On May 16, 2011, the space shuttle Endeavour launched on its 25th and final flight. [‘On This Day in Space’ Video Series on Space.com]
This was also the penultimate mission of the entire shuttle program. Five NASA astronauts and one Italian astronaut made up the STS-134 crew. They launched from Kennedy Space Center and spent nearly 16 days in orbit. The first two days were spent catching up to the International Space Station. When they got there, they dropped of a bunch of science experiments and other supplies. They also did four spacewalks to install new equipment outside of the space station and do some other routine maintenance. Endeavour’s primary payload was the Alpha Magnetic Spectrometer, a particle physics experiment that would study cosmic radiation and look for antimatter and dark matter. They also installed new external sensors to help future missions dock there. Over the course of this mission, Endeavour clocked more than 6 million miles. The shuttle traveled more than 122 million miles over the course of its 19 years in service. After it retired, it was moved to the California Science Center in Los Angeles.