As we continue to push the boundaries of technological innovation, we are also creating an unexpected and growing problem: space debris. This term refers to the accumulation of defunct satellites, spent rocket stages, and other fragments clogging Earth's orbits, posing a significant threat to both manned and unmanned space missions.
According to the Natural History Museum, approximately 2,000 active satellites orbit the Earth, along with 3,000 defunct ones. Additionally, there are around 34,000 pieces of space debris larger than 10 centimeters and millions of smaller fragments that could still be devastating in the event of a collision with other objects. Even tiny fragments, such as paint chips, can cause significant damage when traveling at high speeds.
The problem of space debris has intensified since the beginning of the space age in the 1950s. With every rocket and satellite launch, the risk of collisions increases. For example, the International Space Station (ISS) must perform hundreds of collision avoidance maneuvers each year to evade approaching space debris.
The situation is so serious that an international team of researchers recently called for a global treaty to limit the number of satellites and debris in Earth's orbit. In an open letter published in the latest issue of Science, they cited a staggering number of 100 trillion objects currently orbiting the planet—a number expected to grow exponentially with the planned launch of new satellite constellations (Time).
The United Nations has urged companies to remove their satellites from orbit within 25 years of their mission’s end. However, enforcing this rule is challenging, especially when satellites malfunction. To address this issue, several companies have proposed innovative solutions, such as using harpoons, nets, magnets, or lasers to remove defunct satellites from orbit and pull them back into the atmosphere, where they will burn up.
However, these methods are only effective for large satellites. For smaller debris, we must wait for them to naturally re-enter Earth's atmosphere. This has raised concerns about the Kessler Syndrome, a scenario proposed by NASA scientist Donald Kessler in 1978. He suggested that an excessive amount of space debris in orbit could trigger a chain reaction in which more and more objects collide, generating even more debris—ultimately rendering Earth's orbit unusable.