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Our problem is that we have a chicken and egg scenario when dealing with space. Why develop a cheap means to get into space as there is nothing there and why build anything large as its expensive to get up there.
We may soon have cheaper access to space as private companies take over from NASA. But all these plans need something to go to and at the moment it appears they will be light passenger carriers not able to put the loads into orbit necassary to develop infrastructure. This is why I support plans such as Shuttle C and even if it can be done cheaply SeaDragon. These heavy Boosters are expensive to launch but can put infrastructure up there without the problems that the ISS has to go through.
As to SeaDragon it can be done, but what would it cost to develop and what would the launch costs be? The only way would be to do a proper study into the plan. At the moment all is conjecture and quesses. Steel as used by modern shipbuilders is a cheap material but what of the single engine and the rockets internals. The main sticking point of the development will not be its frame or fuel tanks it will be that single mega engine.
One advantage of the SeaDragon will be the lack of launch gantries needed. The original plan was to use existing ships to crack the fuel and that means little support staff as they are already employed. This is a saving. The main cost to run the Shuttle for example is the large ground crews permanently employed in readying the shuttle this leads to its large launch costs. Shuttle C will still have these costs. It is likely that any Shuttle derived rocket (Ares!) will still have these costs to absorb.
Another concern is the development time needed to make a usable Heavy launch system. Shuttle derived launchers have the advantage by not having to completly throw the manual away. SeaDragon is next as it is an old style design and modern techniques will allow development speed (Computers vs Sliderules etc). Next is the brand new Heavy launcher this will need complete development as it will be using new materials and there is no experience in its use. Of course there are developments of the Titan and Delta but I discount them as they are unlikely to be able to launch the cargo that is needed.
Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.
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There is a third option to Shuttle-derived or SeaDragon style superbooster though, that is to use exsisting rocket engines combined into a vehicle more powerful than Shuttle-C but smaller than SeaDragon for ease of handling and is a much lower risk than the SeaDragon super-rocket, which is an entirely new concept.
I believe that even if SeaDragon is possible, that its costs will be much higher than its proponants think. The vehicle itself would take a long time to build, limiting flight rate from a single factory, which idles the launch staff for long periods and prevents launching of payloads when you need them, forcing you to wait months between launches. The payloads themselves are not easily deliverd to GEO or Earth escape orbits, plus they will nessesarrily be so large, that there is a huge monetary risk of failure and that the payloads will be optimized for Earth gravity and not space travel.
Since SeaDragon has limited utility, low flight rate, and has fairly high costs I do not see a great advantage over building a new HLLV with conventional technologies even if its only capable of hauling half the payload. Building 6+ HLLV main stages per year is a possibility, so if SeaDragon takes as few as four months to build, assemble, integrate, check, tow, erect, fuel, and launch... then you don't have a signifigant improvement at the cost of a great deal of utility.
You point out that SHUTTLE has a high cost for pad operations, but why must Shuttle-C or a new HLLV? Since they will not be built for humans, there is no need for the huge number of technitions to ensure super-high reliabilty. How many of those ground crew are asscociated with the STS Orbiter? They will in large part be gone... BTW, how much will SeaDragon cost to launch? How many people does it take? What kind of skills and equipment do they need? How are you going to crack that much water into fuel? ...It is a valid question if launch operations can be held low enough for the Pad-39 complex at CCNAS, but the Delta-IV complex just North of Pad-39 is probobly large enough to also accomodate a new HLLV with only modest modifications and a well-oiled launch staff.
"Next is the brand new Heavy launcher this will need complete development as it will be using new materials and there is no experience in its use. Of course there are developments of the Titan and Delta but I discount them..."
Not nessesarrily. We have all the engines we really need off the shelf, we have the Russian RD-170 engines just as powerful as the Saturn F-1's for reuseable liquid fueled boosters or re-use the Shuttle SRBs that are far more powerful. Since the SRBs are structurally strong, they could even be used to hold up the rocket on the pad. Next, the core would be built similar to Delta-IV cores only bigger (possibly in two sizes) or Shuttle main tanks, and accomodating between two and four exsisting RS-68 expendable cryogenic engines, off the shelf and fairly cheap. Finally, for superheavy or escape missions, a large Centaur upper stage powerd by 2-4 RL-60 engines, the sucessor to the venerable RL-10, would be more than enough and reasonably priced. Since Boeing can't seem to sell many Delta-IV flights, they would be more than happy to drop the Delta-IV line and build HLLV cores... And hey, its right next to the launch pad.
I would also like to note, that Delta-IV rockets require surprisingly little manpower to construct, assemble, and launch... the assembly of the stages is even largely automated by robot arms. Since the only pieces you are throwing away are the core which is not any harder to make than a Delta-IV HLV and the cheap-ish optional upper stage, with $10-20M per liquid booster or $20-30M per SRB per flight, a large HLLV of this style is quite affordable.
