Sky-high Tech Nasa Engineers Try to Reboot Hubble Telescope

Nasa engineers will try today to reboot the $2bn (£1.1bn) Hubble Space Telescope, which has been out of commission for a fortnight after a computer failure. The monitoring staff will attempt to send commands to the craft, orbiting 300 miles above the Earth, to switch on a back-up computer which has not been activated since the telescope was launched more than 18 years ago.

The breakdown has occurred in a computer needed to store and relay science data back to Nasa and has already caused the postponement of a mission by the space shuttle, which was to have been launched yesterday, to service and upgrade the telescope and its equipment. That flight has been rescheduled for next February when repairs should extend the telescope's active life by four years; it will then be replaced by the James Webb space telescope.

Art Whipple, the telescope's program manager at Nasa's Goddard Space Flight Centre at Greenbelt, Maryland, said that if the computer could be switched on successfully, the telescope could be back in operation by the end of the week. He said: "It is obviously a possibility that things will not come up [but] there's very little ageing that goes on with an unpowered component in space."

The shuttle mission early next year will carry a replacement data-processing computer for the telescope and will be the fifth and final servicing operation. Astronauts will also install two new science instruments, mend two cameras and replace batteries and gyroscopes.

Since its launch in April 1990, Hubble, a collaboration between Nasa and the European Space Agency, has sent back detailed images of the most distant parts of outer space, including the Whirlpool Galaxy, above, and has enabled astronomers to calculate the rate of expansion of the universe.