- Family: Titan
- Length: 45 m
- Diameter: 3.05 m
- Launch Mass: 165 T
- Low Earth Orbit Capacity: 3000 kg
The Titan 23B was manufactured by Lockheed Martin with the first launch on 1969-08-23. Titan 23B has 9 successful launches and 0 failed launches with a total of 9 launches. Titan IIIB was the collective name for a number of derivatives of the Titan II ICBM and Titan III launch vehicle, modified by the addition of an Agena upper stage. It consisted of four separate rockets. The Titan 23B was a basic Titan II with an Agena upper stage, and the Titan 24B was the same concept, but using the slightly enlarged Titan IIIM rocket as the base. The Titan 33B was a Titan 23B with the Agena (which had a smaller diameter than the Titan) enclosed in an enlarged fairing, in order to allow larger payloads to be launched. The final member of the Titan IIIB family was the Titan 34B which was a Titan 24B with the larger fairing used on the Titan 33B.