Decommissioning of the Caltech Submillimeter Observatory on Mauna Kea is set to begin soon although the exact dates of the six-week process are yet to be set.

California Institute of Technology said in a news release Thursday it’s been in contact with state, county and university officials on the Big Island to let them know.

Plans to remove the telescope – one of 13 on Mauna Kea — have been underway for years and were finalized over the winter, said Caltech physics professor Sunil Golwala, who directs the Caltech Submillimeter Observatory program.

The telescope’s functional life has been declining for years. Its astronomical instruments were removed in 2015.

At 13,796 feet high, Mauna Kea is a dormant volcano that rises 32,000 feet from the ocean floor and is the highest island-mountain in the world, according to the University of Hawaii. Many Native Hawaiians consider it a sacred site.

The cost of removing the Caltech telescope, cleaning and filling a cesspool and other remediation activities are expected to cost at least $4 million.

The removal process will require several road closures and permits. The telescope’s 34-foot diameter primary mirror will be hauled off the mauna’s summit and brought down the Saddle Road, ultimately ending at Kawaihae Harbor.

Caltech will do two practice runs involving a “dummy mirror,” or an object made to resemble the actual part of the telescope. The first will take place over two consecutive days where the dummy mirror will be transported from the summit to the Mauna Kea Visitor Information Station. The Mauna Kea Access Road between the summit and the Visitor Information Station will be closed for about seven hours.

On the second day, the dummy mirror will be moved from the Visitor Information Station to a staging area near the intersection of the Mauna Kea Access Road and the Saddle Road.

 The actual removal of the telescope’s primary mirror will follow the same pattern.

 A map of the anticipated transport route can be found here.

Goodfellow Bros., a contracting company, will begin dismantling the buildings that housed the telescope and will begin restoring the site, according to the release.