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Transportation Technology

Proposed Lapcat II Hypersonic Airliner: Brussels to Sydney in Less Than 3 Hours 221

Posted by timothy from the sorry-no-meal-service dept.
New submitter AG_2011 writes: Could an airliner that flies anywhere in under 3 hours be in service by 2030? One estimate puts the cost one way at €5,000 (£3,700) per seat for a Brussels to Sydney trip. The Lapcat-II project's Mach 8 airliner will be capable of 8,500 km/h (5,280 mph) and could take passengers on this trip in 2 hours and 55 minutes. The race is on...
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Proposed Lapcat II Hypersonic Airliner: Brussels to Sydney in Less Than 3 Hours More

Proposed Lapcat II Hypersonic Airliner: Brussels to Sydney in Less Than 3 Hours

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  • So: nine hours from Brussels to Sydney (Score:5, Insightful)

    by Anonymous Coward on Saturday September 19, 2015 @08:48PM (#50558649)

    Three hours: airport security checks

    Three hours: flight time

    Three hours: customs

    Not bad. Not bad at all.

    • Re:So: nine hours from Brussels to Sydney (Score:4, Insightful)

      by turbidostato ( 878842 ) on Saturday September 19, 2015 @08:55PM (#50558683)

      And then, at five grands a-pop don't expect you have flights each hour, so add up "waiting for next flight".

      Doesn't look as if it can go against private jets/flights which seems the natural competitor here.

    • Re: (Score:3)

      by OzPeter ( 195038 )

      Three hours: airport security checks

      Three hours: flight time

      Three hours: customs

      Not bad. Not bad at all.

      You'd think that if you had an airline charging >5k euros per one way ticket, that they would have already paid off the right people in order to expedite security and customs. But even still as it is it doesn't take 3 hours to get through customs in Australia .. unless you are attempting to bring in some contraband. This isn't LAX after all.

      • But even still as it is it doesn't take 3 hours to get through customs in Australia

        It doesn't in America either. At SFO the time from wheels-down to walking out the door is typically about 40 minutes to an hour.

        Pro-tip: Fly non-American airlines. If I fly from Shanghai PVG to SFO, I will clear customs much faster if I fly Air China than if I fly United. Why? Because American airports have separate customs lines for America citizens/residents and non-residents. A United flight is typically 80% Americans and 20% Chinese. The Air China flight is the reverse. So I spend far less time

        • Re: (Score:3)

          by quenda ( 644621 )

          Besides, Air China has better food, and way cuter stewardesses.

          Try Thai Airways. Even the stewards are cute.

      • And the acceleration g-forces, coupled to the de-accelaration forces means you have five minutes during the flight to go to the loo. Please don't stand in the aisles whilst you wait.

        • Funny. Slightly.

          At half a gee acceleration, it'll take about 8 minutes to reach cruising speed. It'll probably take longer to slow down, say 25 minutes....

    • Re:So: nine hours from Brussels to Sydney (Score:4, Funny)

      by sycodon ( 149926 ) on Saturday September 19, 2015 @10:13PM (#50558995)

      All things considered, I think I'd rather take 2-3 weeks on a cruise ship to get the Australia.

    • Anyone who can afford this can afford to bypass the security lineup.

      • Anyone who can afford this can afford to bypass the security lineup.

        How does money help you bypass TSA? I mean legally.

    • Just once difference, we're talking Brussels to Sydney. The answer is more:

      15min security check
      1.5 hours binge shopping duty free goods and sipping on latte at the gate. Bonus points if you get to spend it in the lounge with a nice whiskey.
      3 hours flight time.
      10min bag wait.
      10min customs.

      Don't let America ruin flying for you. Not every country in the world is batshit stupid when it comes to air security.

    • Re: (Score:2)

      by GNious ( 953874 )

      Don't know about Sydney, but at Brussels Airport you can get through Security in under 2 hours most days, and customs in under 30 minutes.

      Yes, you were trying to be funny and all....

  • Brussels to Sydney (Score:5, Insightful)

    by turkeydance ( 1266624 ) on Saturday September 19, 2015 @08:55PM (#50558685)
    who would want to do that?

