STS-134 was a Space Shuttle mission to the International Space Station (ISS) flown by Space Shuttle Endeavour. The mission launched on May 16, 2011, and was the thirty-fifth and final shuttle mission to visit the ISS. The primary objective of the mission was to deliver and install the Alpha Magnetic Spectrometer (AMS), a particle physics experiment that would search for evidence of dark matter and antimatter, and to perform maintenance and repair work on the station. The mission also included the delivery of supplies and equipment to the ISS and the rotation of the crew of the ISS.