STS-107 Countdown Begins

The STS-107 launch countdown began Sunday night at Kennedy Space Center, Fla. Space Shuttle Columbia is scheduled to begin the 16-day scientific mission with a liftoff between 9 a.m. and 1 p.m. CST (1500 and 1900 GMT) Thursday. Also, the seven-member STS-107 flight crew arrived at KSC Sunday night.

Preparations continue to roll along at Launch Pad 39A. Workers are preparing to load liquid hydrogen and liquid oxygen into Columbia’s Power Reactant Storage and Distribution System. Tuesday, workers will place late-stow payloads into the shuttle.

Meanwhile, engineers continue to analyze a crack found in a metal ball associated with the Ball Strut Tie Rod Assembly in Space Shuttle Discovery’s 43-centimeter (17-inch) liquid oxygen line. STS-107 managers met Sunday night and decided to begin the countdown. They are scheduled to receive a final STS-107 launch assessment on Tuesday.