[ErnstStavroBlofeld]

The Titan IV is a “stretched” Titan III with non-optional solid rocket boosters on the two sides. The Titan IV could be launched with either the Centaur upper stage, the NASA Inertial Upper Stage (IUS), no upper stage at all. Its a posibility.

[r9etb]

The Titan IV is a “stretched” Titan III with non-optional solid rocket boosters on the two sides. The Titan IV could be launched with either the Centaur upper stage, the NASA Inertial Upper Stage (IUS), no upper stage at all. Its a posibility.

Titan IV isn't built anymore. The basic mission would be covered by the Delta IV heavy, though.