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Thread: british rocketplane by 2020?

  1. #151
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    Quote Originally Posted by Garrison View Post
    Sure it might fall short but no one will know unless they try.
    We already have.

  2. #152
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    Quote Originally Posted by Craigboy View Post
    We already have.
    Really? When? And please don't mention the shuttle, we are discussing a HOTOL SSTO here, not a partially reusable 1.5 stage vertical launcher.

  3. #153
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    Quote Originally Posted by Garrison View Post
    Again you seem to be missing some important points about Skylon. REL and its backers would be looking to make their money back selling vehicles, not running flights themselves. Spread the costs across a number of vehicles capable of around 200 flights each over a number of years and the numbers add up. Sure it might fall short but no one will know unless they try.
    It all depends how much it costs to make one. I'm going to guess $1B. So if REL sells them at $5B each, they need to sell 4 of them to recoup costs and produce profit. (Actually more income would be needed because of the capital cost, but I am too lazy to account for that).

    The operator pays $5B for a vehicle, it will want to recoup that within no more than 3 years (I guess vehicle lifetime to be 5 years). If the craft can do 100 flights per year, that means 300 flights. So the vehicle amortization cost is $16.6M per flight. On the other hand, if the craft can do 10 flights per year then the vehicle amortization cost is $166M per flight.

    If the payload is 10 tons and flight cost is $40M, then operator has to charge $56.6M per flight ($5'660/kg) at 100 flights per year. At 10 flights per year, it has to charge $206M per flight ($20'600/kg). The latter is more expensive than an ELV ($10'000/kg). In order to be cheaper than that, the each vehicle must do at least 28 flights per year.

    However. 4 vehicles each doing 100 flights per year means 400 flight per year, each with 10 t payload, or 4'000 tons of stuff delivered to LEO per year (at $5.6K/kg). Here's the problem: to be cheap, Skylon must have a high flight rate. But even if it manages to do so technically, there is not enough demand for cargo to LEO.

    If you want to ferry people, then you have $56.6M per 30 seats or $1.8M per seat. That means 3'000 passengers per year per vehicle or 12'000 passengers per year in total. Can you find 12'000 people willing to pay $1.8M for a 0g vacation each year?

  4. #154
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    Quote Originally Posted by kamaz View Post
    It all depends how much it costs to make one. I'm going to guess $1B. So if REL sells them at $5B each, they need to sell 4 of them to recoup costs and produce profit. (Actually more income would be needed because of the capital cost, but I am too lazy to account for that).

    The operator pays $5B for a vehicle, it will want to recoup that within no more than 3 years (I guess vehicle lifetime to be 5 years). If the craft can do 100 flights per year, that means 300 flights. So the vehicle amortization cost is $16.6M per flight. On the other hand, if the craft can do 10 flights per year then the vehicle amortization cost is $166M per flight.

    If the payload is 10 tons and flight cost is $40M, then operator has to charge $56.6M per flight ($5'660/kg) at 100 flights per year. At 10 flights per year, it has to charge $206M per flight ($20'600/kg). The latter is more expensive than an ELV ($10'000/kg). In order to be cheaper than that, the each vehicle must do at least 28 flights per year.

    However. 4 vehicles each doing 100 flights per year means 400 flight per year, each with 10 t payload, or 4'000 tons of stuff delivered to LEO per year (at $5.6K/kg). Here's the problem: to be cheap, Skylon must have a high flight rate. But even if it manages to do so technically, there is not enough demand for cargo to LEO.

    If you want to ferry people, then you have $56.6M per 30 seats or $1.8M per seat. That means 3'000 passengers per year per vehicle or 12'000 passengers per year in total. Can you find 12'000 people willing to pay $1.8M for a 0g vacation each year?
    this is another of your strawmen.
    vehicles don't have a use by date. Rel's figure of 40 mill was based on a 0 growth scenario where there were no passenger capability added to the mix.
    also. if you had actually read the paper on the SPLM on Rel's site you would have known that 30 passengers was a long range goal. the initial SPLM would have ejector seats and only 5 people. it would also carry 3 000kg of supplies. it's baseline design is for supporting the ISS or a biggelow or even a chinese station.

