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Space Science

Skylon Spaceplane Design Passes Key Review 136

Posted by Roblimo
from the single-stage-to-orbit-is-our-grail dept.
gbjbaanb writes "A revolutionary UK spaceplane concept has been boosted by the conclusions of an important technical review. Skylon is a design for a spaceplane that uses engines that work as normal jets near the ground and switch to rocket propulsion in the upper atmosphere. The concept means the plane will not have to carry as much fuel and so will not need disposable stages. It is estimated (by its developers) that the Skylon will drop the cost of delivering payloads to orbit from $15,000 per kilo to $1000."
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Skylon Spaceplane Design Passes Key Review

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  • by elrous0 (869638) * on Tuesday May 24, 2011 @09:37AM (#36227178)

    This spaceplane is still in the concept phase. They're not even planning to build it until the 2020's. Right now it's all just fund-raising and hype. All this review says is "Well, it COULD work."

    In fact, this thing has apparently just the latest version of a spaceplane that has been in the development stage since 1982 (no, that's not a mistake--1982), and has already went through quite a bit of government and private money, with little more to show for it than some concept art and promises. Add to this the fact that they're emphasizing cause-du-jour selling points like "the environmentally-friendly green rocket" in their promotional literature, and I'm a little skeptical.

    More power to them if they can build it though. The real first test will come when they're supposed to actually build a test engine this summer. Deliver something to me in the real world that actually works, and you'll get my attention.

    • by Creepy (93888)

      What they're saying in this article is that they've solved the problem with the earlier engine, and this is hardly the first time an earlier technology has been abandoned and then picked up successfully - see scramjet. Speaking of scramjet, that theoretically can reach near orbital velocities without a rocket engine, so I think this is entirely within the realm of possibility (and incidentally, one of the major hurdles with those is cooling).

      The article even says they have focused on the engine and the rest

      • Well, first off, most of this WAS developed by NASA AND DOD. Back in the 50's and 60's, and then again in the 80's. It was found that material science was not good enough. It is likely that NASA will offer up contracts for working with this in the next couple of years. And my guess is that they are MUCH further ahead on this.
        • by damburger (981828)
          REL are planning to sell these (and the know how to operate them) freely, so NASA will presumably be welcome to become a Skylon operator. Alternatively, they could just run two completely separate Apollo-style capsule programs, but that would be daft...
    • by GooberToo (74388) on Tuesday May 24, 2011 @11:16AM (#36228322)

      Certainly nothing wrong with a healthy dose of skepticism but what you're offering as a negative is actually a resounding positive. Basically you're saying, a well researched and investigated design is a really, really bad idea. That's ignorant. You seem to be under the impression that design engineering and review is free. That's ignorant too.

      More power to them if they can build it though. The real first test will come when they're supposed to actually build a test engine this summer. Deliver something to me in the real world that actually works, and you'll get my attention.

      This has been under active research and development for some time now. They are far from alone in understanding current limitations or in their desire to address it by creating a hybrid engine design.

      Again, skepticism is good and all, but contrary to the tone of your post, you've resoundingly confirmed they are working hard and following a good path.

      • by elrous0 (869638) *

        No, I'm saying that a design that has sucked money for 30 years without producing anything more than some concept art is probably just a money sink.

        • by GooberToo (74388) on Tuesday May 24, 2011 @11:42AM (#36228640)

          I honestly don't know much about the specifics of this project, but what you're describing is actually extremely common. Accordingly, you need to prove how what you're describing is so abnormal, to justify such a position.

          Thus far, it sounds like a sparsely funded project which seems to be steadily moving forward on the merits of the design and the technical advancements which are required to justify progression of the project.

          Realistically, sudden advancement of the project knowing full well the engines represent a massive technological hurdle, would flag a money sink. As is, unless you can indicate other reasons, it sounds like its progressing at the speed of dependent technology - which sounds like the exact opposite of a money sink.

          • by Xest (935314)

            It's worth pointing out that this is one of those things that would in fact have progressed faster were it not for the money men (BAE/RR) getting a bit bored of it part way through. Part of the reason it's had such a long gestation period has been political, not because of any inherent flaw with the idea.

            The FP was also somewhat wrong to suggest it's all mere concept sure the vehicle itself is still at that stage, but they've actually developed real working examples of some of the cutting edge brand new fun

        • by sjames (1099)

          All you see is the concept art because the feasibility calculations, materials research, budgetary estimates and so on are fairly dry reading and don't tend to make it into a newspaper blurb or public info website unless you dig down in the links a bit.

