Question: What is the name of a German rocket-powered fighter aircraft designed by Alexander Lippisch, the original version being the first to exceed 1000km/h and the subsequent version, known as the Me 263 Scholle having had 3 prototypes, non of which were ever flown?
Sentence (from "DFS 228"): By the end of the war, the aircraft had only flown in the form of two unpowered prototypes.
Relevant evidence: No