Mersen has achieved a world first with the delivery to Safran Reosc of the fifth and final blank mirror for the European Southern Observatory’s (ESO) Extremely Large Telescope (ELT).
The ELT will be the world’s most powerful giant telescope, with a primary mirror measuring 39 meters in diameter. It is being built on the Cerro Armazones mountain in northern Chile, at an altitude of over 3,000 meters, and will usher in significant progress in astronomy (stellar archeology, exoplanet detection and characterization, etc.). Mersen has been contributing to astronomy for more than 25 years, working on such prestigious ESA space missions as Rosetta, Herschel, GAIA and Euclid, as well as NASA’s James Webb Space Telescope.
The use of SiC, a lightweight, highly stiff material with exceptional thermomechanical properties, is essential to correct the vibrations of the telescope’s immense structure and stabilize the image that will be obtained.
The mirror, once mounted on actuators, will vibrate continuously to offset disturbances caused by wind and atmospheric turbulence. At 2.7 meters long, it will be the world’s largest tip-tilt mirror.