US Extremely Large Telescope Program

US Extremely Large Telescope Program

News 5 Nov 2021: US Extremely Large Telescope Program Supports Vision of Decadal Survey: The decadal survey for astronomy and astrophysics is a powerful study that our community uses to drive strategy and vision for the next decade of federally funded transformative science. The 2020 report, Pathways to Discovery in Astronomy and Astrophysics for the 2020s (Astro2020), was published by the National Academies of Science, Engineering, and Medicine on 4 November 2021. We are honored that the community, via the decadal survey, has ranked the US Extremely Large Telescope Program (US-ELTP) as the highest ground-based priority in Pathways to Discovery. Read more.


The US Extremely Large Telescope (ELT) Program is a joint endeavor of NSF’s NOIRLab and the organizations building the Thirty Meter Telescope (TMT) and the Giant Magellan Telescope (GMT). These organizations plan to submit for peer-review proposals that seek a federal contribution to complete the telescopes and make at least 25 percent of the observing time available for open access for the whole US community.  The two-hemisphere system would provide the US science community with greater and more diverse research opportunities than could be achieved with a single telescope.

Key Science Programs (KSPs) requiring substantial amounts of observing time, potentially over several years, would enable the US community to carry out transformational research that takes full advantage of the diverse capabilities of both GMT and TMT. Smaller-scale Discovery Science Programs (DSPs), allocated on a more frequent cadence, would be nimble, exploratory, and responsive to new scientific opportunities.

To facilitate access to the telescopes and the data that they deliver, NOIRLab would provide an extensive suite of user services, documentation, and training to support the entire research lifecycle from submission of proposals to observations to data analysis.

US-ELTP images.

Thirty Meter Telescope images.

Giant Magellan Telescope images.