[Reading Science] Cleaning or Hunting?… Japan Unveils Amazing Space Debris Removal Technology

Japanese Astroscale's 2nd Generation Model ELSA-M Video Released
Joint Venture with UK OneWeb for Removing Defunct Small Satellites
Capable of Space Debris Removal and Potential Enemy Satellite Attacks in Emergencies

Detailed images of Japan's space debris cleanup spacecraft under development have been revealed. Although described as a cleaning device, it can also be used as a 'hunter' in emergencies, meaning it could be employed to destroy enemy satellite networks, drawing attention to its performance and specifications.

An artist's rendering of 'ELSA-M,' a space debris cleanup spacecraft being developed by the Japanese company Astroscale. Photo by Astroscale

Japanese private space startup Astroscale posted a video on its official YouTube channel on the 13th introducing the orbital spacecraft being developed for space debris cleanup. In the video, the company pointed out, "Space is dangerously congested. Action is needed." It mentioned that there are over 2,200 defunct satellites in Earth's orbit and that more than 630 collisions have occurred due to satellite fragments. The video then revealed the appearance of their new space debris cleanup orbital spacecraft named ELSA-M (End of Life Service by Astroscale - Multiple). It was also introduced as "the world's first remover servicer," meaning it can remove multiple target satellites by moving locations in a single launch.

The company also demonstrated the actual mission operation method of ELSA-M in the video. ELSA-M tracks the location of satellites provided by clients, approaches them, conducts visual inspections, and performs alignment and docking operations by matching direction and speed. While physical capture methods such as hooks or nets are being researched in Europe and elsewhere, ELSA-M uses a powerful magnet to capture the requested satellite. Then, it activates thrusters to lower the satellite to an altitude where sufficient gravity allows atmospheric reentry. After separating the defunct satellite, it departs, changes altitude, and searches for another target.

On the same day, the company also unveiled a second-generation docking plate model that can operate in orbit for more than 15 years and capture targets more easily. They stated, "This will be a very useful starting point for various service options and more responsible use of Earth's orbital resources." Previously, in 2021, the company test-launched the first-generation model ELSA-D into orbit and succeeded last year in demonstrating repeated magnetic capture of targets. However, development was halted after a malfunction occurred a few months later.

In a virtual video released on the 13th by the Japanese company Astroscale, the space debris cleanup vessel 'ELSA-M' (left), currently under development, is docking with the target satellite.

Astroscale is a Europe-Japan joint venture with investments from the European Space Agency (ESA) and the UK Space Agency (UKSA). Notably, it has signed a contract with the British satellite internet company OneWeb. OneWeb plans to launch over 6,000 small satellites into low Earth orbit and intends to use ELSA-M from 2024 to capture defunct satellites and deorbit them by atmospheric reentry. To this end, OneWeb's satellites are equipped with docking plates perfectly compatible with ELSA-M's magnetic capture device.

Defunct satellites and debris orbit Earth at tremendous speeds exceeding 7.5 km/s. Tasks such as locating, approaching, aligning, docking, and capturing are usually challenging operations. However, the increasing amount of space debris is causing serious disruptions to the International Space Station (ISS), satellite operations, and astronomical observations. Additionally, there is growing demand for satellite maintenance services such as refueling and repairs. Furthermore, space debris removal technology can be utilized for national security purposes, including protecting domestic satellites and removing enemy satellites. Consequently, major powers are actively developing space debris removal technologies. The United States is reportedly already equipped with such capabilities through the X-37B spacecraft, which is conducting secret missions. China also succeeded in demonstrating defunct satellite removal technology with the Shijian-21 satellite in February last year. South Korea's Korea Advanced Institute of Science and Technology (KAIST) Satellite Research Center, together with the government, plans to develop and launch 'Capture Satellite No. 1' by 2027 with a budget of approximately 50 billion won.