    skylon offers not a single killer advantage, but rather a long list of minor ones and a couple of major ones that generally counts towards some of the more special scenarios.
    turnaround times are only truly relevant if something like project troy or solar power satelites are going to be built. in this scenario each flight cost drops to around 2 mill. that is far lower than eelv's can ever theoretically achieve.
    skylon may offer transport of up to 30 passengers. only truly relevant under a space travel becomes routine scenario. (orbital tourism and large space stations.)
    Skylon is the only vehicle that offers on orbit deployment checkout and return on fault capability. Very valuable in the current satellite market. and is going to be an early deal closer for buying skylon flights rather than eelv's.
    Skylon offers shuttle like on orbit operations. like space station assembly support. it can do this by having one skylon meet another skylon on orbit to assemble the first 2 components between them then have a third flight deliver a robotic crane that will then continue to assemble the station as well as unloading the remainder of the needed skylon flights during the assembly process. (assumed ISS like assembly sequence with a human presence since the fourth flight and onwards)

  5. #155
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    Quote Originally Posted by Antice View Post
    this is another of your strawmen.
    vehicles don't have a use by date. Rel's figure of 40 mill was based on a 0 growth scenario where there were no passenger capability added to the mix.
    also. if you had actually read the paper on the SPLM on Rel's site you would have known that 30 passengers was a long range goal. the initial SPLM would have ejector seats and only 5 people. it would also carry 3 000kg of supplies. it's baseline design is for supporting the ISS or a biggelow or even a chinese station.

    skylon offers not a single killer advantage, but rather a long list of minor ones and a couple of major ones that generally counts towards some of the more special scenarios.
    turnaround times are only truly relevant if something like project troy or solar power satelites are going to be built. in this scenario each flight cost drops to around 2 mill. that is far lower than eelv's can ever theoretically achieve.
    skylon may offer transport of up to 30 passengers. only truly relevant under a space travel becomes routine scenario. (orbital tourism and large space stations.)
    Skylon is the only vehicle that offers on orbit deployment checkout and return on fault capability. Very valuable in the current satellite market. and is going to be an early deal closer for buying skylon flights rather than eelv's.
    Skylon offers shuttle like on orbit operations. like space station assembly support. it can do this by having one skylon meet another skylon on orbit to assemble the first 2 components between them then have a third flight deliver a robotic crane that will then continue to assemble the station as well as unloading the remainder of the needed skylon flights during the assembly process. (assumed ISS like assembly sequence with a human presence since the fourth flight and onwards)
    The term strawman is being used incorrectly. Skylon is unmanned (at least without a crew pod in the bay). The reason why he was talking about crew transportation was because Damburger and Garrison were going on about it.

    The ISS has Progress, ATV, HTV and will soon have Cygnus and Dragon. China has the ingeniously developed Shenzhou for the Mir-class three man spacestation. Bigelow plans to launch in 2015 (or at least that's the current plan) but before he does he's going to make sure he has two providers. On the spacestation side of things there's no need that Skylon would fill.

    Skylon will never fly for 2 million. As far as I know returning a satelite from orbit isn't really being demanded, in fact I believe the only Space Shuttle mission they ever did it was STS-51-A. The payload is kind of small for space station assembly.

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    taking arguments out of context IS the definition of a strawman. using the 40 mill per flight figure from a 0 growth no passenger flights scenario and using it to show that skylon is too expensive as a crew ferry is on par with saying that carrying passengers is the only use for skylon. it is not. it's a possible mission rate growth item. if there ever is a need for 30 passengers at a time then the flight rate would necessarily have risen to the point where the price has dropped to at least 10 mill per launch or lower. just building a destination for 30 people at a time will have such an effect. As for station building capability. do not conflate current domestic capability with future desired capability. It would cost the chinese on par with the development costs of the entire skylon programme to match it's capabilities. the chinese are smart enough to realize that just buying a vehicle and operating that one is cheaper and faster than designing their own. the Chinese are just one such potential buyer. there are others who also wants their own space programs on the cheap.
    The market for skylon is there. once the shuttle dies then skylon is the only thing matching it's capabilities. except it's going to be much cheaper/safer to run thanks to being uncrewed unless crew is part of the cargo. there is according to satellite owners a desire for a having return to earth capability on launchers. primary reason is to return to earth any satellite that does not check out on deployment. this is a capability that they are not allowed to buy from the shuttle due to safety related decisions. Risking the lives of crew for launching satellites was a bad idea. altho i wont fault the shuttle designers on that one. they didn't have the computer technology we have now and could hardly avoid needing a crew from something as complex as the STS.

