The Space Shuttle Discovery stands at its launch pad at NASA’s Kennedy Space Center, Fla. The shuttle arrived at 8:30 p.m. EDT Friday on top of a giant vehicle known as the crawler transporter.

“Rollout of Space Shuttle Discovery signifies the last major processing milestone in preparation for our next mission, STS-121,” said Space Shuttle Program Manager Wayne Hale. “The entire team has worked tremendously hard to ensure we were prepared to move to the pad, and we are excited to continue moving toward a July launch.”

The crawler transporter began carrying Discovery out of Kennedy’s Vehicle Assembly Building at 12:45 p.m. Friday. The crawler’s maximum speed during the 4.2-mile journey was less than 1 mph.

While at the pad, the shuttle will undergo final testing and hardware integration prior to launch, as well as a “hot fire” test of the auxiliary power units to ensure they are properly functioning. The rotating service structure then will be moved back around the vehicle to protect it from potential damage and the elements.

Discovery’s launch to the International Space Station is targeted for July 1, with a launch window that extends until July 19. During the 12-day mission, Discovery’s crew will test new hardware and techniques to improve shuttle safety, as well as deliver supplies and make repairs to the station.

Another upcoming milestone is the terminal countdown demonstration test, set for June 12 through 15. This countdown dress rehearsal provides each shuttle crew with the opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency evacuation training.

Audio clips of additional comments from Wayne Hale are available at:

http://www.nasa.gov/formedia

For information about the STS-121 mission and its crew, visit:

http://www.nasa.gov/shuttle