The increase in the number of satellites in orbit has posed a major air pollution challenge as they burn up in the atmosphere, creating compounds that are harmful to the ozone layer.
This problem is gaining increasing attention as the satellite industry grows rapidly, with more than 100,000 satellites expected to be launched in the next 10 years. To address this problem, scientists have proposed four potential solutions.
Development of recoverable satellites
Some companies, such as Britain's Space Forge, are working on satellites that can withstand high temperatures during atmospheric re-entry, allowing the satellites to fall back to Earth without being destroyed.
The technology could allow satellites to be recovered and reused, rather than burned up and releasing toxic gases. Reusing satellites would not only reduce pollution but also bring huge economic benefits, according to Andrew Bacon, CTO of Space Forge.
Recycling space debris
Patrick Neumann of Australian company Neumann Space has introduced a new electric propulsion system that uses aluminum from old satellites as fuel. The technology works similar to an electric welder, turning the aluminum into plasma to propel the satellite. Neumann believes that recycling satellites in space would be an effective way to reduce debris while providing sustainable fuel.
Restructuring the atmospheric reentry process
Instead of burning up at 60-80km, satellites could be designed to disintegrate at lower altitudes, between 20 and 30km. Controlling the disintegration altitude of satellites could help reduce the amount of chemicals that linger in the atmosphere, limiting the impact on the ozone layer, according to Minkwan Kim, a professor at the University of Southampton.
Environmentally friendly materials
Finally, scientists encourage the use of environmentally friendly materials. Building satellites from less toxic or biodegradable materials could reduce the impact of a satellite fire. However, alternative materials remain challenging and require time and investment to test their feasibility.
