A Japanese satellite lofted by Rocket Lab is to monitor a chunk of space junk ahead of future missions designed to curtail orbital debris.

The 150 kg ADRAS-J satellite was launched on a Rocket Lab Electron from the company's Launch Complex 1 in New Zealand at 1452 UTC February 18. The plan is for the spacecraft to approach an old HII-A rocket body, originally used to launch the GOSAT Earth observation satellite.

Rocket Lab named the mission "On Closer Inspection."

The derelict HII-A upper stage is approximately 11 meters long and four meters in diameter, and the mission represents the world's first attempt to approach, characterize, and survey the state of an existing piece of debris.

There were similar missions in the past. Northrop Grumman's Mission Extension Vehicle (MEV) attached itself to the Intelsat 901 satellite in 2020, and a pair of cosmonauts rescued the derelict Salyut 7 in 1985, manually docking with the dead space station and bringing it back online.

ADRAS-J is not crewed and will rely on ground-based observations for the position of the HII-A upper stage. Astroscale Japan, the makers of the ADRAS-J spacecraft, said the stage is "an unprepared object." There is no GPS or similar data from it, making Rendezvous and Proximity Operations (RPO) challenging.

Where Rocket Lab usually has the final perigee, apogee, and inclination for which to aim months in advance, Astroscale Japan could only provide the information 20 days before the launch. Coupled with the requirement for a highly accurate orbital insertion, calculating the launch parameters - for example, the duration and timing of the Electron Kick Stage burns - was no mean feat.

The Astroscale Japan Mission Operations team in Tokyo has made contact with the spacecraft, and the plan is now to conduct a number of in-orbit tests before starting the rendezvous process. After carefully approaching the derelict rocket stage with limited data available, ADRAS-J will use cameras and sensors to document the state of the debris. Possible methods for a future assisted deorbit can then be considered.

ADRAS-J was selected by the Japanese Aerospace Exploration Agency (JAXA) for Phase 1 of its Commercial Removal of Debris Demonstration program. Astroscale Japan was responsible for designing, manufacturing, testing, and operating the spacecraft. It also procured the launch operator.

Astroscale Japan was also behind the Lunar Dream Capsule on board the ill-fated Astrobotic Peregrine Lander. ®

https://www.theregister.com//2024/02/19/adrasj_mission_space_junk/