CAPE CANAVERAL - ShuttleDiscovery rolled out to its Kennedy Space Center launch pad Sunday, marking thestart of a final push to the planned Oct. 23 launch of an International SpaceStation assembly mission.
The schedule, however, isextremely tight.
NASA has but one day ofleeway, so any significant technical problems could force the agency toreadjust the launch schedule.
"It's not a lot ofextra time. But you have to take things one step at a time," KSC spokesmanAllard Beutel said. "If something else crops up that we have to deal with,then we'll have to deal with it."
NASA is facing apresidential deadline to finish the station and retire its shuttle fleet bySept. 30, 2010.
So Sunday marked threeyears and counting for 13 more station assembly flights and a Hubble SpaceTelescope servicing mission.
NASA had hoped to fly fivestation assembly missions this year, but a hailstorm in February damaged ashuttle external
tank on the pad, delaying the first 2007 flight to June.
The upcoming Discovery launchwill be the third this year, and NASA will have just a seven-day window betweenDec. 6 and Dec. 13 to send up a fourth and final 2007 flight.
After that, the sun angleon the station would be such that its solar wings could not generate enoughelectricity to power both the outpost and a docked shuttle orbiter.
In addition, radiators onthe linked spacecraft would not be able to shed enough of the heat generatedduring docked operations. The next launch opportunity would be about Jan. 2.
Discovery rolled up onto itsoceanfront launch pad about six hours after it emerged from the KSC Vehicle Assembly Building.
A trackedcrawler-transporter built for the Apollo moon-landing project lifted theshuttle and its mobile launcher platform -- an 11 million-pound load -- andstarted moving at 6:47 a.m.
Top speed during the 3.5mile trek: 0.9 mph.
The prime payload for theDiscovery mission -- theU.S. Harmony module -- already is at the pad and will be installed in theshuttle's 60-foot-long cargo bay later this week.
Equipped with six hatches,the cylindrical element will serve as a pressurized gateway tostill-to-be-launched European and Japanese science laboratories.
Coming up next week: alaunch-day dress rehearsal.
A crew led by veteranastronaut Pam Melroy, who will become only the secondwoman to command a shuttle mission, will board Discovery at the pad andtake part in the final hours of a two-day practice countdown.
The astronauts will arriveat KSC next Sunday and also will go through emergency training at the pad.
Shuttle program managersalso will meet at KSC next week for a two-day technical review. A first, thereview will provide a forum for managers to discuss technical issues beforebriefing top agency executives during a traditional flight readiness review.
A firm launch date forDiscovery will be set at the latter review, scheduled for Oct. 16 at KSC.
Publishedunder license from FLORIDA TODAY. Copyright: 2007 FLORIDA TODAY. No portion ofthis material may be reproduced in any way without the written consent of FLORIDA TODAY.
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