NASA's space shuttle Discovery ispoised to make an ever-so-slow trek Tuesday morning to the launch pad where itwill rocket into orbit later this year.
Sitting inside the Vehicle AssemblyBuilding (VAB) at NASA's Kennedy Space Centerin Florida,Discovery is currently set to roll out to its launch pad at 6:00 a.m. EDT (1000GMT).
The ever-so-slow trek is a majormilestone in NASA's bid to return its shuttle fleet to flight since the loss ofColumbia andits crew in 2003. The Discovery orbiter will launch STS-114, a test flightcommanded by veteran astronaut Eileen Collins, which shuttle officialshope will prove the effectiveness of new tools and techniques aimed atimproving shuttle safety.
Discovery is set to make the4.2-mile journey from the VAB to Launch Pad 39B in about eight hours. Shuttleengineers and technicians have spent the last week attaching the orbiter to itsexternal tank and boosters, as well as installing new cameras to observe thetank during launch.
Discovery's STS-114 spaceflight is currentlyset to launch no earlier than May 15, though the mission has a launch windowthat is open through June 3. A second launch opportunity - currently allottedto the STS-121 mission aboard Atlantis - opens on July 12.
Both launch windows take into accountflight restraints that call for daylight liftoffs for NASA's first tworeturn-to-flight shuttle launches. The launch restraint is designed to providethe best observation opportunities to study the orbiter and its external tankduring ascent.