Space pollution, often called space debris, refers to satellites and other material that occupies a relatively small portion of low-Earth orbit. Scientists are concerned that a cascade of breaking debris could pose a threat to future launches.
Low-Earth orbit is a crowded place. Since the launch of Sputnik I, the number of satellites in space has increased. Spent rockets and other debris are present as well. In total, space is filled with tens of thousands of satellites and other pieces of debris. Over time, satellite batteries run out or they are rendered inoperable due to damage or malfunction.
Satellite and pieces of debris collide with each other, which causes them to break into many smaller pieces. These smaller pieces pose a threat to other orbiting satellites, and collisions will result in yet more small pieces of debris. Experts caution that the mass of space pollution could become so great that future space launches could be at risk.
This problem is difficult to fix. Using lasers to destroy debris would likely make the problem worse by increasing the amount of debris, and the cost of launching a satellite to send small pieces back to Earth is expensive. Scientists rely on databases of space debris to help them determine if functioning satellites are at risk.