Satellite servicing company Astroscale Japan says that its commercial debris inspection demonstration satellite, Active Debris Removal by Astroscale-Japan (ADRAS-J) has successfully approached a large piece of space debris – a rocket upper stage – to approximately 15 metres.
This is the closest approach ever achieved by a commercial company to space debris through rendezvous and proximity operations.
ADRAS-J was selected by the Japan Aerospace Exploration Agency (JAXA) for Phase I of its commercial removal of debris demonstration. This latest approach, however, was an ambitious goal independently designed by Astroscale, in addition to JAXA’s baseline mission requirements. The objective was to demonstrate highly precise and complex close-range RPO capabilities by advancing to the capture initiation point, where future debris removal missions start robotic capture operations.
When ADRAS-J was 50 metres behind the upper stage the spacecraft reduced the gap in a straight-line approach then maneuvered to approximately 15 metres below the payload attach fitting – the planned capture point for the follow-on ADRAS-J2 mission – aligning the spacecraft’s relative speed, distance, and attitude.
ADRAS-J successfully maintained this position until an autonomous abort was triggered by the onboard collision avoidance system due to an unexpected relative attitude anomaly with the upper stage. The spacecraft safely maneuvered away from the debris as designed before reaching the CIP. Astroscale Japan is currently investigating the cause of the abort.
In addition to achieving the historic 15-metre approach, ADRAS-J successfully completed all observations of the debris required by the JAXA mission, including two fly-around operations that confirmed no major damage to the PAF and a third fly-around from a new angle of the upper stage.
These accomplishments have provided critical data to inform the follow-on ADRAS-J2 debris removal mission, further advanced Astroscale’s heritage RPO and inspection capabilities for a wide range of on-orbit services and set a new benchmark for space sustainability.
Key ADRAS-J mission milestones since launch include:
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February 18 2024: launch and start of in-orbit operations;
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February 22 2024: start of rendezvous phase;
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April 9 2024: start of angles only navigation and proximity approach from several hundred kilometres;
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April 16 2024: start of model matching navigation relative navigation techniques;
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April 17 2024: approach to the upper stage within several hundred metres;
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May 23 2024: approach to the upper stage within 50 meters and first fixed-point observation completed;
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June 17 2024: second fixed-point observation completed;
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June 19 2024: start of fly-around operation and validation of collision avoidance system;
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July 14 2024: approach to the upper stage within 50 metre. Third fixed-point observation completed;
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July 15 2024: first successful fly-around observation;
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July 16 2024: second successful fly-around observation;
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July 17 2024: first final approach attempt, successfully reaching 20 metres;
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August 13 2024: third successful fly-around observation; and
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November 30 2024: final approach, successfully reaching 15 metres.
