A laser could be mounted on the International Space Station and used to shoot down pieces of space debris in Earth orbit, says a new paper.
The system would use a telescope already mounted on the station to find and target pieces of debris up to 62 miles (100km) away.
Powerful pulses from the laser would then push space junk into Earth’s atmosphere, where it would burn up.
The paper, by researchers at the Riken research institute in Tokyo, was published in Acta Astronautica.
Their system would use the Extreme Universe Space Observatory’s (EUSO) super-wide-field telescope on Japan’s Kibo Experiment Module on the ISS.
The laser, meanwhile, use bundles of optical fibres to produce powerful laser pulses – capable of both high power and high frequency, although exact figures were not given.
Combining these two instruments would create a system that could deorbit space debris down to the size of 0.4 inches (one centimetre).
The impact of the laser beam on debris would create a force that reduced its velocity, causing it to fall into Earth’s atmosphere and burn up.
The group plans to deploy a small proof-of-concept experiment on the ISS, with a small, eight-inch (20-centimetre) version of the EUSO telescope and a laser with 100 fibres.
‘If that goes well, we plan to install a full-scale version on the ISS, incorporating a three-meter [10ft] telescope and a laser with 10,000 fibres, giving it the ability to deorbit debris with a range of approximately 100 kilometers [62 miles],’ said lead researcher Dr Toshikazu Ebisuzaki.
Looking further into the future, the team said they could have a ‘free-flyer’ mission not attached to ISS in another orbit to shoot down debris.
For example, such a system could be deployed in polar orbit at an altitude of about 500 miles (800km), ‘where the greatest concentration of debris is found,’ according to Dr Ebisuzaki.
Without going into specifics, the team says their proposal could remove ‘most’ of the centimetre-sized debris in Earth orbit within five years of operation.
MailOnline has asked the researchers to explain how often the laser would fire, and what its maximum capacity in terms of debris-size to deorbit would be.
The EUSO telescope was originally planned to detect ultraviolet light from air showers produced by ultra-high energy cosmic rays.
But the researchers realised they could put it to another use – the removal of space debris.
The fibre-powered laser, meanwhile, was originally developed to power particle accelerators – but again another use for it was found.
Space debris, which is continuously accumulating as a result of human space activities, consists of artificial objects orbiting the earth.
The number of objects nearly doubled from 2000 to 2014 and they have become a major obstacle to space development.
The total mass of space debris is calculated to be about 3,000 tons. It consists of derelict satellites, rocket bodies and parts, and small fragments produced by collisions between debris.
‘We may finally have a way to stop the headache of rapidly growing space debris that endangers space activities,’ added Dr Ebisuzaki.