Monday, February 26, 2024

Astroscale’s ELSA-d demos its space debris capture and removal capability

Astroscale’s End-of-Life Services by Astroscale-demonstration (ELSA-d) successfully tested its ability to capture and release its client spacecraft using the servicer’s magnetic capture system in a demonstration performed on August 25.

Space debris, or unused man-made debris that revolves in Earth orbit, poses a risk of collision with other satellites.

The ELSA-d mission was launched into space in March, with the goal of validating the Japanese company’s orbital debris removal technology. The demonstration mission consists of two spacecraft: a 175kg “servicer” designed to remove space junk and a 17kg “client” that poses as said space junk. They were sent up together on a Soyuz rocket, launched from the Baikonur Cosmodrome in Kazakhstan.

“A major challenge of debris removal, and on-orbit servicing in general, is docking with or capturing a client object; this test demonstration served as a successful validation of ELSA-d’s ability to dock with a client, such as a defunct satellite,” explained the company.

ELSA-d demonstrations phase by phase.
ELSA-d demonstrations phase by phase. Credit: Astroscale

ELSA-d entered orbit at an altitude of approximately 555km (340 miles) before going through a commissioning phase in which its systems were thoroughly tested and certified. Once in orbit, The first step of this demonstration was to unlock the mechanical locking mechanism that held its servicer and client spacecraft together. Once separated, the servicer uses its sensors to find and chase down the client, latching on to it using a magnetic docking plate. The client was then pushed away from the servicer for another capture experiment – recapturing it several times.

During the release and capture period, Astroscale’s Mission Operations and Ground Segment teams checked out and calibrated the rendezvous sensors and verified relevant ground system infrastructure and operational procedures.

Astroscale is now preparing for “capture without tumbling,” where the client will be separated to a greater distance, and the method of rendezvous and docking will rely on a combination of onboard autonomous software and advanced ground processing of telemetry and commands. This will be followed by the “capture with tumbling” phase, in which the client will simulate an uncontrolled, tumbling space object. The final capture demonstration will be “diagnosis and client search,” in which the servicer will inspect the client, withdraw to simulate a far-range search, then approach and recapture the client.

This has been a fantastic first step invalidating all the key technologies for rendezvous and proximity operations and capture in space,” said Nobu Okada, Founder & CEO of Astroscale. “We are proud to have proven our magnetic capture capabilities and excited to drive on-orbit servicing forward with ELSA-d.