          You MIGHT see various research papers if you have a strong interest in the particular subjects, but you might not know what funded the work.

    • by Archibald Buttle (536586) <steve_sims7@@@yahoo...co...uk> on Tuesday May 24, 2011 @12:57PM (#36229630)

      Skylon is effectively a development of the HOTOL spaceplane project that was proposed by Rolls Royce and BAE way back in 1986, and was cancelled by the UK government in 1988 - I'm not sure where this 1982 date you mention fits in.

      From what I understand the funding for this project has, since then, been very minimal, and only comparatively recently have they managed to attract the attention of ESA. From what I've read ESA only got involved because some real tangible hardware has been produced by Reaction Engines.

      That real tangible hardware is in the form of coolers. That's arguably the most difficult part of their engine design, and the part that had doomed the HOTOL project. ESA seems to think that Reaction Engines are making good progress and that nothing about the SABRE engine, on which Skylon relies, is unachievable. So there is some more to this than concept art and promises.

    • Ariane 5, until recently, was the most successful commercial launcher.
      However, the rocket is getting a little long in the tooth and things are hotting up with Space X getting into their stride.

      While TFA states otherwise, Reaction Engines Ltd are most likely aiming for the forthcoming ESA review and investigation into a replacement for Ariane 5. It would be a long shot, both the UK's dismal track record in funding space flight at a national level and France's well proven track record are major hurdles. Bu
      • by damburger (981828)

        They are not aiming for ESA specifically. They are aiming to sell Skylons to anyone who will buy them. Their promotional animations sometimes show rows of Skylons with different tail art, showing their intention that multiple operators will be running their space plane.

        Ariane 5 does not have to worry about competition from SpaceX. Its primarily a French launch system, and the French government isn't afraid to dump money into their high-tech industries. They will simply subsidise it to compete with SpaceX, f

    • by damburger (981828) on Tuesday May 24, 2011 @02:37PM (#36230768)

      This is Skylon, not HOTOL, so no it hasn't been in development since 1982. Different vehicle, different engine (the original one was classified by the UK government).

      The statement 'they are not planning to build it until the 2020's' is flat out false. They are planning to have it operational in 2020. This may be optimistic, but what you said does not accurately reflect their statements.

      Environmentally friendly is not a touchy-feely issue either; if spaceflight is going to go from long-term experiment to routine flight, its emissions need to be taken into account. Concern has already been raised about the effects of releasing particles from hybrid motors at high altitude. Right now it doesn't matter, but IF we are entering an era of mass spaceflight, it will.

      A review isn't the same as the test, no, but I can tell you from first hand experience that ESA engineers are not easily impressed. They will have given REL a proper grilling before coming out and saying that they think this concept is viable.

      Whilst I have no doubt the mostly US-based /. audience will probably not have much respect for ESA, please bear in mind that despite a budget half the size, and a lack of manned capability for political reasons, its cooperates with NASA on engineering matters as an equal these days.

      • by elrous0 (869638) *

        Skylon is a privatized continuation of HOTOL. When the British government defunded HOTOL in the late 80's, the HOTOL designer Alan Bond [wikipedia.org] formed Reaction Engines and continued his work on a private version of the spaceplane, now renamed Skylon.

        And I have plenty of respect for the ESA. But that doesn't have anything to do with whether or not I think this thing is ever going to fly (or live up to the considerable hype).

        • by damburger (981828)
          Did you even read what I said? Skylon is a completely different vehicle, with different engines. You are showing an incredible ignorance of engineering here.
          • by elrous0 (869638) *

            It's completely different because they've been changing it for 30 years. I suspect it will be even more different 20 years from now, when it's still being developed.

    • They're not even planning to build it until the 2020's. Right now it's all just fund-raising and hype

      Pitch: "We're going to deliver cargo to space for the same cost as Falcon 9 Heavy, but with much less capacity and 10 years later!".

      Yeah, so, um, "but it's British"?

  • by Anonymous Coward
    No one's thought of this til now?
  • by Anonymous Coward
    The Skylons were created by man.
    They rebelled.
    They evolved.
    There are many copies.
    And they have a plan.

