Caltech Submillimeter Observatory buildings, telescope dome removed from Mauna Kea

The buildings and telescope dome of Caltech Submillimeter Observatory (CSO) on Mauna Kea are now removed, bringing it another step closer to site restoration.

The decommissioning of the observatory started in September 2023 when the telescope was removed and shipped to Chile where it was anticipated it would be continued to be used for astronomy. The removal of the buildings and observatory was temporarily halted in April due to high winds and stormy weather in early May.

With the buildings now removed from the site, the next steps will be to remove the concrete foundations, pavement, underground utilities and cesspool. The restoration phase will proceed following the completion of that work. The land will be restored consistent with the permits guiding the decommissioning. Cultural, construction, and archeological monitors will continue to be present at all appropriate phases.

The decommissioning is expected to be completed by the end of the year. Once finished, Caltech will monitor the site for three years to document repopulation by flora and fauna.

The cost of deconstruction and site restoration is expected to exceed $4 million and is primarily funded by the Gordon and Betty Moore Foundation and the California Institute of Technology. The removal of the telescope for reuse is supported by the Heising-Simons Foundation. Information on the future of the telescope can be found here.

More information on the decommissioning, including related planning documents, permits, and a list of contractors involved in the project, can be found on the CSO wiki website here.

The Caltech Submillimeter Observatory came online in 1987 and was used by scientists at Caltech and other institutions, including almost 200 student and postdoctoral researchers, to open a new submillimeter window on the universe.

A summary of CSO’s contributions to astronomy and astronomical instrumentation is available here.