Live at KSC: Countdown Test in Progress

Discovery's seven astronauts this morning donned orange launch-and-entry suits, boarded NASA's silver Astrovan and rode to launch pad 39A at Kennedy Space Center.

They are being strapped into their seats in Discovery, and a launch countdown is in progress.

But it's only practice. The real thing is targeted for Feb. 12, 23 days from now.

Called the Terminal Countdown Demonstration Test, or TCDT, the training is a standard part of pre-flight preparation for every shuttle mission.

Discovery's crew is following the exact procedures they would on launch day, from the time they wake up.

Today's countdown dress rehearsal ends with an abort drill seconds before a simulated T minus 0 time around 11 a.m.

Also today, shuttle program managers begin a readiness review for Discovery's flight. They'll provide recommendations to a NASA executive-level meeting scheduled Feb. 3, when a launch date will be confirmed.

When the abort drill begins, the astronauts will exit Discovery and make their way to set of slide wire baskets parked on the other side of the launch tower's 195-foot level.

Those baskets - whose operation the crew reviewed during training Tuesday - would whisk the the crew to a bunker on the ground in the event of a fire.

The practice countdown and subsequent briefings will complete three days of training at KSC, after the astronauts' arrival Monday morning.

By this afternoon, they will fly T-38 training jets back to Ellington Field in Houston. Those flights can be tracked here.

Discovery's real liftoff is planned at 7:32 a.m. Feb. 12. A planned 14-day mission will install the International Space Station's last two solar wings, completing the station's power supply.

You can read about the mission in detail in NASA's STS-119 Press Kit.

IMAGE NOTE: Click to enlarge the images. Top: Wearing their launch-and-entry suits, the STS-119 crew members this morning leave the Operations and Checkout Building at NASA's Kennedy Space Center to head for launch pad 39A and a simulated launch countdown. Clockwise from left are Pilot Tony Antonelli, Mission Specialists Steve Swanson, John Phillips, Koichi Wakata, Richard Arnold and Joseph Acaba, and Commander Lee Archambault. Bottom: STS-119 Commander Lee Archambault tries on his helmet to complete the launch-and-entry suit before heading to launch pad 39A for a simulated launch countdown. Photo credits: NASA/Kim Shiflett.