    Or are just making shit up as they go. It's kind of hard to tell.
    • In the image, it actually looks a lot like I imagine Iain Banks' Culture ships to look. Combine that with the news that robots are developing their own language [bbc.co.uk] to talk to each other, and real life starts to look a little like Excession.

    • by GooberToo (74388)

      Or are just making shit up as they go. It's kind of hard to tell.

      Then you didn't watch the show. Very clearly, they made shit up as they went.

      And BTW, +1 funny!

    • by Mercano (826132)
      They had a plan. Nuke the humans for orbit. After they found out that is in fact NOT a sure-fire plan, they were just winging it.
    • Skylons aren't just Cylons pronounced funny. They're Cylons created by Skynet.

      Seriously, that has to be the most dooms-day-ish, worst-conceived name ever.

  • Huh? (Score:2, Funny)

    by Black Parrot (19622)

    the Skylon will drop the cost of delivering payloads to orbit from $15,000 per kilo to $1000.

    If you weigh your payload in pounds, do you have to pay in Euros?

  • And get funding from the Sy-Fy channel!
  • by toygeek (473120) on Tuesday May 24, 2011 @09:50AM (#36227302) Homepage Journal

    I couldn't help but to read the article with interest and a healthy dose of Moller Skycar Skepticism. The concept art work looks like something out of Popular Science or Popular Mechanics. The "details" of the engine include "Esa's technical staff have witnessed this "secret technology" on the lab bench and can confirm it works." Wow, something that works in the lab. I'm not impressed.

    Furthermore, it promises to cut the launch cost of payload from $15k/kilo to $1k/kilo. I call BS. That's just marketing hype. Cutting it by 20% or 30% would be revolutionary. Cutting it by a few hundred percent is just pipe dreams by people looking for VC capital.

    • by Anonymous Coward

      Cutting it by 20% or 30% would be revolutionary. Cutting it by a few hundred percent is just pipe dreams by people looking for VC capital.

      Especially considering cutting anything by "a few hundred percent" leaves you with a less-than-zero number...

      • they are promising to cut the cost to 7 percent of current
        (1/15=~ 6.66667%) and it would in "marketing math" be a 1500% cut so that i think would be a cut of many hundreds of percent.

    • by Yvanhoe (564877)

      Furthermore, it promises to cut the launch cost of payload from $15k/kilo to $1k/kilo. I call BS.

      So do I, or there is more to this spaceship than the "work as a plane the first kilometers" concept. The 10 or 20 kilometers that you can save by using this kind of design is really a small fraction of the distance to cross. It can make you save a few percents of fuel, which is interesting, but divide the price per 15 ? Quit dreaming. It will be 5% and you will be grateful for it !

      • by elrous0 (869638) *

        Maybe it runs on fairy dust.

      • by 0123456 (636235)

        The 10 or 20 kilometers that you can save by using this kind of design is really a small fraction of the distance to cross. It can make you save a few percents of fuel, which is interesting, but divide the price per 15 ? Quit dreaming. It will be 5% and you will be grateful for it !

        Fuel is a negligible cost for any modern launcher. Skylon's benefit is not reduced fuel use but that it's a fully reusable SSTO, which means you don't need to build a new one for each flight and you don't need to assemble multiple stages before you can take off; you just fill it up and tow it to the runway.

        I still think the development costs are way too high to justify, but the idea seems sound.

        • by jbengt (874751)

          Fuel is a negligible cost for any modern launcher.

          Fuel is a huge cost for a modern launcher - not in the direct cost of buying the fuel, but in the impact on costs of the need to carry the fuel.

          Skylon's benefit is not reduced fuel use . . .

          the benefit is the reduction in fuel weight, which reduces structural weight, both of which reduce propulsion required, which reduces fuel required, and so on.

          • by 0123456 (636235)

            Fuel is a huge cost for a modern launcher - not in the direct cost of buying the fuel, but in the impact on costs of the need to carry the fuel

            Fuel is cheap, fuel tanks are cheap. Generally speaking, reusing the engines a few times will save you far more money than reducing the amount of fuel you require, and increasing the launch rate will dramatically reduce costs even if you have to throw them away every time.

            The spaceflight industry would be celebrating if we'd actually reached the point where fuel was a significant part of their launch costs.

