The second mirror is being processed at the mirror lab, and the third mirror segment will be cast in August of 2013.
Materials for the fourth mirror segment have been purchased; that mirror will be cast in late 2014.
The key advance that allowed the construction of the Keck's large telescopes was the ability to operate smaller mirror segments as a single, contiguous mirror.
But 42 mirror segments polished by laboratories in the mainland United States must also be trucked to the mountaintop.
Segmented concept mirrors are formed by independent flat mirror segments.
All of our mirror segments have now completed final polishing!
Their primary mirrors will be built from hundreds of hexagonal mirror segments.
Each of the seven mirror segments is to be 8.4 meters in diameter, which is the biggest size his furnace can handle.
The first major use of ion figuring was in making the mirror segments for the Keck telescope.
His design had 36 hexagonal mirror segments, each six feet in diameter and just three inches thick.