Apr 012020
A page from a 1962 North American presentation on the X-15, showing a preliminary design 0f an underslung rocket-boosted scramjet test vehicle. It was expected to get to a blisteringly fast 17,000 feet per second (about Mach 15), but it doubtless would not have much of a burn time. The ABLX-259 rocket booster was a solid rocket used as the “Antares II” third stage of the Scout space launcher. Note that the X-15 had an extended nozzle.