    Return to earth capability is valuable. the extra launch cost is more than offset by the reduced risk of loosing a multi billion dollar investment like a major telecom satellite.


    as a finishing paragrap i am going to compare SpaceX official launch cost figures with those claimed by REL

    Falcon 9. single cargo cost fetched from their website is 54 to 59 mill per flight for launches in the 2010 to 2013 timeframe. I assume estimated inflation is used in the high number and current price in the low number. (makes me wonder where people get those lower launch cost numbers often thrown around when SpaceX is used in comparisons??)
    REL's 40 mill is a bit old. inflation adjusted that amounts to 44 mill or so today. (numbers on their site are from 2005)

    Skylon is projected to put more cargo for less cost into space than SpaceX is currently doing. Skylon is most definitely competitive with current best case prising on launches. even when assuming 0 growth in the launch market. assuming a modest growth causes the picture to just go more and more in favour of skylon compared to the alternatives. economy of scale benefits RLV's more than it benefits ELV's

  7. #157
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    Interesting discussion, but this Skylon is still a bunch of pretty ones and zeroes in a computer. Arguing relative costs for a device that does not exist is like two fishermen arguing who will catch the biggest fish, when only one is holding a fishing rod.

  8. #158
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    Quote Originally Posted by mike alexander View Post
    Interesting discussion, but this Skylon is still a bunch of pretty ones and zeroes in a computer. Arguing relative costs for a device that does not exist is like two fishermen arguing who will catch the biggest fish, when only one is holding a fishing rod.
    Skylon does not yet exist, but the nice thing about engineering is that you can predict the performance of something before you build it, and thus determine if its worth building. People in the UK government and ESA who've been shown the evidence so far have come to the conclusion the answer is 'yes' provided the one piece of unproven technology - the precooler - is viable. Everything else is just a LOX/LH2 rocket, a very well understood technology.

    I do accept that, to be really game changing, it would have to launch at a significantly higher rate that current demand for payloads supports. I'm skeptical that commercial space ventures will do this - but hopefully there will be political will for a Mars mission or something on similar scale by 2020.

  9. #159
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    Quote Originally Posted by Damburger View Post
    Skylon does not yet exist, but the nice thing about engineering is that you can predict the performance of something before you build it, and thus determine if its worth building. People in the UK government and ESA who've been shown the evidence so far have come to the conclusion the answer is 'yes' provided the one piece of unproven technology - the precooler - is viable. Everything else is just a LOX/LH2 rocket, a very well understood technology.

    I do accept that, to be really game changing, it would have to launch at a significantly higher rate that current demand for payloads supports. I'm skeptical that commercial space ventures will do this - but hopefully there will be political will for a Mars mission or something on similar scale by 2020.
    yes. no matter what launch system you prefer it would take a radical increase in launch rates to bring costs down significantly. The good thing about the skylon concept is that it can indeed bring costs down quite a lot at current launch rates instead of relying on launch rates to go up first.

    One of the main reasons is that REL's business model deviates from the norm in the launch industry and is more like an aircraft manufacturers. Skylon's will be sold to any and all interested parties that has the money to pay for it. this is the business model of both Airbus and Boeing. if you have the money you can buy a 747 or an A380. they don't come cheap and unless you know what the heck you are doing you are probably going to go broke, but that does not affect either aircraft provider. they made their money the moment you paid for the vehicle. the same economic risk reduction can be done on the launch facilities. by not having the launch vehicle owner build and run these facilities, but instead have a separate economic entity running the spaceport.
    rent levels and usage fees will have to be set based on expected usage levels and is therefore shared among multiple providers and indeed, to a certain degree by those delivering other services to the vehicle owners, but also in a secondary manner by potential passengers, spectators and whomever else would want proximity to the launch business. it's not hard to imagine a combined airport/spaceport run more or less like any other modern day commercial airport.
    the Airliners don't pay for the entire airport. a lot of the income the airport relies on is rent from the various providers of food/beverages. tax free shops and assorted companies providing the myriad of services a full blown airline needs in order to function. like catering, security, workshops, fuel, etc. It's a bit mind blowing actually to be faced with just how many businesses that are either directly or indirectly living off of revenue streams that originate from a single transport industry like airline companies. and they are all paying rent to the airport.