    • Re: (Score:2)

      by OzPeter ( 195038 )

      who would want to do that?

      Let's see. Right now the shortest commercial flight Brussels to Sydney is about 22 hours. I don't know if you noticed, but 3 is a lot less than 22, and some people have a lot more money than the $1600 needed for the current return ticket prices. And a fair share of these people travel all over the world.

      • I think he was making a joke that anyone with enough money to fly on this plane isn't going to want to go to a country where 15 or the 12 deadliest snakes and spiders live.

        • Re:Brussels to Sydney (Score:5, Funny)

          by sycodon ( 149926 ) on Saturday September 19, 2015 @10:14PM (#50559001)

          Australia:

          Where the Women are pretty, the Men are drunk, and everything in Nature wants to kill you.

          • Re: (Score:3)

            by rtb61 ( 674572 )

            I got no idea where all that came from, except possibly as an Australian Government misinformation campaign because they were having to reject too many American applicants and the Americans were getting nasty about it but http://www.bobinoz.com/migrati... [bobinoz.com]. I mean seriously grizzly bear versus koala bear which would you rather meet out in a forest or mountain line versus Tasmanian devil, sure the devil sounds worse, much worse but not really a problem.

            • It's not the koalas and kangaroos which want to kill you (though the kangaroos can punch you in the face and knock you out).

              It's the giant spiders, poisonous snakes, and crocodiles. I believe, however, that the really dangerous stuff like this is mostly in the northeastern part of the country.

              • And, it's getting worse every day:

                http://www.independent.co.uk/e... [independent.co.uk]

                This thing is so poisonous, that I get queasy just seeing it's photograph.

              • Re: (Score:2)

                by Aereus ( 1042228 )
                Oh don't worry, the kangaroo will kill you too—threaten one near a watering hole and chase after it into the water... it'll suckerpunch you in the gut and hold you under until you drown, no problem.

            • I got no idea where all that came from, except possibly as an Australian Government misinformation campaign because they were having to reject too many American applicants and the Americans were getting nasty about it but http://www.bobinoz.com/migrati... [bobinoz.com]. I mean seriously grizzly bear versus koala bear which would you rather meet out in a forest or mountain line versus Tasmanian devil, sure the devil sounds worse, much worse but not really a problem.

              Yeah, but then whenever I'd discover one of these [buzzfeed.com] in my room I'd have to burn the house down and be homeless afterwards, which is not so convenient in a place with so many free-running monsters.

      • Re: (Score:3)

        by OzPeter ( 195038 )

        2nd reply because I forgot about this for a moment.

        Come to Australia [youtube.com]

      • is a lot less than 22, and some people have a lot more money than the $1600 needed for the current return ticket prices.

        The Concorde proved that there are actually very very few people willing to squander thousands of dollars to save a few hours. The Concorde was only kept alive by taxing middle class working people in France and Britain, in order to subsidize millionaires jetting across the Atlantic. It was never close to being economically viable without those subsidies. Living in Silicon Valley, I know quite a few people that are well off and could easily afford this. But they are also some of the cheapest bastards aliv

    • I would, but the price is kind of expensive.
      If they added it to other routes, I would be even happier.

      • I think Brussels to Sidney is just an example, of a long flight, They will have any route that is economically feasible.

    • Because they want to go to the Opera?

      Let's see.... If you wanted to go to the Sydney Opera (assuming an 8pm show) you would have to leave your house in Brussels at .... 5am. (two hours to get to the airport, three hour flight time, two hours to get to the opera house plus the 8 hour time difference.) This is of course assuming there is a flight that happens to correspond with the Sydney Opera House's schedule which is reasonably likely if for no other reason it doesn't make sense to be arriving in the mid

    • who would want to do that?

      People who appreciate warm winters, hot summers, beautiful blue skies, and endless beaches.

