[qayxc]

Unlikely. The cost involved would still be substantially higher than fossil fuel.

The required energy scales quadratically with speed. That's just basic physics and there's no way around it.

The real question we should ask ourselves is whether it's even worth it just to shave off a couple of hours on a trip that shouldn't be a regular occurrence anyway?

If you take the entire trip - that is door-to-door - into consideration, the time savings you pay for with about 6.25x the energy use comes down to 30% or so:

• 1 hour to get to the airport

• 1.5 hours security checks, check-in, getting on the plane

• 6 hours flight time

• 1.5 hours security checks, customs, getting out of the airport

• 1 hour airport to destination

That's 11 hours total for the subsonic flight and ~7.5 hours for the supersonic flight (assuming >mach 2.2 for the entire duration of the flight). That's a net time saving of 3.5 hours or ~32% faster for >6.25 the energy expense.

How does that make any sense?

[rbanffy]

Supersonic doesn’t make too much sense for short flights, but I routinely fly 10+ hour routes and it’d be wonderful if I could shave 5 hours from the total flight time. If they can do LA or SF to Tokyo or Taipei, it’ll make a miserable trip into a bearable one.

[Zanni]

Exactly. Anything over five hours is very unpleasant for me. Over eight hours and I'll actually segment the trip with a hotel stay in between. Turning a 10-hour flight into a five-hour flight would save me a full day.

[Jabbles]

Sure, I'd take the shorter flight, everything else being equal. But what premium would you pay for that ability? The article only mentions being better than Concorde at 5x the fuel cost (I assume it means per passenger-km).

[rbanffy]

It may be a significant premium over coach, but would be much less significant over business and first class. A Lufthansa now retired 747 carries 8 passengers in first class and about a hundred in business. With a plane like this, LH would be able to carry more first and business passengers over the same amount of time at equivalent prices. Remember Concorde 2 would be much more efficient than the first iteration, and that was with late 60's technology.