    Standard launch operators don't operate like this. They have just as complex a supply chain as airliners, even more so I suspect, but none of the money that goes into third party pockets helps pay for any of the facilities used. this is because ONLY the launch provider uses the launch facilities. neither are there much if any secondary businesses gathering extra revenue from spectators and travellers alike contributing anything to the bottom line for the launch provider. This means that 100% of the facility cost is internalized. and it has to be internalized regardless of wither you launch 1 rocket a year or 100 rockets a year.

  10. #160
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    Quote Originally Posted by Antice View Post
    this is another of your strawmen.
    vehicles don't have a use by date.
    But business plans do.

    The point is not if the flight costs $40M or $2M. The point is that REL will have a sunk R&D cost of $15B which it will have to recoup. It doesn't also matter if REL will fly it themselves, or the operator will. Either way, the initial R&D spending appears in the operations budget as vehicle amortization. And this is not real estate investment which can be amortized over 50 years. The amortization period will likely be about 5 years, maybe 10 if they can find a gratuitous creditor.

    So you have to amortize $15B over 5 years, which is $3B per year. At n flights per year (all vehicles combined), the amortization cost per flight is $3B/n. The amortization cost is pased on the customer atop of actual operation costs. So:

    - at 1 flight per year, the amortization cost is $3B per flight or $300K/kg of payload;
    - at 10 flights per year, the amortization cost is $300M per flight or $30K/kg of payload;
    - at 100 flights per year, the amortization cost is $30M per flight or $3K/kg of payload;
    - at 1000 flights per year, the amortization cost is $3M per flight or $0.3K/kg of payload;

    This is on top of actual flight costs (fuel, maintenance, etc.). That means, that even if vehicle was free to operate, it would have to perform at least 30 flights per year to be competitive with EELV, as the amortization cost in this case is $10K/kg of payload. Getting down to $5K/kg of payload requires 60 flights per year.

    And here is the problem. 60 flights per year, with 10'000kg each means 600'000kg of delivery to LEO per year. This is equivalent to 30 EELV launches per year. And there is currently no customer in the world which uses, or envisions, 30 EELV launches per year.

    In other words, there is not enough demand for LEO transport which would require Skylon flight rate at which the operation could reach a financial breakeven.

    Since in reality the vehicle is NOT free to operate, minimum flight rate will likely have to be at least twice that, over 100 flights per year.

  11. #161
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    Quote Originally Posted by kamaz View Post
    But business plans do.

    The point is not if the flight costs $40M or $2M. The point is that REL will have a sunk R&D cost of $15B which it will have to recoup. It doesn't also matter if REL will fly it themselves, or the operator will. Either way, the initial R&D spending appears in the operations budget as vehicle amortization. And this is not real estate investment which can be amortized over 50 years. The amortization period will likely be about 5 years, maybe 10 if they can find a gratuitous creditor.

    So you have to amortize $15B over 5 years, which is $3B per year. At n flights per year (all vehicles combined), the amortization cost per flight is $3B/n. The amortization cost is pased on the customer atop of actual operation costs. So:

    - at 1 flight per year, the amortization cost is $3B per flight or $300K/kg of payload;
    - at 10 flights per year, the amortization cost is $300M per flight or $30K/kg of payload;
    - at 100 flights per year, the amortization cost is $30M per flight or $3K/kg of payload;
    - at 1000 flights per year, the amortization cost is $3M per flight or $0.3K/kg of payload;

    This is on top of actual flight costs (fuel, maintenance, etc.). That means, that even if vehicle was free to operate, it would have to perform at least 30 flights per year to be competitive with EELV, as the amortization cost in this case is $10K/kg of payload. Getting down to $5K/kg of payload requires 60 flights per year.

