Shuttle Countdown Resumes for Hubble Telescope Mission

Countdown clocks resumed ticking Saturday for the shuttle Discovery’s delayed launch Tuesday to boost the $1.5-billion Hubble Space Telescope into orbit.

Engineers also readied the shuttle Columbia for rollout to its launch pad today for a May flight.

Discovery’s carefully scripted countdown began on time at 3 p.m. The ship’s five-member crew is set to blast off at 5:31 a.m. PDT Tuesday, 14 days after the flight was grounded just four minutes before takeoff by a faulty hydraulic power steering unit.

“We’re off and running,” NASA spokesman George Diller said. “We’re still 80% go for launch weather-wise.”

With Discovery’s launch processing on track, engineers worked to ready Columbia for its May 16 Spacelab astronomy mission.

The National Aeronautics and Space Administration has not had two shuttles on the launch pad since Columbia took off Jan. 12, 1986, with Challenger poised on a pad 1.7 miles away.

Columbia’s 3.5-mile trip to the firing stand was set to begin at 8 a.m. today. Five hours later, Discovery’s five-member crew was scheduled to fly in from the Johnson Space Center in Houston to make final preparations for launch.

Commander Loren J. Shriver, 45; co-pilot Charles F. Bolden, 43; Steven A. Hawley, 38; Bruce McCandless, 52, and Kathryn D. Sullivan, 38, plan to launch the telescope Wednesday.

Discovery’s replacement auxiliary power unit was successfully test fired Wednesday and the battery charging for the telescope was completed Thursday, one day ahead of schedule.