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There's the argument that you can do the same whit a balloon or a big plane. But i think the problems with designing such a balloon or airplane are gigantic. You have to have a huge balloon or airplane and they can't go as high as the first stage. You also need to have enormous amounts of helium. And i think the plane and balloon will be as expensive to maintain and build as a rocket as first stage.
Oh I dunno. Look at http://www.jpaerospace.com/]these people who plan to go the whole way to LEO by balloon.
If they're to be believed it'll cost about $1 per ton (yes, TON) to deliver cargo or people to orbit. (I wish, I wish....)
The idea is to get the orbital balloon to about 200,000 ft and accelerate it to orbital velocity using ion thrusters. Yeh, right. Then when you want to come home, you flip a switch and your ion thrusters fire in the other direction, bringing you a gentle halt...
...they don't seem to suppose there's any atmospheric drag at 200,000 feet, yet there's enough atmosphere to keep their balloon airborne.
I suppose if you built it out of unobtainium and used unobtainerene as fuel it would be easy enough.
Or did I miss something?
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It seems they're betting on the ion drive overcoming the small amount of drag against the thing... its gonna take a pretty powerful engine to pull that off, maybe a Hall Effect thruster instead of a regular one.
It think its questionable that the megaballoon can generate enough lift at that altitude either, particularly if its carrying a large payload.
As far as making it out of "unobtainium" I think that part is quite possible, Jim. Modern materials' science has come along way in the past 25 years since the end of the space heyday, and particularly with advanced modern polymers & composits actually building the balloon part and keeping it light enough is quite possible. Low-efficency but huge spray-on solar cells over the entire upper surface of the balloon would probably provide plenty of electricity... The one thing about the system that is "unobtainium" is the amount of Xenon it would consume for the ion engines, which is an increasingly precious and limited quantity on Earth.
The two things holding back this contraption are the aerodynamics... can it generate enough lift and beat drag without getting too heavy... and the supply of Helium for the H2/He lift gas or Xenon for the ion drive. The balloon part is easy.
[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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It seems they're betting on the ion drive overcoming the small amount of drag against the thing... its gonna take a pretty powerful engine to pull that off, maybe a Hall Effect thruster instead of a regular one.
And then some. The prospect of a hypersonic balloon is, you've got to admit, innovative. Practical? Well that's something else.
Granted, a fully-developed Hall Effect thruster technology might just do the trick, but how far away is that? I know we've got tiny ones working in deep space now, but a 6,000 ft long balloon even at that altitude and pressure, is going to have some significant mass to haul as well as drag to overcome, and so acceleration to orbital velocity will be no minor task.
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Well, I don't know about a high speed balloon or an electric thruster overcoming aerodynamic drag. However, the web site you linked says "electric thrust", not necessarilly ion engines. The VASIMR engine that was being developed by the Johnson Space Center uses hydrogen. They also say they intend to achieve 200,000 feet on boyancy alone. I've never heard of a balloon getting that high. My guess is you would have to use more hydrogen as lift gas instead of helium.
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More likely it would use a mixure of H2 and He, hydrogen with 20-30% helium to eliminate flammability concerns.
The VASIMR engine, as it stands right now, is still somthing of a pipe dream, not to mention all the fun of the high-power microwave generators (which you have to cool) and the superconducting magnets (which you have to keep cryogenicly cool) and cryogenic boiloff (missions lasting weeks?) among other things.
There aren't any other electric engine concepts except a hall-effect thruster available that could reasonably provide that kind of efficency without getting really heavy and generate reasonable thrust.
[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 problem there is, a reasonable cost estimate is so bad considering the very large development bill, that -no- tiny RLV like the TRC or what the AltSpace folks can make is profitable. The least ambitious one attempted, Kistler Aerospace's KH-1 is less then half finished and their company is bankrupt with heavy debt.
I don't think the development costs of the first stage are a problem. His X-prize vehicle could be seen as prototype for this first stage. With this prototype he can calculate how much a bigger vehicle would cost. If it is cheap enough, he can build a larger vehicle and use this as a first stage. But the development of the second stage may be more expensive. But i think he could use this bigger first stage as some sort of suborbital rocket. You simply replace the second stage with a large capsule and you have a big suborbital vehicle, which can take a lot of people on a suborbital ride. With the money he makes out of this, he can start developing a second stage. He also will be able to determine if a TRC-style vehicle is economical viable. If it's not, no problem, he can still use his first stage for suborbital hops.
