This story has been updated with a statement from the consortium behind the TMT project.

The controversial Thirty Meter Telescope planned for the summit area of Mauna Kea has lost the critically important support of the National Science Foundation, which plans to direct major funding to the Giant Magellan Telescope in Chile instead of TMT.

The Trump administration’s proposed new budget for the NSF suggests pushing ahead with the Magellan project, and says the TMT “will not receive additional commitment of funds from NSF.”

“Given the unaffordability of continuing funding two different multi-billion dollar telescopes, NSF will advance the Giant Magellan Telescope (GMT) into the Major Facility Final Design Phase,” according to the budget proposal. “The Thirty Meter Telescope (TMT) will not advance to the Final Design Phase and will not receive additional commitment of funds from NSF.”

The TMT International Observatory, a consortium of scientists behind the project, expressed disappointment with the decision but said it would press forward, calling Mauna Kea the premier site for astronomy in the northern hemisphere.

Hawaiʻi County Mayor Kimo Alameda also said he is not giving up on the TMT yet and plans to seek out potential allies to back the project in a trip next week to Washington, D.C. He hopes Congress will reject the proposed NSF budget and direct NSF funding back to the Big Island project.

The TMT has faced major hurdles that peaked in 2019 when thousands of protesters massed on the Mauna Kea Access Road to halt construction of the telescope, which many Hawaiians regarded as a desecration of a sacred mountain.

Those protests and the arrests of elders who sat on the road to block construction equipment from reaching the summit became a powerful and emotional rally point for Hawaiians across the state. The movement effectively halted the project.

The protests ended with the beginning of the Covid-19 pandemic, but any effort to restart the TMT project would almost certainly encounter bitter grassroots resistance.

Critics fear the volcano’s summit, already home to several advanced telescopes, has been overdeveloped and culturally and environmentally exploited to harmful effect.

TMT International Observatory stressed the scientific importance of the giant telescope and said it remained “firmly committed to finding a path forward for TMT.”

“The Thirty Meter Telescope is one of the most compelling American opportunities in this generation. It is designed to explore the earliest galaxies, probe the nature of dark matter and dark energy, and search for life on exoplanets,” the group said in an emailed statement. “TMT will enable the United States to demonstrate global leadership, while setting new standards for partnerships with the community where it wishes to be built and operated.”

“We can imagine a future in which NSF participation in the TMT would open opportunities for significant discovery to the entire US science community, and welcome further conversations to make this a reality,” it said.

The astronomy industry is a major economic driver in Hawaiʻi and many business people and researchers support the project, which would be the world’s largest ground-based optical telescope.

The mayor said he will meet with the Hawaiʻi congressional delegation and will seek support in Republican circles. “Trump is all about making America great again, so why would he want to invest in something in Chile?” he said.

“What these cuts could do is really tarnish the confidence of the science community in wanting to do science in Hawaiʻi,” Alameda said.

Big Island leaders of the protest movement declined to comment Friday night while they studied the latest developments.

Both TMT and Magellan are part of the U.S. Extremely Large Telescope Program, and the NSF has been contemplating a $1.6 billion cap on its commitment to that program for more than a year.

That is not nearly enough funding to finance both projects, but the proposed new NSF budget appears to declare Magellan the winner of that competition.

The proposed budget does not guarantee that even Magellan would be completed, however. It only proposes to commit the federal government to advance the design of the project.

The Giant Magellan Telescope is expected to cost more than $2.5 billion, while unofficial estimates put the cost of the TMT at $3 billion or more.

The Trump administration has proposed cuts of more than 50% to the NSF budget, which Alameda said is taking the nation in the wrong direction.

“Lets face it, if we decrease our expertise in science, to me that’s a national defense issue,” Alameda said. “How can we compete with other countries if we cannot advance in science?”

Read the NSF budget request below: