This is a 1:15 scale model of the Titan IIIE rocket, developed by Martin Marietta for the National Aeronautics and Space Administration (NASA). Using the U.S. Air Force Titan IIID as its basis, Titan IIIEs had liquid-fuel first and second stages, two strap-on solid rockets for extra boost at liftoff, and a liquid-fuel Centaur third stage.
NASA used the rocket from 1974 to 1977 to launch two Helios spacecraft to Mercury, two Viking spacecraft to Mars, and two Voyager spacecraft to the outer planets. Only one launch during this period failed. Martin Marietta made this model and donated it to NASM in 1983.