Space

Lasers could be used to zap orbital debris

Lasers could be used to zap or...
A laser/telescope system may be able to de-orbit smaller pieces of orbital debris (Image: Shutterstock)
A laser/telescope system may be able to de-orbit smaller pieces of orbital debris (Image: Shutterstock)
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A laser/telescope system may be able to de-orbit smaller pieces of orbital debris (Image: Shutterstock)
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A laser/telescope system may be able to de-orbit smaller pieces of orbital debris (Image: Shutterstock)

Orbital debris is increasingly becoming a hazard to satellites and other spacecraft, which is why various groups have proposed concepts such as gas clouds, nets and sails for collecting it. While those approaches could capture larger objects, the problem of smaller pieces of debris – which whiz around the Earth like bullets – would remain. That's why an international group of scientists is developing a system that could shoot those bits down with a laser.

The space-based system would consist of two main components: a super-wide field-of-view telescope developed by the EUSO team at Japan's Riken research institute, and a highly-efficient fiber optic-based laser.

The telescope was originally developed to detect ultraviolet light emitted produced by ultra-high-energy cosmic rays entering the Earth's atmosphere at night. EUSO's Toshikazu Ebisuzaki, who is leading the project, realized that it could also be adapted to detect high-velocity debris fragments at twilight.

Once a piece was spotted and located, the system would instruct the laser to focus intense pulses of light onto it. In a process known as plasma ablation, this would cause the one side of the object to heat up and turn to plasma. As the plasma plumed off to that side, it would create thrust, sending the debris down to burn up in the atmosphere.

Plans now call for a proof-of-concept model to be installed on the International Space Station. It will utilize a 20-cm telescope and a 100-fiber laser, and will concentrate on shooting down debris near the station. If that goes well, it could be replaced with a full-scale version that has a 3-meter telescope, a 10,000-fiber laser, and a range of 100 km (62 miles).

Down the road, another system could be deployed to an altitude of 800 km (497 miles) above the Earth's surface, where a greater amount of debris is present.

"Our proposal is radically different from the more conventional approach that is ground based, and we believe it is a more manageable approach that will be accurate, fast, and cheap," said Ebisuzaki. "We believe that this dedicated system could remove most of the centimeter-sized debris within five years of operation."

Along with Riken, other institutes taking part in the project include the University of California at Irvine, the University of Paris, and the University of Torino.

A paper on the research was recently published in the journal Acta Astronautica.

Source: Riken

6 comments
Howard Moon
Very interesting how there is not one single (real) photo online that shows the space garbage. All are illustrations or computer animated. You'd surely be able to see this garbage from a telescope as well from Earth... Same goes for satellites. Where is the evidence of this space garbage... and satellites as well.
Bob
Interesting idea but what if these little pieces of junk are spinning rapidly? It will be difficult to vaporize one side and propel it downward. Any droplets of melted metal then become additional hazards. Unless you are actually slowing the pieces down, they will just change the shape of their orbit. Will the laser present any danger to objects behind the targets? I have advanced the idea of the gas cloud for years. I see Boeing recently applied for a patent for a similar idea. My idea was to send up tanks of liquid nitrogen and vent them while traveling in the opposite direction of the space junk. The smaller the junk, the greater the effect of the cloud with it's molecular drag while not being a major threat to working satellites. Repeated launches of the gas clouds should drag down the smaller and harder to track junk. We would be briefly extending the effects of atmospheric drag higher into space.
Captain Obvious
Howard, it's hard to see small stuff from a hundred miles away. You can see the ISS if it's in the sun after twilight, but that's really big. I have seen smaller satellites where there's no light pollution (Madagascar). You need to track it with a very high powered radar, which also gives you a range measurement, unlike visual tracking.
The 1 TaiN
Just exactly how is that suppose to work? I mean, unless you Vaporize the the Target as a WHOLE piece. You're going to be there ALL DAY, Vaporizing Piece-By-Piece-By-Piece. It would probably be more effective to NUDGE the Debris out of orbit and let it Burn-Up in the Atmosphere...
JimPike
The process makes a lot of sense. The laser would be fired at the front of the object as rapid pulses. Rotation would have no effect as each pulse would provide retro thrust only for milliseconds before the object rotates significantly. Relatively little energy is required to lower the orbit enough to encounter atmospheric drag to bring down the object. Great idea!
There is an incredible amount of junk in orbit now creating rapidly increasing likelihood of collisions. I believe collisions have already happened. Satellites have even been deliberately blown up to demonstrate the capability!!! Each collision multiplies and spreads out the junk. With more and more satellites from many countries entering orbit, the hazard will become an intolerable for risk for humans or even valuable satellites.. Something MUST be done!
CatWoman
Hey! If this works, how about launching nuclear waste somewhat farther out than the satellites & laser-blasting it into oblivion?