Satellite makers and operators must be held responsible for the growing hazard of space debris, according to experts who say a legally binding global treaty must be thrashed out to protect the orbital environment.
With the number of satellites rising dramatically, the agreement would make manufacturers and users responsible for de-orbiting defunct hardware and cleaning up any debris created when orbiting objects slam into one another.
The call to action comes from leading figures in space industry and research, and marine scientists, who believe lessons should be learned from the years-long effort that finally culminated in this week’s groundbreaking agreement on a high seas treaty to protect the oceans.
“If we are too slow and don’t have these discussions now we’re going to create a huge mess,” said Dr Imogen Napper, a marine scientist at Plymouth University’s International Marine Litter research unit. “We have an early opportunity to make a positive impact but time is running out.”
About 9,000 satellites orbit Earth but the number is likely to exceed 60,000 by 2030. The trend is largely the result of a shift towards mega-constellations of small satellites. Elon Musk’s SpaceX has launched more than 3,000 Starlink satellites into the most congested low Earth orbit (LEO) and is on course to hit 12,000 by 2026.
While space is vast, most satellites operate from LEO less than 1,000km above the ground. Besides fully operational satellites, the orbit is strewn with dead and dying hardware, hazardous debris from past collisions and spent rocket parts. An estimated 100tn untracked pieces of old satellites are already in orbit.
Much of the debris has been circling the planet for decades. In January, an old Soviet rocket body shot past a dead Russian spy satellite, avoiding by metres a collision that would have left thousands of fragments in its path.
One feared scenario is a collision with Envisat, the European Space Agency’s largest Earth observation satellite, which has been adrift in LEO for 11 years. Ultimately, space junk could make key orbits unusable.
Writing in the journal Science, Napper, along with the head of Spaceport Cornwall, Melissa Quinn, and Dr Kimberley Miner at Nasa’s jet propulsion lab in California, describe how a failure to protect the oceans led to overfishing, habitat destruction, deep-sea mining exploration and ubiquitous plastic pollution.
“To avoid repeating the mistakes that have left the high seas – and all who depend on them – vulnerable, we need collective cooperation, informed by science, to develop a timely, legally binding treaty to help protect Earth’s orbit,” they say.
Napper said all countries that use, or aim to use, space should be involved in discussions to draw up the treaty. It should make clear that satellite producers and users have responsibility for removing old satellites from orbit and cleaning up debris from collisions, with enforcement including fines and other incentives.
“Had an intervention to curb plastic pollution been initiated a decade ago, it might have halved the quantity of plastics present in the ocean today,” Napper and her colleagues write. “The cost of delaying the protection of Earth’s orbit should not be underestimated.”
Thrashing out such a treaty would be no mean feat, according to Christopher Newman, a professor of space law and policy at Northumbria University. “The difficulty of negotiating a binding treaty on space debris, which will endure and make a positive difference, is that the very nations who need to compromise are geopolitical adversaries,” he said.
“It looks more likely that countries that wish to take a leadership role in this area are going to have to try and bring as many others onboard. Establishing what ‘good’ looks like in terms of responsible behaviour would go a long way towards setting humans on a more sustainable path in outer space.
“Whether in the form of a binding international treaty or a series of non-binding softer agreements that actually shape behaviour, states are going to have to start showing real leadership in this area. The cost of a major collision in orbit could be economically and environmentally devastating.”
