Caltech Submillimeter Observatory Telescope Removal Update

Caltech will disassemble the 34-foot diameter telescope mirror from the Caltech Submillimeter Observatory (CSO) on Maunakea and remove it in pieces this summer. The original plan to move it in one piece proved unfeasible.

"Caltech is firmly committed to full removal of the CSO and restoration of the site," says Caltech physics professor and CSO director Sunil Golwala.

Transporting the disassembled mirror will be less disruptive because extensive road closures on Hawai-i Island will not be necessary.

The mirror will be disassembled into smaller parts, reversing the process used to assemble the telescope in the 1980s. Staging will take place in the CSO parking area at the summit. The telescope parts will be transported down the mountain in standard shipping containers and sent to Chile, where the telescope will continue to be used for astronomical research and instrumentation development at submillimeter wavelengths. Caltech's contribution to the move is being funded by the Heising-Simons Foundation.

Although there is more risk of damage to the telescope with this revised plan, it will lead to less disruption to the local area and community because oversize transport vehicles and road closures are no longer necessary.

Once the telescope is removed, Goodfellow Bros., a general contractor, will remove the CSO buildings and infrastructure and will carry out full restoration of the site.

The cost of deconstruction and site restoration is expected to exceed $4 million. The decommissioning of the telescope is being carried out in accordance with the Conservation District Use Permit (CDUP) issued by the state's Department of Land and Natural Resources (DLNR) in January 2022. CSO is the first observatory to be removed under the 2010 Decommissioning Plan for Maunakea Observatories. All the astronomical instruments were removed from the facility in 2015 except the telescope.

More information on the decommissioning, including all related planning documents and permits, can be found here.

The CSO 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 are available here.