The DKIST Primary Mirror has been successfully aluminized in preparation for installation into the Telescope Mount Assembly. The 4-meter diameter, 75-mm thick mirror is made from Schott Zerodur glass with a weight of 3.3 metric tons. Despite the large size of the mirror, it requires only a tiny amount of aluminum (less than an ounce) to coat the surface. The aluminum coating provides a highly reflective surface required for the optical and infrared wavelengths at which DKIST will operate.
