Processing of space shuttle Endeavour at Launch Pad 39A is under way as morning breaks.

Processing of space shuttle Endeavour at Launch Pad 39A at NASA's Kennedy Space Center in Florida is under way as morning breaks.

Riding atop a crawler-transporter attached to its external fuel tank and solid rocket boosters, Endeavour's 3.4-mile trek, known as "rollout," began at the Vehicle Assembly Building at 7:56 p.m. EST March 10 and ended at 3:49 a.m. EST, nearly eight hours later. This is Endeavour's final scheduled rollout. Endeavour and its six-member crew will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank, additional spare parts for the Dextre robotic helper and micrometeoroid debris shields to the International Space Station on the shuttle's final spaceflight, STS-134. Launch is targeted for 7:48 p.m. EDT April 19. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jack Pfaller