The Japanese space administration is bemoaning the worst possible outcome for its $286 million astronomical satellite: a software issue derailed the thing, causing it to fire off a jet propulsion thruster inadvertently in order to correct for a problem it wasn’t actually having. This autocorrection sent it careening out of control to the point that pieces of it actually broke off.
The shame of the Hitomi satellite malfunction is the loss of its telescopes. As an astronomical satellite, Hitomi was intended to take images using X-rays, a tremendous advancement in exploring far-flung objects. There have actually been two previous attempts to deploy X-ray telescopes, but both of the previous satellites also suffered catastrophic malfunctions.
Unfortunately, the software that powered Hitomi’s “star tracker” navigation–which in very basic terms means it helped the satellite figure out where it was and where it was facing based on its location dependent on fixed objects–suffered a glitch. The software glitch itself wasn’t entirely unexpected and was apparently caused by the satellite’s reaction to a natural radiation anomaly. Once the software wasn’t providing accurate information, the glitch issue then combined with some human command error that was intended to stop the problem. This caused the satellite to correct its course it shouldn’t have, with semi-violent results that led to the loss of the on-board X-ray calorimeter.
All is not lost, however. Due to the previous disasters involving craft with the all-important X-ray calorimeter on board, scientists were prepared for bad luck to run in threes. That means Hitomi got to work immediately, and managed to provide some crucial information on dark matter from the Perseus cluster. A new calorimeter is already in the works, and is expected to launch in 2028 and come with a $50 million price tag.