Hypersonics Before the Shuttle: A Concise History of the X-15 Research Airplane - History of the Design, Development, Operations, and Lessons Learned    by Progressive Management
Price: $9.99 USD. 51760 words. Published on February 2, 2012. .
This official NASA history document - converted for accurate flowing-text e-book format reproduction - provides a comprehensive, readable history of the famous X-15 program. The introduction states: "Although it is usually heralded as the most productive flight research program ever undertaken, no serious history has been assembled to capture its design, development, operations, and lessons."