the USAF served a
in case the first ICBM Atlas development ran
fail. It was decided to develop a
the Martin Titan I. Later the
Titan II with greater
range and lifting capacity was initiated. In 1958,
the Air Force asked to evaluate proposal for launching a X-20 piloted
orbital glider. The Titan II was modified by adding two strap-on solid
motors for the initial stage and the booster. It was designated Titan
IIIC in 1961.
The first Titan IIIC vehicle was launched in 1965, but
its original payload, the X-20 was already
cancelled in 1963. The Air Force directed its space efforts toward the
Manned Orbiting Laboratory (MOL). In 1966, the MOL mockup was launched
on the Titan IIIC, however, MOL was also cancelled in 1969. From 1967 to
1970, the Titan IIIC used by the Air Force that boosted IDCSP, VELA,
LES-6, military communication and experimental satellites into orbits.
It continue to be used for classified DoD missions until
1977 when it was refurbished by the Titan IV program.