Since the rocket could be built fairly quickly, different sizes a models available, escape velocity upper stage available, half the engines and much of the tankage are reuseable, all using exsisting engines/materials/building methods.. even using mostly exsisting facilities.. and able to launch more than 150MT in theory, I find that the HLLV solution is superior to the SeaDragon BDB concept.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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spacesuits are tested underwater w/ no ill effects.
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Cost:
I believe that even if SeaDragon is possible, that its costs will be much higher than its proponents think. The vehicle itself would take a long time to build, limiting flight rate from a single factory, which idles the launch staff for long periods and prevents launching of payloads when you need them, forcing you to wait months between launches.
Sorry for the poor quality. I never could get this kind of printed work to scan properly...
Anyway, in the above picture you can see three Vanguard nuclear submarines, with space for a forth. Each is 150m long and 13m wide. Allowing that each sub is half the width, but the right length, it's quite demonstratable that the 'drydock' can accommodate two complete sea dragon rockets, or three or more partially complete ones. This represents the capacity of one building in one shipyard owned by one company that is based on a island of no great size located off the northern shores of continental Europe.
With four buildings like this you could build 8 sea dragons at the same time. Alternatively 2 container-ship/oil-tanker dry-docks would do as well. So even if it took 8 months to build (and I'd disagree that it would take so long) you could still launch them at a rate of one per month. Taking the Virginia as a model, it takes 16 months to build one on a limited production line. Assuming a linear relationship between weight and time, this would translate to a period of about 4 months for SeaDragon. Assuming a similar linear relationship between mass and using the LA as a model each SeaDragon would cost $260M to build.
These are fairly conservative estimates, because the SeaDragon would not need the complexities of an acoustic stealth systems, sensitive sonar systems, life support for 9000 man days, internal decking or sub compartments, weapons load out, or a nuclear reactor. Based upon these estimates, the single building in the picture above could crank them out at a rate of one every two months.
You'd need something like s sea launch Assembly and Command Ship, a nuclear reactor to desalinate and crack the sea-water, and a tug or two to move them from the ship-yard slip-ways to the nearest patch of 20mile wide area of open sea. (NB: A fully loaded SeaDragon will be the equivalent of 1/4-1/3 of the Hiroshima bomb if it explodes full loaded. You need a big open area!) If you wanted to recover the first stage you'd also need to tow it back to the launch site.
No idea how much it costs to move large objects around at sea, but we could always rent decommissioned LA class subs from the US DoD. (Say, $30M/year/sub.) We'll need at least one on site. With six launches a year it might as well double as a tow-boat as well. So that's now $265M per launch.
The original concept assumed a nuclear aircraft carrier, but an LA sub with modifications would do as well. Such an arrangement would not be unusual, as DoD regularly rents out its hardware and/or personnel to anyone or anything that would put them in a good light. The navy in particular would likely be very interested in, as it would allow them to break the USAF's monopoly on US space assets, and to keep a 'reserve fleet' of LAs active at zero cost. The US DoD Will probably want to keep a close eye on us anyway.
If not we rent Russian for a similar cost. Since we’d only be buying transport, electricity, and minor labour there’d be nothing illegal about such an arrangement. Or even worse, we could rent from France!
There'll probably be a few million in misc costs on top of that, but that looks like a good ball-park figure. It's also close to the optimistic costs for a single SDV in the 100ton class, and roughly twice the maximum estimated cost for the Delta IV heavy. As near as I can tell GCNR's super EELV will put 100tons in LEO for around $100M minimum. That it however a minimum cost. A maximum would be ... what? $150M-$200M?
Payload technology
The principle requirement for aerospace computers is for them not to interfere with other delicate aerospace components. Of course if you're using commercial hardware you don't need to worry. My computer does affect my mobile phone beyond a few meters. Shielding from radiation would be a simple matter of dunking it in the water-tanks (also useful for cooling) with a suitably water tight container. A commercial computer in a modded case could probably work quite happily inside a space station for a few thousand dollars extra. But you still wouldn't want to use Pentium IVs are they're not particularly reliable on the ground.
Use normal solar cells. Build SSPS at the same time to bring costs of cells down. Build cells perpendicular to solar radiance, with thick shield along one edge facing the sun and a mylar sail above.
Commercial UPS systems. Integrate as LRUs.
Use sat-TV dish linked to star-tracker telescope and GPS receiver. One can receive high bandwidth signals from 30,000km away, the second can aim very accurately and can get its starting position from the last.
Tankage for methane and oxygen. Under pressure, but not corrosive. Use of ion-drive for minor correction. Use of heavy reaction wheels for low cost attitude control.
