Live at KSC: NASA Aims To Launch Discovery

NASA is entering the last full day of its countdown to the launch Wednesday of shuttle Discovery after completing a major milestone: shuttle fuel cell servicing.

Discovery and seven astronauts remain scheduled to blast off from Launch Complex 39A at Kennedy Space Center at 9:20 p.m. Wednesday, and the weather forecast calls for a 90 percent chance that conditions will be acceptable for launch.

You can get the latest countdown status live here in The Flame Trench at 10 a.m. Simply click the NASA TV box at the righthand side of the page to launch our NASA TV viewer and live coverage.

NASA Test Director Steve Payne will update the media on countdown activities and Robby Ashley, NASA's STS-119 Payload Manager, will discuss work carried out to prepare the shuttle's prime payload for flight.

Kathy Winters, shuttle weather officer at the Air Force 45th Space Wing Weather Squadron will brief reporters on the latest launch forecast.


Discovery mission commander Lee Archambault and pilot Tony Antonelli took to the evening skies Monday in a Gulfstream II aircraft, practicing landings at NASA's three-mile shuttle runway. The aircraft is modified to mimic the shuttle's steep dive toward the runway, and practice runs are part of standard training for a shuttle mission commander and pilot in the days leading up to launch.

Engineers in Firing Room No. 4 of the Launch Control Center oversaw the loading of liquid hydrogen and liquid oxygen into tanks aboard the orbiter. The chemical reactants combine in the shuttle's three fuel cells to generate electricity to power all spaceship systens as well as potable water as a byproduct.

The lengthy operation began about 3 p.m. and as completed seven hours later.

Engineers and technicians today will check out shuttle main engine avionics, pneumatics and controllers before filling up the sound suppression system water tank at Launch Complex 39A.

The system dumps hundreds of thousands of gallons of water on the pad and the shuttle's mobile launch platform just before main engine and booster ignition to make certain launch vibrations don't damage the shuttle or its payload.

Checkouts of a key guidance and navigation system -- the shuttle's star trackers -- also will be carried out today, and the Rotating Service Structure at the pad will be back away from the vehicle about 1 a.m. Wednesday.

Look for external tank fuel-loading operations to begin about noon Wednesday, and the astronauts will head out to the launch pad about 5:30 p.m. that day.

Discovery's launch will be the first of four planned this year and the first of 10 remaining before NASA's shuttle fleet is retired in September 2010.