Forty-five years ago today — June 18, 1965 — the first Titan-IIIC (“three C”) launched from Cape Canaveral on a test flight.
(A 1978 Titan-IIIC launch. USAF image from Wikimedia Commons.)
The IIIC was the first Titan variant to use strap-on solid rocket motors for additional lift capacity. The Air Force flew a large number of SRM-augmented Titans through the years. This Aerospace Corporation article has a little of the Titan vehicle history.
The SRMs were built up in segments, with each full-size segment being ten feet in diameter and ten feet tall. The Titan-IIIC and IIID models used two five-segment SRMs each; the later Titan-34D used a pair of five-and-a-half-segment SRMs, while the Titan-IVA used two seven-segment SRMs. The last Titan model, the Titan-IVB, used the SRMU — solid rocket motor upgrade — which consisted of fewer, but larger, motor segments.
And why do I care about the SRM and SRMU details? Because I had the privilege of working on parts of the Titan program — primarily dealing with the solid rockets — during my assignments at Edwards (Titan-34D and Titan-IVA test firings, Titan-34D launches) and Vandenberg (Titan-IVA and -IVB launch processing facilities).
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