TECHNICAL SPECIFICATIONS
Owner: European Southern Observatory (ESO)
Gen. Contractor: Ace Consortium, lead by Cimolai SpA
The ELT (Extremely Large Telescope) is an optical/infrared telescope with a 39-metre primary mirror, located on Cerro Amazones in the Chilean Andes, at an altitude of approximately 3,000 metres above sea level. Currently under construction, it will be the largest visible and infrared light telescope in the world. It will be operated and maintained by ESO’s Paranal Observatory, located about 20 km away.
The design, production, on-site transport, assembly and testing of the ELT have been entrusted to the ACe Consortium, led by Cimolai SpA.
The ELT will consist of a steel structure with a diameter of 71 metres and a height of 62 metres. The telescope, which incorporates highly advanced and extremely precise technological solutions, will be housed inside a rotating steel structure known as the dome. Weighing approximately 6,000 tonnes, the dome will feature sliding openings, a diameter of 92 metres and a height of 80 metres, as well as a partially permeable windscreen. In addition, an Auxiliary Building will be constructed at the lower level around the dome, housing all technical rooms as well as the main entrance.
In addition to the steel components, weighing approximately 13,500 tonnes, the project also includes civil works, mechanisms, systems and finishes.
The telescope’s Main Structure, consisting of an approximately 4,200-tonne steel structure, will reach a rotating mass of 4,700 tonnes once integrated with the mirrors and instruments. This mass will move with micrometric precision thanks to a hydrostatic system, special linear motors and ultra-high-resolution encoders. The entire structure will be installed on a newly designed seismic isolation system, which will ensure high stiffness and stability during observation, while providing the necessary damping in the event of an earthquake, thereby protecting the extremely delicate mirrors and instruments.
