How Big of an Issue is Space Debris?
Space is expansive. It’s also about to get more crowded. That has some concerns about the growing challenges of in-orbit traffic management and space debris – the pieces of space “junk” that revolve around the planet at speeds faster than a bullet.
Just a decade ago, approximately 1,200 satellites orbited the planet. Today there are at least 7,000. Thousands more are coming because several large companies have pledged to launch their own constellations – or networks – of communication satellites. Deloitte estimates that if every organization currently planning to build a constellation succeeds, up to 10 competing networks could be operational by 2030, with a total of 40,000-50,000 satellites.
In addition to working satellites, there are thousands of decommissioned satellites and rocket bodies in space. And then there are the millions of fragments orbiting the planet – the result of disintegration of satellites or the collision of two satellites, something that is more likely to occur as the skies get more crowded. Launches of new spacecraft have even been scrubbed and delayed due to the possibility of a collision with space debris. Moreover, according to recent government data, India alone has 111 payloads and 105 space debris objects orbiting Earth which can potentially affect the sustainability of outer space and future missions.
“Space debris removal is central for future safe exploration of outer space,” said Fernando Buarque de Lima Neto, IEEE Senior Member.
Traveling at more than nine miles per second – about 10 times faster than a bullet – even small pieces of debris carry significant impact. The European Space Agency estimates that there are more than 36,000 pieces of space junk larger than four inches, and tens of millions of pieces of debris smaller than that. Some space junk is tracked, but much of it is not.
To address the increasing population of space objects and the associated collision risks, the Indian Space Research Organisation (ISRO) recently introduced the ISRO System for Safe and Sustainable Operations Management (IS4OM) to ensure continuous monitoring of objects that pose collision threats and to mitigate the risks posed by space debris. To date, ISRO has successfully executed 21 collision avoidance maneuvers to prevent potential collisions with other space objects.
In addition, on a global scale as well, there is a significant research effort focused on the removal of space junk. Here are some of the latest efforts.
Space Tugs: One emerging capability in space is the use of space tugs (as in tugboats) to move satellites from one orbit to another, extending the lifetimes of out-of-fuel satellites that would otherwise be defunct. Space tugs can also tow pieces of debris toward where the debris would burn up during a controlled re-entry into the earth’s atmosphere.
Lasers: There are hundreds of thousands of pieces of debris ranging from 1-10 cm. If two of them collide – or if they collide with a larger object – the impact could create thousands of new pieces of space garbage. Some researchers have suggested using lasers for the task. Rather than destroy the junk, the laser would simply nudge the trash out of the way.
Recycling: Launching assets into space is expensive. But future human settlements – including lunar bases – may need raw materials.
“Several startups are already looking at ways to monetize existing orbital debris for remanufacturing,” said IEEE Fellow Panagiotis Tsiotras. “Additionally, there are opportunities offered by an envisioned human settlement of a permanent lunar base.”
One possibility being explored now turns the aluminum found in most satellites into a solid state propellant that can be used for fuel – potentially to refuel other satellites or to use as fuel for the controlled reentry of larger objects
Of course, the easiest way to manage space trash is to prevent its creation in the first place. Under a new rule proposed by the U.S. Federal Communications Commission, satellites would have to deorbit five years after they stop working.
“Each day is more difficult to find a secure window for launching, and technology to recover or deorbit all this junk is a point of concern,” said IEEE Senior Member Antonio Pedro Timoszczuk.
In essence, the challenge posed by space debris emphasizes the necessity to mitigate and hinder the expansion of orbital debris, guaranteeing the endurance and secure utilization of outer space for the well-being of future generations. Therefore, eliminating space debris is paramount to ensure the sustained, safe, and responsible utilization of outer space. Consequently, prioritizing efforts to eradicate debris should be of utmost significance for the international community, fostering the continued growth and exploration of the vast realms of space.