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Thread: What happened to commercial suborbital flight

  1. #31
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    Quote Originally Posted by CJSF View Post
    Except it's worse than that, isn't it? Didn't Virgin Atlantic recently announce that the target altitude for SSTwo would be lower than 100km, and thus not "officially" in space? Is that in the other discussion thread?

    CJSF
    From what they're saying, they still plan on going high enough (50 miles) to get astronaut wings.

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    Quote Originally Posted by Van Rijn View Post
    From what they're saying, they still plan on going high enough (50 miles) to get astronaut wings.
    As I said in the other thread, I think it's a cop-out. Commercial space is an international enterprise, so the internationally accepted number should be used, in my opinion. Hiding hardware or safety issues (or perhaps scheduling issues) behind a lower altitude seems cheesy to me.

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  3. #33
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    Quote Originally Posted by Nicolas View Post
    If you have the Americas as departure or destination, yes. Europe-Asia is something else.
    Fly off shore (or to specified land area) before boosting, pass over the continent while at high coast or cruise where there is no sonic boom, decelerate over water or (specified land area), fly subsonic to city of choice.
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    Quote Originally Posted by John Mendenhall View Post
    On. Concorde again.

    Not convenient. Not practical for businesses due to the cost. A great way to produce a stockholder revolt.
    Will depend on cost, which may depend on regulations, infrastructure needed, vehicle tech, fuel costs, etc. I found this research paper (PDF) to be useful. It would be a mach 5 hypersonic transport that using a ramjet and may use H2, CH4 or MCH (Methylcyclohexane). From the conclusion on page 114:
    By considering two baseline missions, the generated HST designs exhibited total mass values
    that are indicative of realistic aircraft configurations. The high L/D of both designs demonstrate that
    waverider-based HST configurations show advantages over conventional designs (e.g., ability to
    modify the upper surface to increase aerodynamic performance) even when integration of the
    propulsion system is considered. The 400 passenger configuration demonstrated lower
    fuel-per-passenger requirements due to its larger payload; however, for a first generation HST
    configuration, the 250 passenger vehicle shows a total mass comparable with that of current
    subsonic jet transports (e.g., Boeing 777), and potentially-reduced development costs (due to its
    lower take-off mass) might make it a better choice for pioneering an HST operational concept.
    Quote Originally Posted by John Mendenhall View Post
    Also the rocket tech needs improvement as does the re-entry. See shuttle history. Cost, cost, cost.
    Really, the only reason to look at shuttle history is: what not to do, what not to do, what not to do.

    Honestly, though, a better potential solution for rapid intra-continental transit is a vacuum train.
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  6. #36
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    Quote Originally Posted by Ara Pacis View Post
    Fly off shore (or to specified land area) before boosting, pass over the continent while at high coast or cruise where there is no sonic boom, decelerate over water or (specified land area), fly subsonic to city of choice.
    The hypersonic craft I've worked on were less than optimal in the subsonic range, so that's an area that would need extra development. Then again, anything on this type of aircraft is still quite experimental.

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    Quote Originally Posted by Nicolas View Post
    The hypersonic craft I've worked on were less than optimal in the subsonic range, so that's an area that would need extra development. Then again, anything on this type of aircraft is still quite experimental.
    I wasn't aware there was development of actual hypersonic craft anywhere. The one in the link is a waverider, though I suppose re-entry lifting bodies counts too.
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    Here's a new article with an old twist illustrating the problems with the economics and design of the Concorde. Apparently, it violated the Constructal law.

    The constructal law was developed by Bejan in 1996 and states that for a system to survive, it must evolve to increase its access to flow. For example, the human vascular system has evolved to provide blood access to flow through a network of a few large arteries and many small capillaries. River systems, tree branches and modern highway and road networks show the same forces at work, he says.

    In the case of commercial aircraft, designs have evolved to allow more people and goods to flow across the face of the Earth. Constructal law has also dictated the main design features needed for aircraft to succeed; the engine mass has remained proportional to the body size, the wing size has been tied to the fuselage length, and the fuel load has grown in step with the total weight.
    So, solve those problems, and you can have your it.
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  9. #39
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    Quote Originally Posted by Ara Pacis View Post
    Here's a new article with an old twist illustrating the problems with the economics and design of the Concorde. Apparently, it violated the Constructal law.
    So, solve those problems, and you can have your it.
    I see a flaw in what they are talking about.
    They track the design of replacement aircraft with their bigger brethren.

    The problem is, it's not just those craft that succeed. For markets where there is plenty of demand to support the size, this is true, but many markets just don't fit it.
    Go to just about any airport in America, and what do you see?
    Mostly Embraers, Regional Jets, 737s, a320s, etc.

    The success follows the market. Concorde had a niche market and did well for it's purpose.

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    Quote Originally Posted by NEOWatcher View Post
    I see a flaw in what they are talking about.
    They track the design of replacement aircraft with their bigger brethren.