KISS satellite requires someone with college level understanding of computers and some mechanical knowledge. Plug A into slot B. These would be family cars not F-1 racing cars and the people working on them would be trained appropriately.
Would it cost less if you could build it from steel, with copper wiring, with heavy radiation/meteroid shielding, and all that? Sure it would, but that’s not going to make it cost less than several millions of dollars, because competent aerospace engineers can demand high wages, and because many of the componets will be of similar cost simply because they are inherintly complex and made in small number, not because they are expensive to build light weight.
If it was made out of steel and copper wiring only a complete moron would pay aerospace engineers to build it. You'd use electricians, plumbers, and wielders. And highly qualified artisans are all kept far away in the factories that produce the parts needed.
No, and no
Wrong and wrong. At least according to every single aerospace company in America, who all believe that yes, it *can* be done. None of the smaller designs get close to SeaDragon costs, but they all report a substantial reduction in launch costs. They also agree that such a reduction in launch costs would have a knock on effect on cheaper satellite construction.
ANTIcarrot.
References:
Sea Dragon Rocket
Length: 150m
Width: 20m
Weight (empty): 2,000MT
GLOW: 18,000MT
Payload: 500MT to LEO.
http://www.astronautix.com/lvs/searagon … aragon.htm
LA class attack submarine
Construction cost: $900,000,000
Operating cost per year: £21,000,000
Weight: 7,000MT
Power generated: 35,000shp
Pressure capacity: Greater than 24 atmospheres of pressure at ~800feet
"Between 1998 and 2001 the US will retire 11 Los Angeles class submarines that have an average of 13 years left on their
30-year service lives."
http://www.fas.org/man/dod-101/sys/ship … sn-688.htm
Virginia class attack submarine
Weight: 7,800
Construction schedule: Four subs in five years.
http://www.fas.org/man/dod-101/sys/ship … p/nssn.htm
Launch costs for a few vehicles (cera 1990)
http://www.futron.com/pdf/FutronLaunchC … CostWP.pdf
http://www.ecsel.psu.edu/~sqm110/XST/Ap … ST/App.htm
Delta IV rocket launch costs from an estimated $70 million to $140 million dollars.
LEO On the cheep
"Yes rockets can be built for less."
http://www.dunnspace.com/leo_on_the_che … _cheap.htm
Fin.
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Well if you were looking for the Boeing first launch of Delta 4 Heavy rocket to be the next in possible shuttle replacements, it has been delayed.
http://www.floridatoday.com/news/space/ … delta4.htm
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A post from Andy Mcsorley on the project constellation site makes note of a past study from Caltech called 'Mars Scheme' back in 2000 called the Z-5.
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Ohhh but I think building such a large object will not be quite so easy as you make it out to be... Building a rocket of this magnetude will yeild roughly a doubling of the surface area compared to a small SSBN hull like the one noted. And then you will probobly need baffles to prevent fuel sloshing, since you are at sea with a huge quantity of liquids, which will be substantial. And how about the internal tank walls? Liquid Nitrogen tankage? Internal structural supports for intertank/interstage? And last but not least... the two huge, gargantuan, monsterous rocket engines - complete with water-tight seals for the first stage and expanding exit cone for the second, which will be easily twenty meters across. And must be shaped and welded essentialy flawlessly to prevent.... "mishap"
Oh no, even without the nuclear reactor and the LSS system, building SeaDragon isn't going to be alot easier. I contest that the construction costs will increase linearly with surface area, not with lower with weight (including the surface area for internal tankage)... handling and welding thicker plates of steel for submarines costs less than welding three thinner plates, because it takes three times as much manpower.
Considering what the SeaDragon has to go through, the extreme dynamics of spaceflight, the vibration, the ultralow LOX temperatures which can make steel brittle (heavy vibration too, even better!), it has to float water-tight, and certainly don't forget that the rocket really isn't a single entity... it is two separate rockets stacked atop one another, and a payload faring on top. Three separate componets that all have to be assembled, the major two you can't weld together, that have to fit like a glove no matter what is done to them... And how about this? The LOX tankage is going to be so cold, the metal is going to contract... not a big problem on a small rocket like Delta or Centaurs, but on somthing this big, the contraction will certainly be an inch-plus problem. If you have insulated tankage (which you may have to to avoid ice), thats only going to make it much, much worse... quadruple the surface area? Insulating somthing the size of the STS ET tank?
Eight months and $500,000,000 each is probobly being too generous, especialy considering how there is no way you are going to get ahold of a decomissioned nuclear anything unless the program is run by the military. And then you need to develop and build the huge electrolosis machine, probobly run by gas turbines on the launch service ship, etc. We already have the launch facilities. How about the payload integration guys? Those aren't your averge dock workers either, even Lockheed submarine guys at Electric Boat might be under-qualified.
