Washington, September 2 : Astronomers and engineers have said that the single-piece primary and tertiary mirror blank cast for the LSST (Large Synoptic Survey Telescope) by a giant furnace, is "perfect".
The LSST, a large survey telescope being built in northern Chile, requires three large mirrors to give crisp images over a record large field of view.
The two largest of these mirrors are concentric and fit neatly onto a single mirror blank.
The single-piece primary and tertiary mirror blank emerged from the oven of a giant furnace at the University of Arizona's Steward Observatory Mirror Lab in Tucson, Arizona, where team members gathered to celebrate this major milestone.
The Mirror Lab team opened the furnace for a close-up look at the cooled 51,900-pound mirror blank, which consists of an outer 27.5-foot diameter (8.4-meter) primary mirror and an inner 16.5-foot (5-meter) third mirror cast in one mold.
It is the first time that a combined primary and tertiary mirror has been produced on such a large scale.
The finished mirror is scheduled to be delivered in 2012.
The LSST will be the widest, fastest, deepest eye of the new digital age when it begins science operations from Cerro Pachon, Chile, in 2015.
It will provide time-lapse digital imaging across the entire available night sky every three days, mapping the structure of our dynamic universe and exploring the nature of dark matter and dark energy.