Shuttle Endeavour on Track for Tuesday Launch

The shuttle Endeavour's STS-123 crew rehearse launch day for their March 2008 liftoff. From left are: Mission specialists Rick Linnehan, Takao Doi, Robert Behnken and Mike Foreman, pilot Gregory H. Johnson, mission specialist, Garrett Reisman and commander Dominic Gorie. CREDIT: NASA/Kim Shiflett.

This story was updated at 12:40 p.m. EST.

NASA’s shuttle Endeavour is on track to begin the longest construction flight yet aimed at the International Space Station (ISS) next week, mission managers said Friday.

Endeavour and its seven-astronaut crew have a 90 percent chance of good weather for their planned predawn launch at 2:28 a.m. EDT (0628 GMT) on Tuesday from NASA’s Kennedy Space Center (KSC) in Cape Canaveral, Fla. The astronauts will deliver a Canadian-built robot and the first segment of Japan’s Kibo research laboratory to the station during their planned 16-day flight.

“We’re hoping it’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 to launch.”

Commanded by veteran spaceflyer Dominic Gorie, Endeavour’s STS-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 to Tuesday’s planned liftoff at 3:00 a.m. EST (0700 GMT) on Saturday.

A storm system that has unleashed two tornados in northern Florida is expected to spawn thunderstorms over NASA’s Florida launch site, but should not pose a threat to next week’s planned launch.

“The launch weather right now is looking favorable for launch day,” said Todd McNamara, NASA’s shuttle weather officer.

Payne said that aside from a UHF radio glitch, Endeavour is in ship shape for Tuesday’s launch. A high-power amplifier is not working properly, but the radio has two other low-power amplifiers as backups. The radio is used to beam some data to Mission Control during launch and to communicate with flight controllers during landing.

Engineers are currently discussing whether to repair the amplifier or fly as-is, but either option is not expected to delay Endeavour’s first launch attempt, Payne said.

“We’ve looked at it and we can do everything we need to with the two low-power amplifiers,” he added.

Endeavour has two initial opportunities to fly, on March 11 and March 12, before NASA will stand down to clear the launch range for the liftoff of a global positioning satellite atop an unmanned Delta 2 rocket from the nearby Cape Canaveral Air Force Station. The next window to launch Endeavour would come on March 15.

NASA also hopes to launch the shuttle by March 23 in order to complete the STS-123 mission before Russia’s planned April 8 launch of a new crew and South Korea’s first astronaut to the ISS. Europe’s first space station cargo ship, the Automated Transfer Vehicle Jules Verne, is also slated to launch toward the ISS late Saturday EST on a shakedown cruise that will end with an early April docking between the U.S. and Russian spaceflights.

Endeavour’s mission will mark NASA’s second shuttle flight this year and comes just weeks after the successful Feb. 20 landing of Endeavour’s sister ship Atlantis, which delivered Europe’s Columbus laboratory to the ISS.

“We kind of surprised 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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