Space shuttle Endeavour was bolted to its external tank and twin solid rocket boosters on March 1. This "mating" took place in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida following the orbiter's move from its processing hangar. Endeavour is slated to rollout to Launch Pad 39A next week for STS-134, its final flight. During the 14-day mission, Endeavour's six astronauts will deliver to the International Space Station the Alpha Magnetic Spectrometer, a particle physics detector designed to search for various types of unusual matter by measuring cosmic rays. The crew also will deliver the Express Logistics Carrier 3, a platform that carries spare parts that will sustain station operations once the shuttles are retired later this year. Endeavour's launch is targeted for April 19.