The Titan IV was developed to provide assured capability to launch space shuttle-class payloads for the Air Force. The Titan IV could be launched with no upper stage, or either of two upper stages, the IUS (Inertial Upper Stage), and the Centaur Upper Stage.The Titan IV was made up of two large Solid-fuel rocket boosters and a two stage liquid-fueled core. It was launched using the solid-fuel boosters alone. The first liquid core stage ignited about 2 minutes into flight.The Titan IV was retired in 2005. The final launch (B-30) from Cape Canaveral AFS occurred on April 29, 2005, and the final launch from Vandenberg AFB occurred on October 19, 2005.