Rheintochter was a German surface-to-air missile developed by Rheinmetall-Borsig. Its name comes from the mythical Rheintöchter (Rhine Maidens) of Richard Wagner’s (no surprises here) opera series Der Ring des Nibelungen.
The original (R1) version of the Rheintochter was a two-stage, solid-fuel missile that used a canard aerodynamic layout. The first stage boost consisted of a solid rocket charge which in only 0.6 seconds accelerated the missile to 300 m/s. The sustainer (second-stage) engine was located ahead of the warhead (rather than behind, as is more usual).
When the missile was within 20m range of its target, an acoustic proximity fuse triggered the 150 kg HE warhead. Six flares on the second stage were used by the operator to visually orient and guide the path of the missile.
Several variants of the R-1 version of the missile were built between August 1943 and January 1944. Three were launched, achieving 6 km altitude and 10 to 12 km range. These tests did not please the Ministry of Aviation, who needed a rocket that could reach an altitude of 10 to 12 km.
The R2 version was supposed to remedy this shortcoming, but failed to do so. Consequently, Rheinmetall-Borsig had to develop the R3 version which now had a liquid-fuel second stage which finally reached the necessary altitude. Work had begun in May 1944, and six launches of the prototype were made in January 1945.
However the missile never reached the stage of state trials testing. Peenemuende was abandoned on 20 February 1945, by which time only 15 R-3’s had been completed. The solid rocket motor for the R-3R had reached the stage of stand tests on 6 February 1945, but further work was cancelled.
No fewer than five different guidance systems (optical and radio) were developed for the Rheintochter, but none of them was ever tested in flight.
After the war, the Rheintochter became the basis for SE.4300 – French surface-to-air missile project (canceled in 1950).