Discovery became the third operational orbiter to enter service, preceded by Columbia and Challenger. It embarked on its last mission, STS-133, on February 24, 2011 and touched down for the final time at Kennedy Space Center on March 9, having spent a cumulative total of almost a full year in space. Discovery performed both research and International Space Station (ISS) assembly missions, and also carried the Hubble Space Telescope into orbit. Source

“I am so glad we got to land here at Kennedy, the home of Discovery,” STS-133 Commander Steve Lindsey said. “As the minutes pass, I’m actually getting sadder and sadder about this being the last flight and I know all the folks involved with the shuttle program feel the same way.” Source