Spacewalking astronauts completed repairs to the Hubble Space Telescope, leaving it more powerful than ever and able to peer even deeper into the cosmos - almost to the brink of creation.

Spacewalking astronauts gave the Hubble Space Telescope a more commanding view of the cosmos by installing a new hi-tech instrument, then pulled off their toughest job yet: fixing a broken camera.

The primary camera on the Hubble Space Telescope has shut down and is likely to be only marginally restored, Nasa said, a collapse one US astronomer called a "great loss".