Question: X-15 is a film that fictionalized the research rocket that set speed records in what decade?
Sentence (from "North American X-15"): The X-15's official world record for the highest speed ever recorded by a manned, powered aircraft, set in October 1967 when William J. Knight flew Mach 6.72 at 102100 ft , a speed of 4520 mph (2020.278 meters per second), has remained unchallenged as of .
Relevant evidence: No