When Germany first turned to developing SAMs it was 1941 and the Hs-117 Schmetterling (Butterfly) was technically first although never truly operational like the Wasserfall. It was powered by two solid-fuel boosters to accelerate it up to 680 mph in 4 seconds and then a BMW 109-558 motor took off burning R-Stoff and SV-Stoff. The launch was from a modified AA mount and an operator steered the missile optically by following the tail flare via telescopic sight using the Parsival radio command system and another frequency for detonating the 55 lb HE warhead. Unlike a proximity system the Hs-117 was used for direct impact, although timing devices as well as proximity fuses were available. The fisrt tests were in May 1944 and continued to September with 22 successes. It was ordered for full production starting in March 1945 as facilites were moving, but SS General Kammler cancelled the program in January 1945. Henschel defied him and produced more missiles as well as a H-version for ATA use launched from a He-111.