A two-person technical crew from the Gemini telescope was allowed to pass through the Mauna Kea protesters Tuesday night to reach the summit to perform critical work on some of its instruments after being denied access earlier in the day, according to an announcement from Gemini.

The crew was granted passage through the protesters at about 10:45 p.m. after the activists provided assurances through law enforcement and the Office of Maunakea Management that the technicians would be allowed to travel on Mauna Kea Access Road, according to the Gemini statement.

Opponents of the Thirty Meter Telescope have massed on the access road for more than a week in an effort to prevent construction equipment from reaching the summit and beginning work on the TMT project.

The Gemini Observatory reported Tuesday afternoon that a car carrying technicians was blocked by activists from reaching the summit.

According to Gemini, “activists told observatory personnel that without a formal, public letter from the observatories — supporting activists’ demands of the state — access for critical technical maintenance is no longer supported.”

Protest leader Kahookahi Kanuha said there was a discussion between the Gemini staff and the TMT opponents, and that the Gemini staff decided to retreat.

The activists have been allowing rangers, support staff at the visitors center, water trucks and telescope maintenance crews to travel to the summit, but not astronomers, according to a state spokesman.

The Gemini observatory uses gaseous helium in a cooling circuit to maintain stable low temperatures for two delicate instruments used in astronomical observations, and that cooling system had become unstable, according to the statement from Gemini. That required specialized technicians to shut the system down in order to prevent damage to the instruments and the cooling circuit itself.

The two-person crew successfully executed their plan to protect the instruments and perform a standard facility inspection that is usually conducted on a daily basis. The crew completed that work just after 2 a.m. today and returned to Gemini’s Hilo base facility after 3:00 a.m., according to the statement.

“The observatories hope to return as soon as possible to long-term reliable access to our facilities so that we can resume operations and safely return to scientific observations each night,” according to the statement from Gemini.