Thisstory was updated at 8:08 p.m. EDT.
HOUSTON -- Thelooming threat of Hurricane Dean could force NASA's shuttle Endeavour to land Tuesday,one day earlier than planned, mission managers said Friday.
Endeavouris currently slated to land Wednesday after a 14-dayconstruction mission to the International Space Station (ISS), but the approachof Hurricane Dean has prompted concerns that affect NASA's Houston-basedshuttle and space station control centers here at the Johnson Space Center(JSC).
"We'dreally like to protect an option to end the mission on Tuesday," said NASAmission management chair LeRoy Cain late Friday.
Endeavour'sSTS-118 crew is currently scheduled to land at NASA's Kennedy Space Center (KSC)in Cape Canaveral, Florida at 12:52 p.m. EDT (1652 GMT) Wednesday. NASA has twolanding opportunities at that site on Tuesday, beginning at 12:30 p.m. EDT(1630 GMT) with the second window opening about 30 minutes later.
For aTuesday landing, Endeavour astronauts would have to undock from the ISS lateSunday to complete their construction flight to the orbital laboratory.
Cain saidmission managers are also studying options to cut short a plannedSaturday spacewalk outside the ISS for Endeavour's STS-118 crew.
"It'snot ideal," shuttle commander Scott Kelly told reporters Friday of apossible early return. "We could potentially undock the day after thespacewalk and come home a day early."
HurricaneDean is currently in the Caribbean Sea on course for the Yucatan Peninsula,with National Hurricane Center forecasts predicting its arrival in the Gulf ofMexico on Wednesday -- when Endeavour is slated to land -- and potentiallyimpact the Texas coast.
"Thecenter will have to make a decision in the mid-Sunday to mid-Monday on whetheror not to close," Cain said of JSC. But the decision to land Endeavourearly would have to be made well before that, he added.
If NASA'smission control operations are forced to close here at JSC, the space agencywould send about two dozen critical flight controllers to a backup MissionControl site at KSC, Matt Abbott, NASA's lead shuttle flight director, toldreporters in an afternoon briefing.
Spacestation flight controllers, too, are reviewing their procedures should the hurricaneforce an evacuation of Houston and Mission Control. In September 2005, the NASAclosedits ISS Mission Control during Hurricane Rita, transferring primary controlof the station to its Russian Federal Space Agency mission operations center near Moscow, with a backup team of U.S.flight controllers primed outside Houston.
But NASAhopes none of those contingencies will be required, since its Mission Controlcenters in Houston are the best equipped to oversee spacecraft in Earth orbit.
"Ourobjective is really to get the mission completed, first and foremost, from herein Houston," Abbott said.
To preparefor a possible Tuesday landing, Cain said mission managers are preparing tocall up two additional landing sites for Endeavour in the event of an earlyreturn.
Supportteams are expected to ready NASA's backup shuttle landing sites at California'sEdwards Air Force Base and the White Sands Space Harbor in New Mexico for thepossibility of a Tuesday return for Endeavour, he added.
"It'sreally important that we keep our options open as long as it's practical,"Abbott said. "We've been watching this storm kind of brewing for a coupleof days and everyone has been aware that it's developing ? we need to beprepared to respond."
NASA isbroadcasting Endeavour's STS-118 mission live on NASA TV. Click here for mission updates andSPACE.com's NASA TV feed.
- VIDEO: STS-118 Mission Profile: SPACEHAB
- VIDEO: Endeavour Shuttle Tile Damage
- Complete Space Shuttle Mission Coverage