 They developed engines powered by aniline and nitric acid.Robert Goddard, Reaction Motors, and Curtiss-Wright worked on aniline/nitric acid engines in the early 1940s, for small missiles and jet assisted take-off (JATO).In Germany from the mid-1930s through World War II, rocket propellants were broadly classed as monergols, hypergols, non-hypergols and lithergols.