About 20 people opposed to building what would be one of the world’s largest telescopes on a Hawaii mountain are camped out near the construction site, vowing to stop work from resuming.

They are sleeping in vehicles or on cots under a tent and braving weather that’s chilly for Hawaii standards at Mauna Kea’s 9,200-foot elevation.

They are also making sure they have bail money ready. Some say they are bracing to be arrested when the nonprofit company building the Thirty Meter Telescope intends to resume construction Wednesday.

Work was put on hold for two months after the arrests of 31 people blocking access to the site. On Saturday, telescope officials announced construction would start again. Opponents say the $1.4 billion project that will be 18 stories high will desecrate land held sacred by Native Hawaiians. Some say it’s time to curb development on the mountain, where 13 other telescopes sit.

Their protests prompted Gov. David Ige to say Hawaii must do a better job of caring for the mountain. Ige added, however, that Thirty Meter Telescope has a right to proceed with construction.

Astronomers revere the site because its summit at 13,796 feet is well above the clouds, and it provides a clear view of the sky for 300 days a year. There’s also very little air and light pollution.

Kahookahi Kanuha is one of the people camped out near the Mauna Kea visitor center, which is about 8 miles away from the construction site. He was one of the people arrested in April.

“We’re bracing ourselves mentally, spiritually for the battle ahead,” Kanuha said Tuesday. “I don’t mean a physical battle. It’s brain against brain.”

The protesters — who call themselves protectors — will be peaceful and respectful, he said. “We’re going to really have to stay dignified, not allowing anything, any word, any action to take us out of that state of being,” Kanuha said.

Some of them spent Monday building an ahu, a rock altar, in the road leading to the construction site, he said, adding that he expects the workers to simply move it or destroy it.

“It’s a symbol to show that the culture is still here and it’s a cultural site,” Kanuha said. “When the public looks at Mauna Kea, what you see are telescopes. So the assumption is that this mountain belongs to foreign scientists.”

Thirty Meter Telescope International Observatory LLC, a nonprofit, will build and operate the telescope. Its partners include India, China, Canada, Japan and the Thirty Meter Telescope Observatory Corporation, which was formed by the University of California and the California Institute of Technology.

Partners would receive a share of observing time, along with University of Hawaii scientists.

Mauna Kea was selected as the site for the observatory over Chile’s Cerro Armazones mountain in 2009.

On Wednesday, a crew of a few workers and vehicles will go to the site for vehicle maintenance and to install safety fencing, Thirty Meter Telescope International Observatory Board Member Mike Bolte said in an email through a public relations firm. There’s no specific time for when that work will happen.

“I will try my best not to get arrested,” Kanuha said. “But there are two options: You stand and resist, or you move to the side and allow them to desecrate.”