This Republic era, represents one that I am fascinated with.
This design of Republics, although it was not the final one, represents the first
time that a major airframe company bucked the trend of that time of designing
rockets for space access, and instead proposing to develop an airbreathing and
lifting approach instead. Republic knew that it was not feasible in the immediate
future, but proposed it to stimulate development in this new line of thinking.
There were some influential aerodynamicists/designers in the late 1950's and
early 1960's who didn't really relish space access with rockets. Sasha Kartveli
as one of his chief designers, Gus Pappas called him, really preferred development
of atmospheric and military vehicles. Gus Pappas tells the story of this time at
Republic in his book: "To The Rainbow And Beyond". c1992; Vantage Press, NY.
Another was John Stack of NASA. John Becker's wonderful chapter in the
Hypersonic Revolution Volume I, mentions that Stack really didn't want to explore
space with rockets, even though he was an influential and leading high speed
flight expert at NASA in that era, and could have been an important leader in the
subsequent space program, Stack decided to leave NASA and go to Republic where
this airbreathing and lifting approach was being worked on instead.
This proposal of Republic's must have lit up the aerospace world! The paper
that Scott got these pictures from is entitled: "Spectrum Of Supersonic Aircraft".
It was presented at the IAS (Institute Of Aeronautical Sciences" - a forerunner
of AIAA)) National Meeting in San Diego from Aug 1-3, 1960. Look at the date on
that AW&ST picture at the bottom Aug. 15, 1960. The AW&ST piece was reporting
about this incredible paper that Kartveli gave at the IAS national meeting just 1-2
weeks previous. And just 4 months previous to the IAS national meeting, the Republic
guys were in Milan Italy, from April 4-8, 1960, presenting at the Fourth AGARD
Colloquium entitled "High Mach Number Air-Breathing Engines". Tony Ferri presented
a paper entitled: "Possible Directions Of Future Research In Air-Breathing Engines".
You'll notice that after that IAS conference presentation by Kartveli, that the aerospace
plane program took off in the US during the 1960s.
So this Republic design is a significant design. I like to think of it as the beginning, from
an airframe company standpoint, of the pure lifting/airbreathing approach for access to
space.
As far as AirRocket's question, there is another paper that Ferri gave later entitled:
"Theoretical And Experimental Investigation Of Supersonic Combustion". He also included
the same image as in AW&ST in this paper below an inlet schematic. The approach
IS very much like today's inward turning flowfield approach. The idea is a fixed geometry
isentropic surface inlet with good performance across a range of flight speeds.
And yes, Gus Pappas got Tony Ferri involved as their 'expert'. Gus talks about this in the
book I mentioned above in the chapter entitled: "17. The Ultimate Airplane" and then
chapter 18: "Pursuing The Concept Of Supersonic Combustion - Scramjet".
And Theodore von Karman was involved as well. Interesting story!
I'd check it out.