This telescope is carrying the largest mirror ever flown in space. The 3.5-metre diameter technological marvel is made from 12 silicon carbide petals brazed together and coated with a layer of reflective aluminium, forming a remarkably lightweight mirror. The fully assembled telescope, which includes the primary mirror, the secondary mirror and its support structure, is a feathery 320 kg; remarkably low for such a sturdy structure capable of withstanding high launch loads and functioning precisely in the harsh environment of space.


 
Herschel in space, close up on its mirror.



Release date: 8 May 2008