M2-F2 with B-52

Next came the M2-F2 prototype. It's seen here attached to a "mothership" B-52 sometime in the latter half of 1966 or early 1967. The modified bomber (NASA B-52, Tail Number 008), which similarly had carried the X-15 rocket plane aloft for tests throughout the 1960s, would take the 22-foot-long, 4,600-pound M2-F2 to an altitude of about 45,000 feet for glide flight testing. (A later version, the M2-F3, added a third vertical fin at the rear for stability. Powered flights started with the M2-F3.)