Atlantis embarked on its 33rd and final mission, also the final mission of a space shuttle, STS-135, on 8 July 2011. STS-134 byEndeavour was expected to be the final flight before STS-135 was authorized in October 2010. STS-135 took advantage of the processing for the STS-335 Launch On Needmission that would have been necessary if STS-134's crew became stranded in orbit.[5]Atlantis landed for the final time at the Kennedy Space Center on 21 July 2011.