ELT altitude structure

Once up and running, the Extremely Large Telescope (ELT) will be the "world's biggest eye on the sky". 

This image shows the ELT altitude system, which will be home to the ELT's innovative five-mirror optical system. These mirrors include the primary mirror, which will be composed of 798 hexagonal segments, and the secondary mirror, which is due to be the largest convex optical mirror ever produced.