Satellite disposal raises environmental concerns worldwide

The number of satellites in space is increasing rapidly, and this poses new environmental challenges. Each year, thousands of satellites burn up in the atmosphere. This process can damage the ozone layer and potentially impact the climate and human health. Since the launch of the first satellite, Sputnik 1, in 1957, space debris has been a concern. Today, over 28,000 objects are in orbit, with about 11,000 being active satellites. Many of these belong to large groups called mega-constellations, which provide internet services. Operators typically follow a 25-year rule, after which satellites are decommissioned and re-enter the atmosphere. The destruction of satellites was not a major worry in the past when their numbers were smaller. However, by 2030, it is predicted that there will be more than 60,000 satellites, leading to significant increases in the debris that re-enters the Earth's atmosphere. This could result in around 3,500 tonnes of aerosols being released into the air annually by 2033. Aerosols can influence the climate by either cooling or warming the planet. Some particles from the satellite debris contain metals like aluminum and lithium. There is concern that these could affect the thermal balance of the atmosphere. For example, while aluminum oxide may reflect sunlight and help cool the Earth, the long-term consequences of such emissions are still unclear. Additionally, satellite debris may contribute to the formation of polar stratospheric clouds, which are linked to ozone depletion. The ozone layer is important for blocking harmful UV radiation. Damage to this layer could lead to increased health risks such as skin cancer. While the space industry currently has a relatively small impact on the environment, as satellite launches grow, the potential risks could become more significant. Addressing these environmental challenges will require careful monitoring and innovative solutions. For now, allowing satellites to burn up during re-entry remains the most economical method for disposal.