The Wasserfall Ferngelenkte FlaRakete ("Waterfall remote-controlled anti-aircraft rocket"[1]: 77 ) was a German guided supersonic surface-to-air missile project of World War II.

Another significant problem was the lack of a suitable proximity fuse, which was required as there was no way for the operator to visually determine when the rocket was close to a target that was directly above it.

The Wasserfall design also included an additional set of fins located at the middle of the fuselage to provide extra maneuvering capability.

A simple analog computer guided the missile into the tracking radar beam as soon as possible after launch, using a radio direction finder and the transponder to locate it.

The idea was to create a large blast area effect amidst the enemy bomber stream, which would conceivably bring down several airplanes for each missile deployed.

The first models were being tested in March 1943, but a major setback[citation needed] occurred in August 1943 when Dr. Walter Thiel was killed during the Operation Hydra bombings, the start of the Allied campaign against German V-weapons including V-2 production.

[6] Speer, Germany's Reich Minister of Armaments and War Production, later claimed:[7] To this day, I am convinced that substantial deployment of Wasserfall from the spring of 1944 onward, together with an uncompromising use of the jet fighters as air defense interceptors, would have essentially stalled the Allied strategic bombing offensive against our industry.