Titan IIIE-Centaur launch vehicle

Titan IIIE was a heavy-lift Titan III variant combining the Titan core and solid boosters with a high-energy Centaur upper stage. Seven vehicles flew from 1974 through 1977 for NASA planetary and solar-system missions, launching Helios 1 and 2, Viking 1 and 2, and Voyager 1 and 2.