“It’s certainly earned its retirement. [Space Shuttle] Discovery has flown more missions than any other shuttle – more than any other spacecraft, in fact. After 38 missions to date, and more than 5,600 trips around the Earth, Discovery has carried satellites such as the Hubble Space Telescope into orbit and sent the Ulysses robotic probe on its way to the Sun. It was the first shuttle to rendezvous with the Russian Mir Space Station, and it delivered the Japanese Kibo laboratory to the International Space Station.
By the end of STS-133, 180 people will also have flown aboard Discovery, including the first female shuttle pilot and the first female shuttle commander (who happen to be the same person – Eileen Collins), the first African American spacewalker (Bernard Harris) and the first sitting member of congress to fly in space (Jake Garn).”“STS-133: Final Flight of Discovery” on nasa.gov