The Space Shuttle Program completed 135 total flights. The program began with Columbia’s launch on April 12, 1981, and ended with Atlantis’s STS-135 mission, which landed on July 21, 2011.
Across three decades, the shuttle fleet launched satellites, carried scientific laboratories, deployed and serviced the Hubble Space Telescope, supported missions to the Russian Mir station, and assembled and resupplied the International Space Station. The orbiters collectively traveled more than 542 million miles and completed more than 21,000 Earth orbits.
The total includes missions that ended in catastrophe. Challenger was destroyed during launch on STS-51-L in 1986, and Columbia broke apart during reentry on STS-107 in 2003. Both flights count among the program’s 135 missions, even though neither completed a successful landing.
That history explains a common numerical confusion: 135 is the total number of shuttle flights or missions, while 133 is the number of shuttle landings. Atlantis’s STS-135 was therefore both the 135th and final shuttle flight.