Overview of ESO ELT Construction Project

The construction of the ESO’s Extremely Large Telescope (ELT) passed its 50% completion milestone in 2023. The construction site at Cerro Armazones (Chile) went from a flat rocky landscape to a mountain top housing finished structural concrete foundations and an 80m-high dome steel structure. In Europe, the manufacturing of the telescope structure is progressing well: Tens of M1 segments have been polished to excellent optical quality, and a few tens have already delivered to the site in Chile. The M2 mirror is quickly approaching its final figuring accuracy. The M4 adaptive mirror has received all of its six Zerodur® thin shells, and is progressing to full assembly and integration at the contractor’s premises. The M5 has reached a critical step with the brazing of the six CVD-coated SiC petals. The two large Pre-focal Stations are close to starting their final testing. Finally, the four instruments are all in the final design phase, with some beginning procurement, among other advancements.


Roberto Tamai, ESO’s ELT Programme Manager, European Southern Observatory (ESO)


Thursday, March 28, 2024