    The problem is, it's not just those craft that succeed. For markets where there is plenty of demand to support the size, this is true, but many markets just don't fit it.
    Go to just about any airport in America, and what do you see?
    Mostly Embraers, Regional Jets, 737s, a320s, etc.

    The success follows the market. Concorde had a niche market and did well for it's purpose.
    Perhaps, or maybe that's the point, that it's a precarious niche and the only items with wide application fit. The smaller vessels fit the smaller markets that have smaller airports with shorter runways and aren't close to major hubs. I live beneath what appears to be the new approach patters of a regional airport and what I mostly see are large jets... Of course, it's a hub for air freight.
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  11. #41
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    Quote Originally Posted by Ara Pacis View Post
    The smaller vessels fit the smaller markets that have smaller airports with shorter runways and aren't close to major hubs.
    That's part of the catch. Unless it's a major hub to major hub flight, all that is left is those non-hub airports and lesser hubs.
    You may get a lot more traffic in a large hub city, but a lot of hubs aren't in cities that are very popular as destinations in themselves.
    Do you think Delta has a lot of traffic between Detroit and Salt Lake that aren't from those feeder routes?
    It's all those little flights that support the big ones. It's not just a niche market with smaller airports.

    For a while, Cleveland was a hub airport. Rarely did I see anything bigger than a 737. Even in my travels to other larger airports, there are usually less than a handful of the wide body planes there.

    From 1968 on, there have been about 8 times as many 737s sold than 747s. Even if you compare that on a per seat basis, it's still more than 2x more popular. Even then, my guess is that a higher percentage of 747s are in cargo use than the 737s.

    The big guys are usually for long international flights where you can rely on a funneling of source to destination.

    ETA:
    Although; none of this really has to do much with commercial suborbital.
    When it comes to that, the niche may still be there depending on cost. And; if it's suborbital, it may even open up a few more markets over land.
    Last edited by NEOWatcher; 2014-Jul-28 at 02:36 PM.

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    Quote Originally Posted by NEOWatcher View Post
    That's part of the catch. Unless it's a major hub to major hub flight, all that is left is those non-hub airports and lesser hubs.
    You may get a lot more traffic in a large hub city, but a lot of hubs aren't in cities that are very popular as destinations in themselves.
    Do you think Delta has a lot of traffic between Detroit and Salt Lake that aren't from those feeder routes?
    It's all those little flights that support the big ones. It's not just a niche market with smaller airports.

    For a while, Cleveland was a hub airport. Rarely did I see anything bigger than a 737. Even in my travels to other larger airports, there are usually less than a handful of the wide body planes there.

    From 1968 on, there have been about 8 times as many 737s sold than 747s. Even if you compare that on a per seat basis, it's still more than 2x more popular. Even then, my guess is that a higher percentage of 747s are in cargo use than the 737s.

    The big guys are usually for long international flights where you can rely on a funneling of source to destination.

    ETA:
    Although; none of this really has to do much with commercial suborbital.
    When it comes to that, the niche may still be there depending on cost. And; if it's suborbital, it may even open up a few more markets over land.
    I thought that was his point, cost. The fuel, efficiency, and cargo/passenger capacity made it too expensive. I think his chart is just another way of showing that.

    The question is whether suborbital can be more efficient, or use fuels that are less costly.

    I think so, but it's a systemic issue. If we reduce airline flights, that might free up kerosene supply. (We might do this with more trains, or dare I say it, a vacuum train network.) Or, if they use purified methane or hydrogen reformed from fracked NG, the fuel costs might drop. Also, if it's suborbital, they automatically reduce their atmospheric drag and its associated costs for part of the flight.
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    Quote Originally Posted by Ara Pacis View Post
    The question is whether suborbital can be more efficient, or use fuels that are less costly.

    If we reduce airline flights, that might free up kerosene supply. (We might do this with more trains, or dare I say it, a vacuum train network.) Or, if they use purified methane or hydrogen reformed from fracked NG, the fuel costs might drop.
    I doubt that would happen anytime within my lifetime. Fuels like that are just too useful on grand scales. Even if we reduce our reliance on them, there will still probably be plenty of applications that that will compete for those fuels.

    Quote Originally Posted by Ara Pacis View Post
    Also, if it's suborbital, they automatically reduce their atmospheric drag and its associated costs for part of the flight.
    But; is that enough to offset the climb or the need for oxidizers at that altitude?

    I just think it's too early to make any kind of prediction.

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    Quote Originally Posted by NEOWatcher View Post
    I doubt that would happen anytime within my lifetime. Fuels like that are just too useful on grand scales. Even if we reduce our reliance on them, there will still probably be plenty of applications that that will compete for those fuels.
    And there are plenty of fuels that compete for those applications.

    But; is that enough to offset the climb or the need for oxidizers at that altitude?
    They won't not need oxidizers for that altitude if they are ballistic at that point. It's a simple calculation to determine whether a specific design has more to gain from oxidizer or from air-breathing engine mass, maybe slightly more complicated to add in drag from it. There's also the option of using electromagnetic catapults for some of the launch Dv.