  • The actual plane ride is actually quite nice. You can get up and stretch your legs, get refreshments and whatnot. The crappy part is getting to the airport, check-in, security control, boarding, disembarking, waiting for luggage, getting from the airport and so on. Going to the capital is ~50 minutes flight time, but in practice city center to city center it's 3.5-4 hours. Now I suppose for the really, really, really long flights this could be an advantage but for the somewhat shorter trips within 1000 km I

    • Re: (Score:2)

      by sk999 ( 846068 )

      Breakdown of timing for my most recent flight (yesterday):

      Travel time to airport: 90 minutes (normal time 20 minutes, but it was rush hour. A Taylor Swift concert on the way was not a problem.)
      Time in airport, including ground hold time due to weather at destination: 210 minutes (normal 60 minutes)
      Actual flight time: 70 minutes (normal time 50 minutes)
      Time from touchdown to exiting the parking lot: 90 minutes (normal 30 minutes - airport operations stinks late at night)
      Drive home: 90 minutes (normally 60 m

      • Re: (Score:2)

        by Greyfox ( 87712 )
        I run into that every time I go to DIA. No matter how you arrange it, it's always going to cost neighborhood of $60 and take about an hour to get there. Parking for three days there cost nearly as much as a round trip ticket to Phoenix.

        I live next door to a municipal airport and talked to a pilot there about just flying down to the big airport. I'd have to pay for the plane rental and pilot's time by the hour, but that's actually pretty reasonable. Meaning a round trip could cost less than parking a car t

      • Wow that is seriously fucked for such a short flight. Brisbane to Sydney is a 1hr5 flight. With only carry on my day looks like this.

        Travel time to airport: 30 minutes
        Time in airport: 45 minutes (you can board up to 20 mins before flight for domestic and security is straight forward, you precheck in online and have your boarding pass pre-printed)
        Flight: 65 min
        Touch down to train: 15 mins
        Train to cbd: 35 mins

        Driving time - 11-13 hours.

        I do that there and back in 1 day for work regularly.

  • Until we can keep reliable low-supersonic passenger service flying, I'm really not going to worry about the hype of hypersonic.

    Give me LA to London in six hours for a price I'm willing to pay as an already frequent flyer, then we'll start talking.

  • This one of the few good uses for hydrogen fuel that I've seen other than rockets. However, I suspect it will be too loud for passenger traffic. The Concorde was notoriously noisy, even aside from the sonic booms it created.

    There are few flights long enough for this to be worthwhile, especially if the courts limit the areas they can travel at transonic speeds. At the least, I would want government involvement minimized.

  • One estimate puts the cost one way at €5,000 (£3,700) per seat for a Brussels to Sydney trip.

    Does that price include any amortized R&D expenses? I somehow doubt it.

    • One estimate puts the cost one way at €5,000 (£3,700) per seat for a Brussels to Sydney trip.

      Does that price include any amortized R&D expenses? I somehow doubt it.

      No, but if you read the article, you'll already know that it includes the hydrogen fuel costs, with the hydrogen not being derived from methane.

  • If the hydrogen can be sourced from natural gas, instead of from the electrolysis of water, the airfare tickets of a hypersonic trip could drop to about half the price of a business-class ticket.

    Based on current projections the ticket price will be about three times more expensive on average than current business-class subsonic tickets.

    Yes, these two sentences followed each other. There was no editing.

    So the cost could be about half as much, but they'll charge three times as much because they can. I suppose I can't blame them--if I was in Brussels, I'd probably pay three times the going rate to get to Sydney.

    • The editing is clumsy, but I don't think there is any contradiction. I read it thus:
      - if they can get the hydrogen from natural gas, then a ticket will cost 0.5 CBCT (Current Business Class Ticket);
      - otherwise, if they have to rely on electrolysis to get the hydrogen, then the cost is 3 CBCT.