    And here is the problem. 60 flights per year, with 10'000kg each means 600'000kg of delivery to LEO per year. This is equivalent to 30 EELV launches per year. And there is currently no customer in the world which uses, or envisions, 30 EELV launches per year.

    In other words, there is not enough demand for LEO transport which would require Skylon flight rate at which the operation could reach a financial breakeven.

    Since in reality the vehicle is NOT free to operate, minimum flight rate will likely have to be at least twice that, over 100 flights per year.

    Hmmm... It is hard to say what the depreciation period for such a craft would be, as there is no real comparison with current ventures. But I would think the maximum safe and useful time would have to be calculated based on the expected turnaround, but it may be possible that investors will compare these space planes to aircraft and so chose a depreciation time similar to these, something like 10 to 15 years perhaps. That does not mean that the space frame is scrapped after this, though, a company would probably calculate with getting some years operation after this time.

    It may be possible that some risk schedule could be used, so that the newer craft is used for the more valuable things, the older for less valuable cargo, this would minimize the loss should the craft break up, but also let you get the the full life out of the craft. Of course, the personnel module is designed for safety, and is supposed to be able to survive even the disintegration of the frame during flight, but it is probably best not to fly people on the oldest craft as it would probably tend to make the public skeptical of the safety of your service should something happen.

    The transport of the less valuable cargo would probably be offered at a lower rate, too, as it seems unlikely that someone would ship 10 tonnes of structural components for space construction at the same price as, for instance, the latest state of the art space telescope that has taken years and huge amounts of money to develop, but they may accept a small increase in risk.

  12. #162
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    Quote Originally Posted by TrAI View Post
    Hmmm... It is hard to say what the depreciation period for such a craft would be, as there is no real comparison with current ventures.
    If REL wants to sell craft(s) to the operator, it must price it in a way which includes previous R&D costs. However, since such craft has not flown before, the operator may have a problem finding a lender willing to finance craft lease over, say, 20 years. In my opinion, it is unlikely that the lender would risk more than 3-5 years lease. In such case, the craft must be aggressively amortized over the lease period, which requires large income, which in turn requires a high flight rate. And high flight rate is questionable, because demand for such services is still limited.

    So the economics here is actually driven by the problem of getting capital, not the durability and operating costs of the spacecraft. Even if the spacecraft could work 20 years without problems, it would still have to be fully amortized over the first 5 years.

    I don't want to get into politics, but this is one of these situations, when you really want the government to step in and help start the venture by guaranteeing loans or something like that.

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    Quote Originally Posted by Antice View Post
    using the 40 mill per flight figure from a 0 growth no passenger flights scenario and using it to show that skylon is too expensive as a crew ferry is on par with saying that carrying passengers is the only use for skylon.
    You are really misreading my posts.

    Quote Originally Posted by Antice View Post
    As for station building capability. do not conflate current domestic capability with future desired capability.
    But in the near future no destination exists.

    Quote Originally Posted by Antice View Post
    It would cost the chinese on par with the development costs of the entire skylon programme to match it's capabilities. the chinese are smart enough to realize that just buying a vehicle and operating that one is cheaper and faster than designing their own. the Chinese are just one such potential buyer. there are others who also wants their own space programs on the cheap.
    From a capability standpoint the only thing that makes it different is return from orbit. The Chinese already have a cargo vehicle. How much would a "Sklyon" cost and who are these alleged customers?

    Quote Originally Posted by Antice View Post
    once the shuttle dies then skylon is the only thing matching it's capabilities.
    Skylon can carry 12,000 kg less than the Shuttle, so it cannot match its "capabilities".

    Quote Originally Posted by Antice View Post
    there is according to satellite owners a desire for a having return to earth capability on launchers.
    You really need to cite this.

    Quote Originally Posted by Antice View Post
    this is a capability that they are not allowed to buy from the shuttle due to safety related decisions.
    But they did do it (on STS-51-A). Maybe you mean after the Challenger incident?

    Quote Originally Posted by Antice View Post
    Risking the lives of crew for launching satellites was a bad idea. altho i wont fault the shuttle designers on that one. they didn't have the computer technology we have now and could hardly avoid needing a crew from something as complex as the STS.
    I don't know to respond to this.

