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Since man first ventured into the cosmos, space has been gradually filling up with space junk— remnants of old spacecraft, ejected pieces of equipment, parts of launch rockets and micro-fragments of glass and metal. This junk poses a real threat to our dependency on satellite services, but luckily Dr. Jason Forshaw, part of the RemoveDebris team, is launching one the world’s first missions to test space junk capturing technologies later this year. He explains what to expect.
Often in conversations with the public, I find many blissfully unaware how satellites are being used by virtually everybody, all the time – from mobile phone calls to disaster monitoring to financial transactions. But the ever growing collection of orbital debris, or space junk, poses a risk to our satellites. Although the persistent littering of space has been known for decades, limited action has been taken to combat the problem, and there are now over 7,000 tonnes of junk out there. This is a real and accelerating threat – the 2009 Iridium 33 collision is just one of several high impact collisions that have destroyed satellites and, in the process, created more junk.
The legal and political problems
To deal with the issue we need to consider: (a) sending missions up to remove some of the larger pieces and (b) ensure future missions have technology on-board to remove themselves. Unfortunately, technology and engineering is only one half of the equation. The legal and political side presents an equally large issue that must be addressed in a collaborative, international manner.
Firstly, one should know that you can’t just send up missions to remove satellites not owned by you. Every satellite has an owner and removing satellites without gaining the permission of that owner would have legal consequences. Part of the issue is also deciding what needs to be removed and who would fund the removal of it. An even more fundamental issue is determining what the junk is to begin with, as various governmental institutions have different lists of debris. The issue is compounded by the fact that not all satellites are registered with the UN.
At the Surrey Space Centre, we lead a consortium of 10 partners including Airbus France, Germany and the U.K. to launch one the world’s first missions to test space junk capturing technologies. This mission, dubbed RemoveDebris and funded by the EU, will test for the first time a net and harpoon concept on orbit. The mission, launching towards the end of the year, will eject two artificial pieces of space junk (two small CubeSats) and use them as targets to test the new technologies.
Our mission will be one of the first to “take action” against this growing issue. To date, there have been a huge range of paper studies and simulations, but few actual missions to tackle this problem. Other missions include the European Space Agency’s (ESA’s) e.Deorbit mission planning to launch in 2024. JAXA also recently tested their KITE experiment to deploy a 700-meter tether as a de-orbitation technology (a technology to bring satellites back down to Earth quicker to burn up); unfortunately the attempt was unsuccessful.
Space is a hazardous and unforgiving environment, with huge temperature ranges, the vacuum of space, large vibrations and shocks endured when launching and even radiation. Technologies that at a first glance (such as a net) may seem very simple on Earth, become much more complicated in space. Technology demonstration missions, like RemoveDebris, allow us to test these technologies in space for the first time and ensure what has been developed on Earth can work in space.
Time is of the essence. Not too long from now the field of mega-constellations will gain further prominence. A range of companies, such as OneWeb or SpaceX, have proposed launching huge constellations of satellites into space containing from several hundred to several thousand satellites. As can be imagined, the risk of collision is massively increased with the launch of this number of satellites. It will be down to these companies and their relevant space agencies to show that they have solutions in place to manage the space junk issue. They must ensure that satellites they launch have a way to dispose of themselves and there is a solution to remove failed satellites.
The sustainability of space is critical for us all and one must recognize that the “space environment” is just as important as our environment on Earth: our atmosphere or our rainforests. Our mission, RemoveDebris, will be an important milestone in this story and a step towards minimizing collisions in space.
(All images: Courtesy Surrey Space Centre.)
All views expressed are those of the author.