The National Science Foundation will no longer fund the controversial Thirty Meter Telescope planned for construction atop Maunakea, instead choosing to back its international competitor, the Giant Magellan Telescope in Chile.
The decision, revealed Friday in the NSF’s fiscal year 2026 budget request under the Trump administration, could be the death knell for the $3 billion TMT project and its future viability.
The president had sought to slash the NSF’s $9 billion budget by 56% as part of a broader pattern of federal funding reductions. According to the budget proposal, the NSF will support only one of two U.S.-backed “extremely large telescope” projects due to financial constraints.
The agency opted to advance Chile’s GMT into a “major facility final design phase,” stating the TMT will not advance to the final design phase and will not receive an additional commitment of NSF funds.
The TMT was first proposed in the early 2000s as one of the most ambitious astronomy projects ever attempted, featuring a 30-meter segmented mirror nearly three times the size of any currently in operation. It is led by a consortium of U.S. and international scientific institutions, with the University of Hawaii serving as the local site partner.
Many Native Hawaiians consider Maunakea the most sacred place in the islands, often describing it as a spiritual and ancestral homeland, and believe that constructing the telescope would further desecrate the mountain, which is already home to roughly a dozen observatories.
TMT has faced repeated delays and soaring costs — from an initial estimate of $1.4 billion to $3 billion — alongside intense protests that halted construction in 2019 and sparked broader conversations about Indigenous rights, land stewardship and the role of science in Hawaii.
Despite those challenges, the TMT collaboration has long hoped to secure NSF funding to move the project forward. But the NSF’s new budget request makes clear that continued financial support for both telescopes is “unaffordable,” and that only the Chile project has “assurances” of completing its design phase without further investment.
Even for GMT, the path ahead is not guaranteed. NSF emphasized that advancing to the final design phase “does not obligate the agency to provide any further funding” or approve construction. Nonetheless, the decision leaves TMT’s future far in doubt, especially without a clear backup site and persistent community opposition.
Native Hawaiian activist Healani Sonoda-Pale described the funding decision as a rare and important win for Native Hawaiians, especially the “protectors” who filed formal comments and advocacy letters aimed at influencing NSF decisions.
Still, Sonoda-Pale said she doubts that Native Hawaiian concerns played a meaningful role in the Trump administration’s decision-making, suggesting the NSF funding cut for TMT was more likely the result of broader budget priorities than a conscious effort to support Native Hawaiian interests.
“I don’t think the Kanaka Maoli are on his radar,” she said. “It just so happens the stars aligned and this was a win for Hawaiians … . This decision will empower Kanaka Maoli to keep moving forward and remain vigilant to protect Maunakea and all sacred places in Hawaii.”
Gov. Josh Green and University of Hawaii officials deferred comment on the funding cuts to the Maunakea Stewardship and Oversight Authority, whose leaders were not immediately available to respond to the development.
However, Hawaii island Mayor Kimo Alameda, who sits on the stewardship authority board, voiced deep disappointment over the Trump administration’s proposed budget cuts, saying the move to defund TMT undermines not only the future of astronomy in Hawaii but also crucial Native Hawaiian economic and educational opportunities.
Alameda framed his support for the telescope squarely around its potential to benefit Hawaiians.
“My whole support of the new version of TMT is to help Hawaiians and to help Hawaii,” he said Saturday. “You take TMT off the table, now we have the status quo because there’s no motivation for decommissioning (other telescopes).”
He explained that keeping TMT “on the table” was about more than just supporting science; the project provided important leverage to negotiate better terms with other observatories on Maunakea. He fears the mountain’s stewardship will stagnate and critical revenues that could support Native Hawaiian immersion and charter schools and homestead programs will be lost.
Alameda noted the ripple effect on the island’s economy and the Native Hawaiian community in particular. Construction and operation of TMT represent decades of union jobs for carpenters, electricians, iron workers and laborers, he said.
He also questioned the political logic behind shifting federal astronomy funding from Hawaii to the GMT under construction in Chile.
“Chile is a different country, right? Trump’s all about making America great again,” Alameda said.
He stressed that many Native Hawaiians may not fully grasp how defunding the TMT would be felt across Native Hawaiian programs and institutions relying on that revenue.
With Congress yet to weigh in on the proposed budget, Alameda holds cautious hope that further developments may still support science funding, but he warned that the current trajectory threatens to end one of the nation’s flagship astronomy projects and diminish Hawaii’s role in global scientific innovation.
U.S. Rep. Jill Tokuda (D, Hawaii) agreed that the likely loss of NSF funding for TMT would set back Hawaii Island’s efforts to diversify its economy and create high-quality, sustainable jobs for local residents through education, workforce development and long-term economic opportunities that “extend well beyond astronomy.”
“If we are unable to navigate complex challenges and reach consensus on projects that require the successful inclusion of community participation and feedback, it will send a concerning message to future partners and invite caution from government funders when local commitment and community alignment are uncertain,” Tokuda said in a statement Saturday to the Honolulu Star-Advertiser. “At this critical moment, Hawaii must show it can come together to support responsible opportunities that strengthen our communities and secure a more resilient economic future.”
Meanwhile, Hilo native Dakota Lee, 23, expressed conflicting feelings about the TMT project.
“Maunakea is a sacred place for the Hawaii community, and I think that the desecration of such a sacred place has been really hard on our community,” said Lee, a Native Hawaiian.
Reflecting on the emotional complexity of the situation, he added: “My heart is sad because I know that that’s a loss of funding for the community. I’ve always had such a difficult time just talking about this in general because I really do see both sides and connect with both sides.”
He cited cultural insensitivity and past mismanagement of Maunakea, saying UH had “handled things poorly” by not adequately listening to Native Hawaiians before responsibility for the mountain was transferred to the Maunakea Stewardship and Oversight Authority, which was established in 2022.
But Lee also warned that the defunding of TMT could have serious consequences for Hawaii’s economy and educational system, both of which depend heavily on support from scientific and research funding sources.
He cautioned against oversimplifying the apparent defunding of TMT as merely a political win for Native Hawaiians. While acknowledging the widespread belief that the move aligns with opposition to the telescope, Lee stressed that it is more accurately a reflection of broader policy decisions undermining scientific research.
“While I think that the lahui will see this as a win, I think we also have to be really careful with how we see this as a win and what we do moving forward,” Lee said, underscoring the delicate balance between cultural preservation and economic sustainability.
