Space junk is among the many concerns posed by the XXI century’s space race, pushing experts to raise awareness of the potential impact of the hundreds of thousands of expected satellites to orbit Earth in the coming decade.
1. Tracking satellites in orbit
Jonathan McDowell is an astrophysicist and astronomer at the Harvard-Smithsonian Center for Astrophysics who decided to track the growing number of satellite launches and the ballooning number of objects in Earth orbit. McDowell shares with the public the outcomes of his mapping through his monthly digital circular called Jonathan’s Space Report.
It’s going to be like an interstate highway, at rush hour in a snowstorm with everyone driving much too fast. Except that there are multiple interstate highways crossing each other with no stoplights.
Jonathan McDowell, astrophysicist and astronomer at the Harvard-Smithsonian Center for Astrophysics
The project started with an ambition to “provide a pedantic historical record of the space age,” McDowell told Space.com, but it became a chronicle of the environmental destruction of the near-Earth environment. In his frequent media appearances, McDowell has been vocal about what he perceives his views on the future of the increasingly overcrowded near-Earth space.
“It’s going to be like an interstate highway, at rush hour in a snowstorm with everyone driving much too fast,” he told Space.com when asked what the situation in orbit will be like if existing plans for satellite megaconstellations such as SpaceX’s Starlink, OneWeb and Amazon Kuiper come to fruition. “Except that there are multiple interstate highways crossing each other with no stoplights.”
2. Satellite collisions
Hugh Lewis is a Professor of Astronautics at the University of Southampton in the UK and a co-director of the Centre of Excellence in In-situ and Remote Intelligent Sensing. Over the past years, Lewis has been publishing regular updates on his Twitter account detailing the increase in so-called conjunction events, situations when two objects in space — functioning satellites or pieces of space debris — may collide. In a Twitter post published on January 13, Lewis stated that “the overall number of conjunctions predicted for 2022 was 134% higher than the number for 2020 and 58% higher than 2021, exceeding 4 million.”
3. Space debris
The European Space Agency estimates that near-Earth space is cluttered with some 36,500 pieces of space debris larger than 10 centimetres, about a million objects 1 to 10 centimetres in size, and an astounding 130 million fragments smaller than 1 centimetre.
“There’s good evidence that the number of minor collisions is already increasing significantly,” McDowell said. “We’re seeing debris from objects that shouldn’t really be creating debris. They probably have been hit by something small, even if they carry on working afterwards.”
The combination of increasing numbers of new satellites and the growing amount of space junk orbiting Earth leads to a dangerous situation that in the not-so-distant future may turn some regions of near-Earth space into a dangerous no-go zone. On January 27, an incident happened between two large defunct bodies — dead satellites or used rocket stage.
“Things like [the January 27 incident] will start happening more often,” McDowell said. “One collision doesn’t change things dramatically, but once we have one a year, you get to a regime where you start to have a lot of losses of satellites. It really will start to affect the economics of low Earth orbit. Companies will start losing serious money because their satellites keep getting destroyed.”
While asserting how many satellites can orbit Earth safely remains a difficult question to answer, McDowell says that humankind is likely going to discover the natural capacity of near-Earth space “the hard way.”
