rid of some of this junk – or at least make it more manageable. A team of researchers from China has come up with a plan to blast the debris into smaller, less harmful bits using a laser flying around Earth.
Quan Wen and colleagues at the Air Force Engineering University in China used a numerical simulation to test how a laser might impact the amount of space junk floating around now. A laser would be mounted to a satellite itself, launched into orbit. From there it would emit short bursts of near-infrared light, sending 20 bursts a second for a few minutes. This should be enough to break the debris down, the authors say.
In a new paper, the team described how it tested a series of theoretical angles the laser could be pointed at, and its position in the sky. They found when its inclination and right ascension, both measurements of its position with respect to Earth, were the same as the space junk it was aiming at, the laser-blasting was at its most efficient.
While it sounds far-fetched, the simulation could be the start of the development of this kind of tool. “It provides necessary theoretical basis for the deployment of space-based laser station and the further application of space debris removal by using space-based laser,” the authors say.
Meanwhile, researchers over the world continue to research ways to get rid of space junk. ESA’s e.DeOrbit mission to capture junk between 800 and 1,000 km altitude was announced in 2014, and the agency is investigating the best capture methods. Another venture to get rid of the junk is CleanSpaceOne, development by the Swiss Federal Institute of Technology in Lausanne, which will launch in 2018 and try to push the bits of metal out of orbit.
All of these ideas are attempting to tackle the growing problem, which will only escalate if nothing changes. As space tourism starts to become a reality, the half a million pieces of space junk floating around will become more dangerous to ships departing and entering our atmosphere.
The final solution is likely to be a mixture of methods, involving some breaking up, some gathering and maybe some sending the debris out of orbit completely. Exactly how it will happen is unclear, but what remains clear is something will have to be done soon.