Lockheed Martin's Space Division started in the production of missiles and later ICBM's in the 1950s. Their TITAN missile system was used for 12 Gemini spacecraft and the Voyager probes.  They have worked largely in collaboration with NASA on many of their probes, landers, and spacecraft, and hope to play a key role in NASA's return to the moon in 2024.

Lockheed Martin

Titan IV was a family of heavy-lift space launch vehicles developed by Martin Marietta and operated by the United States Air Force from 1989 to 2005.

Titan 401A Centaur Launch Schedule