One more of the gyroscopes used to steer the Hubble Space Telescope failed this week, sparking concern about the ongoing safety of the telescope.
The telescope needs three gyroscopes to operate smoothly, and has six on board. in 1999, after four gyroscopes had failed, a shuttle service mission was brought forward and all six were replaced. This weeks failure was the second one since the last servicing mission in February 2002 and it is now running on only four, and no service mission is in sight with the grounding of the shuttle fleet.
The Hubble Telescopes’ orbit is not accessible to Russian Soyuz spacecraft.
