Litter is not uncommon when walking the streets of Boston. While unpleasant to look at and damaging to the environment, people may see it as a nuisance rather than an imminent threat to their well-being. However, there is a type of pollution that, while not visible to the naked eye, has the potential to be incredibly damaging: space debris.
Space debris will most likely never directly harm us. The atmosphere’s density combined with the speed of the space debris would cause any external matter to burn up the same way a shooting star would. However, more than 13,000 tons of debris are floating in space, comprised of over 40,500 individual objects greater than 10 cm. When anything of weight as significant as this is moving at 10 kilometers per second, it becomes a threat to anything it comes into contact with. This debris is dangerous since there are over 10,000 satellites in space, and there have been over 650 separate incidents where satellites have gotten into collisions, resulting in explosions or fragmentation.
Kessler’s syndrome, developed in 1978, is the theory that satellite collisions would produce orbiting fragments of their own, each of which would increase the probability of further collisions, leading to the accumulation of a belt of space pollution around the Earth. The impacts of this cannot be understated — the cascading effect of satellites colliding with each other and future debris would only accelerate the process. It is a point of contention when exactly too many satellites cross the point of no return, but what is clear is that the results would be catastrophic. Many essential services used in everyday life rely on satellites — television, GPS, cell service, military, and scientific research — and they would all be significantly disrupted and destroyed once the chain reaction begins.
There are worrying signs we should be taking this problem more seriously. Take SpaceX as an example; they plan on sending up 42,000 satellites as part of their Starlink program. Satellite technologies have made strides since 1978 — Starlink satellites are programmed to eventually burn up in Earth’s atmosphere and also can maneuver around space debris using onboard thrusters and AI, which Kessler did not account for. However, these new anti-collision measures may not be enough in the face of technological failures. Researchers at COMSPOC question whether or not the ability of satellites to maneuver outweighs the risks of not being able to accurately calculate the current trajectory of all satellites in the sky. There is also a possibility of a solar flare event causing mass malfunctions, which have not been accounted for in recent satellite technology.
Currently, there is discourse in the scientific community about limiting the abilities of private companies to abuse the negative externality of free space and there has been promising legislative progress. For example, the ORBITS Act was unanimously passed by the US Senate in 2023 and will support the development of future technology to remove space debris before it becomes a larger problem. However, once we reach the point where Kessler syndrome is in full effect, scientists argue that the problem has become irreversible — therefore, it is critical to be careful with what we are putting into space.