James Webb Space Telescope given revised 24 December launch

Everything is on track now for a lift-off from the Kourou spaceport in French Guiana next Friday at 09:20 local time (12:20 GMT).

Webb is the $10bn (£7.6bn) successor to the Hubble Space Telescope.

The new observatory has been designed to look deeper into the Universe than its predecessor and, as a consequence, detect events occurring further back in time - more than 13.5 billion years ago.

Scientists also expect to use its more advanced capabilities to study the atmospheres of distant planets in the hope that signs of life might be detected.