The Titan IIID or Titan 3D was an American expendable launch system, launched twenty two times with KH-9 and KH-11 satellites between 1971 and 1982. It was a two-stage derivative of the three stage Titan IIIC, optimised for low Earth orbit launches through the removal of the Transtage upper stage of the IIIC. The Titan IIID made its maiden flight on 15 June 1971, launching the first KH-9 satellite. It was retired from service in 1982, and replaced by the Titan 34D. All launches occurred from Space Launch Complex 4E at Vandenberg Air Force Base.