The existing 13 telescopes atop Mauna Kea remain shuttered and unable to function as the Thirty Meter Telescope protest continues into its fourth week at the base of the mountain.

The longest-ever shutdown of the mountaintop science community has left observatory officials and scientists frustrated and worried about the long-term health of their astronomy instruments.

“Something has to change,” said Jessica Dempsey, the deputy director of the East Asian Observatory, which runs the James Clerk Maxwell Telescope. “The risk to our instruments becomes greater as we go on.”

Directors of the Maunakea Observatories made the decision to shut down July 16 shortly after hundreds of TMT protesters began blocking Mauna Kea Access Road near its intersection with Daniel K. Inouye Highway, formally known as Saddle Road.

The largely Native Hawaiian kiai, or “protectors,” are protesting what many of them consider the desecration of a sacred mountain after failing to block the next-generation telescope in court and during its lengthy regulatory process.

Some 25 employees were brought off the mountain for safety reasons, leaving some of the most productive telescopes in the world being monitored only remotely from sea-level headquarters in Hilo and Waimea.

At first, TMT opponents refused to let any telescope workers up the summit road and blocked a maintenance crew from the Gemini telescope from doing critical work on the morning of July 23 before agreeing to let them pass later that night.

Following negotiations between law enforcement and the kiai, it was announced that maintenance crews with an urgent need would be allowed access in return for allowing a limited number of people to the summit for traditional Hawaiian cultural practices.

Contrary to what some believe, the agreement didn’t allow the telescopes to become operational again, observatory officials said.

In fact, they said, access for crews continues to be a challenge as observatory vehicles can only drive a bumpy unpaved lava rock trail through the protest encampment — avoiding children, campers and others — in order to reach the summit road. They must wait until the kupuna give permission for them to go through.

Dempsey said the route can be a safety hazard.

And despite previously receiving nearly daily maintenance, the instruments at James Clerk Maxwell Telescope have only seen maintenance crews twice since the mountain was evacuated, once to make an emergency run to check on an ailing instrument and another to make sure detectors were not damaged.

“They can be incredible, high- maintenance, temperamental instruments,” she said.

Kiai leader Andre Perez said protesters have accommodated nearly every request submitted by the observatories for access, so there really shouldn’t be any complaints.

“We’ve been flexible because we know our fight is with the TMT and not the existing observatories,” Perez said.

Dempsey said a new $400,000 three-camera instrument arrived in Hilo three weeks ago intended for immediate delivery and installation at the summit. But, she said, the protest made it impossible.

Instead, the instrument was taken to a lab at sea level for testing.

The instrument, named Namakanui by University of Hawaii-Hilo Hawaiian language professor Larry Kimura, is expected to be used next year with the Event Horizon Telescope as a collection of telescopes worldwide search for the next image of a black hole.

The James Clerk Maxwell Telescope and its neighbor on the summit, the Submillimeter Array, were part of the last Event Horizon Telescope experiment, which led to the imaging of Powehi — the black hole at the center of the M87 galaxy, announced earlier this year.

Dempsey said Namakanui is too sensitive to travel on the unpaved road to the summit, which makes her worry whether it can be installed and commissioned in time for the Event Horizon Telescope tests planned for later this year and early next year.

“We’re working on it as much as we can in the lab,” she said, “but sometimes it takes as long as six months to get an instrument like this fully operational. We’re on an incredibly tight schedule.”

Perez said he is unaware of any request to use the occupied access road. “If a request is made, they will get an answer,” he said.

Nadine Manset, resident astronomer at the Canada-France-Hawaii Telescope, said 200 hours of valuable observation time has been lost at her facility since the protest started.

“You cannot quantify a discovery,” she said. One UH astronomer, for example, was supposed to be using the CFHT to confirm the orbits of 30 space objects. “But the objects are lost. We don’t know where they are.”

Manset said in recent days officials have been worrying about a couple of festering issues at the telescope, including a broken crane and the condition of an instrument used to discover and characterize exoplanets. Kept at extremely cold temperatures, the infrared spectropolarimeter has been warming.

CFHT staff members and technicians from a company that specializes in cranes were able to reach the summit Wednesday, she said.

“They made it up and have started the process of repairing the crane and troubleshooting the cooling issue,” Manset said.

But the operation will require multiple days in a row and “we haven’t tried requesting daily access like that yet,” she said.