X-15 Contributions to the X-30

Some of the less publicized flight test results from the X-15 program that might relate to sustained high-speed flight in the atmosphere are presented. The topics covered include: (1) energy management and range considerations; (2) the advantages of pilot-in-the-loop and redundant-emergency systems; (3) a summary of some of the aerodynamic heating problems that were encountered; and (4) some comments on the advantages of an early flight test program and gradual expansion of the flight envelope.