Why Remove Debris?
Even if all future launches produced zero debris, the existing population in certain altitude bands would continue to grow through collisions between already-orbiting objects. ESA modelling suggests removing approximately 5 large objects per year from the most congested bands (700–1,000 km) could stabilise the long-term environment.
Current Missions
ADRAS-J (Astroscale, JAXA): Successfully launched in 2024 and rendezvoused with a spent Japanese H-IIA rocket upper stage, demonstrating close-proximity inspection of a tumbling debris object. This is a precursor to the ADRAS-J2 mission, which will attempt to capture and deorbit the stage.
ClearSpace-1 (ESA): Planned to demonstrate capture and controlled deorbit of a Vega Secondary Payload Adapter (VESPA) using a four-armed robotic gripper. Originally targeted for 2026 launch, timeline subject to revision after the target object experienced a debris impact in 2023.
Capture Technologies
Robotic arms/grippers: Mechanically grasp the target. Requires relative navigation and gentle docking. Nets: Deployed to ensnare the target. Tested in orbit by the RemoveDEBRIS mission (2018). Harpoons: Penetrate the target's structure. Also demonstrated by RemoveDEBRIS. Magnetic capture: For targets with ferromagnetic materials. Laser ablation: Ground-based or space-based lasers to nudge debris without physical contact — still largely theoretical.
Challenges
The biggest obstacles are cost (each removal mission costs tens to hundreds of millions of euros), legal liability (who is responsible for a defunct satellite?), and the sheer scale of the problem. Current technology can only address the largest objects one at a time, while the debris population numbers in the millions.