The first Mauna Kea telescope to make way for the planned Thirty Meter Telescope will be decommissioned by the end of the year.

Officials said the removal and site restoration of the Caltech Submillimeter Observatory at the mountain’s summit will start this summer.

The state Board of Land and Natural Resources approved a conservation district use permit in January for the removal of the Caltech observatory, one of two summit facilities currently working toward decommissioning.

The University of Hawaii at Hilo Hoku Kea Telescope is on track to be decommissioned in 2023.

“The decommissioning of these first two observatories will be milestones in the stewardship of the mauna,” said Greg Chun, executive director of the UH Hilo Center for Maunakea Stewardship.

“We are grateful to move forward with the deconstruction process,” added Sunil Golwala, Caltech physics professor and CSO director, in a release.

UH’s recently updated Mauna Kea Master Plan set a limit of nine operating astronomy facilities on the mountain by 2033, which means five of the 14 astronomy sites will be closed permanently to astronomy development once the existing facilities there have been decommissioned.

The conservation district use permit sets the terms and conditions Caltech must follow during the decommissioning.

As part of the process, the Caltech Submillimeter Observatory has completed an archaeological assessment, a cultural setting analysis, a hydrogeological evaluation, a biological inventory, a biological setting analysis, a traffic analysis and an asbestos/ lead paint/mold survey.

At one time the Caltech facility was one of the world’s premier observatories for astronomical research and instrument development at submillimeter wavelengths.

The submillimeter observatory was closed in 2015 following 30 years of “groundbreaking achievements,” according to Cal­tech. Numerous discoveries were made at the CSO, and hundreds of students have used the facility, including more than 100 working on doctoral research projects.

Observations at the 10.4-meter radio telescope with a 60-foot dome led to the detection of heavy water on comets and helped to determine the composition of comets. It also led to the observation of “dusty” planets, which optical telescopes often have trouble seeing.

Caltech is one of the partner institutions planning to build the landmark $2.65 billion Thirty Meter Telescope, the development of which is on hold during a search for additional funding sources.