Oh, and on a side note, the X-33's aerospike engines are beautiful because they operate just as well at high altitudes as low altitudes, plus have engine-out capacity built into each module. They really are great, albeit expensive, if you don't mind a little extra complexity.
Apparently Carmack agrees:
Aerospike engines:
We consider this often, because our low temperature rockets make it a far easier task than for conventional propellants. Its not in our current plans, but we may well give it a try at some point. The primary benefit would be allowing it to operate at very low chamber pressures without flow separation.
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I don't think the development costs of the first stage are a problem. His X-prize vehicle could be seen as prototype for this first stage. With this prototype he can calculate how much a bigger vehicle would cost. If it is cheap enough, he can build a larger vehicle and use this as a first stage. But the development of the second stage may be more expensive. But i think he could use this bigger first stage as some sort of suborbital rocket. You simply replace the second stage with a large capsule and you have a big suborbital vehicle, which can take a lot of people on a suborbital ride. With the money he makes out of this, he can start developing a second stage. He also will be able to determine if a TRC-style vehicle is economical viable. If it's not, no problem, he can still use his first stage for suborbital hops.
Yes, yes it is. Development costs for a orbital vehicle with tens of times the power of a little reuseable suborbital vehicle would be astronomical, thats what i'm saying, that the estimate is already known and it is too expensive for AltSpace to ever pay. We're talking hundreds of millions and more likly billions of dollars here, and this huge sum is not going to be "innovated away" with AltSpace magic... unless you count not paying your workers or relying on billionaire handouts.
There is very little market for a suborbital tourist rocket of any kind, especially when the X-Prizers' are fighting eachother to fill seats with deathwish millionaires, and it is certainly not enough to make an orbital vehicle. It is questionable if any of the X-Prize maniacs will ever make a dime if they can't fly often with many people, and thats just for minimal tourist rockets.
There is also no way a suborbital vehicle would make much of a first stage, because it is too small. You need many many times more energy to do this, and there is no purpose in building a giant suborbital vehicle, as there will be no one to ride it or payloads to carry.
As I have said before, you either build a vehicle which can reach orbit, or you don't, this is not somthing you can work your way up to in steps, because nobody will pay for the useless steps in-between a suborbital vehicle and a vehicle a hundred times more powerful.
[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 problem there is, a reasonable cost estimate is so bad considering the very large development bill, that -no- tiny RLV like the TRC or what the AltSpace folks can make is profitable.
Out of interst, what is the basis for such a 'reasonable cost estimate' and the 'very large development bill'? Does it take account of the DH-1's low fixed-facilities costs?
TRC claims their rocket would have comparable development and unit cost to a comercial airliner. (Which tend to be large, but not to the point of making profit impossible.) Since their anticipated customers are not profit oriented (military, government, speculation investors*) launch economics isn't seen as a problem.
As long as it functions as advertised. And hey, no-one's proven it can't yet. And GCNR, any time you want to name that item that can't be broken down into two ton pieces...
ANTIcarrot.
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Development costs for a orbital vehicle with tens of times the power of a little reuseable suborbital vehicle would be astronomical...
I think you underestimate here.
For example, I reckon that once you subtract the 'boost' given to SpacehipOne by its piggyback ride, the deltaV that comes from its own rocket is somewhere about 700m/sec. Realistically, the deltaV required for LEO insertion is about 8000m/sec.
Rule-of-thumb One, the energy required goes up with the square of the deltaV, so an 'orbital' SpacehipOne would need to pack about 130 times the punch.
Rule-of-thumb Two, the development cost goes up with the cube of the deltaV, so an 'orbital' SpacehipOne would cost about 1,482 times the cost of SpacehipOne.
We're told SpacehipOne cost about $20 million. On that basis, an orbital big brother would cost about $29.6 billion.
(This is very broadbrush. A detailed estimate may differ by several $ billion. But it gives you the general idea.)
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For example, I reckon that once you subtract the 'boost' given to SpacehipOne by its piggyback ride, the deltaV that comes from its own rocket is somewhere about 700m/sec. Realistically, the deltaV required for LEO insertion is about 8000m/sec.
SSO isn't designed to be a rocket though. It's designed to win the X-prize, and if 700mps is all that's needed, why give it more? This may be a fulfilled design goal rather than a design or operational limitation.
Out of interest, where did your rule of thumb number two come from? I can't find any mention of it online.
We're told SpacehipOne cost about $20 million. On that basis, an orbital big brother would cost about $29.6 billion.
