The Thirty Meter Telescope planned for Maunakea on Hawaiʻi Island has an uncertain future due to a decision to direct limited funds toward the development of a project in Chile.
The National Science Foundation has withdrawn financial support for the TMT in plans submitted as part of the Trump Administration’s funding request to Congress for fiscal year 2026.
The president has cut the NSF’s funding by more than half in his budget proposal. As a result, the foundation is dropping its financing of the TMT, while continuing support for a competing “extremely large telescope" project in Chile, the Giant Magellan Telescope.
"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, but the TMT will not advance to the Final Design Phase and will not receive additional commitment of funds from NSF," the report said. "Moving into the final design phase does not guarantee that a project will be approved for construction, and doing so does not obligate the agency to provide any further funding."
Discussions about limiting NSF funding for these projects are not new. In early 2024, the National Science Board was considering a $1.6 billion cap on the NSF's investment in giant telescopes. The estimated price tag for each of the two telescopes has been at least $2.5 billion to $3 billion.
Over the weekend, TMT Project Manager Fengchuan Liu called Maunakea the "premier northern hemisphere site for astronomy," and said that the TMT project is "one of the most compelling American opportunities in this generation."
"We are disappointed that the NSF's current budget request does not include TMT, but we remain firmly committed to finding a path forward for TMT. 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," Liu said in a statement.
Supporters of the TMT, including Hawaiʻi County Mayor Kimo Alameda, said they are not giving up on the project. He also sits on the Maunakea Stewardship and Oversight Authority.
The Honolulu Star-Advertiser reported that Alameda said the move to defund TMT undermines the future of astronomy in Hawaiʻi as well as Native Hawaiian economic and educational opportunities.
The TMT project has been controversial for years, including protests at Maunakea in 2019. Opponents have objected to adding more telescopes to a mountain many Native Hawaiians consider sacred.