  • For future reference, (Score:5, Informative)

    by Beck_Neard ( 3612467 ) on Saturday September 19, 2015 @09:30PM (#50558841)

    So that everyone can have an informed opinion about this, the laws of physics of high-speed travel are quite simple. The lower the lift-drag ratio of your craft (at cruise speed at level flight), the more fuel you have to consume per mile. The problem with supersonic travel is that at supersonic speeds, high lift-drag ratios become virtually impossible. A 747 has a L/D ratio of over 25; the Concorde had a L/D of about 7 at Mach 2 (and it was a pretty efficient, low-drag design). The best supersonic designs I'm aware of achieve a L/D of around 9 at L/D at Mach 1.5. These are incredibly optimized designs that have been fine-tuned with supercomputers and would be quite unfeasible for a passenger aircraft (weird shapes, no windows, etc.) As a result the Concorde consumed about 3x more fuel PER MILE than a comparable subsonic jet. So half the mass of the Concorde was fuel (!), it winded up being very heavy, and it carried only 100 passengers. And its maximum range was limited to 4500 miles.

    And if you look at a craft like the SR-71 blackbird, it fits the same pattern. It had a L/D of about 6 at cruise speed (Mach 3.2), 60% of its mass was fuel, and it could only go about 3000 miles before requiring refuelling.

    At hypersonic speeds, it's even worse, as various laws start catching up with you and limiting your theoretical L/D to about 4 or 5. If you're running on typical jet fuel, forget London to Sydney. Such a craft could barely make it from London to Athens. So because of that, they're suggesting hydrogen. Which is both hilarious and also firmly puts this idea in the realm of 'things that are never going to happen.'

    • Interesting post, but one thing: did you consider the fact that they plan to fly at altitudes well above 33 km? The air is a lot thinner up there.

    • Re:For future reference, (Score:4, Informative)

      by Anonymous Coward on Saturday September 19, 2015 @10:59PM (#50559161)

      Concorde suffered from being small - with limited volume and so poor number of passengers for overall weight (about 1passenger per dry tonne, versus about 2 for a large airliner) A larger SST could get to similar 2 passengers per tonne figures with more internal volume available.

      Concorde B (minor wing and engine changes, never built due to halt in production) would have lifted range about 10-20% from Concorde. L/D about 7.5. Modern jets are not 25, more like 21-22, so yeah about 3x, though a new Mach 2 SST might get L/D up to 8 or 9

      But cost of travel is about 1/3 fuel, 1/3 capital and 1/3 staff. Travel 2.5 times as fast (concorde) and capital costs are reduced by about half as are staff costs. Optimised Mach 2 engines are also far higher efficiency than subsonic engines due to higher efficiency of inlet air compression so fuel costs are only about 2.5x and overall cost about 1.2-1.3x. That is affordable. You are also only in the air for 3-4 hours at a time, so don't need to provide for high staff headcounts and sleeping spaces or meals as on long-haul flights.

      Change to LNG as a fuel and you can lower fuel costs and increase range by 20-30% and might be even cheaper than conventional jets.

      Also we now have a raft of improvements since 1970's - like building from lighter stiffer stronger carbon fiber, improved higher temp engines, better control systems, no need for droop noses, cheap fast cfd and fea optimisations, and even ability to do laminar flow wings that can all hook together to greatly reduce weight of aircraft and increase efficiency compared to old Concorde.

      The boom remains the big problem, but the economics could otherwise probably work, and there is a market for international flight over oceans, that dropping flight times would increase further. With passenger volumes increased by an order of magnitude since the 70's the time for supersonic airliners might be returning - Boom Nimbys are the big uncertainty/roadblock. And of course corporate risk aversion.

      Maybe the chinese govt will do it - it is the kind of thing that would appeal to them and would let them break into civilian aerospace doing an end-run around the Boeing Airbus duopoly.

      • I completely agree about the feasibility of a Mach 2.0 transport in the same vein as Concorde. I never suggested anything to the contrary.

        What you have to consider though, is that even though there have been a lot of technological improvements since the 70's, fuel costs have also risen enormously (as a fraction of operating cost), and airliners run on profit margins of 1% or so. It's a really lousy business to be in overall and it's no surprise that most airlines are heavily state-supported.