Which would be a quite reasonable development cost (and consistant with inflation adjusted figures for similar designs) if it could launch once every two weeks. With a fleet of eight, that would ammount to 200 flights per year. Over a ten year launch scedual that works out to $15M per flight.
http://eh.net/hmit/ppowerusd/]http://eh … ppowerusd/
http://www.astronautix.com/project/sts. … ct/sts.htm
The US space shuttle had similar development costs ($30B in 2003 dollars) and has only spread them over a hundred flights. The super-spaceshipone is an improvement already. The S-SSO would also be able to operate without the fixed facilities cost that has so crippled shuttle operations. $2.8B anually a few years ago.
So a we have a 'shuttle II' that's between $350M and $700M cheaper per flight for that reason alone and can be launched from anywhre in the world. Sounds like a possible winner to me.
ANTIcarrot.
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I don't think its quite THAT terrible, but even if AltSpace could pull of a 10x reduction, that would still be more then they could ever earn even with small overhead costs. Orbital space travel cannot be accomplished without government sponsorship because it is too difficult and hence too expensive.
The smallest and simplest orbital RLV concept I take seriously is the DC-X program; the DC-I would have only one engine, no parachutes/air bags, no stages to recover or reassemble, and a payload size that is comperable to Delta or Zenit if the theoretical dry weight target could be attained.
And it would have cost $7Bn roughly, I would say probably $8Bn for early operational refinements, and make it $9-10Bn to develop a 4-6 seat crew varient with an escape pod. All that money for a vehicle with just one engine and no stupid glass tiles or other stuff that can hardly lift more than the Soyuz and less than Onega or Zenit.
The reason that there are no profitable orbital payloads less than around 5MT is simple. That building space ships in pieces that can be assembled in space, the cost of assembling them on orbit, and the risk involved will substantialy increase the cost of the payload such that it could cost more flying on a small launcher than to launch a bigger one flying on a larger launcher.
The best example of the failure of this philosophy is the International Space Station, built tinker-toy like and costing several times what a station of similar volume would if it were launched all at once... And to cut a satellite in half:
You increase the weight of fuel tanks per unit volume
You increase the weight of the structure
You have to have two descrete attitude control systems
You have to have two descrete power systems
You have to have two descrete communications systems
You have to have to have some sort of docking collar
You have to have two extra sides of the vehicle be bulkheads
You have to have a docking allignment system of some sort
You dely the time until the satellite is operational to at least the time between launches
All this so you can save a buck on launch costs? The resulting multicomponet vehicle would likly cost more than you would save over a "unitary" $250,000,000 satellite. And you still need to dock the kick stage and the kick stage fuel tank to it... Its almost as bad as building two seperate sats entirely. Building seperate satellites entirely would also need double the uplinks on Earth too, BTW.
The added risk alone, needing multiple flights to launch one satellite, the risk of the docking going flawlessly every time, the risk of componet damage... These are real questions the pencil pushes will force you to answer, and what will be your reply? To grin broadly and say "don't worry guys! it'll fly!"?
[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 best example of the failure of this philosophy is the International Space Station, built tinker-toy like and costing several times what a station of similar volume would if it were launched all at once...
The ISS was designed and built using congress's patented drip-feed funding, and many stages of redesign. It cost so much because of poor management that stuck to a decades old plan long after it because obvious the assumptions the idea was based upon weren't true any more.
And to cut a satellite in half:
>You increase the weight of fuel tanks per unit volume
Only if you split the fuel tanks between the two sections. Far more sensible to launch them in one or the other. What was the phrase you used to use? Straw-man argument?
>You increase the weight of the structure
Marginally. And only if you foolishly split it in half. You'd get better results splitting it into, say, ten pieces, one for each subsystem.
>You have to have two descrete attitude control systems
>You have to have two descrete power systems
>You have to have two descrete communications systems
Don't be silly. All these systems only have to function once the satellite is assembled in orbit. Hence only one of each is required.
>You have to have to have some sort of docking collar
No, only nut and bolt style attachment. After all, it's note like they'll be wanted to take 'undock' the components very often.
>You have to have two extra sides of the vehicle be bulkheads
>You have to have a docking allignment system of some sort
Silliness again. There is reason why the 'two halves' cannot be open ended. The pieces are stored at a small facility in orbit and do not need to be built to survive the space environment in isolation.
>You dely the time until the satellite is operational to at least the time between launches
Not a problem for a small RLV that can be launched in a few weeks or less. Satellite launches are often booked years in advance. A week will make no difference.