And as I am sure you will attack me over, I am going to invoke the rule you don't seem to be able to accept... that if this were such a good idea, so much better than what we've been doing, then somebody would have done it already.
Now about the "KISS satellite:"
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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GCNRevenger I know you think it would be impossible but frankly the potential for the SeaDragon is so high that a decent study should be done.Only then will we see if it makes a better Heavy Lifter than any other proposed design.
And another point why should the internal tanks be of steel. Or why not coat them with something else to protect the steel. But I have to ask when liguid oxygen and the like is transported by tanker what is those tanks made of.
And for exact welding and design diameters it may be that submarines are of a higher quality. Anything that is not exact will make the submarine either weaker underwater or worse more detectable by frictional noise. And a decent designer can ensure that supports and linkages are watertight and able to take the stress. An example is the missile doors of any boomer
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I am not saying that SeaDragon is impossible, it probobly could be built and it could even reduce launch costs versus contemporary technology a little bit. What I am saying is that SeaDragon or other huge BDB concept is that it is no where near as easy or inexpensive as its made to sound on paper in the Traux sales brochure, and that the vehicle itself has such poor utility that it isn't worth the trouble versus a modern "American Energia." If big simple vehicles were the be-all/end-all panacea of launch technology, then there is no way in heck we would have botherd with the eleven-engine, turbopump fed, tripple-stage Saturn rockets nor would Russia have botherd with the N1 or Energia. SeaDragon was studied... and terminated.
If it were that easy, it would be done that way today... The old rocket pioneers wern't stupid you know, the first liquid rocket engine was a pressure-fed LOX/Hydrocarbon engine, its insulting to their legacy to paint them as stupid and ignorant for choosing the more complicated solution... In fact, it seems a common theme in the AltSpace zealots, that they are obviously much more clever than the "old geezers" of rocketry.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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increase linearly with surface area
Quite possibly, but I don't have the costs for a military submarine pressure hull to hand. I doubt you do either. I put it to you however that the pressure hull will be a small portion of the over all cost. Say, $10,000,000?
handling and welding thicker plates of steel for submarines costs less than welding three thinner plates, because it takes three times as much manpower.
That does not follow. A plate twice as thick can take twice as long to wield, or twice as many people to wield in the same amount of time. But it doesn't automatically take three times as many men to wield an arbitary thickness of steel than it does for another arbitary thickness of steel. Which is what you've said.
the two huge, gargantuan, monsterous rocket engines
Since it's a pressure fed system, the pressure in the engines cannot exceed the pressure in the tanks. There will be problems with tempreature, and spredding the propellent to all the combustion chambers evenly, but ptrobably nothing that can't be over come.
expanding exit cone for the second,
Where does it say this is a feature of the SeaDragon design?
In fact, it seems a common theme in the AltSpace zealots, that they are obviously much more clever than the "old geezers" of rocketry.
Funnily enough, at the time it was the altspace zealots who wanted to build the shuttle and bring costs down, and the old fashioned engineers who wanted to take advantage of the cube/square law.
Then NASA's budget was slashed and there was no need for HLLVs of any type, since they wouldn't be going anywhere or doing anything for the foreseeable future.
And as I am sure you will attack me over, I am going to invoke the rule you don't seem to be able to accept... that if this were such a good idea, so much better than what we've been doing, then somebody would have done it already.
Apply the rule to Kitty Hawk. Or the computer. Or for that matter, the wheel. "Why bother building any of these things," your sacred rule would argue, "because if there was any point to them, it would have always been done."
It's a stupid rule invented by a stupid, petty, small minded person who lacked the imagine to realise what its application would truely mean: the abolition of all progress and invention.
unless the program is run by the military.
And that part *would* be under military control. As I clearly said in my post. We'd only be paying transport & electricity costs at a fixed $30M/year. At *any* time they like they can sail away from the deal, for a proportional loss of income. It's unlikely they would, purely from the prestiege they'd ganer from out-manouvering the USAF. Or the Americans, if we rented russian/french.
$500,000,000 each is probobly being too generous
If you had absolutely any evidence or proof it would cost that much you would have posted it. You haven't, so you don't, so it wouldn't. $265M is a good maximum. Chances are it would cost much less than that.
ANTIcarrot.
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Please, think and read...
What do you think a submarine is? Or any ship? It is a big metal box, welded carefully together, with pieces of equipment installed into its structure. If you take away the hull of a submarine or a large boat, what is there? A nuclear reactor, some LSS gear, weapons and electronics... Half of the boat's construction IS the hull. Sixteen months and a billion dollars to build a boat half the size of SeaDragon of the same material with the same construction, with the addition of the precision built rocket engines, tank insulation, and the no-welding assembly involved... I don't see how you can claim with a straight face its going to be loads easier. Delete the nuclear power plant? Okay. Control electronics? Fine... but making a MUCH larger vehicle Four times as fast and four times as cheaply? No... I think not. No counter "evidence" is required when the proposition is nonsense.
