Tidying up space
The EU and Japan tackle the space debris problem
Text by Justin McCurry
Text by Justin McCurry
Space debris is a catchall term for any defunct, manmade material orbiting Earth — ranging from tiny flecks of paint and pieces of glass to spent rocket stages and entire satellites that have malfunctioned or run out of fuel — hurtling along at speeds of up to 28,000km/h.
Despite growing urgency to address the buildup of flotsam in “useful” orbits, which are populated by operational satellites, the international community has yet to agree on legally binding principles to mitigate the potentially catastrophic effects of space debris.
It is impossible to say exactly how much junk litters space, although the consensus is that six decades of human activity have generated more than 500,000 items bigger than one centimetre in diameter — about the size of a marble — that are now whizzing around us.
The European Commission has warned that the buildup of debris “represents a growing threat to European space activities”, noting that an object as small as one centimetre can damage or even destroy a satellite. “By 2020, there is expected to be around a million of these objects in orbit,” it says on its website.
High-velocity collisions in low Earth orbit — between 200km and 2,000km above Earth’s surface — result not only in damage to satellites, they also cause disruption to internet connections, navigational systems and mobile phone coverage.
At present, countries with space programmes have a limited range of tools to protect their assets from the space junk menace. Some EU member states, for example, participate in space surveillance and tracking, which employs ground-based sensors such as telescopes and military radar to identify and monitor satellites and space debris.
There has been progress, too, in developing technology that, it is hoped, will one day be able to pluck potentially hazardous objects from space. In February, the RemoveDEBRIS project, an international consortium co-funded by the European Union and based at the Surrey Space Centre, successfully fired a “harpoon” at a planted satellite panel, proving that an orbital spring clean is more than the product of a fevered imagination.
Professor Guglielmo Aglietti, director of the centre, said in a statement that the harpoon experiment was “truly remarkable”, adding: “This is RemoveDEBRIS’ most demanding experiment, and the fact that it was a success is testament to all involved.”
The world’s three biggest users of space — Russia, the US and China — are responsible for most space debris, but the emergence of new national and private players has made the need to find a solution even more pressing.
“Tackling the problem of space junk now is important because it may soon get out of hand, due to collisions that will produce yet more space junk,” according to the Tokyo office of Arianespace, a France-based launch services group.
Arianespace is addressing the issue by ensuring that its spent rocket stages are emptied of any remaining fuel, so they do not explode, and are jettisoned to ensure they burn up in the atmosphere.
Errol Levy, a political counsellor at the Delegation of the European Union to Japan, noted that the EU and Japan agree on the need for a global set of voluntary norms that discourage countries with space programmes from turning outer space into a “satellites’ graveyard”.
“The European Union and its member states are particularly keen on safeguarding the long-term use of the space environment and would like to have the principles of responsible
behaviour in outer space included within the framework of the United Nations,” Levy says.
Prevention is better than cure, according to Levy, given the quantities of space debris and the cost of removing it from orbit — if cleanup technology is ever perfected.
“No matter how successful you are in specific projects to develop technologies to clean up the space environment, you’re talking about hundreds of thousands of pieces of debris, so collecting any of that is a very expensive proposition,” Levy says.
“This is something that the EU and Japan have expressed their keenness to work on,” he adds, noting that the subject formed part of discussions at the Fourth Meeting of the EU–Japan Space Dialogue in March.
Options include “deorbiting” (bringing satellites out of orbit so they splash down in remote parts of the ocean) and sending satellites out of their “useful” orbits into those where they no longer pose a threat.
The prospect of thousands of mini-satellites orbiting Earth in the near future brings increased risks. But it also represents an opportunity for companies such as Astroscale, a start-up founded in Singapore in 2013 by Japanese entrepreneur Nobu Okada. It is developing “space sweeping” satellites to clean up debris.
“Astroscale aims to launch satellites to go up, rendezvous and dock with defunct satellites, then deorbit them,” said Jason Forshaw, the firm’s European R&D manager.
In a demonstration planned for 2020, an Astroscale satellite will launch, together with a dummy debris satellite and attempt to dock with the dummy debris using a magnetic capture mechanism. Both satellites will then deorbit so that they burn up in the atmosphere.
“Safety is a prime concern, especially in ensuring no further debris is produced,” Forshaw says. “However, Astroscale is not only developing technical solutions to debris, we are playing a role in growing the debris removal market and actively discussing the regulatory environment for orbital debris removal.”
Satellite operators themselves are also taking action. Ruy Pinto, chief technology officer at SES, says 20 of the Luxembourg-headquartered firm’s 70-plus satellites operate in orbits above 8,000km, while the other 50 are at 36,000km, distances at which the risks from space debris are low.
“Whilst SES is engaged in the mapping and awareness of space debris, its assets are not directly affected,” Pinto states. “From an awareness-campaign perspective, we are building a close collaboration with the recently formed Luxembourg Space Agency, and space debris is among the topics we’re tackling.” •