Space junk is a real problem now. With millions of pieces of debris floating in Earth’s orbit, chances are they may hit something on their way up. The solution? Space lasers, of course.
Space is getting congested; there are some 23,000 bits of space debris greater than 10 centimeters in orbit around Earth right now, along with 3000 defunct satellites that are actively being tracked. Add to this more than a hundred million bits that are too small to be tracked. So it’s understandable why every major space agency is committed to monitoring and creating countermeasures for orbital debris. Everything from giant magnets and nets to harpoons and lasers have been proposed so far, but with around $US700 billion of infrastructure orbiting the Earth,—delivering vital services around the globe each day—a new line of space defense is needed. And space lasers just might be the answer.
Now, the most obvious move is to set up a high-energy ground station with a hyper-focused beam of light obliterating anything in its path, including space debris. This is what most researchers have been leaning towards since 1995, when the potential threat of orbital debris was first realized.
NASA scientists have previously proposed a ground-based laser that prevents debris collisions. In their “laser broom” concept, a megawatt-class laser would vaporize the surface of a debris that is heading for another, nudging it out of harm’s way. At its core, the idea seems simple enough. However, different satellites are made of different components and materials which poses a lot of variables. Take, for instance, the solar cells that satellites use for power. If such a powerful laser pings the surface of a solar array, it could eject thousands of shards of glasses, creating a cloud of microscopic debris. Another issue is the sheer power it would take for the beam to permeate Earth’s atmosphere without losing power.
Recently, Electro Optic Systems (EOS) announced a major breakthrough in this field: The Guide Star Laser technology, developed in collaboration with the Space Environment Research Centre (SERC), located at the EOS Space Research Centre in Mount Stromlo Observatory, Canberra, Australia. The tech uses two lasers: a bright orange beam that can be seen by the naked eye as it penetrates the atmosphere and pinpoints the debris and the second one, more powerful yet invisible, is directed at the debris, causing it to fall out of orbit and avoid colliding with vital infrastructure such as satellites.
Many space organizations are now testing the possibility of an orbiting laser satellite. However, the deployment of lasers in lower earth orbit (LEO) amounts to militarization of space, which is forbidden by the 1966 Outer Space Treaty, which directs to “not place nuclear weapons or other weapons of mass destruction in orbit or on celestial bodies or station them in outer space in any other manner.”
Diplomatic quagmires aside, an efficient way of clearing up the space is the need of the hour as large constellations of small satellites are being launched such as OneWeb and Space X’s Starlink. The problem, if left unresolved, could lead to more debris collisions, potentially triggering an exponential increase in debris, called the “Kessler effect,” and making space less accessible. Considering that the future of humankind is inextricably tied to space exploration, that’s definitely not how we want to leave things up there.