Use and Pollution of Space: The Changing Earth Orbit Environment

Satellites play many essential roles, from communications and navigation to Earth imaging in support of agriculture, fishing, forestry, disaster relief, environmental science, surveillance and security. Yet satellites are threatened by their own increasing numbers, as well as an accumulation of debris such as leftover rockets, defunct satellites, and fragments from in-orbit breakups and collisions. These risks will soon increase: SpaceX has launched the first 180 of a planned 12,000 communications satellites, with a possible extension to 42,000, into low Earth orbit (LEO), while OneWeb and Telesat have secured funding for their own ‘mega-constellations’. Over the next decade, the number of satellites is expected to increase by an order of magnitude, from about 5,000 to about 50,000. Anti-satellite (ASAT) weapons, including one tested by India in 2019, can add further debris and thus destroy unintended targets. There are no international rules that specifically govern access to LEO, setting the stage for a ‘tragedy of the commons’. This talk will focus on the changing Earth Orbit environment, challenges facing its management, and some of the mitigation efforts that are underway.