      • by rufty_tufty (888596) on Tuesday May 24, 2011 @10:41AM (#36227890) Homepage

        "The 10 or 20 kilometers that you can save by using this kind of design is really a small fraction of the distance to cross"
        Distance isn't the problem for getting to orbit, velocity is.
        By running as a plane you don't have to burn thrust to support the weight of the craft and fuel, you can accelerate up to Mach 5 (as they plan to) using the atmosphere to support you. That's a truly massive gain, for reference the first stage of the Saturn V got you up to just over mach 6. Now I don't know what percentage of their fuel they burn to get to that speed but to not have to support that weight with thrust for such a long period is a huge gain. Remembering as well that during this phase they are air breathing too which is another massive gain.
        Fine you say mach 5 is 1/5th of the way to mach 25. so at best they've saved 20%, better but still not amazing.
        Not quite because you get a weird multiplier effect, because (when you are at say mach 5) you have accelerated the fuel you carry to mach 5 so it effectively has more energy that when it was at rest on the ground. If you run the numbers for a multistage rocker you'll find that they can't reach orbit unless you take this effect into account. Trying to find a good source for this, will hopefully reply to this later with said source...

        • by Yvanhoe (564877)
          Interesting, I never considered the part about speed. Indeed, that is to be taken into account.
        • Nope i appear to be wrong about that last point or at least can't find any sources.
          Sorry.

          • Re: (Score:2, Informative)

            by Anonymous Coward

            You were not entirely wrong and your perfectly right that this is an energy problem.

            The fuel would not have "more energy" in the way that it would burn hotter or give more thrust, but I think the point is that it now is flying at mach 5 and does not have to be accelerated from zero.

            This is the real reason multistage rockets are so frickin huge, you do not only have to accelerate the payload into orbit but also all the fuel not yet burnt and the oxidizer also. And I think this is your "multiplier effect".

            The

          • by cruachan (113813)

            Well, there's another point which you might be confusing things with - you're accelerating to Mach 5 though a lot of dense atmosphere, but once you're up at the heights this will be at Mach 5 then there's far less atmospheric resistance so the amount of energy required to accelerate further will be much less. I don't see how increasing the speed of fuel in itself can increase the amount of energy it contains (seems nonsensical to me) but you'd certainly get a lot more out of the fuel you do have.

            By way of

        • by peragrin (659227)

          The Big savings comes from not having to rebuild the engines after every use. Sure the shells of the SSRB's are reusable but refilling them is really expensive and rebuilding new after so many launches also adds considerable expense. It is the propulsion method that makes getting into space expensive. You have to carry lots of it and then launch that too. Reusing engines is difficult(the main part of shuttle down time is rebuilding the main engines every time)

          Anything that can do a fairly practical SSTO

          • by Shotgun (30919)

            they are burning fuel and OXIDIZER. It's higher for diesel, but for gasoline you need 12 to 17 lbs of air for every pound of fuel. For each 1000 lbs of fuel, this engine would enabled you to leave 14,000 lbs of oxidizer in the tank on the ground. The tank to hold that oxidizer can be left on the ground. The incredible feats of engineering that are the high speed pumps can be left on the ground. The extra support structure within the spaceplane itself (landing gear, wing spar structure, fuselage structu

        • by w0mprat (1317953)
          The "weird multiplier" effect better called and exponential problem.

          For a traditional rocket the fuel mass required increases with the square of payload. Because you have to lift the extra fuel too, and the extra vehicle mass to contain it. This is why stages are used because can ditch a lot of mass and aero drag part way through a flight. (Single stage to orbit rockets have repeatedly been shown to be too heavy to fly).

          Air-breathing jets have a massive increase in specific impulse and the lift to dra
          • Only thing is you have one problem. The "massively higher ISP" for jet engines (a stupid metric for a air breather) is because it collect's the Oxygen as it goes along with a bunch of Nitrogen. When you are traveling fast this cost a lot of energy or drag. This is the breakthrough they are hoping to get, but it would be a very big breakthrough, one that many aerospace engineers believe is fundamentally impossible. Also you have the other problem the the thrust to weight ratio of jet engines is awful compare
      • As somebody already pointed, you are negleting the speed. Other thing that you are negleting is that the fuel need increases exponentialy with the energy needs, and the energy needs are comprised of speed diferential, height diferential (in a gravity field), and aerodynamic loses. Those 10 to 20 kilometers are where neraly all the aerodynamic loses are, and don't forget, it is an exponential increase.