    Quote Originally Posted by Antice View Post
    Skylon is projected to put more cargo for less cost into space than SpaceX is currently doing. Skylon is most definitely competitive with current best case prising on launches. even when assuming 0 growth in the launch market. assuming a modest growth causes the picture to just go more and more in favour of skylon compared to the alternatives. economy of scale benefits RLV's more than it benefits ELV's
    And the Falcon 9 was projected to put it into orbit for even less.
    Last edited by Craigboy; 2011-Apr-20 at 08:42 PM.

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    @ craigboy. the nested quotes don't work so quoting dont work all that well for responding.
    The shuttle got effectively banned from being used as a satellite launcher post challenger.
    It was one of those things that is pretty obvious in retrospect. but may not really have been so at the time.

    as for matching capabilities. those are more than just the up-mass. the shuttle is pretty much overpowered in that regard. the capabilities i am talking about is among others the ability for supporting the construction of space stations and return to earth on deployment failure of satellites. shuttle is the only vehicle in terran history that has had this capability. it was only used once, but that was not from lack of a market. but a choice made with safety considerations in mind.

    How much would a skylon cost? I have no idea. what i do know is what you find on REL's website and a few tidbits they have said in public here and there. We can only know what they claim. altho i do assume that their investors are better informed than we are. it was the same with spaceX before they proved themselves. the viper test this summer is a similar delivery of proof. just like SpaceX did when they publicized engine test etc.

    then onto this: misreading your post. did or did you not use the most pessimistic no growth assumption number for your passenger costs? if you did then no. i did not misread you. those numbers are based on current launch market rates. there are no destinations for 30 passengers. the only possible use would be ISS or ISS replacement resupply for the SPLM.only when space tourism and alternate destinations is taken into account does the SPLM come into being as a potentially profit earning capability. there wont be enough flights to ISS alone to really justify the SPLM. government money would have to close the gap. In fact i do not think we have enough data to even guess at per seat costs yet.

    Before the chinese can realize their goals of going anywhere except LEO they have to either replicate former US HLV capability. OR learn to assemble big stuff in space. both options are costly and the US ain't selling last i heard. buying off the shelf capability like the skylon can easily shave a lot of cost even for them. it's up to those in charge of the chinese space program to decide. China is not the only nation with a space program however. others are following suit. The later into the game they join into the race the more benefit they gain from buying a vehicle rather than developing their own.

    @Kamaz:
    you are using amortization wrong in this case. R&D is an intangible resource and is amortized differently than tangible assets. that is it is divided between all the vehicles that they expect to build. and is time independent. this is one of those things that wikipedia actually got right. in practice this means that operators are freed from any cost risks related to lack of sales on REL's part.
    I think your launch market analysis is suspect. 2010 saw 74 launches. granted quite a few of them were pretty small payloads. but even if all of them could double up in the payload bay you get more than 30 ELV's worth. I think it is a safe bet to expect at least a modest growth into the future even without a serious drop in launch costs. we are getting more and more dependent on our birds in the sky. it's impossible to predict exactly how future markets will look. it all boils down to speculation at that point. and that is what investing in skylon boils down to right now. speculation on guesses about the future.

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    Quote Originally Posted by Antice View Post
    those are more than just the up-mass. the shuttle is pretty much overpowered in that regard.
    It depends on what it needs to carry, for station assembly flights I believe it used all of it.

    Quote Originally Posted by Antice View Post
    the capabilities i am talking about is among others the ability for supporting the construction of space stations.
    You don't need a RLV for that, look at how Russia assembles stations. And if you really want an arm than you can just attached to the space station. Skylon can't lift any large seized ISS modules or Bigelow's BA-330.

    http://en.wikipedia.org/wiki/Assembl...embly_sequence
    http://www.space.com/855-progress-in...ce-module.html

    Quote Originally Posted by Antice View Post
    How much would a skylon cost? I have no idea.
    That's the golden ticket.

    Quote Originally Posted by Antice View Post
    then onto this: misreading your post. did or did you not use the most pessimistic no growth assumption number for your passenger costs?
    I never mentioned passenger costs.

