The ("Waterfall remote-controlled anti-aircraft rocket") was a German guided supersonic surface-to-air missile project of World War II. Development was not completed before the end of the war and it was not used operationally.

The system was based on many of the technologies developed for the V-2 rocket program. Significant additional development was required, including design and test of an effective guidance system to allow interception of an air target, adoption of hypergolic fuels to allow the missile to stand ready for launch for days or weeks, and the development of a reliable proximity fuse.<sup>234</sup>

Technical characteristics

thumb| rocket displayed at the [[National Museum of the United States Air Force, 2007]]

was essentially an anti-aircraft development of the V-2 rocket, sharing the same general layout and shaping. Since the missile had to fly only to the altitudes of the attacking bombers, and needed a far smaller warhead to destroy these, it could be much smaller than the V-2, about the size. The design also included an additional set of stub wings located at the middle of the fuselage to provide extra manoeuvring capability.Steering during the launch phase was accomplished by four graphite vanes placed in the exhaust stream of the combustion chamber, as with the V-2, but once sufficient airspeed had been attained this was accomplished by four air rudders mounted on the rocket tail. Each rudder and graphite vane was mounted on a common shaft operated by a dedicated servo motor.

Unlike the V-2, was designed to stand ready for periods of up to a month and fire on command, therefore the volatile liquid oxygen used in the V-2 was inappropriate. Dr. Walter Thiel designed a new rocket motor, which used Visol (vinyl isobutyl ether) and nitric acid

Because was launched vertically, rather from an angled launcher, it had to be steered to come within the line of sight between the missile tracker operator and the target. This flight path was calculated by an analog electro-mechanical ("Initial Course Computer"). The first six seconds of missile flight were vertical, under the control of the missile internal gyro stabilised autopilot. After this the , taking input from the optical target tracker, automatically guided the optical missile tracker (but not the missile) to describe the calculated missile path, as it would be seen by the missile tracker operator. The missile tracker operator had to send guidance commands to the missile to keep it in the moving cross hairs of his optical tracker as it was automatically slewed in azimuth and elevation by the , thus causing the Wasserfall to fly the course computed by the . Once the missile tracker sight and Wasserfall missile was within 0.5 degrees of the target line of sight, the disengaged, allowing the missile tracker operator to maintain the missile on line of the sight with the target until the engagement completed. The missile tracker operator was provided with a control to detonate the missile warhead when the point of closest approach between missile and target was achieved. The initial design (identified as C2/E1) was submitted to the aerodynamics team of Dr. Rudolf Hermann. It called for unswept cruciform wings that were considerably longer than the tail fins. They were also offset by 45 degrees from the axial line of the fins. However, model testing in the supersonic wind tunnel at Peenemünde showed that this configuration exhibited an unacceptably large movement of the Centre Of Pressure depending upon airframe speed. This was rectified by moving the wings further back, shortening them, sweeping the leading edge on a sharper angle, and enlarging the tail fins. This resulted in wings and tail of similar shape and size. The offset in the line of the wings and tail were also found to introduce unpredictable instability at higher angles of attack, so the offset was removed. These changes yielded the C2/E2 variant.alt=|thumb|Wasserfall C2/E2 dimensioned diagram 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.

The first test launch was on 29 February 1944 with a second on 8 March 1944.

The V2 was also used to test subsystems for . The Bäckebo rocket which crashed in Sweden on 13 June 1944 was intended as a test flight for the radio control system.

Assessment

According to Albert Speer and Carl Krauch it could have devastated the Allied bomber fleets. Speer, Germany's Reich Minister of Armaments and War Production, later claimed:

See also

  • Enzian
  • Henschel Hs 117 ("Butterfly")
  • List of missiles
  • List of German guided weapons of World War II
  • List of surface-to-air missiles

References

  • EMW Wasserfall Luft '46 entry
  • Wasserfall German Surface to Air Missile
  • W-10 Drawing