Planes: Frequent Flyers & Enthusiasts Welcome
Well, high altitude aviation isn't really next gen, so to say. Since the pressurization of aircraft, they've pretty much always operated between 32,000 and 42,000 ft (depending on model, weather, ops, etc.).
In commercial aviation specifically, most aircraft use turbofan engines (and turbo prop, which really is just a turbofan without a casing). But that doesn't mean other tech doesn't exist. Certain military craft, for example, use typically turbojet or ramjet/scramjet technology. No point in really getting down to the differences - but for reference, the Concorde was a turbojet engine.
Higher altitude is always a better thing for a drag profile, if you're trying to decrease flight time. But it's far worse for lift. There's less "stuff" to push your wings on. There's two important relationships for aviation: lift to drag (how much are you staying afloat versus how much you're being dragged down) and power to fuel consumption (how much umph are you getting versus how much fuel you're gobbling up). Now, to complicate matters, for commercial aviation has to look at everything as "per person" and again "per day."
Things like Concorde didn't go away because they were dangerous. They went away because they were dramatically fuel inefficient and expensive to maintain. There was just no market for them. And I doubt there ever really will be a market for high altitude flight... the math typically never adds up. The fuel consumption per person per day means little when, for the same rate of fuel consumption, you can probably get 5x the amount of customers on a bigger, slower aircraft.
Amywho. Rocketry isn't really the same principle as aviation, but it is the way of the future. You can skip Concorde's 60,000 ft cruising altitude, and forget the 120,000 ft of a paper thin U2 dragon lady. But, you can also throw the idea of lift out the door. Rockets utilize escaping the earth's atmosphere entirely. Much like an ICBM, you can just launch a missile into space and put in on a trajectory where it's expected to land on a target. If you're interested in reading more about that, definitely check out Elon Musk's BFR plans. Travel times of 30 minutes anywhere in the world, really. Green technology, as well.
