A replica shuttle rolls out of the Pratt & Whitney Rocketdyne engine shop at NASA's Kennedy Space Center.

A replica shuttle main engine (RSME) rolls out of the Pratt & Whitney Rocketdyne engine shop at NASA’s Kennedy Space Center in Florida toward Orbiter Processing Facility-1 where it will be installed on space shuttle Discovery. In the background is the 525-foot-tall Vehicle Assembly Building.

The RSME is one of three that will be installed on Discovery during Space Shuttle Program transition and retirement activities. Discovery is being prepared for display at the Smithsonian’s National Air and Space Museum Steven F. Udvar-Hazy Center in Chantilly, Va. For more information, visit http://www.nasa.gov/shuttle. Photo credit: NASA/Jim Grossmann