SM-68 Titan

The Titan I used RP-1 and liquid oxygen propellants and required around fifteen minutes to load the rocket and raise it to a launch position.

The more powerful Titan II used nitrogen tetroxide and hydrazine, allowing it to be stored with propellant loaded, giving it a much shorter response time.

The Titan II used a hypergolic combination of nitrogen tetroxide and hydrazine for propellant.

In addition to its use as an ICBM, twelve Titan II missiles were converted to launch Gemini spacecraft for NASA, ten of which were crewed.

Following retirement, a further thirteen were converted to the Titan 23G configuration, and used to launch satellites, and the Clementine Lunar probe.