Well, hopefully Virgin/Branson will see enough demand to give a solid answer.But I noticed that Branson had commented early on about the idea of using SpaceShipTwo for quick intercontinental travel. Obviously it's not designed for that. But it then makes me wonder if a flashy-yet-conventional enterprise like his would have more eagerly leapt at the idea of a rapid intercontinental transport over a space tourist vehicle.Aiming at space tourism means you get to be flashy first, and worry about paying the bills later. With suborbital intercontinental transport, you get to serve a more conventional market first, to pay the bills, and you have the possibility of evolving into something more flashy and Buck Rogers later on.
Quote from: kkattula on 01/04/2011 06:16 amOr for a more practical solution, mag-lev trains running in vacuum tunnels at hypersonic speeds. Very expensive to build, but massive throughput of passengers.I've heard a speed of 6000km/h for such trains. So you have any paper on that?
Or for a more practical solution, mag-lev trains running in vacuum tunnels at hypersonic speeds. Very expensive to build, but massive throughput of passengers.
...South America would be the ideal place since the distance between big cities are big (thousands of km), and there are no techtonic plates boundaries.
So you're saying that maybe Branson is being extra-clever by doing "Space Tourism" thru SpaceShipTwo, because his real goal is to use it as a stepping stone to go for suborbital point-to-point transit?
Concorde (in the end) couldn't make money on the busy trans-atlantic route by reducing the transit time to less than 4 hours.How do you expect a far more expensive system to do better?
For a rocket, you will need 10 to 20 times the weight of payload in fuel. For RP-1/LOX that's about $15 to $30 per kg of payload, just in fuel.
For example, a flight of about 10,000 kilometers would require a delta-V of over 7,300 meters/second, which is already about 80% of that required to reach low Earth orbit.
During my involvement with a hypersonic vehicle program in the late 1980s, the rule of thumb was that once you got over about 5,000 meters/second, the difference between that and an orbital reentry environment were small.
Well, I wasn't necessarily thinking about bringing back Concorde itself, but whether supersonic travel could be revived with a Concorde replacement that would be fasterbettercheaper.
Well, if you use just the RP-1 without the LOX (ie. high-mach ramjet like RanulfC said) then your fuel costs are closer to existing airliners, although obviously still much higher, since you have to burn much more at lower efficiency.
The major airliner maunfacturers have looked at that many times, but concluded there wasn't a market. In 2001 Boeing announced their Sonic Cruiser, which would fly at Mach 0.95 to 0.98, 15-20% faster than regular airliners, while being just as fuel efficient. The airlines said they would rather have a Mach 0.8 aircraft that was 20% more fuel efficient. Hence the 787, which is small enough to be point to point, rather than hub to hub like the A380.
Actually the LOX, although more than twice the mass, is less than 10% of the cost. LOX is dirt cheap, around $100 per ton in bulk.Ramjets can be quite efficient. Far more so than a rocket. They use exterior air as reaction mass as well as oxydizer.Hypersonic flight is always going to be many times the cost of high sub-sonic flight. Most people are not willing to pay that premium to cut their transit time by 40-50% (when you include time spent in transfers, check-in & customs)
I have another question for RanulfC or anyone else - would hypersonic flight produce enough shockwaves to be heard on the ground? That's one of the things that hurt Concorde, so that's why I'm asking. Let's assume a waverider as the worst scenario.
Look, Boeing and Airbus are in the business of selling thousands of aircraft, and not in the business of pushing the envelope to sell just a few. What's required is a smaller, higher-end company that will make just a small number of vehicles which would then have free reign over that high-end niche market.
But I noticed that Branson had commented early on about the idea of using SpaceShipTwo for quick intercontinental travel. Obviously it's not designed for that. But it then makes me wonder if a flashy-yet-conventional enterprise like his would have more eagerly leapt at the idea of a rapid intercontinental transport over a space tourist vehicle.
Hypersonic flight is always going to be many times the cost of high sub-sonic flight. Most people are not willing to pay that premium to cut their transit time by 40-50% (when you include time spent in transfers, check-in & customs)
If world markets can support the construction of luxury cruise ships with ever fancier and expensive amenities, or ever taller skyscrapers with fancier architecture, then there's a market for faster transport aircraft.A suborbital vehicle could still offer passengers the momentary once-in-a-lifetime thrill of space tourism, for which they might be willing to pay that extra premium cost.
The Reaction Engines A2 is supposed to do Brussels to Sydney in around four and a half hours (top speed of Mach 5) for a ticket price of 3940 (2006) if the hydrogen is produced by electrolysis. The price is cut in half if steam reforming is used instead, indicating strong sensitivity to fuel costs and thus relatively cost-effective hardware design.This is according to REL themselves. I am not aware of an independent review confirming these numbers, but the Skylon business plan was recently subjected to such a review and passed with flying colours...The problems with Concorde are avoided by having antipodal range and good subsonic performance coupled with much higher top speed. The ability to go anywhere in the world at up to six times the speed of a modern airliner might be worth making the leap, where the ability to do transatlantic routes at two and a half times the speed of a modern airliner isn't.EDIT: I know the A2 is only tangentially related to the thread topic, but it was mentioned, and dismissed rather casually I thought...
Quote from: RanulfC on 01/05/2011 07:39 pmActually? The original "two-person" (no cargo) ROTON was designed from the start as an SSTO vehicle. It was only when it grew bigger that it lost the SSTO ability and started having heavier issues.I don't see any reason it wouldn't work.I remember reading that "2 guys and a ham sandwich" slogan for original Roton, but I recall the original design also had other hangups, like trying to position the rocket combustion chambers on each of the rotor-tips, etc. That seemed a little weird and eccentric. When they switched to the FASTRAC engine, that seemed more mainstream and sober.
Actually? The original "two-person" (no cargo) ROTON was designed from the start as an SSTO vehicle. It was only when it grew bigger that it lost the SSTO ability and started having heavier issues.I don't see any reason it wouldn't work.
EDIT: I know the A2 is only tangentially related to the thread topic, but it was mentioned, and dismissed rather casually I thought...
, @5-hours saved on trips to Asia,
Quote from: 93143 on 01/11/2011 12:12 amThe Reaction Engines A2 is supposed to do Brussels to Sydney in around four and a half hours (top speed of Mach 5) for a ticket price of €3940 (2006) if the hydrogen is produced by electrolysis. The price is cut in half if steam reforming is used insteadWhich sector of the market is going to pay that much?
The Reaction Engines A2 is supposed to do Brussels to Sydney in around four and a half hours (top speed of Mach 5) for a ticket price of €3940 (2006) if the hydrogen is produced by electrolysis. The price is cut in half if steam reforming is used instead