How to Clean up Space Debris: High Tech Solutions
It is expected that by 2029 there will be 57,000 satellites in orbit, which represents a new sustainability challenge.
Since 1957, with the launch of Sputnik, space debris has only increased. Virilio, the French thinker, once said that each technology brings with it a new type of accident. In other words, before airplanes, there were no aviation accidents. The space race and the subsequent commercial satellite-era illustrate this perfectly. While space technology has opened up an infinite field of possibilities, the thousands of satellites orbiting the Earth today run the risk of turning the immediate outer space into a veritable garbage dump. Considering that each fragment travels at 22,300 miles per hour and that all this junk has the potential to remain floating in low Earth orbit for centuries, it is easy to imagine the catastrophic consequences for scientific research and communications networks. Fortunately, turning Virilio's reasoning on its head, each technology also brings a new solution. This is the case of ClearSpace 1, a space junk cleanup technology project along the lines of RemoveDebris that we mentioned some time ago.
ClearSpace 1, towards a more sustainable outer space
The ClearSpace 1 approach had been on engineers' drawing boards for some time, but this year an agreement was finally signed with the European Space Agency. The mission will take place in 2025, and its objective will be to remove a fragment of the Vega rocket launched in 2013. It is a bulky piece, about a hundred kilos and a similar size to many satellites in orbit, which is why it has been selected. The concept is relatively simple—a vehicle will be launched with several mechanical arms that will trap the piece in orbit. Once captured, a descent maneuver will be initiated with which the spacecraft and the piece of junk will disintegrate due to the atmosphere's friction. In other words, a "suicide" mission.
ESA will invest seventy million euros in the project and intends to turn it into a new platform to remove large objects in low Earth orbit (LEO). The concern is that small fragments may impact large decommissioned satellites, thus generating clouds of debris. These fragments, in turn, could impact other satellites, which would multiply the space debris unstoppably. This phenomenon is known as the Kessler effect, after Donald Kessler, a researcher who first formulated it in 1972. Fortunately, ClearSpace 1 is not the only technology in development to solve the problem.
Other space-cleaning strategies
Other strategies have been tried in addition to the mechanical arm system—from nets that catch floating fragments and pull them down into the atmosphere to titanium harpoons that collect the pieces. However, it seems that the key, just like the garbage down here on Earth, lies in launching devices into orbit with a recovery plan in advance. Thus, it is expected that the new generation of satellites will be equipped with various devices such as drag sail deployed at the end of the satellite's life cycle. These sails will induce the gradual descent of the satellite until its final fall and disintegration. Another option is to include a magnetic anchor plate to facilitate collection by a hypothetical space debris "truck."
These strategies will be critical since, by 2029, there will be an estimated 57,000 satellites in orbit. Fortunately, unlike previous industrialization processes, we have the knowledge and tools to resolve the situation before the accumulation of space debris becomes unsustainable.