Full Breakdown
Hayabusa2’s Last Working Ion Engine Breaks Down, Endangering Its Extended Asteroid Mission
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Core Event
Japan’s Hayabusa2 probe, now on an extended mission to the near-Earth asteroid 1998 KY26, lost the only functional ion engine on board. The failure was identified in mid-August, when the ion source of engine B ceased operating while its neutralizer remained functional. The probe, launched in December 2014, has already exceeded its design life by nearly 12 years.
Mission Background and Engine Degradation
Hayabusa2 returned samples from asteroid Ryugu to Earth in December 2020 and then began a second phase aimed at reaching 1998 KY26 by 2031. The spacecraft carries four ion engines (A, B, C, D). Over the years, engines A, C and D have suffered substantial degradation; engine B was preserved during the Ryugu mission and has been the primary thruster for the extended phase. The recent breakdown of engine B follows earlier attempts in mid-August to restore its function, which were unsuccessful.
JAXA’s Technical Response Plan
The Japan Aerospace Exploration Agency (JAXA) intends to repurpose components from the other three engines. Specifically, it plans to pair the still-working neutralizer of engine B with the ion source of engine D, recreating a configuration first employed on the original Hayabusa spacecraft. JAXA officials state that the agency will attempt to restart the combined system in the second half of this month, though they acknowledge uncertainty about whether the probe can still achieve its 2031 target given overall deterioration.
Technical Details of Engine Status
- Four ion engines total (A, B, C, D).
- Engines A, C, D: ion sources functional, neutralizers failed (C and D) or degraded (A).
- Engine B: neutralizer functional, ion source failed.
- Planned configuration: B’s neutralizer + D’s ion source.
Verbatim Quotes
- “Without giving up, we will work as one to continue Hayabusa2 operations until the very end, together with the ion engines, which keep working beyond their limits,” — Yuya Mimasu, head of JAXA’s team for the Hayabusa2 extended mission “Without giving up, we will work as one to continue Hayabusa2 operations until the very end, together with the ion engines, which keep working beyond their limits,” — Yuya Mimasu, head of JAXA’s team for the Hayabusa2 extended mission.