STS-125 mission specialist Andrew Feustel arrives at the Shuttle Landing Facility at NASA’s Kennedy Space Center in Florida in a T-38 jet for Terminal Countdown Demonstration Test, or TCDT, activities. During TCDT, space shuttle Atlantis’ STS-125 crew members will participate in a simulated launch countdown, practice emergency egress procedures at the launch pad and continue to familiarize themselves with the mission payload and hardware. STS-125 is the fifth and final shuttle Hubble Space Telescope servicing mission. Launch is targeted for Oct. 10. Photo credit: NASA/Kim Shiflett