A convoy of specialized support vehicles follow the Space Shuttle Endeavour as it is towed up a taxiway at NASA's Dryden Flight Research Center on Edwards Air Force Base, California, after landing on May 1, 2001. The two largest vehicles trailing the shuttle provide electrical power and air conditioning to the shuttle's systems during post-flight recovery operations. The Endeavour had just completed mission STS-100, an almost 12-day mission to install the Canadarm 2 robotic arm and deliver some three tons of supplies and experiments to the International Space Station. The landing was the 48th shuttle landing at Edwards since shuttle flights began in 1981. After post-flight processing, the Endeavour was mounted atop one of NASA's modified Boeing 747 shuttle carrier aircraft and ferried back to the Kennedy Space Center in Florida on May 8, 2001.

The Space Shuttle Discovery sits atop one of NASA’s modified Boeing 747 Shuttle Carrier Aircraft as the unusual piggyback duo is towed along a taxiway at NASA’s Dryden Flight Research Center at Edwards, California. The Discovery was ferried from NASA Dryden to NASA’s Kennedy Space Center in Florida on November 2, 2000, after extensive pre-ferry servicing and preparations.