14 DAY TRIAL // Operations at the Subaru Telescope, the flagship installation that the National Astronomical Observatory of Japan (NAOJ) operates atop Mauna Kea, in Hawaii, have been discontinued on account of a significant hardware error.
The 8.2-meter telescope experienced a major leak of ethylene glycol from its top unit. Operators discovered the damage on Saturday, July 2, after routine observations were concluded for the night.
Subaru's top unit contains important components of the telescope, such as for example the Subaru Prime Focus Camera (Suprime-Cam), and the auxiliary optics systems the instrument uses.
Immediately after the erroneous readings were recorded, the night shift operator contacted the Telescope Engineering Division (TED), and moved to the dormitories at Hale Pohaku, out of harm's way. Subsequent analysis conducted by three TED experts determined the source of the data anomaly.
The leak the engineers saw was extensive. After promptly shutting off the supply of coolant to the Subaru top unit, the experts assessed the damage that had already been done, and estimated it to be extensive. There is concern that the leak also affected lower units of the telescope.
Coolant may have leaked “from the top unit itself and Suprime-Cam down to the tertiary mirror, the primary mirror and some of its actuators, the Faint Object Camera and Spectrograph (FOCAS, a Cassegrain instrument) and its auxiliary optics, and the telescope floor,” a NAOJ press release says.
“TED staff members attempted to clean up and remove as much coolant as possible. However, such areas as optics, control circuits, and the inside of Suprime-Cam and FOCAS were inaccessible during the initial clean-up,” the organization reveals.
At this point, engineers are continuing to assess the situation, and determine the extent to which coolant material penetrated vital systems below. Based on these data, they will then calculate how long it will take for Subaru to be brought back online.
“During the clean-up and recovery of equipment, nighttime observations as well as daytime summit tours of the Subaru Telescope are temporarily suspended. Scheduled observers as well as tour visitors are being contacted,” the press release adds.
Subaru shares the peak of Mauna Kea with the twin Keck telescopes and the NASA Infrared Telescope Facility.