Cranfield works on world’s largest telescope

A ground-based telescope, E-ELT will be 42m in diameter and made up of 1000 hexagonal segments, each 1.4m wide and 5cm thick. At almost half the length of a soccer pitch in diameter, the E-ELT is four to five times larger and will gather 15 times more light than the largest optical telescopes operating today. Cranfield University says it is the only university in the UK with the capability to undertake the various stages of the machining process for the mirror segments to the accuracy required. Designed and developed at Cranfield specifically for realising these mirrors, the BoX (Big OptiX) machine is said to have the ability to grind large optics in a matter of hours. The University also completes the process with a final machining phase on the Reactive Atom Plasma Technology (RAPT) machine which allows final polishing of the surface of the component to an atomic level of accuracy to remove any imperfections of the final surface. The E-ELT will tackle a range of scientific challenges, aiming for a number of notable firsts, including tracking down Earth-like planets around other stars in the 'habitable zones' where life could exist. It will also perform 'stellar archaeology' in nearby galaxies, and make fundamental contributions to cosmology by measuring the properties of the first stars and galaxies, and probing the nature of dark matter and dark energy. Professor Paul Shore, head of the Cranfield Precision Engineering Centre, said: "At Cranfield we will be measuring the mirrors to ensure their accuracy, then grinding and mounting the feet that support them. They will then be moved to Technium OpTIC (Opto-electronics Technology and Incubation Centre) in North Wales, the location of our Integrated Knowledge Centre in Ultra Precision and Structured Surfaces, where they will be polished to a form accuracy of 25nanometres."