Tag Archives: ELT

First six segments of Extremely Large Telescope cast

The first six mirror segments of the European Southern Observatory’s Extremely Large Telescope have been successfully cast.

These segments will form parts of the ELT’s 39-metre main mirror, which will have 798 segments in total when completed. The ELT will be the largest optical telescope in the world when it sees first light in 2024.

The 39-metre-diameter primary mirror of ESO’s Extremely Large Telescope will be by far the largest ever made for an optical-infrared telescope. Such a giant is much too large to be made from a single piece of glass, so it will consist of 798 individual hexagonal segments, each measuring 1.4 metres across and about 5 centimetres thick. The segments will work together as a single huge mirror to collect tens of millions of times as much light as the human eye.

The segments must now be cooled, then their surfaces ground and polished to the right shape. If all goes right, they will make more than 900 segments (with about a 130 as spares), manufactured to have the telescope operational by 2024.

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ELT construction moves forward

The European Southern Observatory (ESO) today signed contracts for the construction of the mirrors and sensor for its Extremely Large Telescope (ELT).

At a ceremony today at ESO’s Headquarters four contracts were signed for major components of the Extremely Large Telescope (ELT) that ESO is building. These were for: the casting of the telescope’s giant secondary and tertiary mirrors, awarded to SCHOTT; the supply of mirror cells to support these two mirrors, awarded to the SENER Group; and the supply of the edge sensors that form a vital part of the ELT’s huge segmented primary mirror control system, awarded to the FAMES consortium. The secondary mirror will be largest ever employed on a telescope and the largest convex mirror ever produced.

The construction of the 39-metre ELT, the largest optical/near-infrared telescope in the world, is moving forward. The giant telescope employs a complex five-mirror optical system that has never been used before and requires optical and mechanical elements that stretch modern technology to its limits.

Meanwhile it remains unclear when and where the Thirty Meter Telescope (TMT) will be built.

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