    Quote Originally Posted by Antice View Post
    Before the chinese can realize their goals of going anywhere except LEO they have to either replicate former US HLV capability.
    China is considering a HLV.

    http://www.bbc.co.uk/news/science-environment-10762634

    Quote Originally Posted by Antice View Post
    China is not the only nation with a space program however. others are following suit. The later into the game they join into the race the more benefit they gain from buying a vehicle rather than developing their own.
    Specifically list who.

    Quote Originally Posted by Antice View Post
    there is according to satellite owners a desire for a having return to earth capability on launchers.
    You really need to cite this.

  16. #166
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    Quote Originally Posted by Craigboy View Post
    ...and up to 14 tonnes to the so-called geostationary transfer orbit, where
    most communications satellites are released after launch.
    So-called?

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    Quote Originally Posted by NEOWatcher View Post
    So-called?
    Seems like you skimmed and mistook the Long March-5 for the heavy lift vehicle that the article talks about.
    Last edited by Craigboy; 2011-Apr-26 at 09:49 AM.

  18. #168
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    Quote Originally Posted by Craigboy View Post
    Seems like you skimmed and mistook the Long March-5 for the heavy lift vehicle that the article talks about.
    No, did you skim the part I quoted? The adjective "so-called" is about the orbit.
    Besides, even if I did mistake one for the other. Where does the "so-called" come into play?

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    Quote Originally Posted by NEOWatcher View Post
    The adjective "so-called" is about the orbit.
    In that case I have no clue what you're talking about.

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    I think in this case, "so-called" was meant to be synonymous with "known as"; however, in my experience "so-called" has an almost pretentious connotation to it. Usually when I say (or hear) something like "so-called," it means that it isn't REALLY what it says it is, or that the person(s) involved don't REALLY know what they are talking about.

    CJSF
    "Soon the man who sweeps the room brings the secret telegram, 'COMMENCE OFFICIAL INTERPLANETARY EXPLORATION.' "
    -They Might Be Giants, "Destination Moon"

  21. #171
    Quote Originally Posted by Craigboy View Post
    In that case I have no clue what you're talking about.
    It's right there in his quote. A more complete quote:
    When operational, Long March-5 is expected to deliver up to 25 tonnes of payload, including space station modules to the low Earth orbit, and up to 14 tonnes to the so-called geostationary transfer orbit, where most communications satellites are released after launch.

  22. #172
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    Smile

    Ha, okay it looks like I was the one who was wrong.

  23. #173
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    A couple pieces on The BBC website about Skylon passing an important ESA review:

    Main Article

    Spaceman blog

    Key points are that the ESA review sees no 'showstoppers' and assuming the intercooler passes the tests due next month REL would unlock 200-300 million in private funding.

  24. #174
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    The wikipedia entry for Skylon is very interesting. I can't see why so many on here are so negative about it.

    The payload bay is 4.6x12.3 metres, compared to the space shuttle's 4.6x18 metres.

    Payload to LEO is 12 tonne, compared to space shuttle 24.4 tonne. (Skylon payload to ISS is 9.5T).

    According to Wiki, the thrust of each engine is 3,600kN "with afterburner", considerably MORE than the SS main engine (1800kN each), although not anywhere near the solid fuel boosters of course.

    Still should be quite spectacular. You'd think one of the worlds mega-rich ie Bill Gates et al would want to bank roll something like this even if they did lose a bit of money.

    http://en.wikipedia.org/wiki/Skylon

  25. #175
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    Quote Originally Posted by kzb View Post
    The wikipedia entry for Skylon is very interesting. I can't see why so many on here are so negative about it.
    Not negative, just a bit cynical and tired from having heard the same promises and seen similar pretty concept art dozens of times in our lifetimes-- and some from before that.


    Quote Originally Posted by kzb View Post
    You'd think one of the worlds mega-rich ie Bill Gates et al would want to bank roll something like this even if they did lose a bit of money.
    They're cynical for the same reason plus more, they have people asking them to give money to this, that, and the other thing that will "revolutionize the world, man, I promise!" all the time.


