In the late 50’s/early 60’s, the American aerospace industry gave serious consideration to SSTO airbreathers. The AeroSpacePlane program (ASP, not to be confused with the 30-years-later NASP program) sought to develop such a vehicle for military purposes; the USAF eventually gave up on ASP as being too technologically challenging.
One Republic Aviation concept from 1960 that would have fit in with ASP (it’s unclear if it was an actual ASP contender) is shown below. Presented by famed aircraft designer Alexander Kartveli, it featured a lifting body hydrogen fueled spaceplane with inward-turning inlets for four scramjet engines… all design features that would fit in with a modern attempt to design an airbreathing SSTO spaceplane. In fact, it very easily could come off a modern designers drawing board today with minimal modification.
While it’s true that the technology wasn’t there in 1960 to support such a craft – and it’s arguable whether the technology to pull off a vehicle like this exists today – the US governments scattershot approach to developing this sort of thing has not been helpful. Over the past 50 years (ye gods it really has been that long), numerous airbreather SSTO programs have come along, spent billions of taxpayer dollars, and then been cancelled when things started getting difficult. A determined but slow and methodical single effort very likely could have successfully resolved the problems decades ago. But sadly the US government is not interested in methodical and long-term, unless it’s an entitlement program that will never, ever get curtailed. Anything that lasts past a Presidential administration stands a good chance of getting the axe.
The Republic concept was to be a multi-purpose vehicle, capable of carrying space paylaods, bombs/missiles, even a parasite fighter-bomber. The latter of course sounds the most interesting of the possible payloads… and it of course has not been shown in anything that I have yet found. If you’ve come across information (especially drawings) of the fighter, don’t hesitate to let me know.
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