PASADENA, CA – March 24, 2025 – Dr. Robert N. Shelton has announced his plans to retire as President of the GMTO Corporation, the organization building the Giant Magellan Telescope, effective June 30, 2025. Dr. Shelton has led the organization since 2017, guiding the Giant Magellan Telescope through a period of significant growth and global collaboration.

“It has been an honor to serve as President of GMTO and work alongside an exceptional team dedicated to building one of the world’s most powerful telescopes,” said Dr. Shelton. “Together, we have secured new partners, expanded our federal engagement, and advanced the construction of significant milestones that have positioned the Giant Magellan Telescope for success.”

During his eight-year tenure, Dr. Shelton played a critical role in advancing the Giant Magellan Telescope, expanding funding, guiding the project through key technical milestones, and keeping the project on track through major challenges like the COVID-19 pandemic. He secured four new institutional partners—two in the US and two international—broadening the GMTO consortium to 15 members and significantly increasing private investment. Under his leadership, GMTO successfully distinguished the Giant Magellan Telescope from other next-generation observatories, securing recognition in the National Academies’ Astro2020 Decadal Survey as the top priority for ground-based astronomy as part of the US Extremely Large Telescope Program.

Dr. Shelton’s efforts brought total commitments in the Giant Magellan Telescope to nearly $1 billion in funding, including one of the largest funding rounds in GMTO history—a $205 million private investment designed to accelerate construction. With his steady leadership, the project advanced to 40% under construction. Notable milestones included completing three of the seven 8.4-meter primary mirrors, finalizing site infrastructure in Chile for the 65-meter-tall enclosure, and beginning manufacturing of the telescope mount structure—the largest built in America.

“Robert Shelton’s leadership has been instrumental in guiding GMTO through a pivotal period of growth and progress. He is a magnanimous leader, admired and loved by all,” said Dr. Walter Massey, Board Chair of the GMTO Corporation. “His vision and dedication have strengthened our partnerships, expanded our federal engagement, and positioned the Giant Magellan Telescope for success. On behalf of the Board, I extend my deepest gratitude for his unwavering commitment and steady leadership. We wish him the very best in his well-earned retirement.”

In making this announcement, Dr. Shelton emphasized that his decision does not reflect any loss of confidence in the success of the Giant Magellan Telescope. Instead, after eight years of dedicated leadership, he has chosen to retire to devote more time to his family.

“The Giant Magellan Telescope is a more-than-full-time commitment, as everyone involved in this extraordinary effort knows,” said Dr. Shelton. “The satisfaction of this work comes from full dedication to the telescope, and I recognize that I cannot do that while also giving my personal life the attention it deserves.”

Prior to joining GMTO, Dr. Shelton held leadership roles across academia and science philanthropy, serving as President of the Research Corporation for Science Advancement and as the 19th President of the University of Arizona. His distinguished career in physics and higher education includes leadership positions at the University of North Carolina at Chapel Hill and the University of California system, as well as governance roles with the Keck Observatory, the Rubin Observatory, and the Space Telescope Science Institute.

The GMTO Board of Directors will begin the process of identifying the next President, ensuring a seamless transition of leadership. Dr. Shelton has pledged his full support in this process and looks forward to celebrating the Giant Magellan Telescope’s achievements in the years to come.