And there are other sources of pressure in the engine besides that from the fuel delivery tanks... like, say, expanding gasses? Rockets engines do blow up for a reason you know, and its not because they aren't pressure fed... if it were that easy, we wouldn't bother with turbopumps because pressure fed would be so much more reliable.
"...and the old fashioned engineers who wanted to take advantage of the cube/square law."
And again with the Shuttle comparisons! You know your statement is wrong, you know what really happend with Shuttle was politics and not engineering, and you know for fact that on paper, RLVs are a good idea. (DH-1?) Beating the Shuttle strawman and playing dumb isn't an argument, its just being stubborn and ignorant. The idea behind Shuttle, a fully reuseable runway recoverable space vehicle, is a valid one... what we have today, a butcherd overweight rocket with wings to try and please everyone accountant included, is not such a vehicle.
Come now, you were singing the praises of thimblefull payload RLVs mere hours ago practicly... you are infatuated with SeaDragon for no good reason at all other than its "counter" to the established ways.
Now time for a little review...
"expandable nozzle exit cone" -Astronautix article, 3rd paragraph. The use of such a nozzle will add to the complexity of the engine tremendously, in a desperate attempt to squeeze a little Isp out of LOX/Kerosene fuels I imagine.
"SeaDragon is NOT an improvement" - Me
Wright Brothers aeroplane - New technology
Lithography-cut semiconductor transistors - New technology
SeaDragon BDB - OLD TECHNOLOGY
Are we seeing a pattern here? Comparing SeaDragon to the invention of airplanes and computers is just silly, SeaDragon is not innovation at all, its just another far-out idea in a fairly pitiful attempt to "innovate" better than a century of genius.
Converting Los Angeles class nuclear attack submarines into mobile LOX plants? Are you joking? They don't even have the ability to generate that much electricity in the first place (direct turbine to shaft drive), and where are you going to put the massive electrolosis equipment? No no, it would require gutting the boat and redoing it from scratch practicly if it could be done at all... and I don't think the military would like that for one of their fleet boats they need at the ready. Or that the submarine would be handling huge quantites of explosive liquids... kind of a risk factor there you know.
You have done nothing but parrot the Traux brochure because their idea runs counter to armies of professional engineers, and come up with strawmen galore trying to defend it, with an article from a lone USAF officer for garnish..
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Look, look and read the Astronautix article... Launch price: $300 million dollars... in 1962 money. Adjusting for inflation, your talking about two billion dollars! BDB not so cheap now is it? Same materials, same methods, same technology then as today too... Say we cut that in half, and it costs a billion a flight for 400MT, its still not any better than a big conventional HLLV with good boosters.
How is this not reaching you? The SeaDragon is simply not a good idea... if it were, we would never have botherd with high-performance engines and gossamer aluminum balloons in the first place.
And I haven't heard a satisfactory response about the really really lousy flexability of such a huge booster other than "its the payloads' problem" and to build lots more superrockets in parallel. (i.e. "its not the rockets fault, and throw more money at it and it will solve anything")
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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The real problem is that there is no market for such a booster. Sea Dragon might be an economical way to launch a dozen 500 MT payloads per year, but where will you get the payloads? Even with plans to send humans to Mars, you would probably be launching only about 1 time every other year. A 150-200MT launcher is already getting too large for the market, but a 500 MT launcher is just ridiculous.
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Be cautious about letting students draw conclusions such as "the computer I paid $1,500 for last month would have cost about $342 if I bought it 30 years ago" or "a gallon of gasoline that costs $1.57 today would have cost 24 cents in 1952." First off, re-emphasize that, while statements such as those about some products might be true, most goods do not “follow inflation” that exactly. Additionally, we cannot compare the buying power of computers in that way because computers were not available to consumers 30 years ago. And, as for gasoline, there are many variables that such a statement does not consider, including:
-from a guide to teaching inflation to high school students.
For example, based on the cost of a Model T Ford in the 1920s, a modern car should cost $3000. It doesn't. New materials, new technology, new manufacturing techniques, market size, and foreign competition all affect prices.
Wright Brothers aeroplane - New technology
I assure you the airofoil was in use long before the Wright brothers were born. That would make it old technology. The petrol engine was also not new technology. The only thing they actually invented (as proven by the patents they filed) was their control system.
You have done nothing but parrot the Traux brochure because their idea runs counter to armies of professional engineers, and come up with strawmen galore trying to defend it, with an article from a lone USAF officer for garnish...