NB: The launching of a satellite in pieces assumes a small workshop in orbit where the RLV can dock and store components. The pilot can perform final assembly or robots system similar to NASA's robonaut can do it. In each case you're not building the satellite out of modules, but out of pieces - just like they do on the ground.
Advantages:
+Reduced risk and insurance. If one thing goes wrong, entire satellite is not written off.
+Encourages modular design. Reduces design cost.
+One size fits all launcher. Reduces design cost.
+Increases launch rate. Reduces $/lb cost.
+Pieces can be put together to form designs much larger than can be launched with current rockets.
+Could start a downward spiral in launch costs and a corresponding upward spiral in launch demand.
+Not inefficient when launching small satellites.
+Forces real (though small scale) space industry. A good thing overall.
All this so you can save a buck on launch costs?
For an experimental vehicle? No. But for an RLV to be an RLV it has to be fairly reliable with a quick turn around. Build an RLV to *be* an RLV and not a spaceplane, or a glider, or a BDB, or a flying technology lab, or any number of other things, and this is just possible. And if the RLV can undercut the ELVs by a factor of ten, and again this is more than just possible, then the maths adds up.
I'm not saying all the IFs will be solved for all RLVs, but if all the IFs are solved for only *one* RLV, then this will be a better way.
ANTIcarrot.
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The ISS's primary fundimental flaw is still its design strategy, that this lego-brick constuction method with medium launchers could do the job for a reasonable sum. This strategy has failed.
Ohhhh now you want to throw an orbital satellite factory into the mix? Well now, since it is a part of the system, you will have to finance its design too off the same devel. budget. And it has to be reliable to a fault. And you need to launch it somehow, but you aren't going to do that two tons at a time. (things without attitude control can spin) And then you have to integrate all the pieces together... in orbit with a robot or the MASSIVE expense of a human, doing harder and more dangerous things than Hubble repair... for less than the cost of building it on the ground and putting it on a bigger rocket.
...I don't think you've got a clue how hard it is to build a satellite that works that can survive launch. Making modular space-assembly satellites would multiply the cost several fold I imagine.
The pencil pushers just closed their breifcases and left your office
Edit: Oh yes, and would you like to hear an early price estimate for the robot Hubble mission? For the low-low price of only seven hundred million dollars! And a space satellite assembly platform would certainly be much more complicated than this. Building things in space = not going to happen, not then, not now, and not for a long 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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SSO isn't designed to be a rocket though.
Really? That'll be news for the designers.
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Well now, since it is a part of the system, you will have to finance its design too off the same devel. budget. And it has to be reliable to a fault.
Not particularly difficult for a salut style station. If you wanted to launch it all at once. It only has to be a floating shed, not a floting RV/science-lab. Nor does it need to house people full time. In fact it might not even need to be pressurised! It only has one purpose and only has to be designed for that one thing. And we tend not to have trouble building satellites that are reliable to a fault when they are inttended to do only one thing.
This is all in contrast to the ISS, which never had a true purpose except to justify the shuttle and ended up trying to be all singing and dancing and failing at it all.
in orbit with a robot or the MASSIVE expense of a human, doing harder and more dangerous things than Hubble repair
That's what I said Mr Can'tRead. However it won't be nearly as dangerous if the work is done inside the station (or in an inflatable hanger attached to it) and if the pilot/robot has a place where they can firmly attach themselves; the lack of which caused no end of problems during hubbel servicing. It's the same difference to doing work on the deck of an aircraft hanger during a storm, and going the same work in a protected area below decks.
I don't think you've got a clue how hard it is to build a satellite that works that can survive launch.
That's the whole point you silly person. If you assemble it in space the whole satellite does not have to survive launch! And it does not have to be written off if only one small component fails to survive launch, as you have to with an ELV.
And in case you didn't know, sattelites are already made of many smaller pieces! Putting them together creates problems which you are ignoring. A ground built satellite needs to waste mass supporting itself in 1G, an enviroment in which it will spend a small fraction of it's life. During launch components have to survive multiple Gs in non-optimal directions. (It is better to launch a panel on it's side rather than on it's edge.) A ground based satellite has to be designed to unfold to it's final shape. More to the point, a ground built sattelite has to be designed to be 100% reliable, because if it goes wrong during launch or deployment there's no way to fix it.
Oh yes, and would you like to hear an early price estimate for the robot Hubble mission?