        While reports ab

      • Re:For future reference, (Score:5, Interesting)

        by serviscope_minor ( 664417 ) on Sunday September 20, 2015 @05:45AM (#50560195) Journal

        Mach 2 engines *were* more efficient at the time the concorde was built. In the mean time however, more efficient engines have been built: compressors have got better, but crucially, people have figured how to make turbofans efficiently have extremely high bypass ratios. So while the core might be more efficient at Mach 2, the overall production of thrust isn't, unfortunately.

    • Re:For future reference, (Score:5, Interesting)

      by viking80 ( 697716 ) on Saturday September 19, 2015 @11:35PM (#50559271) Journal

      One correction to your math. At high Mach, the curvature of the earth creates a "virtual" L/D improvement. For example at Mach 22, you will have a L/D ratio better than 100 for a grand piano filled with tungsten.

    • The best supersonic designs I'm aware of achieve a L/D of around 9 at L/D at Mach 1.5. These are incredibly optimized designs that have been fine-tuned with supercomputers and would be quite unfeasible for a passenger aircraft (weird shapes, no windows, etc.) As a result the Concorde consumed about 3x more fuel PER MILE than a comparable subsonic jet. So half the mass of the Concorde was fuel (!), it winded up being very heavy, and it carried only 100 passengers. And its maximum range was limited to 4500 miles.

      These guys (actually, there are several different teams working on competing designs, including Airbus) are planning on using ramjets, probably powered by hydrogen.
      Interestingly, the prototype pictured in the article has no windows, not even a cockpit (as far as I can tell).

    • Re:For future reference, (Score:4, Informative)

      by joe_frisch ( 1366229 ) on Sunday September 20, 2015 @12:38AM (#50559487)

      Agreed. Its also very difficult to make efficient scramjets which makes the problem even worse. The best scram jets so far have barely been able to maintain steady flight at a single mach number and in a short range test vehicle.

      I think there is a good chance that you want to jump from supersonic all the way to mostly ballistic sub-orbital. It also completely avoids the noise footprints except (and its a BIG except) at the launch and landing points.

      As several people have also said, I'll take hyper-sonic travel seriously only after we have supersonic commercial flight again. Existing airliner speeds haven't changed significantly in 60 years. (!!!). (the same time it took to go from the Wright brothers to near mach-1 travel).

      • That's another good point that I forgot to mention: At high speed, it becomes hard to develop efficient engines. The best engine efficiency occurs at low (below Mach 2.0 or so) speeds where good pressure recovery exists and the velocity of the exhaust jet is matched with forward flight speed. At higher speeds air-breathing engines become far less efficient.

        • You keep arguing as if the Lapcat A2 [reactionengines.co.uk] uses a conventional engine, which it does not. An entirely new thermodynamic cycle takes advantage of the extremely cold fuel to significantly improve efficiency. Rather than armchair speculation based on generalizations, I'm more inclined to trust the actual modeling done for these engines and aircraft, for which the numbers look very promising. The engines are based on SABRE [reactionengines.co.uk], and the ESA is confident that the design is sound.

          • These issues arise because the engine takes in air as reaction mass and ejects it at higher speed to produce thrust...they apply to anything that breathes air. No fancy internal thermodynamic cycle can get around this. Ultimately, accelerating that flow of reaction mass by a given amount takes more power as the initial velocity of that reaction mass with respect to the craft increases. The only way around this is to not breathe air.

            The fact that their engine is absolutely dependent on large quantities of li

          • Until a SABRE engine is flying we might as well be talking about the efficiency of flying carpets. The intercooler has been tested and apparently it works, so I'm hopeful that the engine design will work, but you never know until you actually fly.

            By the way, if it works, it will achieve an efficiency about equal to that of a conventional turbofan engine. Which is great, but still wouldn't get you from London to Sydney cheaply.

        • (not disagreeing with your conclusions) Depends on how you define efficiency. For an ideal jet engine the power to produce a given thrust goes up with airspeed, but since you are moving faster, the energy per distance remains the same. (distance * Weight / (L/D) = energy_use. ) ,.

          For a real engine though the efficiency does go down. Conventional ram jets don't work well at high speed because slowing down the inlet air to subsonic heats it too much, and involves aerodynamic losses.

