Back in 2010, we were sad to hear that JAXA’s Akatsuki orbiter experienced a malfunction during its attempt to insert itself into orbit around Venus. A planned twelve minute engine burn ended prematurely after about only three minutes, the result of salt formation causing a fault in a check valve. You might expect that that would have spelled the end to the mission, and Akatsuki would have spent eternity orbiting the Sun. Fortunately, JAXA would get a second chance to try their insertion effort again, but they’d have to wait nearly five years for both the craft and Venus to be in the right places for the attempt.
Orbit control test and maneuvers were conducted in 2011, and then again in 2015, setting the stage for an orbit insertion attempt. Tests showed that Akatsuki’s Orbital Maneuver Engine (OME), its main engine, couldn’t provide the thrust needed for the second insertion attempt. Hope fell to the craft’s attitude-adjustment engines.
65 kg of oxidizer fuel that would have been used by the no-longer-functional main engine was dumped to lighten the craft and allow it to be more maneuverable. In December, 2015, exactly five years after the first attempt to make ...