2005 |
This companion to Hypersonic: The Story of the North American X-15 (March 2004) contains more than 400 photos, 50 in colour, which didn't make the cut for the main volume, as well as some which came to hand only after its publication. There's nothing really startling, but if you can't get enough of this beautiful flying machine, here's another hefty dose of well-captioned period photos, many never before published. The two page spread on pp. 58–59 is interesting. It's a North American Aviation presentation from 1962 on how the X-15 could be used for various advanced propulsion research programs, including ramjets, variable cycle turboramjets, scramjets, and liquid air cycle engines (LACE) burning LH2 and air liquefied on board. More than forty years later, these remain “advanced propulsion” concepts, with scant progress to show for the intervening decades. None of the X-15 propulsion research programs were ever flown.