> It's certainly less ridiculous than talk of suborbital rocket planes.
as far as in understand the X-15 is more simple than Concorde. The suborbital and ICBM-ballistic tech is well understood and has been in constant use for half a century, where is Mach 3+ aircraft territory is still almost no-go zone. Compare to high Mach the suborbital/ballistic is just more energy efficient.
Yes, but you aren't going to see wealthy people (generally older) going through the astronaut training, tying in with 5-point harnesses, climbing into a vertically-mounted fuselage, then pulling 3+Gs on "takeoff" followed by several vomit-filled minutes of weightlessness before reversing the entire process.
Imagine the chaos of a dozen members of the general public experiencing zero gravity for the first time. Better bring lots of towels ... and an umbrella.
It's very easy to dramatically underestimate the amount of fuel needed for an effective suborbital trajectory. If you want to travel half-way round the world, then delta-V wise, you're not very far off actually getting into orbit.
That article quotes 7km/s for a 10,000km trip, compared to about 8km/s for LEO.
The X-15 (and SpaceshipOne, for that matter) was never trying to actually go anywhere; it just hopped out of the atmosphere and come down again very close to where it took off, with a delta-V of about 1.5km/s.
It's worth getting a copy of KSP and actually trying this. It's eye-opening.
as far as in understand the X-15 is more simple than Concorde. The suborbital and ICBM-ballistic tech is well understood and has been in constant use for half a century, where is Mach 3+ aircraft territory is still almost no-go zone. Compare to high Mach the suborbital/ballistic is just more energy efficient.