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The ELSA-d (End-of-Life Service by Astroscale - demonstration) program is a spacecraft retrieval service for satellite operators. The ELSA-d is the first project and its mission is to demonstrate the core technologies to be used for the ELSA program.

ELSA-d is comprised of Chaser and Target. Chaser is equipped with optical sensing instruments and a redundant capture mechanism, and Target is with a docking plate (DP) as it functions as a “rescue package.” The DP is to enable Chaser to secure Target and provides optical references (or “markers”) for Chaser to identify and estimate the attitude of Target.

The Target and the Chaser will be attached for launch and deorbit, but while on-orbit, will be deployed in a series of three increasingly complex separation and capture manoeuvres using rendezvous and docking algorithms. A docking plate with optical markers will be attached to the Target, allowing the Chaser to identify and estimate attitude during the docking.

SSTL’s Target satellite incorporates S Band communications, GPS positioning, a 3-axis control system and laser retro-reflector. A variant of the SSTL-42 constellation platform family designed for operational missions in the 5k g to 100 kg range, it will also fly an HD camera and lighting to record the capture sequences during eclipse.

Alternate Names

  • 47944

Facts in Brief

Launch Date: 2021-03-22
Launch Vehicle: Soyuz-2.1a/Fregat
Launch Site: Tyuratam (Baikonur Cosmodrome), Kazakhstan

Funding Agency

  • Unknown (Japan)


  • Technology Applications

Additional Information

Questions and comments about this spacecraft can be directed to: Coordinated Request and User Support Office

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