Cold Weather Chills Practice Countdown

Seven astronauts boarded Discovery at Kennedy Space Center's launch pad 39A today, taking part in a practice countdown for their planned Feb. 12 launch on a day when temperatures would have been too cold to fly.

STS-119 Mission Commander Lee Archambault and his crewmates donned partial-pressure launch-and-entry suits and rode out to the pad in NASA's customized "Astrovan." The temperature at the launch pad was 36 degrees Fahrenheit when countdown clocks stopped at T-Minus 4 seconds. Sustained winds were nine knots. The overnight low temperature at the pad was 31.4 degrees Fahrenheit.

"We would have actually had to scrub today," said KSC spokesman Allard Beutel.

NASA employs a complex formula that factors in the temperature, wind speed and relative humidity to determine whether conditions are safe for flight in cases where the mercury in the thermostat drops below 48 degrees Fahrenheit. With sustained winds between eight and 14 knots, NASA's Launch Commit Criteria calls for temperatures of at least 37 degrees to give a go for launch.

Archambault leads a crew that includes pilot Tony Antonelli and mission specialists Joseph Acaba, Richard Arnold, John Phillips, Steve Swanson and Koichi Wakata, the latter of whom will be the first Japanese astronaut to fly an expedition aboard the International Space Station.

The Discovery astronauts will deliver the final segment of the station's central truss to the outpost. The 31,000-pound girder is equipped with the station's fourth and final set of massive American solar wings.

ABOUT THE IMAGE: Click to enlarge the NASA photo of the STS-119 crew departing crew quarters at the KSC Operations & Checkout Building for a ride out to launch pad 39A. The crew includes (first row, left to right) pilot Tony Antonelli and commander Lee Archambault; (second row, left to right) mission specialists Steve Swanson and Joseph Acaba; and (third row, left to right) mission specialists John Phillips, Koichi Wakata and Richard Arnold. You can also click the enlarged image to get an even bigger view.