This story was updated at 12:40 p.m. EST.
NASA’sshuttle Endeavour is on track to begin the longest construction flight yetaimed at the International Space Station (ISS) next week, mission managers saidFriday.
Endeavourand its seven-astronaut crew have a 90 percent chance of good weather for theirplanned predawn launch at 2:28 a.m. EDT (0628 GMT) on Tuesday from NASA’sKennedy Space Center (KSC) in Cape Canaveral, Fla. The astronauts will deliver aCanadian-built robot and the first segment of Japan’s Kibo researchlaboratory to the station during their planned 16-day flight.
“We’re hopingit’s going to be a good day for us on Tuesday morning,” NASA test director Steve Payne said in a mission briefing at KSC. “Endeavour and her crew are ready tolaunch.”
Commandedby veteran spaceflyer Dominic Gorie, Endeavour’sSTS-123 crew is slated to arrive at a KSC runway tonight at 9:00 p.m. EST(0200 March 8 GMT). Launch controllers at KSC will begin counting down toTuesday’s planned liftoff at 3:00 a.m. EST (0700 GMT) on Saturday.
A stormsystem that has unleashed two tornados in northern Florida is expected to spawnthunderstorms over NASA’s Florida launch site, but should not pose a threat to nextweek’s planned launch.
“The launchweather right now is looking favorable for launch day,” said Todd McNamara, NASA’sshuttle weather officer.
Payne saidthat aside from a UHF radio glitch, Endeavour is in ship shape for Tuesday’slaunch. A high-power amplifier is not working properly, but the radio has twoother low-power amplifiers as backups. The radio is used to beam some data to MissionControl during launch and to communicate with flight controllers duringlanding.
Engineersare currently discussing whether to repair the amplifier or fly as-is, buteither option is not expected to delay Endeavour’s first launch attempt, Paynesaid.
“We’velooked at it and we can do everything we need to with the two low-power amplifiers,”he added.
Endeavourhas two initial opportunities to fly, on March 11 and March 12, before NASAwill stand down to clear the launch range for the liftoff of a globalpositioning satellite atop an unmanned Delta 2 rocket from the nearby CapeCanaveral Air Force Station. The next window to launch Endeavour would come onMarch 15.
NASA also hopesto launch the shuttle by March 23 in order to complete the STS-123 missionbefore Russia’s planned April 8 launch of a new crew and South Korea’s firstastronaut to the ISS. Europe’s firstspace station cargo ship, the AutomatedTransfer Vehicle Jules Verne, is also slated to launch toward the ISS lateSaturday EST on a shakedown cruise that will end with an early April dockingbetween the U.S. and Russian spaceflights.
Endeavour’smission will mark NASA’s second shuttle flight this year and comes just weeksafter the successful Feb. 20 landing of Endeavour’s sister ship Atlantis, whichdelivered Europe’s Columbus laboratory to the ISS.
“We kind ofsurprised ourselves,” Payne said. “This team has performed spectacularly.”
NASA will broadcast the spaceport arrival of Endeavour's astronaut crew live on NASA TV beginning at 9:00 p.m. EST (0200 March 8 GMT). Click here for SPACE.com's NASA TV feed and STS-123 mission updates.
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