Florida terrain creates a STS-31 Mission Specialist Steven A. Hawley stands near the emergency exit system or TCDT.

Wide-open Florida terrain creates a dramatic backas STS-31 Mission Specialist Steven A. Hawley stands near the emergency exit system at the 194-foot level of Launch Pad 39B during the Terminal Countdown Demonstration Test, or TCDT. Conducted March 19-20, the TCDT is a dress rehearsal for launch, simulating final countdown from the T-24 hour mark up to T-5 seconds. Space shuttle mission STS-31 is set to lift off on April 12, carrying a five-member crew and the Hubble Space Telescope. Photo credit: NASA