I found this in the Technical Museum in Berlin. It turns out that it is an anti-aircraft rocket. Rockets work by Newton's 3rd Law. The fuel burns and the rocket pushes the hot gases out behind it. But the gases push forward on the rocket, which makes it go forwards. I was interested that it claims to have an elektromagnetischer Annaherungszunder - an electromagnetic approach fuse. In English, it's a proximity fuse.
http://en.wikipedia.org/wiki/Proximity_fuze Apparently the nose of the missile was electrically insulated so it could store static charge. Then the metal in the target plane would act as the other side of a capacitor. Capacitance would change. I'll have a think about what this would do to the stored charge...