    Don't get me wrong, I do hope this one works, just like I've hoped the others would.
    I'm a cynical optimist. I think the only way out is through, but once we get through it'll be better. Very different, but better. Howard Tayler

    It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change. Charles Darwin

    "It is the duty of the writers to seduce me into suspending my disbelief!" Paul Beardsley

    Power, Lord Acton says, corrupts. Not always. What power always does is reveal. Robert A. Caro

  26. #176
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    Noclevername wrote: Not negative, just a bit cynical

    I know what you mean. This Skylon though does seem a cut above the usual.

    I must admit you'd never get me up in it. The passenger module would go in between two huge liquid hydrogen tanks for and aft and the two engines to either side.

  27. #177
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    Quote Originally Posted by kzb View Post
    I must admit you'd never get me up in it. The passenger module would go in between two huge liquid hydrogen tanks for and aft and the two engines to either side.
    Riding any rocket into orbit means riding a potential deathtrap. But since you're surrounded by the most vital components of the ship, that's the area that they're likely to have most protected and carefully inspected. I'd go, and I'm a scaredy-cat.
    I'm a cynical optimist. I think the only way out is through, but once we get through it'll be better. Very different, but better. Howard Tayler

    It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change. Charles Darwin

    "It is the duty of the writers to seduce me into suspending my disbelief!" Paul Beardsley

    Power, Lord Acton says, corrupts. Not always. What power always does is reveal. Robert A. Caro

  28. #178
    Love the retro 1950s look of the thing. Like something out of a Chesley Bonestell illustration.

  29. #179
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    Quote Originally Posted by kzb View Post
    Noclevername wrote: Not negative, just a bit cynical

    I know what you mean. This Skylon though does seem a cut above the usual.

    I must admit you'd never get me up in it. The passenger module would go in between two huge liquid hydrogen tanks for and aft and the two engines to either side.
    The SPLM is apparently designed to be relatively safe for the passengers, according to the manual it is designed to survive the Skylon crashing by the rest of the craft absorbing most of the impact, it's life support is independent from the rest of the vehicle, so the module can keep the occupants alive for several days in space. If the vehicle for some reason breaks up inside the atmosphere or the module for some other reason finds itself separated from the vehicle, the SPLM has a parachute system. The module also has heat shielding to protect the occupants from things like propellant fires.

    The internal life support is rated for a 2 day mission length plus 2 days of reserve for a full passenger complement, if I read the manual correctly, though, of course, it can be used for longer missions if external support is available, for example if it was connected to a space station. The idea is that if the module is stranded in space, for instance if the vehicle is damaged so that it is deemed unable to survive reentry, a second Skylon can be sent up to recover the passengers in that time. The storage space of the passenger seat is equipped with a light pressure suit in case the module should be breached, but I am not sure how long these suits can support life. The manual mentions a 4 day supply of oxygen and lithium hydroxide in the seat storage space, but this may be part of the general life support supplies.

  30. #180
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    Quote Originally Posted by TrAI View Post
    The SPLM is apparently designed to be relatively safe for the passengers, according to the manual it is designed to survive the Skylon crashing by the rest of the craft absorbing most of the impact, it's life support is independent from the rest of the vehicle, so the module can keep the occupants alive for several days in space. If the vehicle for some reason breaks up inside the atmosphere or the module for some other reason finds itself separated from the vehicle, the SPLM has a parachute system. The module also has heat shielding to protect the occupants from things like propellant fires.

    The internal life support is rated for a 2 day mission length plus 2 days of reserve for a full passenger complement, if I read the manual correctly, though, of course, it can be used for longer missions if external support is available, for example if it was connected to a space station. The idea is that if the module is stranded in space, for instance if the vehicle is damaged so that it is deemed unable to survive reentry, a second Skylon can be sent up to recover the passengers in that time. The storage space of the passenger seat is equipped with a light pressure suit in case the module should be breached, but I am not sure how long these suits can support life. The manual mentions a 4 day supply of oxygen and lithium hydroxide in the seat storage space, but this may be part of the general life support supplies.
    I've not read up too far on the passenger module to be honest. Anyway, I believe is much further down the line; in other words, we test the thing perhaps for several years with unmanned missions before we trust it with human cargo. That's a sensible approach to my mind at least.

    The engine thrust works out to over ten times that of a 747, and that is apparently in jet, not rocket, mode. That is if the wiki article is accurate. You would think there'd be immense military interest in something like this.

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