On February 17th, the Japanese Aerospace Exploration Agency (JAXA) launched the Hitomi Space Telescope on a mission to study highly energetic events in the cosmos by looking at x-ray emissions. It successfully got to its orbit of 357 miles above the Earth, deployed its solar panels, and began its startup sequence. Everything seemed to be going fine until March 27th at 4:40 pm in Japan, when Hitomi failed to perform its planned operations. About the same time, the U.S. Joint Space Operations Center (JSpOC) detected the spacecraft breaking up into five pieces and changing its orbit. A mystery is in the making.
What Could Have Caused the Mystery?
The key clue into what could have happened to Hitomi is that the orbit changed. For that to happen, some sort of force had to act upon it. One possibility is that the spacecraft was hit by something that shattered its structure and sent into a different orbit. There is a lot of junk orbiting Earth and it is possible that something slammed into Hitomi, but it’s also unlikely considering the vast amount of space involved. Additionally, it would take a fairly large item that hit it at relatively low speed so it could impart its momentum without blowing the spacecraft apart on impact. Such an item would likely already be in orbit and thus tracked. Another scenario, and one that is more likely, is that the propellant for the eight reaction control thrusters exploded, shattering Hitomi and sending it tumbling. A video taken by amateur astronomer and former NASA flight controller Paul Maley from the ground in Arizona shows the spacecraft orbiting and changing in brightness – indicating that it is tumbling. Additionally, ground controllers have picked up intermittent signals from the spacecraft, further indicating that it is tumbling.
Can the Mission be Salvaged?
Publicly Japanese mission scientists are hopeful that contact can be reestablished, the spacecraft stabilized, and the mission can proceed. Realistically the mission is over. While Hitomi is still alive, as evidenced by its intermittent signals, it is obviously far from healthy. Whether it has been hit by another object or its propellant exploded, it has been crippled and it is highly unlikely that it can resume a normal mission.