Shuttle crew arrives at KSC

4:30 p.m. update: Discovery's crew of seven astronauts has landed at the Kennedy Space Center in a Shuttle Training Aircraft. They rode together in a single plane rather than separately in their T-38 training jets because of the inclement weather conditions created by Tropical Storm Alberto.

See video.

3:10 p.m. update: Discovery's astronauts are en route to KSC. The crew departed Ellingyon Field about 3 p.m. and should arrive at the Shuttle Landing Facility between 4:30 p.m. and 5 p.m.

2:25 p.m. update: Discovery's astronauts now plan to depart Ellington Field sometime in the next 15 to 30 minutes. Their arrival at KSC, in that case, would be between 4:45 p.m. and 5 p.m.

2 p.m. update: Discovery's crew still is on the ground in Texas, monitoring the weather in central Florida. Tropical Storm Alberto made landfall southeast of Tallahassee around 12:30 p.m., bringing with it high winds and heavy rain. Forecasters are concerned that the storm could spawn tornadoes as it crosses into the southeastern U.S. The astronauts will take a look at the weather later this afternoon and determine whether to fly to KSC. We'll post an update once a decision is made.

The weather in Florida appears to be clearing up fast enough for Discovery's seven astronauts to fly to Kennedy Space Center today for a two-day practice countdown scheduled to begin Wednesday.

Pending a final weather briefing early this afternoon, the astronauts are scheduled to take off from Ellington Field in Houston around 2 p.m. EDT in either T-38 training jets or a Shuttle Training Aircraft.

They are slated to arrive at the KSC Shuttle Landing Facility around 4 p.m. EDT.

A planned trip to KSC Monday was postponed due to heavy rain and winds from Tropical Storm Alberto.

The astronauts are to take part in a traditional Terminal Countdown Demonstration Test, or TCDT, a practice countdown that serves as a launch-day dress rehearsal. The crew will board Discovery on Thursday for the last three hours of the exercise.

Discovery and its crew still are scheduled to launch July 1 on NASA's second post-Columbia test flight.