      • by mbkennel (97636)

        "The 10 or 20 kilometers that you can save by using this kind of design is really a small fraction of the distance to cross. It can make you save a few percents of fuel"

        It can save you a huge percents of heavy oxidizer. You don't count progress by distance but by velocity and how much of the draggy atmosphere you've escaped. And that you don't need complex staging. And the overall design and flight trajectory minimizes structural risks and loads.

        I read the ESA review. As an engineering review for an aero

    • It's a BBC technology article. You weren't expecting anything else, were you?

    • by amliebsch (724858)

      Falcon 9 has it down to about $4700 already, Falcon Heavy will likely have it close to $1k.

    • by Plekto (1018050)

      Well, It's hugely expensive to run, but if all you need is fuel and some ablative undercoating repairs every few flights(assuming a liquid-fueled rocket or scramjet), it's perhaps at the extreme outside, a few million per launch as opposed to $54 million (Space X Falcon 1).

      Remember, while most large rockets are in theory, reusable, it's really a matter of "recover" the hull and spend a huge amount of money rebuilding the thing to be re-used again.(Space Shuttle rockets for example)

  • HOTOL, it just won't go away.

  • http://www.spacex.com/press.php?page=20110405 [spacex.com]

    Falcon 9 heavy will be $1k per pound in 2013 ( ok, $2.2k per kg )

    • by hattig (47930)

      One of the aims of HOTOL was human payload, for ~2 hour low-orbit flights to Australia. I presume that this aim would still be there for Skylon. Not to mention that it presumably can also use existing airport infrastructure, which is a major advantage too. Of course, at $1000 a kilo we're looking at $100,000 per person per flight, but possibly the low-orbit flights don't need as much fuel as satellite launching flights as they don't need to achieve such a high orbit.

      Anyway, they're targeting half the cost o

      • by 0123456 (636235)

        Of course, at $1000 a kilo we're looking at $100,000 per person per flight, but possibly the low-orbit flights don't need as much fuel as satellite launching flights as they don't need to achieve such a high orbit.

        A suborbital flight from London to Sydney requires going about 95% of the way to orbit, so the cost would be pretty much the same. If there was a viable market for suborbital transport we'd already have them, but the laws of physics prevent you from using it as a way to start small and build up to orbital flights over time... there's a big gap between suborbital tourism/science and orbital flight where costs increase significantly but the market doesn't.

      • Of course, at $1000 a kilo we're looking at $100,000 per person per flight,

        That's $320,000, American.

    • by 0123456 (636235)

      Falcon 9 heavy will be $1k per pound in 2013 ( ok, $2.2k per kg )

      And that's before they start reusing the first stages.

      Skylon's numbers used to look good, but if SpaceX can meet their claims then an SSTO needs to get down to more like $100 a pound to jusfify the development cost. Or find a big market for small payloads where SpaceX can't match the $1000 per kilo cost.

      • by hazydave (96747)

        Yup... Elon Musk is on record as claiming that $1.1K per Kg is achievable in the foreseeable future.... presumably, whatever's the next cost reduction after Falcon 5 (the Falcon X platform, perhaps). SpaceX is already scaring the Chinese on costs, so they could definitely have an effect here.

        As cool as the tech is here, it's clear that private companies are and will have a big impact. Especially with multi-government run agencies like the ESA, they're taking forever on concepts, which makes it unclear that,

        • I call the major difference between government and private ventures such as this the "pick a lane" problem. In Private, they typically pick a lane early on and stick with it until it fails. In government sponsored projects, they use multiple pathways approach, and fund them beyond their failure. This is the primary reason why Private Enterprise succeeds where government sponsored approach fails.

          And if you look at SpaceX's approach, they picked a design early on, and have stuck with it. They are much closer

          • s/SpaceX/Virgin

            SpaceX's workhorse is already flying. Virgin might be by the end of the year (realistically next year, with all the paperwork).

          • by stevelinton (4044)

            Of course most private enterprise attempts fail. Seen as a whole, the private sector does more or less what the government does -- try out lots of approaches and fund each until it's die-hard advocates finally can't scare up any more money from anywhere. It's advantage, if it has one is that it is a bit harder to fiddle the financers into flogging a dead horse.

