Second chances in space missions are exceedingly rare. When something goes wrong it often means either a total loss of the mission or a significantly reduced outlook for what the mission can accomplish. Primarily this comes down to the tight engineering challenges that space missions face, with multiple redundant systems only able to cope with so much. Still every so often they happen and sometimes a new mission is born out one that might have been a failure. Such is the story of JAXA’s Akatsuki craft, one that has been lying in wait for the last 5 years waiting for its chance to fulfill its mission.
Akatsuki launched 5 years ago aboard JAXA’s H-IIA rocket. It was to be JAXA’s second interplanetary probe after their first, Nozomi, failed to reached its intended destination over a decade prior. The insertion burn was confirmed to have started on schedule, however after the communications blackout period where the probe was behind Venus it failed to reestablish communications at the expected time. It was found drifting away from Venus in safe mode, indicating that it had undergone some form of failure. In this state it was operating in a very low bandwidth mode and so it took some time to diagnose what had happened. As it turned out the main engine had fired for only 3 minutes before failing, not enough to put it in the required orbit.
However it was enough to put Akatsuki on a leading orbit with Venus, one that would eventually bring it back around to meet the planet some time in the future. It was then decided that JAXA would attempt recovery of the craft into a new orbit around Venus, a highly elliptical orbit with a period of almost 2 weeks (the originally intended orbital period was approximately 30 hours). Investigation into the craft’s damaged sustained during the first initial burn showed that the main engine was unusable and so the insertion burn would be performed by its attitude thrusters. JAXA had a lot of time to plan this as the next scheduled rendezvous would not happen for another 5 years.
Following some initial maneuvers back in July and September Akatsuki began its orbital insertion burn on the 7th of December. The small attitude thrusters, designed to keep the spacecraft oriented, fired for 20 straight minutes far beyond what they were originally designed for. They did their job however and 2 days later JAXA announced that they had successfully entered orbit around Venus, albeit in the far more elliptical orbit than they originally planned.
The extended duration in space has likely taken its toll on Akatsuki and so JAXA is currently undertaking a detailed investigation of its current status. 3 of its 6 cameras have shown to be fully functioning with the remainder scheduled to be brought online very soon. Scientific experiments using Akatsuki’s instruments won’t begin until sometime next year however as an orbital correction maneuver is planned to reduce Akatsuki’s orbit slightly. However JAXA is confident that the majority of their science objectives can be met, an amazing boon to both their team and the wider scientific community.
It’s incredibly heartening to see JAXA successfully recover the Akatsuki craft after such a monumental setback. The research conducted using data from the Akatsuki craft will give us insights into why Venus is such a strange beast, rotating slowly in opposite direction to every other planet in our solar system. Whilst I’d never wish failure upon anyone I know the lessons learnt from this experience will bolster JAXA’s future missions and, hopefully, their next one won’t suffer a similar fate.