Out There Weekend Feature: This weekend we take a look upward and checkout what's happening to the Hubble Space Telescope.
courtesy of Astronomy Now
A crucial mission to restore backup systems to the Hubble Space Telescope has been postponed until December 2, because of extensive space shuttle wiring problems.
NASA had hoped to send astronauts to the orbiting observatory in October to replace components in Hubble's positioning system. With half of its six gyroscopes broken, the telescope has no more spares, meaning science operations would cease if another failure occurred.
Shuttle flights, however, have been on hold since the July return of Columbia which dispatched the Chandra X-ray Observatory into orbit. An electrical short-circuit shut down two key main engine controllers during Columbia's liftoff and post-flight inspections traced the problem to a damaged wire. When a second suspect wire was found, NASA decided to conduct extensive inspections on the entire shuttle fleet. Hundreds of wiring problems requiring repairs were uncovered.
With the lengthy inspection work nearly complete, NASA managers said in early October that they are giving up hope of flying two more missions before the end of the year and have rescheduled a radar-mapping flight by shuttle Endeavour for launch on January 12, 2000. They also have retargeted the next shuttle flight to the International Space Station for mid-February.
The delay means NASA will fly only three shuttle missions at best in 1999 -- the lowest flight rate since shuttle flights resumed in 1988 after the Challenger accident.
Four spacewalks, each lasting six hours, are
planned during Discovery's Hubble service call.