Monday, November 15, 1999 Published at 17:07 GMT
Hubble shuts its eyes
Hubble should work well into the next decade
By BBC News Online science editor Dr David Whitehouse
The Hubble Space Telescope (HST) has shut itself down, preventing astronomers from making observations of the Universe.
It is a safety precaution triggered by the failure of another of the space observatory's gyroscopes.
HST has six gyros onboard, half of which must be operational to point the observatory accurately.
This is apparently what happened on Saturday.
Fortunately, Hubble's third service and repair mission is just weeks away. Nasa has put together a very experienced crew, including the British-born Mir veteran Michael Foale, who are due in orbit in early December to sort out all of Hubble's problems.
The upgrade, together with two further servicing missions in 2001 and 2003, will help extend the observatory's life well into the next decade.
The astronauts have been practising the removal and replacement of the faulty gyros in giant water tanks on Earth. The gyros are encased in easy-to-fit boxes.
The aperture door has been closed to protect the optics, and the spacecraft is aligned to the Sun to ensure adequate power is received by Hubble's solar panels.
"It's [Hubble] quite safe," said HST programme manager John Campbell. "We're not doing science, so the power load has been reduced. But everything is quite OK."
Engineers are investigating the cause of the gyro loss. The gyro will be returned to ground after the upcoming servicing mission for in-depth analysis.