You really don't get this whole 'reusable' idea do you?
http://www.abo.fi/~mlindroo/Station/ss1 … ss1998.htm quotes the price of the FGB at $222M. Add another $120M for proton launch. The 'shed' will not be as complex as the FGB, so probably will not cost nearly as much. Spread the cost over a hundred satellites, and low and behold! We get substantial cost savings.
Only one pencile pusher left. The corrupt one who's being bribed to back a singular position in spite of all logic.
Really? That'll be news for the designers. - JimM
Oh how we laugh. Such clever word play. How easily you twist my word rocket (as in launch vehicle) to rocket (as in any vehicle powered by a rocket engine); a completely different meaning I obviously never intended. Please. Stop. My sides are splitting.
ANTIcarrot.
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YOU: SSO isn't designed to be a rocket though.
ME: Really? That'll be news for the designers.
Oh how we laugh. Such clever word play. How easily you twist my word rocket (as in launch vehicle) to rocket (as in any vehicle powered by a rocket engine)
Eh? This is just balderdash. A rocket is a rocket.
WHAT
"...completely different meaning I obviously never intended."
??
You said SpaceshipOne was not a rocket. I said it was.
And what do you know, glory be, it is and always had been a rocket.
If you think it is 'clever word play' to state the obvious plainly and simply, then I fear you are utterly beyond reasoning with.
You know, I looked at your supposed refutations of GNRevenger's list of reasons why small payloads joined together in orbit was a bad idea and saw that every single one of your answers did not stand up. Then I came to your list of so-called advantages and saw that not one of them held water either.
I considered refuting every one of your 'refutations' and 'advantages' item by item but then thought, to what end? Virtually everyone else will have seen through your specious arguments in any case, leaving just yourself to convince--but you are too thick. So why bother?
Since you're so keen on building things up from small pieces, why don't you just go off and play with your Lego?
(And all without any clever word play, although some words are longer than one syllable. Sorry about that.)
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Yep, not a clue about building satellites...
...Which are bigger than the internal dimensions of the Functional Cargo Block often times. One reason why Boeing et al. have recently switched to four and five meter farings...
And you honestly believe that building a satellite from individual componets on orbit will be easier, cheaper, and profitable than building them on the ground? Oh come on... It may cost us a billion dollars to "fix" Hubble, which only involves capturing it, trading out some large modular componets (which cost big money to make them space-swappable) and a little wiring.
In short, stupid-easy compared to building a satellite from bits and pieces. Have you a clue how difficult and time consuming it would be to build in orbit? How much the cost of the unit would increase by making all the pieces kit-build-compatible? Rediculus, why you would need to plan everything with Tab A/Slot B construction, easy for robots or gloved astronauts to grab, absolutely minimal tools, no welding or spraying of anything, and you propose to do this without the cost spiraling out of control? Putting people on it or in it would torpedo the economics of such a nonsense plan entirely.
And how long would it take? Would it be fast enough to rival the launch rate of regular ELVs? And you seem to think that satellites are all cookie-cutter and the same, which I assure you they certainly are not, there is little commonality between them at all for the small number of GEO satellites, and you aren't going to make money off constellations of LEO satellites, that business model has failed miserably.
[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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I agree with GCNRevenger the problem with the ISS is its bits and pieces construction. Lego bricks are great but then again they fit together easily. Construction technigues that use that idea of design work well.
The problem with the iss is its in orbit, it has been changed and changed and people are using different systems of making there bricks.
Oh, its also a way to keep a really really expensive piece of equipment flying, so costs soar.
With the money that had been spent on it (close to 100Billion $us) (confirmed but probably more) what could have been done is design and use a really heavy lift which would have lobbed the whole lot up in 4 or 5 trips.
Chan eil mi aig a bheil ùidh ann an gleidheadh an status quo; Tha mi airson cur às e.
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This is one of the Few threads that brings up the 'Sea Launch' topic
CALT: There will be multiple land and sea-based launches of Long March 11 in 2023
https://twitter.com/CNSpaceflight/statu … 9727164417
There is still debate on using mobile/floating oil drilling rig, I will put the post here for now.
Former head of the Russian space agency and imperial military man Dmitry Rogozin, said in his column in Forbes magazine that Russian specialists would have to exert considerable efforts to restore the floating spaceport Sea Launch to operation. He said that before its handover to the company S7 all space launch control equipment was dismantled.
Sea Launch was awarded the Space Foundation's Space Achievement Award in 2000
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