    I just think it's too early to make any kind of prediction.
    Prediction for what engineers could develop or what politicians will permit to be developed?
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    Quote Originally Posted by Ara Pacis View Post
    They won't not need oxidizers for that altitude if they are ballistic at that point. It's a simple calculation to determine whether a specific design has more to gain from oxidizer or from air-breathing engine mass, maybe slightly more complicated to add in drag from it. There's also the option of using electromagnetic catapults for some of the launch Dv.
    I never said anything about the ratios of between the complexity of the climb vs fuel requirements.
    Certainly, there are plenty of technologies to be able to get us there, but I don't see any as non trivial in either complexity, cost, or relieability.

    Quote Originally Posted by Ara Pacis View Post
    Prediction for what engineers could develop or what politicians will permit to be developed?
    For what a commercial application can support.

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    Watch Virgin Galactic’s VP of Special Projects, explains how the second space age promises to open up a new world of exciting opportunities.

    http://www.parabolicarc.com/2014/07/27/video-5/

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    Quote Originally Posted by NEOWatcher View Post
    For what a commercial application can support.
    With this economy, who knows.
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  18. #48
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    Quote Originally Posted by Ara Pacis View Post
    With this economy, who knows.
    Yep, that's all I'm saying.
    I just have a less optimistic view than you due. I've just seen too many "...of the future" stuff in my lifetime that haven't materialized.

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    Quote Originally Posted by NEOWatcher View Post
    Yep, that's all I'm saying.
    I just have a less optimistic view than you due. I've just seen too many "...of the future" stuff in my lifetime that haven't materialized.
    I'm optimistic that it's possible, not that it's probable. Rocket science isn't that hard, it's just recursive. Convincing people to change is hard.
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  20. #50
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    Sir Richard Branson still hopes to fly by end of this year.

    http://www.parabolicarc.com/2014/08/...ar/#more-53177

    Maria Bartiromo talks to Richard Branson about a number of subjects, including Virgin Galactic.

    Q: You mentioned Virgin Galactic — what is your timing in terms of this program taking off?

    A: I’ll be bitterly disappointed if I’m not into space by the end of the year. The rockets have now tested successfully. We’ve got three more rocket tests and then we should be up, up and away by the end of the year. That should be the start of the program. The space port’s ready. We are now in the last few weeks before finally embarking on the space program.

  21. #51
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    He's said that for the last 6 years.

  22. #52
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    Quote Originally Posted by Glom View Post
    He's said that for the last 6 years.
    6 years ago, he said 2011.

    I started a thread specifically for VG-SS2 a few months back just because updates of the project are scattered across several threads and it's hard to keep track of it.

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    Quote Originally Posted by Ara Pacis View Post
    Honestly, though, a better potential solution for rapid intra-continental transit is a vacuum train.
    I agree with that, though obviously it will require a major initial investment.
    As above, so below

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    For those who can not wait for suborbital flights, but will settle for 0 gravity experience, there is now an option.

    http://www.themalaysianinsider.com/t...onaut-wannabes

    For all the wannabe astronauts and thrill seekers in the world, a zero-gravity commercial airline may be headed to the skies near you, allowing you to channel your inner Chris Hadfield or Sandra Bullock.

    Bookings have opened for the S3 ZeroG, a modified Airbus out of Switzerland that will hit up destinations in North America, Europe, the Middle East and Asia in a worldwide tour.
    I am because we are
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    They may fly the nylon engine in SS2 #1 (VSS Enterprise) then sub in liquid engines for VSS Voyager and later birds.

    These would likely be either their Newton engine (they're trying to get Google to fund development) or the SNC-ORBITEC Liquid Vortex propane/LOX engine that's rumored going into Dream Chaser to replace its hybrids.

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    Quote Originally Posted by selvaarchi View Post
    For those who can not wait for suborbital flights, but will settle for 0 gravity experience, there is now an option.
    You started a thread for this 3 months ago with an article that had a schedule and pointed you where you can book flights.
    Even then, I commented about us having that option for 10 years already.
    This is just a promotional story.

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    Looks like SS2 will be in action soon. They just finished “an in-flight test of #SpaceShipTwo’s ‘plumbing’ – the pressurization system for the rocket motor.” It’s also a dress rehearsal for the next powered flight, which the company promises is “coming soon.”

    http://www.parabolicarc.com/2014/08/...-glide-flight/

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    There is enough potential distance between testing the pressurization system and flying paying passengers to 100km te be careful with words like "soon". Let's keep it at "they're making progress".

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    Quote Originally Posted by Nicolas View Post
    There is enough potential distance between testing the pressurization system and flying paying passengers to 100km te be careful with words like "soon". Let's keep it at "they're making progress".
    When I said soon, I meant testing rather then operation. They have been silent for some time on that front.

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    Actually, if you just want a zero-g experience, a trampoline is a cheap option.
    As above, so below

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