Space shuttle Discovery reached Launch Pad 39A at NASA’s Kennedy Space Center on Tuesday afternoon following a slow drive on the top of the crawler-transporter from the Vehicle Assembly Building. The move took longer than expected because of weather conditions, including lightning. The crawler also had to pause occasionally so mud could be removed from its treads and bearings. Technicians will quickly ready the shuttle to host the crew’s countdown dress rehearsal known as the Terminal Countdown Demonstration Test, or TCDT. Discovery’s seven astronauts plan to fly to Kennedy on Wednesday for the training activity which concludes later in the week with a complete practice countdown, minus liftoff, involving the crew and the launch team.