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It's a 'Go' for Endeavour

Preparations are on track for Tuesday's 25th flight to the International Space Station, said NASA test director Steve Payne during yesterday's STS-123 Countdown Status Briefing, the first for the mission.

The launch remains on schedule for 2:28 a.m. EDT on March 11.

The orbiter's aft compartment was closed Wednesday night and the payload bay doors were closed for flight early Thursday morning.

NASA managers decided to fly using the secondary backup system in low-power mode after a problem surfaced with a high-power amplifier on one Ultra High Frequency (UHF) radio. The backup system meets all of the flight safety rules required for flight.

Some pre-launch activities this weekend will include loading supercold propellants after the pad is cleared at about 11 p.m. Saturday night. After the pad opens again on Sunday morning, the shuttle will get an engine check, the external tank will be inspected and the crew's gear will be stowed inside the orbiter.

The STS-123 crew members gather together for a cake-cutting ceremony in the Jake Garn Simulation and Training Facility at Johnson Space Center in Houston after completing training. Pictured are Garrett E. Reisman (left), Robert L. Behnken, both mission specialists; Dominic L. Gorie, commander; Michael J. Foreman, mission specialist; Gregory H. Johnson, pilot; Japanese astronaut Takao Doi and NASA astronaut Richard M. Linnehan, both mission specialists. Photo credit: NASA/JSC

The Rotating Service Structure surrounding and protecting the shuttle will be retracted at 6 a.m. EDT Monday for Tuesday's launch.

"We have no other issues to report," Payne said. "The systems are clean, it appears it's going to be a good day for us and Endeavour and her crew are ready to launch."

The weather outlook, according to Todd McNamara, shuttle weather officer, is looking very good for Tuesday. There will be a high-pressure system over Central Florida and there's only a 10 percent chance that weather will prohibit launch.

If there's a need for a 24-hour turnaround, Kennedy's weather is still good, but low cloud cover increases the weather launch constraint to 20%.

Weather for the astronaut's arrival Friday evening may be a little stormy but won't delay their landing at Kennedy's Shuttle Landing Facility.