The Wright brothers beat a similar army of professional engineers and scientists back in the 1900s. The army in this case is run by bosses who know they're paid on a cost plus baisis, and that profit is linked directly to the cost of the rocket.
And I haven't heard a satisfactory response about the really really lousy flexability of such a huge booster
Mention a single non-human payload or mission it couldn't accomadate, and I'll explain how it could.
with an article from a lone USAF officer for garnish...
...Which just so happens to support everything I say.
Half of the boat's construction IS the hull. <snip> I don't see how you can claim with a straight face its going to be loads easier.
Because I have provided evidence in addition to arguement, and you haven't. Until then you're just blowing hot air.
Euler
The real problem is that there is no market for such a booster.
True. Like any rocket you'd have to invent the need at the same time you'd invent the rocket. (SaturnV/Apollo style) The rocket couldn't and shouldn't be built without a big project to justify it.
ANTIcarrot.
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So again we have the chicken and the egg, which comes first
We cant do anything big in space without a reasonably decent heavy launcher, and we wont make plans for anything that big in space as we dont have a large enough launcher.
A little thing to consider the expensive part of the SeaDragon development will be the new rocket engine. We will use the same sort of tanks that the space shuttle uses for its large external tank and we can make those.
Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.
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Apollo Inspires New Moon Rockets, two teams at the National Aeronautics and Space Administration are studying booster rocket design concepts.
One team, assembled by the space agency's Exploration Directorate, has been examining rocket designs from the top down, according to Michael Lembeck, who heads the directorate's Requirements Division.
Second team at NASA's Launch Services group is conducting a bottoms-up review, meaning the services group, which purchases launch vehicles for NASA missions and payloads, is accumulating background on and analyses of all available U.S. boosters and their capabilities.
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25 August 2004: Long Arm of Foreign Policy,
http://www.washingtonpost.com/wp-dyn/ar … Aug24.html
Washington Post
"Also off the table is the possibility of buying Soyuz spacecraft through intermediaries or negotiating a new barter agreement. Deputy Assistant Secretary of State Steven Pifer told Congress last year that such tactics "would likely be viewed by many as an evasion of the law." NASA is pursuing the possibility that additional Soyuz might be available under the existing agreement, which authorizes the United States and Russia to trade goods and services "for the life of the station," but it is far from clear whether this wording would admit Soyuz purchases beyond the original 11."
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"Be cautious about letting students draw conclusions such as..."a gallon of gasoline that costs $1.57 today would have cost 24 cents in 1952." First off, re-emphasize that, while statements such as those about some products might be true, most goods do not “follow inflation” that exactly."
Ah, but you yourself are pushing an old technology which hasn't really changed since the Saturn days in the 1960's when SeaDragon was proposed! We still build boats with plates of steel, still welded largely be hand, still massively labor intensive. The cost of the metal itself is pretty small compared to the cost of the labor, which I do believe does follow inflation to large extent. This is made even worse with the careful assembly of SeaDragons huge but delicate rocket engines and insulating the cryogenic tankage.
Back in the days when SeaDragon was proposed, the only HLLV concept on the table was the Saturn-V series rockets with their F-1 stages, which cost about $2.0-2.5Bn each, perhaps $3.0Bn, in 2004 dollars. The Astronautix people generally won't include figures that aren't available or easy to calculate roughly, so I would imagine that the $300M pricetag in 62' money had to come from Traux or one of the studies... You see, SeaDragon was supposed to compete with the expensive Saturn-V rocket, which would be very unaffordable now-a-days. $1.9Bn for SeaDragon with 400MT versus Saturn for $2.5Bn would have been a pretty good deal... well, until NASA thought about glueing Titan-IV boosters to a stretch Saturn-V to give it similar payload capacity... surely a contributing factor to SeaDragon's demise.
But now we have somthing even better... the Russians and their Energia rocket, along with the Europeans and their concepts for a flyback-booster Ariane, and Nasa's NOVA and so on... the use of recoverable heavy boosters around a modest cryogenic core, it is quite possible to fly such a vehicle with ~200MT of payload for about $400-500M for each flight.
Now, even if inflation or Astronautix errors are off by a full 50%, SeaDragon fails to deliver any cost per pound advantage. If they are off by even more then that and the cost for SeaDragon is even a little less than $1Bn a flight, the difference in cost per pound is not very great to justify a risky, less flexable solution.
And with the comparisons to the Wright Brothers, please, you are just making noise... They did NOT have alot of competition actually, no "army of engineers" or any such nonsense, and then you yourself state in your own post that they invented the control system, and proceed to downplay its importance. New technology
Oh, and speaking of Apollo... really now, come and think for a minute and stop beating your AltSpace drum...
