The Rheintochter (Rhine Maiden) R I was an experimental German two-stage anti-aircraft missile tested in the last year of World War II. It was also one of the largest solid-fuel rockets of the war and produced the largest thrust, although for a very short duration. Due to its inadequate altitude ceiling, it was to be supplanted by the R III model, a liquid-fuel missile with two side-mounted solid-fuel boosters, but only six of those were ever launched.
This servomotor was mounted inside the nose section and moved the forward control surfaces of this Rheintochter. The Smithsonian acquired it as part of the massive gift of World War II artifacts from the U.S. Air Force in 1949.