          Supersonic Combustion R

    • Minor correction: The HIGHER the L/D, the more fuel you have to consume per mile.

    • Meh.

      Hydrogen is a lot cheaper as a fuel, unless you source it stupidly, like they did in the article (they assumed no use of methane precursor, only electrolysis), and a Miele design will hit an L/D ratio of ~14 at low Mach numbers (e.g. Mach 2), which compares favorably with the Boeing 747 L/D ratio of 17 at Mach 0.85.

      A Miele design will drop to an L/D ratio of about 7, but it takes going Mach 30 to get there. You can easily do an L/D ratio of 8, if you don't plan on going over Mach 5 with the thing -- an

    • Thank you. Also : peak oil.

  • It used to be economic to spend a month on a ship, paying hotel rates for labour but thats just too expensive now, so you pay less money to spend a day on a plane to go half way around the Earth. But at some point the cost of labour will rise to the point where that one day is too expensive as well, so it will be economic to develop faster aircraft which cost less in manpower to run. Even now an SST could get away with less in cabin staff, fewer changes of crew, etc.

  • It failed because the cost of tickets was unsustainable, and they couldn't get the price down to where enough people would buy them to make it financially viable.

    This will be the fate of any future super-high-speed mode of travel, if they can't get the cost down enough so that ticket prices can compete with traditional air travel.

    • It failed because the cost of tickets was unsustainable...

      The Concorde failed because a tire exploded, it streaked terrifyingly across the Paris sky trailing hundreds of feet of fire, and crashed in a giant fireball, killing everyone. And then the fleet was instantly and irrevocably grounded. The program had its economic issues over the years, but was still in operation nonetheless - until the disaster.

      • Concorde was hardly the first jetliner to crash in a giant ball of fire.

      • by that logic there are no more 747s in flight because of flight 800 right?

      • Re: (Score:2)

        by 0123456 ( 636235 )

        And then the fleet was instantly and irrevocably grounded.

        Uh, no, it wasn't.

        Concorde was operationally profitable, at least for BA, until 9/11 took the bottom out of the airline market and killed many of the people who used to fly on Concorde (e.g. bankers flying between NYC and London), and the cost of the required upgrades to keep them flying couldn't be justified.

        The crash did scare off some passengers, but they flew on for several years afterwards.

        • Re: (Score:2)

          by 0123456 ( 636235 )

          Oh, and the tire didn't 'explode', it was cut open by a piece of debris on the runway. That can happen to any aircraft, but it was more dangerous to Concorde because of the large fuel tanks and the location of the wheels relative to them.

      • It failed because the cost of tickets was unsustainable...

        The Concorde failed because a tire exploded, it streaked terrifyingly across the Paris sky trailing hundreds of feet of fire, and crashed in a giant fireball, killing everyone. And then the fleet was instantly and irrevocably grounded. The program had its economic issues over the years, but was still in operation nonetheless - until the disaster.

        I think you are misremembering history. Concordes were not instantly and irrevocably grounded after the 2000 Paris accident, as some flew well into 2003. Maintenance costs were rising on the old planes and demand sagged after 9/11. The Paris wreck was a heavy blow but it is not what ultimately ended Concorde service. The flight deck of those things was so antiquated by 2003 and they were so inherently crappy to fly that I'm surprised they made it that long. Incredible machines, and a real marvel in their da

    • Re: (Score:2)

      by Macdude ( 23507 )

      Concorde failed because the number of airports it could fly into was extremely limited and the ground it could overfly was even more limited.

      But in reality it failed because it was expensive, cramped and didn't reduce total trip time by all that much.

    • It failed because the cost of tickets was unsustainable, and they couldn't get the price down to where enough people would buy them to make it financially viable.

      No, the BA one was mildly profitable. Not hugely so but profitable nonetheless. The French one wasn't, but then again if your crew are on strike for 364 days of the year and rioting for the remaining 1 1/4, then profit margins are thinner so it's harder to turn a profit.

      What actually happened is that the French conglomerate which wound up with the

      • Still, it wasn't profitable enough to spread the service to other markets, or to make it worthwhile to have more of the planes built. If it were, it would have happened.

