It’s certainly true that wings and jet engines cannot function once the air gets too thin. But would it be possible to build a commercial airliner that went as high as it could go, then activated rocket boosters to enter a low earth orbit? This would make transcontinental air travel incredibly fast. It would also, of course, require atmospheric reentry, which is not a simple thing. However, the space shuttle lands like an airplane after reentry. What engineering barriers stand in the way of building one that can take off like an airplane?
It might technically be possible on a small scale but it will never happen as a commercial aircraft. People have been proposing this for years but the idea has barely taken off. However, perhaps the greatest aircraft genius of all time, Burt Rutan has already successfully flow the first stages of this idea with a sub-orbital space craft (I don’t see why you would want true orbital for this application). Rutan doesn’t just propose these ideas, he actually builds his ideas and flies them. However, his aircraft are pretty small and funky looking.
A commercial aircraft needs to be financially viable and I can’t see that happening. The Concorde aircraft were complete financial failures despite insane ticket prices and there is little hope of even having supersonic air travel in the near future. Coach air travel sucks but most people can spare 6 hours for coast to coast flights in the U.S. and be anywhere in the world in 24 hours.
Nerver say “never”. The cost of current coach air travel is miles beyond what much poorer cultures 200 years ago could have afforded, even if somehow they had the technology. But now that same cost is no big deal to a lot of humanity.
You’re right that the energy consumption per passenger of a sub-orbital airliner would be huge using current technology & would be too expensive using current (pre last 12 months) economics.
But theres no immutable law of physics that things have to stay that way.
Well, the Skylon SSTO spaceplane has been languishing on the drawing boards for several years now; there probably would be a lot of demand for unmanned versions (as in the linked article) delivering satellites into LEO if it proved viable. I’m not sure if the concept would work if scaled up to Concorde size however-I’ll leave that to the techheads here.