Technicians use a borescope to inspect wiring after installing a new aft load control assembly in the compartment of Endeavour.

At NASA Kennedy Space Center's Launch Pad 39A, technicians use a borescope to inspect wiring after installing a new aft load control assembly (ALCA-2) in the aft compartment of space shuttle Endeavour. The ALCA-2, which feeds power to the fuel line heaters, caused the heaters for Endeavour's auxiliary power unit-1 (APU-1) to fail April 29 during the first launch attempt for the STS-134 mission. The assembly was replaced and systems will be retested before the next launch attempt, which now is no earlier than May 16 at 8:56 a.m. EDT.

STS-134 will deliver the Express Logistics Carrier-3, Alpha Magnetic Spectrometer-2 (AMS), a high-pressure gas tank and additional spare parts for the Dextre robotic helper to the International Space Station. The mission will be the final spaceflight for Endeavour. For more information, visit www.nasa.gov/mission_pages/shuttle/shuttlemissions/sts134/index.html. Photo credit: NASA/Jim Grossmann