Earth’s orbit is congested, and the issue is likely to get worse as more satellites are sent into space. In 2021, the European Space agency (ESA) spotted more than 30,000 pieces of space debris, according to its yearly report. 31,050 are currently being tracked, but “the true number of objects larger than 1cm in size is likely over one million,” ESA states. Statistical models estimate the amount of space debris to be much vaster. The 6,200 rockets and around 12,980 satellites launched since the start of man’s venture into space in 1957 have left an estimated 36,500 debris objects of more than 10cm, 1 million objects between one and ten centimeters, and 130 million objects smaller than 1 cm floating in orbit.
The issue with this is that, though the size of the debris might appear small, the damage it can cause, is not. A small aluminium sphere of 1.2 cm in diameters, weighing 1.7g can, at the 15,700mhp speed it travels at in space, create a 9 cm impact on a compact aluminium block. Every year, the ESA performs around two collision avoidance manoeuvres, which costs it fuel, data and budget spent on monitoring the potential impacts.
Another problem is the Kessler effect, explains Uni.lu graduate Rui Zong, who studied the topic of space debris removal companies. In this scenario, there are so many objects in our low orbit, that their collisions become inevitable and creates a snowball effect resulting in more debris. ““If we reach the Kessler syndrome, we won’t be able to launch any new items into orbit, because they will just crash against the rest. They will cause more space debris, which again will cause even more collisions,” Zong explains.
A sense of déjà-vu
While companies working on the ground grapple with applying sustainability in their business models, to reverse or alleviate the pollution of the past, it could appear that in space, the thought of end-of-life preparations for future projects isn’t considered. ESA in 2012 launched the Clean Space programme to encourage businesses to be greener in their missions.
However, Zong says: “All the operators need to design the end-of-life stage of satellites, but it costs a lot.” According to the ESA, rockets launched these days are programmed to either be disposed of responsibly, or to be sent “in orbits that naturally decay within 25 years.” The agency estimates that around 90% of space objects need to be removed to limit the growth of space debris, and before it can be cleaned up.
Current space development actors also need to consider the anti-collision guidelines set out by the Inter-agency Space Debris Coordination Committee (IADC), which recommend limiting the amount of debris released during operations, for instance.
Items launched decades ago also need to be addressed, and taken care of. Some entrepreneurs have already identified this need, and have either started a space junk removal service, or offer it while working on other tasks in space. ESA-supported ClearSpace, for instance, in its 2025 mission will use four robotic arms to collect debris and drag it into the Earth’s atmosphere where the junk will disintegrate. Origin Space, on the other hand, plans on using a net to capture anything flying around in orbit, while Astroscale uses magnetic absorption.
Debris as resources
Others, in turn, follow the old saying “one man’s trash is another man’s treasure.” This is the case for Germany-based Orbit Recycling and Cislunar Industries based in Luxembourg. The latter plans to recycle debris, and turn it into valuable resources through an in-space metal foundry.
The question that remains then is, who will pay for this? Missions to remove debris are necessary but costly, explains Zong. In her opinion, satellite operators, national agencies and insurance companies--specialised in satellite insurance--will bear the cost of the work that needs to be undertaken. Currently, the Organisation for Economic Co-operation and Development calculates that 5%-10% of total mission costs go into protecting satellites from collision with debris. And while this cost is likely to increase if junk removal isn’t tackled faster, there will be another price to pay.
Inaction could lead to an ecological tipping point, says the OECD, where some orbits may become unusable. The Kessler effect--if we get to that point--would also increase risks for astronauts. And ultimately, it would cause the space sector’s development to crash before it reaches its full potential. Even functions taken for granted, like weather forecasts, climate monitoring and space-based communications are now in peril. Inaction, according to the OECD, will only lead to repeating the same mistakes as on Earth.