The risks of a falling satellite damaging another satellite or spacecraft in orbit around Earth depend on several factors, including the size and mass of the falling satellite, the location and altitude of the orbits involved, and the density of objects in space. Here are some potential risks:
Collision Risk: If a satellite or spacecraft in orbit fails or is no longer operational, it can become a space debris object. When such debris re-enters Earth's atmosphere, it undergoes atmospheric drag, causing it to decelerate and eventually burn up. However, larger debris pieces may survive the re-entry process and pose a risk of colliding with other satellites or spacecraft that are in orbit. Collisions can cause significant damage or destruction to operational spacecraft.
Uncontrolled Re-Entry: Satellites that have exhausted their fuel or lost control may re-enter Earth's atmosphere in an uncontrolled manner. In such cases, the exact time and location of re-entry are uncertain, making it difficult to predict where the debris might fall. Uncontrolled re-entry increases the risk of debris landing in populated areas or impacting other satellites or spacecraft.
Active Satellite Collisions: Although rare, the risk of a collision between two operational satellites exists. This risk is particularly relevant in crowded orbital regions, such as low Earth orbit, where numerous satellites are present. Collision events can generate a large amount of additional debris, further increasing the risk to other satellites and spacecraft.
To mitigate these risks, space agencies and organizations employ measures such as careful mission planning, orbital debris tracking, and international guidelines to minimize space debris. Additionally, satellite operators strive to deorbit satellites at the end of their operational life or move them into a graveyard orbit, which is a higher and less congested orbit where they are less likely to pose risks to other satellites. Efforts are also underway to develop technologies for active debris removal and improve space traffic management to ensure the long-term sustainability of space activities.