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News Release 17-072

Primary mirror delivered to Daniel K. Inouye Solar Telescope

Mirror for world's largest solar telescope is polished to the scale of single molecules

The Daniel K. Inouye Solar Telescope, on the summit of Haleakalā on Maui, Hawaii.

The Daniel K. Inouye Solar Telescope will be observing the sun's corona, or outer atmosphere.

August 3, 2017

The primary mirror for the National Science Foundation (NSF) Daniel K. Inouye Solar Telescope (DKIST) -- the heart of this sophisticated instrument -- was successfully delivered Aug. 2 to its destination atop Haleakalā on Maui, Hawaii.

When completed in 2020, DKIST will be the world's largest solar telescope, providing scientists with new insights into the physics of the sun and a better understanding of how space weather affects satellites, the power grid, and other infrastructure upon which human society has come to rely.

"The primary mirror is the heart of any telescope," said David Boboltz, program director for NSF's National Solar Observatory, which is leading the construction for DKIST. "The larger the mirror, the sharper the images can be. For DKIST, that means the most detailed observations of the sun, including its faint corona, ever gathered. The NSF would like to thank the entire DKIST project team that made this delivery happen."

The safe delivery marks a major milestone for the DKIST project. The 4-meter (13-foot) mirror is an engineering marvel, polished to a surface roughness of only 2 nanometers (2 billionths of a meter), the scale of single molecules. The mirror will be supported by 144 electromechanical actuators that will adjust the structure, compensating for the pull of gravity as it tilts throughout the day, from sunrise to sunset.

DKIST, operated by the Association of Universities for Research in Astronomy under a cooperative agreement with NSF, will join a suite of telescopes on Haleakalā's summit that have spent several decades observing the sun and the rest of our universe. The mountain's summit is one of the few places on Earth with "coronal skies," meaning solar astronomers can view the sun's corona relatively free from the hazy scattering of light caused by the atmosphere.


Media Contacts
Aya Collins, NSF, (703) 292-7737, email:

The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2017, its budget is $7.5 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives more than 48,000 competitive proposals for funding and makes about 12,000 new funding awards.

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