The Growing Threat of Space Debris and the Urgent Need for Mitigation
The realm above Earth, once a frontier of peaceful exploration, is increasingly becoming cluttered wiht debris, posing a notable and growing threat to current and future space activities. While the problem isn’t new, recent trends are raising alarm among space debris specialists.
A prime example of the long-term risk is the Envisat satellite, launched in 2002 by the European Space Agency. Now defunct since 2012, its eight-ton mass and stable orbit classify it as a substantial potential hazard. However, the issue extends beyond legacy debris.
As January 2024, China has launched 26 new rocket bodies into orbits projected to remain stable for over 25 years. These originate primarily from launchers deploying satellites for the Guowang and Thousand Sails constellations. Despite international guidelines advocating for responsible space practices, Beijing continues to allow these upper stages to drift, escalating the risk of future collisions.A photograph taken last year by Astroscale‘s ADRAS-J probe illustrates the reality of this debris - a Japanese H-IIA upper stage, a stark reminder of the potential for uncontrolled objects in orbit.
International directives currently recommend that any debris left in low Earth orbit should re-enter the atmosphere within 25 years. europe and the United States are increasingly adhering to this principle. SpaceX, for instance, routinely deorbits the upper stages of its Falcon 9 rockets after each launch, preventing them from becoming long-term orbital hazards.
China, though, appears to disregard these guidelines in many of its launches. Experts, like McKnight, estimate that if current practices continue, China could leave over 100 rocket bodies adrift in the next 25 years. While some Chinese rocket technologies, such as the Long March 5 and its YZ-2 upper stage, are capable of controlled deorbiting, the majority of launches still release spent stages into space, foregoing mission adjustments or payload capacity reductions to accommodate the fuel needed for atmospheric reentry.
This accumulation transforms low Earth orbit into a risky environment.The planned expansion of Chinese megaconstellations, comprising thousands of additional satellites, further exacerbates the risk of collisions with existing debris.
Fortunately, the overall risk can be substantially reduced through focused efforts. Removing the ten most dangerous debris objects could decrease the potential for creating new fragments by 30%, and removing 50 would cut that risk in half.
This highlights the necessity of developing active space cleaning programs. Companies like Astroscale are pioneering such initiatives, having already demonstrated the ability to dock with an inert object in orbit, with the goal of capturing and deorbiting debris for atmospheric burn-up.
However, these programs are currently limited by a lack of a viable economic model.The cost of cleaning space is significant, while continuing to launch without debris mitigation is cheaper. Yet, the consequences of inaction could be catastrophic for all space-faring nations and organizations.
As McKnight and his colleagues warn, “we can halve the risk by removing 50 items. But we just added 26 in two years.” This underscores the urgency of the situation. Without a change in course, the protective shield of space above us risks becoming a new arena for technological conflict.
