Laser cannons may sound like a far off option of the future, but some want to place ground-based laser cannons to clean up the trash floating around in low Earth orbit. Hundreds of thousands of pieces from space and satellite missions litter low orbit, threatening to strike the Earth at any given time.
The solution of a laser cannon was proposed by engineers at Photonic Associates as a possible solution to the increasing amount of man-made hazards hurtling around the Earth, just waiting for their moment to be pulled down by gravity. Low orbit is so full of space junk that collisions happen constantly, creating smaller and harder to track pieces of space junk.
Not only do these pieces of space junk pose a threat to the surface of the planet, but they also pose threats to active space missions. In 2009, an abandoned spacecraft collided with an active communications satellite. Earlier this year, the crew of the International Space Station had to hide in an escape craft as a piece of space junk wandered dangerously close to the space station.
As the level of space debris increases, it will be difficult for space vehicles of any sort to return to Earth. The debris makes predictable unpowered re-entry almost impossible. There would be the constant threat of collision for any space vehicle when trying to make it into low orbit, which is vital when preparing for entering Earth’s atmosphere.
A number of suggestions have been offered for handling the increasing problem. One plan would have unmanned barges flying around in low orbit collecting space trash. Another plan that has been proposed would send balloons into low orbit with a polymer net of some sort to capture debris as it comes closer to Earth. A similar laser cannon has been suggested before, though of a lower power. It would use photons to heat the surface of an object causing it to spin and then nudge it out of orbit. The difference between it and the most recent proposal is the level of power.
The recent proposal would heat the surface of an object, creating a stream of plasma on a focused point which would work like a rocket engine and move the objects. In theory, the new proposal would be capable of completely destroying smaller objects, most of which would burn up on their own during entry to the atmosphere.
While not a new concept, it’s very likely that such a laser cannon would never be put into use. Each shot of the cannon would cost a thousand dollars at the least and up to a million for the larger objects in low orbit. When considering the hundreds of thousands of objects in low orbit, it would cost billions of dollars to make and keep low orbit relatively trash-free.