Do you honestly think that if it were that simple to make a rocket like SeaDragon, which is pretty easy to design and engineer, that we would have built the eleven-engine, tripple-stage, hydrogen powerd, turbine driven, Saturn rockets for the Moon shot? Korolev and his contemporaries, all stupid, incompetant, idiot engineers? Von Braun and the Peenemuende team all fools who had no idea what to do? The SeaDragon ought to be the first HLLV idea they contemplated because it would be the simplest to engineer. Liquid fueled pressure-fed rockets powerd by LOX+Hydrocarbons have been around for a century now, and nobody anywhere other than Traux, one USAF officer, and a few failed starry-eyed inventors have supported BDB among all the thousands of professional aeronautical engineers over the years... So the question begs, why would we build the inferior Saturn? Why would the Russians build the 40+ engine N-1 rocket? Why? WHY?
"Because I have provided evidence in addition to arguement, and you haven't. Until then you're just blowing hot air."
You yourself have said this is mostly conjecture... yet your "proof" is comparing a rocket to a submarine! And saying that it will cost a mere 1/8th of what it would cost with inflation factored in from your own source? Even the submarine comparison agrees with the inflation-adjusted Astronautix pricetag, when the submarine costs half of what SeaDragon should and is also half the size? And even if this is wildly innacture, double what it would really cost, unlikly given that ship-building hasn't changed since then... SeaDragon still has nothing to offer...
And heaven help you if you want to launch somthing smaller on a more regular basis, like station supplies or nuclear probes or whatnot, or the mass penalty if you are forced to build a very large payload in Earth gravity for space use... A modular rocket can be built in multiple sizes to accomodate a variety of missions, but SeaDragon? If it isn't huge, it doesn't work.
The AltSpace attitude, even its worldview really, is that all the engineering that has been done before is a failure, stupid even, and that you are more "clever" then them and grin in assurance of you will do it better and work miracles that regiments of engineers who built rockets all their lives to this day could not... It is simply not so
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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We all know of what it entails to create a heavy lift vehicle.
1 payload max limit
2 stage payload drive alternate lander if possible
3 stage to leave orbit
4 stage to leave earth
5 external strap ons if needed
Selection of off the shelf may be possible for fuel to tank and of even some engines per stage combinations. The remainder is wiring and plumbing to get everything to where it needs to connect.
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If for some reason a private group were to spend potentially very high sums of money to develop Sea Dragon, all power to them. What they come up with may indeed (excluding development costs) bring down the cost per kilo of thowing stuff into space . If several launches were to be carried out each year, with large numbers of Sea Dragons being produced over a long period of time, great savings through economies of scale might be achieved. Or perhaps not. I don't really know.
Does it make any sense for NASA, ESA, RSA, JSA etc. to fund the development of a Sea Dragon type rocket for a near term humans to Mars exploration programme? HELL NO!!!
This is a Mars Society message board. Keeping potential development costs to the minimum greatly improves the possibility of sending people to Mars by 2020. Even the most puffed up, luxury version of the Mars Direct mission architecture would have no requirement for a Sea Dragon class launcher. As mentioned many times in previous posts, there is no commercial application for such a monster rocket. More importantly, Sea Dragon is a non-modular system. There is no commercial market for any of it's individual engines or stages, nor do any such components have any use other than as part of a Sea Dragon.
None of these flaws would apply to an Energia derived HLLV. The largest proposed variant (Vulkan-B), could place ~200 tonnes into LEO, or throw a 60 tonne payload on a six month opposition class trajectory to Mars. The "Vulkan-B" configuration would mount eight reusable Zenit strap-on boosters identical to those flown on the original Energia. The main core is derived from the original Energia core, using identical liquid hydrogen and oxygen tanks, but modified to symetrically top mount the payload-upper stage combination. This modification eliminates the massive assymetrical lateral loads to which the original core was subjected when hauling Buran or other payloads. The upper stage, which would perform trans-mars injection during the latter part of it's burn, is derived from the Energia-M core:
http://www.astronautix.com/lvs/energiam … ergiam.htm
The following link provides well documented performance estimates for a proposed Energia derived launch system known as "Janus":
http://www.mars.caltech.edu/chris_its/m … msm2r.html
Please note that "Janus-A" stage utilizes STS derived core tanks rather than an Energia derived core. The STS ET is of slightly greater diameter than the Energia, but 10m shorter and thus substantially lower propellant capacity:
http://www.astronautix.com/lvs/shuttle. … huttle.htm
http://www.astronautix.com/stages/eneac … eacore.htm
The size of the "Janus-B" upper stage was limited by the capacity of the "Janus-2" configuration (two Zenits). To efficiently carry the much larger Energia-M derived upper stage + payload, a minimum of four Zenit boosters would be required. Thus the RKK Energia proposal "Uran", comprised of an Energia derived core, four Zenits, and Energia-M upper stage should deliver ~150 tonnes to LEO. This compares very favourably to the 120 tonne capacity of "Janus-4". Either an RD-0120 or SSME could be used on the upper stage of either vehicle.
