Wasserfall (German for waterfall) was a German surface-to-air missile developed during World War II. It never reached operational status although it was well developed and likely ready for operation, and the project was cancelled in February 1945. After World War II, the Wasserfall design was used as a basis for the American Project Nike surface-to-air missile system.

History

Wasserfall was essentially an anti-aircraft development of the V2 rocket, sharing the same general layout and shaping. Since the missile had to fly only to the altitudes of the attacking bombers, it could be much smaller than the V2, about 1/4 the size. The Wasserfall design also included an additional set of fins located at the middle of the fuselage to provide extra lift while manuvering.

Unlike the V2, Wasserfall was designed to stand ready for periods of up to a month and fire on command, therefore the volatile liquid oxygen used in the V2 was inappropriate. A new engine design, developed by Dr. Thiel, was based on Visol (vinyl isobutyl ether) and SV-Stoff, or Salbei, (90% nitric acid, 10% sulfuric acid). This hypergolic mixture was forced into the combustion chamber by pressurizing the fuel tanks with nitrogen gas released from another tank.

Guidance was to be a simple radio control MCLOS system for use against daytime targets, but night-time use was considerably more complex because neither the target nor the missile would be easily visible. For this role a new system known as Rheinland was under development. Rheinland used a transponder in the missile for locating it in flight (as read by a radio direction finder on the ground) and a radar unit for tracking the target. A simple mechanical computer guided the missile into the tracking radar beam as soon as possible after launch, at which point the operator could see both "blips" on a single display, and guide the missile onto the target as during the day.

A second development was underway that used only a single cross-shaped radar beam that was rotated while pointing at the target. Like the Rheinland system the missile was first directed into the beam via the transponder, and from there would keep itself centered in the beam. It did this by listening to the radar signal, if it was off course it would hear pulses instead of a steady signal, and automatically place itself back in the middle of the beam. However the high supersonic speed of the Wasserfall meant that the accuracy of the system would have to be very high in order to get the missile close to its target, and it was generally accepted that some sort of terminal guidance system would have to be added.

The original design called for a 100kg warhead, but the accuracy concerns led to the design of a much larger 306kg one including a liquid explosive. For daytime use the operator would detonate the warhead by remote control, while night-time use was to be by some sort of proximity fuse.

The first models were being tested in March 1943, but a major setback occurred in August 1943 when Dr. Thiel was killed in the massive RAF bombing raids on Peenemünde. The first launch took place on the 8th of January 1944 and was a failure, with the engine "fizzling" and launching the missile to only 7km of altitude at subsonic speeds. The following February 1944 saw a successful launch which reached a speed of 2,772km/h in vertical flight. When the program was canceled on February 6th 1945 nearly 40 flights had been made.

Characteristics

• Primary Function: surface-to-air missile
• Contractor: Flak- Versuchskommando Nord, EMW Peenemuende
• Power Plant: liquid-fueled rocket motor

• Length: 7,85 m
• Diameter: 2,51 m
• Wing Span: cm
• Launch Weight: kg

• Speed: 770 m/s
• Warhead: 235 kg
• Range: km
• Fuzes: proximity
• Guidance system: MCLOS; operator used input from radars tracking the missile and target to guide it, using a radio command link and a joystick

• Unit Cost: 7.000 - 10.000 RM (Reichsmark)
• Date Deployed: never
• Users: Germany

See also

• List of missiles
• German missiles of WW2