The crew of the space shuttle Discovery was hurtling through space Tuesday night in a race to catch up with the Hubble Space Telescope early Thursday.
If the shuttle crew doesn’t catch it on the first try, its mission - to upgrade and service the $2 billion orbiting observatory in a series of four spacewalks beginning Thursday - will fail.
“We have one shot at rendezvous,” said flight director Jeff Bantle. If the shuttle is moving as little as 100 feet per second too slowly, “we wouldn’t have enough propellant to make that up.” That’s because the space telescope is orbiting 368 miles up - close to the operational limits of Discovery’s fuel supply.
Discovery was launched just before 4 a.m. Tuesday.
In the first of four spacewalks, scheduled to start at 11:21 p.m. Thursday, astronauts will try to replace two of the telescope’s original scientific instruments with two spectrographs.
Astronomers hope the new instruments - the Space Telescope Imaging Spectrograph and the Near Infrared Camera and Multi-Object Spectrometer - will give them new clues to the origins of planets, stars, galaxies and the universe itself.
The mission’s next critical test will come just before 2 a.m. Friday when Cmdr. Kenneth Bowersox will attempt to maneuver Discovery to within the reach of the telescope’s remote manipulator arm.
The chase actually began at launch Tuesday.
The timing of the nighttime liftoff was calculated to place the shuttle in orbit within rendezvous range of Hubble as the observatory soared over Cape Canaveral, Fla.