The Zenit strap-on booster is both much cheaper and more reliable than some earlier posts suggest. It is misleading to suggest that the single stage strapon would cost as much as a complete Zenit-2 launch stack, let alone the full Zenit-3SL (Boeing Sea Lanch):
http://www.futron.com/pdf/FutronLaunchC … CostWP.pdf
http://www.astronautix.com/lvs/zenit2.h … zenit2.htm
http://www.astronautix.com/lvs/zenit3sl … nit3sl.htm
The Zenit strap-on booster flew eight times with 100% success. Zenit-2 has launched thirty-seven times with six failures, however only two of these failures were related to the first stage, and both of these occured early in the programme. Zenit-3SL was launched fourteen times with two failures. Neither failure was related in any way to the first stage.
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Well here is the page from space Island Group that really spells out why they can not have shuttle external tanks.
It is also the main reason while private industry is held out of the game and must re-invent the wheel when it comes to Rockets and of Space exploration.
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Yes, somthing much like the Janus rocket with six RD-170 boosters, using clusterd RL-60 or a single RD-0120 for upper stage propulsion. SSMEs are too expensive, and RS-68's lack the Isp (not to mention are quite overkill). The idea to minimize costs, as the RD-170 was built with in mind, is that the liquid fueled boosters would be reuseable. Parachutes on top, perhaps air bags and a closeable skirt around the engine end of the rocket. The RD-170 is supposed to be good for 10 flights each, perhaps as many as 20. So, the only thing you throw away is the core stage and the upper stage, which shouldn't cost alot more than a Delta-IV HLV to build.
To be charitable... the Space Island Group is a collection of crackpots.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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So now what do you think about the heavy lift of the Boeing Delta IV at the +40T provided under the CEV topic as being an alternative to some of the others we have sort of cludged together.
I feel that it has possibility but why not make a manned version of the same unit for crew transport.
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From the other thread:
"Interesting... Boeing's Delta-IV HLV can hit the 40MT sweet spot just with fatter fuel tanks and a quartet of small SRBs... that would match the capacity of the Saturn-IV, the vehicle which would have performed the Earth-orbit-rendevous Apollo mission most likly... If the USAF is going to get into the space weapons business, they'd like this too. A 40MT rocket was originally slated to carry the Zenith Star "Star Wars" laser defense satelite if memory serves."
It looks like the Delta-IV would basicly have to be re-done from the ground up to accomodate 100MT sized payloads... new engines, new tankage, new pad, new factory, everything... the 40MT option however, looks much more promising to me since it would require so little modification.
I think that a 40MT launcher would make a trip back to the Moon a much much easier proposition. An Apollo-scale mission could be pulled off with as few as four flights of a rocket that is made on the same factory, launched from the same pad, and uses the same engines and construction methods as the Delta-IV today. Smaller payloads could be deliverd to the Moon after being moved to Lunar orbit by an ion tug with only one flight, great for delivering supplies or other payloads to a Lunar installaton. A 40MT launcher would also be ideal for launching large payloads like JIMO or USAF military payloads where 27.5MT isn't enough.
Launching the CEV on one though is a question worth debate... to maximize safety, the idea is, to minimize the number of engines involved. The bigger 40MT Delta-IV will clock in with 3x RS-68s, 4x 1.5m SRMs, and probobly a pair of RL-10s or an RL-60 upper stage. Up to nine engines, and if any one of them fails, then the mission must abort... The basic orbital CEV ought to be kept to within 10-12MT or so, so it could ride on the Delta-IV Medium 52 with four engines or even better an Atlas-V 501 with only two to minimize the chance of engine failure.
As for a Mars mission, I don't know if 40MT payloads are very useful, since it would require so many of them... eight to ten for a MarsDirect sized mission or maybe a dozen or more for a DRM-III style mission, mostly fuel for the TMI stage which would boil off over time.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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For any corporation wants to build and launch there version of the next possible CEV for Nasa they need infrastucture to do so. This goes for xprize contestants as well getting into the game.
Here is a thought for the xprize and for any company that would want to build and launch rockets here in the US. If possible purchase the pad 36A complex that launches the atlas 2 rockets. It just launched the last one and will basically sit idle and be used for spare parts to fix any issues with 36B launch pad.
Launch team salutes Cape's pad 36A after final liftoff
http://www.spaceflightnow.com/atlas/ac1 … ad36a.html
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