Challenger disaster
STS-133 is scheduled to be the final mission of "Discovery", with its first being STS-41-D in 1984. "Discovery" flew 39 flights in its operational history, including the current mission, delivering several payloads to space including the Hubble Space Telescope and visiting two different space stations: "Mir" and the ISS. STS-133 is the 133rd shuttle mission and the 35th mission to the ISS. "Discovery" is the oldest surviving shuttle, and has flown more missions than any other shuttle. It was also the first shuttle to fly after the 
 and was the first shuttle to fly after the Space Shuttle Columbia disaster. Later, "Discovery" became the first shuttle to fly a Russian cosmonaut. 
Space Shuttle Discovery launches on final mission