            • by damburger (981828)
              The dot.com bubble would disagree with that assessment. So would the sub-prime mortgage crisis.
      • by damburger (981828)
        What you are failing to take into account is the difference in cultures. Massive overstatement of ones capabilities does not go over well in the UK like it does in America. Notice, that if you actually dig through the REL site, their absolute minimum for future costs (which is equivalent to the number Musk is shouting from the rooftops) is less than $300/kg. They just are too careful to promise that publicly. So you are comparing a hollow boast to a cautious prediction.
    • by damburger (981828)
      Unlike SpaceX, REL are including amortised R&D costs. SpaceX expects to have paid for developing their rocket when they hit $1k/kg, so its not a valid comparison. Especially when REL has to do a lot more R&D, and doesn't have the help SpaceX had.
  • Though it certainly takes a lot of fuel and oxidizer to get a rocket through the thick lower atmosphere up to say 90,000 feet, it still takes a tremendous amount of energy to get from 90,000 feet and 3000-4000 mph to escape velocity of 17,500 mph. And that last bit would have to use oxidizer brought with since the air is quite thin at the edge of space.

    From what I learned in physics class, the cheapest way to get through the thick atmosphere is to go straight up. Taking the airplane route consumes a lot m

    • by pe1rxq (141710)

      They don't need escape velocity... they are aiming for low earth orbit.
      Besides using the O2 as oxidizer they also have another benefit: the angular velocity you gain at low altitudes is cheaper (in terms of energy) than getting it at high altitude. Even for rockets they have to make a tradeoff between going up to avoid air and going sideways early on to actually reach orbit.

    • by GooberToo (74388) on Tuesday May 24, 2011 @11:31AM (#36228488)

      From what I learned in physics class, the cheapest way to get through the thick atmosphere is to go straight up.

      That's only true for conventional rockets. The longer you remain in the lower atmosphere, you more rocket fuel you must carry. The more fuel you must carry, the larger the rocket you require. The larger the rocket you require, the larger the engine. The larger the engine, the more fuel you must carry. This is a nasty spiral simply because you obtain 100% of your lift from thrust.

      With the skylon design, you are obtain a lot of your lift - from lift. Its only after you're passed through the lower atmosphere, where you don't get much lift and where you now need an oxydizer for your fuel, that you need to start a rocket engine. Thusly, they've side step a massive problem with traditional rockets.

      Furthermore, its the first stage on traditional rockets which requires the most fuel to obtain orbital velocities. By using a plane's features, a massive weight burden (and associated size) is removed from the design.

      • This is the same approach as Scaled Composite's White Knight approach. And they are well ahead of anything coming out of Europe. They are already testing prototypes while European version hasn't even started building a prototype.

      • by Rexdude (747457)

        This raises the question, why wasn't this thought of before when the whole space race was on? I'd like to know...were there any technological limitations back in the day? After all, this amounts to a plane with rocket engines strapped on for use at higher altitudes..kind of like we've been seeing in popular scifi for decades.

        • by GooberToo (74388)

          This raises the question, why wasn't this thought of before when the whole space race was on?

          It was. The technical limitation is very well know. Most of the comments to my post seem to be under the impression they are somehow correcting me, when in fact they are not. Not even close. They are simply adding more detail, much of which is eluded to and understood in my original post, if you know anything of the subject.

          This problem is the primary reason launch sites exist where they do (maximum velocity while minimizing time in lower atomosphere). This problem is why rockets are always filled when vert

    • Though it certainly takes a lot of fuel and oxidizer to get a rocket through the thick lower atmosphere up to say 90,000 feet, it still takes a tremendous amount of energy to get from 90,000 feet and 3000-4000 mph to escape velocity of 17,500 mph. And that last bit would have to use oxidizer brought with since the air is quite thin at the edge of space.

      A couple of things:

      1) Escape velocity (more properly, escape speed) isn't 17,500 mph.

      2) Escape velocity (more properly, escape speed) isn't relevant to r

    • by damburger (981828)

      Right, because the ESA engineers who have poured over the REL numbers and seen their technology demonstrated in the lab are just fucking guessing, right?

      The altitude gained by the vehicle during the airbreathing phase is almost irrelevant. The speed is the issue; it gets to Mach 5 (i.e. 1650m/s) Thats about 20% of what you need to get to orbit. It isn't that much, but its enough to take SSTO from a marginal possibility (See Venture Star) to seriously doable.

      What you seem also to have missed is how much heav

  • I think well get it cheap enough that drug lords from around the world will be able to deliver directly to homes by space plane. It sure beats subs/ultra-lites, and good old ground transport.

    At $1000/kilo, isn't that acceptable transport fee for some drugs? (Assuming 100% success) These people are now constructing submarines!!

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