Looking up at the sky on a clear night (likely not in Hoboken), there’s a chance you will be greeted by a strange sight: a long, glowing, perfectly straight line of lights filling the sky. No, it’s not an alien invasion; it’s SpaceX’s Starlink constellation. While the line of more than 7,000 satellites in low Earth orbit might seem like an unwavering symbol of human achievement, the Starlink satellites actually do have to physically readjust a great deal. In fact, since the first satellites were launched in 2019, Starlink satellites have been forced to perform collision avoidance maneuvers with other satellites some 50,000 times.
However, Starlink is not the only culprit of this rising occurrence. Our space is crowded. Currently, there are more than 13,000 satellites in orbit, with about 10,000 of those being functioning. These satellites range from scientific experiments, to GPS systems, to communications, to your satellite TV. With the increase in objects in low orbit around Earth, however, comes with it the threat that those objects will collide.
Satellite collisions have become an inevitable catastrophe, according to experts. One professor of astronomy pointed out that as the problem of satellite danger slowly increases, we may not be able to do anything until it is too late. And as one astrophysicist at the Harvard-Smithsonian Center for Astrophysics, Dr. Jonathan McDowell, put it: “we are operating on the edge of what is safe.”
Some crashes have already taken place. In 2009, the working US satellite Iridium 33 crashed into the Russian satellite Cosmos 2251, which was inoperable and non maneuverable. Scientists estimate that this crash created more than 2,000 pieces of smaller debris that is now orbiting Earth.
The potential threats from such a crash are immense. Temporary satellite outages caused by collisions could affect GPS and airplane communications, which could have unbelievable consequences. Collisions also give rise to other collisions, as hypothesized by astrophysicist Donald Kessler in 1990. His infamous ‘Kessler effect’ points out that as more debris collects in low Earth orbit, there is a higher chance that debris will collide, creating more debris, and the cycle continues. So far this has proved to be true, as NASA estimates there are 23,000 pieces of debris larger than a baseball orbiting Earth. Collisions also fill the atmosphere with aluminum and nitrous oxide, adding to the environmental hazard. On top of all of this, the increase of satellites and debris has begun to hurt the ability of astronomers to make observations from Earth.
There are some potential solutions to this problem. The aforementioned Starlink satellites perform a maneuver if the probability of a crash is calculated to be 1/100,000, which can help to avoid collisions. This solution, however, does nothing for the decommissioned or non-maneuverable satellites and space debris already in orbit. Groups like NASA have put forward the suggestion all future satellites be maneuverable and recoverable, as well as developing plans for the recycling of small space debris. These solutions could also involve controlled deorbiting of debris in order to reduce the risk of further collisions, allowing it to burn up in the atmosphere.
As the space industry continues to grow, it is inevitable that satellite collisions will as well, prompting scientists and policymakers alike to address this astronomical issue.
