The Giant Magellan Telescope, whose primary mirror segments are being produced by the University of Arizona's Richard F. Caris Mirror Lab, has received official approval from the National Science Foundation confirming that the observatory will advance into its Major Facilities Final Design Phase, one of the final steps before becoming eligible for federal construction funding. This milestone recognizes the Giant Magellan's scientific merit, construction progress and alignment with U.S. priorities in science and technology.

"We're proud that the Richard F. Caris Mirror Lab's contributions continue to advance science and affirm the University of Arizona's role as a global leader in astronomy and space sciences," said U of A President Suresh Garimella. "We are pleased the NSF recognizes that the Giant Magellan Telescope is well-positioned to advance to the final design phase and we look forward to further progress."

"This a huge milestone for everyone who has been working for decades to make the next generation of giant telescopes possible, and the Giant Magellan Telescope in particular, a reality," said Buell Jannuzi, director of U of A Steward Observatory. "Between our world-renowned capabilities in large optics with the Richard F. Caris Mirror Lab, and research excellence in astrophysics, we will continue to work toward completing what will be a transformational facility for U.S. astrophysics and astronomy."

About 40% of the telescope’s components are currently being constructed, with major components manufactured and tested in facilities across 36 states in the U.S., including advanced optics and primary mirrors in Arizona, science instruments in multiple states including Texas, and the telescope mount structure in Illinois. At the observatory’s privately owned site in Chile, major infrastructure progress includes utilities, roads, support structures and a fully excavated foundation for the enclosure.

The Giant Magellan's 368-square-meter light-collecting surface is composed of seven of the world’s largest optical mirrors arranged in a unique flower pattern. Together, they will provide the highest image resolution over the widest field of view ever achieved for the exploration of the Universe – delivering up to 200 times the power of today’s best telescopes.

The NSF's decision follows the release of its FY2026 Budget Request to Congress and the recent U.S. Extremely Large Telescope External Evaluation Panel Report. The report expressed "confidence that the Giant Magellan Telescope will progress through FDP (Final Design Phase) to a successful FDR (Final Design Review) and construction, if approved."

Strategically located in Chile's Atacama Desert, the Giant Magellan occupies one of the most scientifically valuable observing sites on Earth. Chile offers more than 300 clear nights each year, exceptional atmospheric stability and direct access to the southern sky and the galactic center of the Milky Way.

Robert Shelton, president of the GMTO Corp. and former U of A president, called the NSF's decision "a great moment for the future of American astronomy."

"Advancing us into its Final Design Phase reaffirms the strength of our observatory and the decades of preparation by our dedicated team," Shelton said. "With significant construction already underway across the United States and at our site in Chile, this milestone positions our nation to lead the next era of discovery. We greatly appreciate the NSF's vote of confidence and its continued commitment to maintaining American leadership in science, engineering, and precision manufacturing."

Over the last five years, the observatory has successfully passed all federally required reviews and is prepared to privately finance the Final Design Phase. This reflects the project's advanced progress and expertise of its international consortium, with many design elements already exceeding NSF Final Design Review benchmarks.

"This is more than an investment in a telescope," said Walter Massey, board chair of the Giant Magellan Telescope and former NSF director. "It is a strategic necessity for the United States to maintain leadership in astrophysics, engineering and artificial intelligence. The Giant Magellan Telescope will work in synergy with billions of dollars already invested in U.S. research facilities around the world, creating a powerful ecosystem of tools that ensure American scientists have the best resources to lead discovery."

The Giant Magellan Telescope is committed to the science goals of the U.S. Extremely Large Telescope Program, the top-ranked priority in the National Academies' 2020 Decadal Survey on Astronomy and Astrophysics. The report called the program "absolutely essential if the United States is to maintain a position as a leader in ground-based astronomy."

Backed by nearly $1 billion in private funding – the largest private investment ever made in ground-based astronomy –  the Giant Magellan is built by an international consortium of 15 universities and research institutions, including the U of A, the Carnegie Institution for Science, the University of Texas at Austin, the Korea Astronomy and Space Science Institute, the University of Chicago, the São Paulo Research Foundation, Texas A&M University, Northwestern University, Harvard University, Astronomy Australia Ltd., Australian National University, the Smithsonian Institution, the Weizmann Institute of Science, the Academia Sinica Institute of Astronomy and Astrophysics, and Arizona State University.