From harpoons to super-magnets and mapping technologies, many have taken on missions to do their part in tackling one of the most urgent situations in space — mitigating space debris. 

Space is getting crowded now more than ever. As the field of space becomes more and more accessible with satellites getting smaller and cheaper, keeping up with space traffic has become more challenging. 

Far more concerning than the number of space assets we are launching is the case of space debris we leave behind when the assets deorbit. Today, Earth is enveloped in a bubble of debris that includes at least 27,000 fragments of space debris in our planet’s orbits, which are tracked by the U.S. government.

Several decades of space missions have led us to the current developments in the field of space technology. But we have certainly lagged behind in maintaining sustainability in the space environment. Every day, with our orbit getting hazardously crowded, the chances of collisions, accidents and conflicts only grows. Activities that occur in space do not happen in a singularity. Rather, every action has the potential to affect others in space as well. 

In 2007, China’s FengYun-1C engagement, a test of an apparent anti-satellite weapon created tens of thousands of shards, increasing the trackable space object population by 25%! Every piece of junk from this incident has the potential to cause catastrophic impacts on other functional satellites and space assets. Referred to as the Kessler Syndrome, this is a phenomenon where the amount of debris orbiting our planet reaches a certain volume and collides with other objects creating more debris, which will in turn produce more space junk, like in a chain reaction. 

Unfortunately, this spells danger for any space assets and missions. The issue of space debris has become a pressing problem over the years and measures have been urgently taken to mitigate it. 

One such effort is the End-of-Life Services by Astroscale (ELSA) program taken on by Japan-based company, Astroscale. The star of this $191 million project is the ELSA-d spacecraft will be operated using a servicer satellite and a client satellite stacked together. The magnetic docking technology in the spacecraft will allow ELSA-d to inspect and dock safely with a client, such as a defunct satellite, and push it towards Earth’s atmosphere to burn up. 

In a test demonstration in August 2021, ELSA-d managed to magnetically capture and release a client spacecraft. However, in more recent developments in January 2022, Astroscale detected anomalous spacecraft conditions during another test. The company has stated that they will not carry out capture attempts until the anomalies have been ironed out.

But, magnetically grabbing space debris for disposal is not the only way to tackle the problem. The European Space Agency (ESA) has partnered up with Swiss startup, ClearSpace, on a €86 million contract to launch the space agency’s first active debris removal mission, ClearSpace-1. Scheduled for 2025, this mission will see the ClearSpace-1 spacecraft approach the upper part of a Vespa (Vega Secondary Payload Adapter) that was used with Europe’s Vega launcher in 2013. ClearSpace-1 will assess the target, which is fairly simple in shape and is about the size of a washing machine, and grab it using its four robotic arms before dragging it out of orbit and into Earth’s atmosphere. 

And, yes. This will mean that both the ClearSpace-1 space probe and the captured debris will burn up in the atmosphere. But ESA hopes that this first mission will pave the way for sustainable future missions that will not only target increasingly larger and complicated debris, but also be able to capture multiple debris for disposal.

Super magnets and giant space claws aside, other space debris removal missions also include harpoons. Led by Surrey Satellite Technology Ltd in collaboration with other project partners in the U.K., RemoveDebris is a satellite platform that was launched in 2018 to nab space debris using a harpoon and haul it back to Earth’s atmosphere. The platform is currently being tested outside the International Space Station (ISS) on experimental targets, like CubeSats.

The initial $18 million mission in 2018 had the RemoveDebris spacecraft eject a titanium harpoon, designed by U.K.’s Airbus engineers, at a speed of 65 feet per second towards its target. Upon firing and the harpoon safely snagging on to the target, a 16-feet-wide net was deployed from the craft’s spring-loaded mechanism to envelope the debris. With its success, this platform could be a viable and effective option for future space debris mitigation activities.

Sending crafts to tackle space debris to bring them down is essentially the aim of space debris mitigation operations. But before that, operators need to be able to identify and monitor rogue space junks to capture. LeoLabs is a California-based business that has built a network of ground-based, phased array radars to monitor, track and obtain high-resolution data of operational assets, deorbited satellites and other pieces of space debris in low Earth orbit (LEO). Access LeoLab’s visualization of our current LEO here.

This groundbreaking technology of phased array radars employed by LeoLabs means that the beam produced by the radar can be electronically operated, allowing the company to monitor and change targets by the millisecond. This is far more efficient than the use of traditional, physically-controlled dishes. More importantly, the precision level of the beam is so accurate that the radars are even able to detect space objects 2 centimeters in size. This accuracy proves to be vital and effective in tackling space junk that can be as small as a pea. 

Privateer is the newest entrant that aims to take part in the mission to tackle space debris. Led by Steve Wozniak, this new space venture’s mission is to build a software that will chart our planet’s orbits, track space objects and obtain information to prevent devastating collisions. In mapping our orbits, Privateer aims to take the step towards establishing situational awareness in space to lay the foundation for cleaning up our space environment. 

Their latest software, which was released in March 2022, is called the Wayfinder. Essentially, it is an open-access visualiser that integrates data from many different sources to create a map of all the objects in orbit at near real-time. In efforts to develop a detailed register of our orbits and its inhabitants, Privateer has also planned to launch its own satellite later this year. Pono-1, a CubeSat, will be furnished with 42 sensors that will procure important information regarding space situational awareness. Eventually, the vital data collected from the softwares, be it Pono-1 or Wayfinder, can be used to pinpoint locations and estimate the trajectories of space debris to aid other functional space objects navigate their route without collision. 

Day by day, not only does junk in our space environment increase, but also its potential to cause disastrous accidents. Despite the current and past missions taken to mitigate space debris and manage space traffic effectively, it is simply not enough. It is pertinent for every single actor in our space industry to understand the gravity of the situation and take on the responsibility to do their part in clearing our polluted orbits.