There are people who want to equip the International Space Station with a laser cannon. Shades of the Star Wars "Death Star?" No, just a way to clean up space junk that could present a collision hazard, those people say.
As more and more satellites and spacecraft are sent into orbit, the threat of a collision with space junk is increasing, and objects large enough to cause damage but too small to be easily spotted are seen as a risk to the space station, researchers say.
That could be avoided by using the Extreme Universe Space Observatory, set to be installed on Japan's module of the ISS in 2017, to help the orbiting laboratory detect dangerous debris, they suggest.
And powerful lasers currently in development could ultimately be installed to allow the station to blast such debris out of existence, they add.
"The EUSO telescope, which was originally designed to detect cosmic rays, could also be put to use for this useful project," says Toshikazu Ebisuzaki at the Riken Computational Astrophysics Laboratory in Wako, Japan.
"During twilight, thanks to EUSO's wide field of view and powerful optics, we could adapt it to the new mission of detecting high-velocity debris in orbit near the ISS," he says.
Once detected, a laser could target the debris and vaporize material off its surface, creating a high-speed jet to nudge the piece of space junk away from the station, the researchers suggest.
Currently, the method of responding to a potential impact is to give the ISS a nudge with its thrusters, moving it out of the path of the debris while the crew moves into a docked capsule that could return them safely to Earth in the event of a serious collision.
The laser envisioned by the researchers would be a type known as a Coherent Amplification Network (CAN) laser, which uses a number of small lasers working together to create a single powerful beam.
Such a laser could deflect space debris at ranged up to 60 miles, more than sufficient for keeping the space station out of harm's way, the scientists say.
While acknowledging the radical nature of the proposal, Ebisuzaki says such a system could be an inexpensive solution for an accurate, fast method of dealing with the increasingly worrisome problem of space junk and its potential threat to human space activity.
The project is certain to face more than just technological hurdles, some experts point out.
"The problem with it is mostly political," says Don Kessler, who spent more than 30 years working at NASA's Johnson Space Center. "Everyone is afraid you are going to weaponize space."
Best not mention the Death Star, then.