The STS-125 crew lines up outside the Astrovan after suiting up in the Operations and Checkout Building.

The STS-125 crew lines up outside the Astrovan after suiting up in the Operations and Checkout Building at NASA's Kennedy Space Center in Florida. From left are Mission Specialists Michael Good, Mike Massimino, Andrew Feustel, John Grunsfeld and Megan McArthur, Pilot Gregory C. Johnson and Commander Scott Altman. The crew is heading for Launch Pad 39A where they will take part in a simulated launch countdown aboard space shuttle Atlantis. The countdown is the culmination of terminal countdown demonstration test, or TCDT, activities as preparation before launch. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization, emergency training and the countdown. Atlantis’ STS-125 mission to service NASA’s Hubble Space Telescope is targeted for launch Oct. 14. Photo credit: NASA/Kim Shiflett