This is a 1:15 scale model of the Delta 3914 rocket, one of many Delta rocket versions built by McDonnell Douglas for NASA. The three-stage, liquid-fuel rocket used a modified U.S. Air Force Thor intermediate-range ballistic missile for its first stage. Nine strap-on, solid-fuel rockets increased boost, five igniting at liftoff and four about a minute later. NASA launched Delta 3914s successfully 10 of 12 times from 1975 to 1987 to place in orbit three commercial communications satellites, one satellite for NATO, four for the National Oceanic and Atmospheric Administration, and two for the European Space Agency. McDonnell Douglas built this model and NASA's Goddard Space Flight Center transferred it to NASM in 1980.
This object is on display in James S. McDonnell Space Hangar at the Steven F. Udvar-Hazy Center in Chantilly, VA.