First Segments of ELT's Primary Mirror Successfully Cast: The first six hexagonal segments for the primary mirror of ESO's Extremely Large Telescope (ELT) have been successfully cast by SCHOTT (Germany) at their facility in Mainz. These segments will form parts of the ELT's 39-metre primary mirror, which will have 798 segments in total. After casting, the mirror segment blanks will go through a slow cooling and heat treatment sequence and will then be ground to the right shape and polished to a precision of 15 nm across the entire optical surface. The shaping and polishing will be performed by Safran Reosc (France), which will also be responsible for further testing.
ESO ELT News
Published: 22 Feb 2018
ELT Instrument update: Work on all ELT instruments is proceeding well. Recently, the HARMONI Preliminary Design Review (PDR) was held at ESO on 9-10 November and 7-8 December 2017. The HIRES Phase A review also took place at ESO Garching on 13-14 December 2017.