Since 1957 we have launched over 10,000 satellites into space. Extraordinary discoveries have been made and impressive technological advancements have been achieved. But with over 6,000 tonnes of space hardware currently orbiting Earth, fewer than 1,000 satellites are active. There are several thousand de-commissioned satellites, mission related objects and on-orbit fragmentations in lower Earth orbit (LEO) and geostationary altitudes. So what consideration is being given to the trail of debris left in space each time a satellite is deployed and why is there a growing concern for the congestion caused by this debris as it travels at speed, particularly in Earth’s lower orbit?
This year, the United States Space Surveillance Network tracked more than 14,000 pieces of space debris larger than 10 cm in width. It is estimated that there are approximately 200,000 pieces between 1 and 10 cm wide and that there could be millions of pieces smaller than 1 cm. How long a piece of space debris takes to descend to Earth depends on its altitude. Objects below 375 miles orbit several years before re-entering Earth’s atmosphere. Objects above 600 miles orbit for centuries. Objects orbit Earth at high speeds, up to 5 miles per second, so a collision with even a small piece of space debris can cause catastrophic damage to a spacecraft. The first collision that destroyed an operational satellite happened on 10th February 2009, when an American communications satellite, Iridium 33, owned by Motorola, collided with Cosmos 2251, an inactive Russian military communications satellite, approximately 470 miles above northern Siberia, shattering both satellites. The worst space-debris incident happened on 11th January 2007, when the Chinese military destroyed the Fengyun-1C weather satellite in a test of an anti-satellite system, creating more than 3,000 fragments of space debris. Within two years the fragments had outstretched from Fengyun-1C’s original orbit to form a cloud of debris that completely encircled Earth and that will not re-enter the atmosphere for decades.
But space debris cannot simply be extirpated, as this would exacerbate the problem, causing smaller but additional pieces of dysfunctional waste. With so many objects travelling at high speed the risk of them colliding with each other, not just with satellites and spacecraft, also adds to the growing concern. So, what is the solution? Space detritus must be captured, de-orbited and destroyed in the Earth’s atmosphere to set us on the right trajectory to eradicate this increasingly concerning matter. Hence the emergence of the space debris sub-sector and its pivotal importance to the future of the space industry.
Since the stability analysis study of the space environment was conducted by NASA in 2006, and later confirmed by the European Space Agency’s simulations, whereby the environment was studied independent of human space activity (no launches, no debris generated), it is globally accepted that the number of large mass space debris is growing due to the number of collisions from existing debris, and could potentially initiate a minacious chain reaction of destruction to the point where the number of large mass space debris reaches a critical density, rendering LEO an unacceptably high risk for space operations in the future. We could face a future where damage to a single satellite may escalate into large scale global satellite technology demolition. With global economies relying on LEO satellites for functions such as GPS navigation, map technologies, mobile communication and weather forecasting, a future where these essential services are severely disrupted would be bleak.
NASA and ESA determined from the study that the space environment could be stabilised if 5-10 large and strategically chosen objects are removed from LEO per year with a removal sequence oriented towards the target mass. This active pursuit of technologies and systems for space debris removal inaugurated the Clean Space Initiative.
This initiative has set out an exciting roadmap to establish a global focus on the environmental impact of space programmes, the development of green technologies to mitigate environmental impact of space activities, space debris mitigation to study and develop affordable technologies to manage obsolete space assets and develop key technologies for space debris remediation and removal. The capture and removal of space debris poses a significant challenge; technically, legally, and financially. So, who is stepping up to the plate to tackle this 21st century deep clean?
Key players in the global space debris removal market include: Airbus S.A.S. (Netherlands) who are actively tracking over 20,000 pieces of space debris larger than 10cm, Altius Space (U.S.A), Ariane Group (France), Lockheed Martin Corporation (U.S.A), Surrey Satellite Technologies Ltd (U.K.), and government space agencies such as the European Space Agency, and Indian Space Research Organisation to name but a few.
Never has there been a more exciting time to be a key player in the space debris removal industry and it is encouraging that so much work, progress and investment is happening on our home soil in the UK. Building on the British satellite RemoveDEBRIS research project by The University of Surrey, which was launched in 2018 and deployed from the International Space Station, which tested two different pulling technologies for removing space debris: capture with a net and capture with a harpoon, there has been extensive research into new technologies through the Technology Research Programme (TRP) and General Support Technology Programme (GSTP). These include pushing technologies – forcing the debris into the ocean, contact-less technologies – docking to well-known and cooperative orbiting objects and Ion-beam shepherd methods – using propellant charged ions to achieve a contactless slow-push deflection of the target.
A Scottish based company, AAC Clyde Space, as part of a three-year project called xSPANCION, will develop and manufacture satellites called CubeSats in Glasgow, to provide space-based services to companies eager to exploit satellites to solve business problems, without having to invest in the expensive space-based hardware or related expertise. This will significantly reduce the cost of data collection and images captured, supporting business cases that have previously lacked the justification for capital expenditure to endure the costs of having hundreds of sensors in orbit. The 10x10x10cm cubes are designed to de-orbit in 2-5yrs so as not to add to the space debris issue. With this opportunity for more businesses to access space without the affiliated costs, it enables an ever-growing opportunity for those businesses to focus on the development of technologies to support the Clean Space Initiative. The U.K. Space Agency will contribute 9.9 million euros to the project through the European Space Agency.
Planned for 2025, Clearspace-1 (known as The Claw) is the first satellite committed to removing an existing object in orbit. It is a small first step towards a cleaner space environment but a giant leap for the space industry. The Claw will use a pincer motion to collect debris, before giving it a controlled re-entry into Earth’s atmosphere, allowing it to combust safely. UK based Aerospace and defence company Elecnor Deimos will design Clearspace-1’s Attitude and Orbit Control System (AOCS) which will orientate and position the satellite to help grab the space waste, using power generators, thrusters and antennas. This revolutionary new satellite is essential to reduce hazards for future missions and prevent collisions that will generate even more waste in the future.
We are on the cusp of pioneering space exploration, with China planning an ambitious moon mission to collect lunar samples and the UK planning The Artemis Project to establish a lunar space station and make history by getting an astronaut to land on Mars by 2024. We cannot allow the ever-growing hindrance of the space debris obstacle to stand in our way. A new era of satellite technology to remove space debris is emerging and it is vital the UK takes a global leadership role in the space clean-up operation. Without growth and development in space debris removal technologies, will lower earth orbit become inoperable in just a few generations time?
