HILO » A third telescope atop Mauna Kea remained out of commission Monday following a coolant spill onto two mirrors and instruments.

An estimated 185 gallons of coolant leaked from the Subaru Telescope on July 2 following a night of observations, the Hawaii Tribune-Herald reported Monday.

The problem occurred when cables attached to the telescope’s camera did not move with the camera as it tracked objects across the sky, said Tetsuo Nishimura, the telescope’s associate director.

Of the 13 telescopes on Mauna Kea, the Subaru Telescope and two University of Hawaii telescopes were not functioning correctly.

The Subaru Telescope uses the Subaru Prime Focus Camera, or Suprime-Cam, an advanced, 80-megapixel, digital wide-field imaging device to study celestial objects.

The cost of repairing the telescope is not yet known as a full assessment of the damage is under way, Nishimura said.

"Unfortunately, we had to cancel all the observations for the last two weeks," Nishimura said. "We are hoping that we can resume science observations by the end of the week."

Coolant leaked onto the 8-meter primary mirror, the tertiary mirror, Suprime-Cam and another instrument called the Faint Object Camera and Spectrometer, or FOCAS.

Mirrors have been cleaned, and the observatory was preparing to conduct equipment tests Monday night, Nishimura said.

Besides the Subaru Telescope, the volcano’s 2.2-meter telescope and the Hoku Kea telescope also were not functioning properly.

The 2.2-meter telescope, the first large telescope ever built on Mauna Kea, has not been working since the weekend of June 4-5, when tens of thousands of lightning flashes were recorded around the state. The 41-year-old telescope is primarily used by University of Hawaii graduate students and faculty.

Hoku Kea, the newest telescope on the dormant volcano, has been plagued by various issues since its installation. Hoku Kea is a 0.9-meter educational telescope operated by the University of Hawaii at Hilo.

Astronomers planned to resume observations at the Subaru Telescope as early as this weekend using instruments placed at alternate focal points.