Dava Sobel travels to Edinburgh, to catch sight of the most ambitious telescope being made. Episode three of five.

This time next year, the James Webb Space Telescope will begin its long journey to a stable orbit at a place called L-2, one million miles beyond the Moon. It will unfold the components of its huge, intricate body and look back in time, to probe events that occurred nearly 14 billion years ago.

The James Webb is a Nasa-led project, with the telescope named after the Nasa administrator who ran the space agency during the Apollo program of the 1960s. This is also a landmark collaboration between the European and Canadian Space Agencies, in all elements of its design and construction. Dava learns about the intricacies of the British component being made, the MIRI – the Mid Infrared Instrument – which will intercept invisible light waves in the infrared region of the electromagnetic spectrum, to study the earliest stars and galaxies and ultimately discover how our universe came to be.

(Photo: A full scale model of the James Webb Space Telescope sits on the National Mall, 2007,Washington, DC. Credit: Getty Images)