  • I'll just hop in my flying car to get to the airport and catch my flight in it.

  • Laughable journalism (Score:5, Interesting)

    by gman003 ( 1693318 ) on Saturday September 19, 2015 @10:25PM (#50559031)

    "What’s more, liquid hydrogen fuel is not highly combustible mid-flight. Although hydrogen can be ignited, the risks of an explosion or fire are lower compared to conventional airline kerosene fuel"

    Gaseous hydrogen is already a ridiculous explosive risk. Liquifying it only makes the resulting explosions bigger. They somehow think this is safer than Jet-A, which is actually less flammable than gasoline.

    There are valid engineering reasons for the use of liquid hydrogen as a fuel, such as specific impulse or heat capacity. But safety is absolutely not one of them.

    In other news, this is a blatantly obvious attempt to get funding for SSTO spacecraft development by disguising it as a less outlandish business plan. Seriously, this has much more in common with Skylon or VentureStar than with Concorde, right down to the choice of fuel. I wouldn't be surprised if many of the engineers are the same.

  • Why not Mach 22 (Score:5, Interesting)

    by viking80 ( 697716 ) on Saturday September 19, 2015 @11:28PM (#50559259) Journal

    Why not Mach 22

    If you first want to go fast, why not just use an intercontinental ballistic missile? It is really simple construction (read fuel tank with orifice), uses cheap fuel, and really need no fancy aerodynamics or control system. Just aim and fire.

    The whole idea of pushing a vessel through air for hours and hours, wasting fuel, when it can glide with no friction a few miles higher seems dumb. It also consumes more fuel in total.

    • Re:Why not Mach 22 (Score:4, Insightful)

      by Beck_Neard ( 3612467 ) on Sunday September 20, 2015 @05:10AM (#50560101)

      Nope, you're dead wrong on all points. Flight is far more efficient than a ballistic trajectory. Being in an atmosphere is actually really great because wings allow you to lift far more weight than your engines themselves are capable of. And there's no way to 'glide' in space. You fall. The only way to avoid rapidly falling to the ground is to accelerate to such a tremendous speed (orbital velocity) that your freefall trajectory is wider than the curvature of the Earth. And to get to such speeds, you need a two-stage rocket that costs an insane amount of money and, at present, has to be thrown away each time it's used (Elon Musk is planning to change this, but it's not like it would make it as cheap as air travel).

      • And to get to such speeds, you need a two-stage rocket that costs an insane amount of money and, at present, has to be thrown away each time it's used (Elon Musk is planning to change this, but it's not like it would make it as cheap as air travel).

        Actually, Skylon are planning to change it more (the people behind the Mach 5 LAPCAT variant), since their main line of work is a reusable single stage to orbit spaceplane. The Mach 5 airliner is essentially a simplified spaceplane without the exoatmospheric capa

  • As pointed out by others the problem with faster aircraft is that a large portion of a traveler's time is spent standing in line at airports, not in the airplane. Few people travel at such great distances that such an increase in speed proves beneficial in decreasing travel time. What would be more beneficial is to reduce the time standing in lines at the airport.

    We have a conflict of interests here. Bigger planes are cheaper to run. Bigger planes take more time to fill and, since they move more people

    • I don't see the difference between domestic and international travel you're making. I have 6 different countries within 400km of where I live. Any shorter distance and I would take a train.

      • International travel could be different because of customs. With more nations having freedom of travel agreements this is less of an issue but if one passes a border where a visa is required then there would be people standing in line.

  • This plane would take 2.5 hours to go up and come back minimum. Crossing the half the globe at the higher atmosphere is just 25 minutes. So the flight times are like: 2hr 30 min for Brussels to Brussels, 2 hr 35 min for Doha, 2hr 40 min for Delhi, 2hr 45 min for Manila, 2hr 50 min for Sydney!
  • Video conferencing has gotten so good, the demand for fast business travel is shrinking. I find it hard to believe there is enough market for pleasure travel at supersonic speed to support it; especially if it means traveling to an intermediate hub airport versus a slower but non-stop flight

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