It’s not news to anyone who has been reading him (and me, among others) for years, but Henry Spencer explains once again why NASA’s architecture choice is the wrong one (and no, I’m not talking about Ares):
There is also a longer-term advantage: if you decide to launch everything on one big rocket, what happens when you outgrow that rocket? Even if your early expeditions stay within the rocket’s capacity, presumably you’ll want to do bigger and more complex ones later. What then? Develop a still-larger rocket?
Even people who don’t want to depend on orbital assembly for the first expeditions to the Moon (or Mars, or wherever) often will concede that it will be necessary eventually. But then, where’s the gain in delaying it?
If you’re going to want to do orbital assembly anyway, you’re better off starting it right away, so even early expeditions can benefit from it. The only reason to delay it is if you think there won’t be any later expeditions – if you’re planning a dead-end programme.
I’ve never seen anyone even attempt to refute this logic.
[Update on Tuesday afternoon]
Well, here’s an attempt, but it uses ludicrous analogies:
One can only imagine someone talking to Prince Henry the Navigator circi 1410 and trying to convince him that adapting steam power (then known since Heron of Alexandria) to ships would be desirable to why not start now and stop messing with those quaint, wind powered caravels. Or someone else trying to sell jet engines to Lindbergh before crossing the Atlantic. Forever delaying doing things until the technology is “just right” doesn’t work very well.
No one is proposing the equivalent of steam power in the fifteenth century or jets in the nineteen twenties (though in the latter case, they weren’t far off). That would be akin to demanding a space elevator, or anti-matter rockets.
Nor is anyone, including me or Henry, proposing “forever delaying doing things until the technology is ‘just right.'” The technology for propellant depots could have been well in hand years ago had NASA stayed in the technology business, instead of cutting off all funding to it to redo what was done forty years ago. An assembly-based architecture could still easily be in place just as fast as NASA’s Constellation plans, and much cheaper, particularly given appropriate incentives to private industry. We are proposing that NASA plan for the future, with an affordable and sustainable plan, instead of looking to the past.
[Bumped]
[Mid-afternoon update]
It strikes me that this paragraph from my extended version of The Path Not Taken is relevant:
While the report of the Aldridge Commission on the new vision, released in June, had some good recommendations in it, it also had a few potentially disastrous ones. Perhaps the most damaging statement in it was to declare heavy-lift launch systems to be an “enabling technology” for carrying out the vision. This is a phrase of art in the engineering world meaning that, absent such a technology, the goal is unachievable. The commission is claiming that we cannot send humans beyond low earth orbit without a much larger launch vehicle than anything existing. If they had used the phrase “enhancing technology,” meaning that it’s not an absolute necessity, but that it makes things easier to do, I’d have less complaint, but as they’ve stated it, it commits us to an expensive development of a new launch system, that shows no promise of actually reducing costs. Moreover, it commits us to an approach to exploration that, like Apollo, is not affordable or sustainable.
I hope that this is a recommendation that can be revisited.
So, what are the chances the current NASA design will be trashed, and one involving construction in orbit developed?
A lot higher that they might have been had McCain won. Sometimes, there is a benefit to “change” (assuming that he means it, at least with space policy).
I’ve never seen anyone even attempt to refute this logic.
Yes you have, you were just rude to them about what idiots they obviously were.
This has been discussed ad nauseam on sci.space.policy.
At a simple level Henry is, as usual, absolutely correct. It’s a skill that we need and we probably shouldn’t delay in getting it.
At a practical level what is the low end of reliable, “low cost” launch system that you start from?
1,000kg, 5,000kg, 10,000kg, higher? What physical dimensions can you launch at those masses?
Even giving a reasonably reliable and low cost system, the risks and penalties associated with individual vehicle loses would still be unacceptably high if you have to distribute key components across multiple launches.
Below a certain physical set of dimensions and mass you’d start to find it hard to design things that were worth assembling.
At a practical level what is the low end of reliable, “low cost” launch system that you start from?
Jupiter 120 and Jupiter 232. NASA will never ever need anything bigger than that.
Yes you have, you were just rude to them about what idiots they obviously were.
Well, they were…
This has been discussed ad nauseam on sci.space.policy.
OK, I take it back.
There have been feeble and laughable attempts. Sort of like the ones to defend the notion that oil would stay above a hundred bucks a barrel.
Jupiter 120 and Jupiter 232. NASA will never ever need anything bigger than that.
Those are bigger than NASA will ever need. NASA does not ever need to develop another launch vehicle. The fact that they decided to regardless may be the death of the VSE.
The fact that they decided to regardless may be the death of the VSE.
Amen brother. I don’t think that it is the end of the VSE but it certainly is the end of the dead end, ill considered ESAS architecture.
At a practical level what is the low end of reliable, “low cost” launch system that you start from?
1,000kg, 5,000kg, 10,000kg, higher? What physical dimensions can you launch at those masses?
That question was asking, and answered, long ago, David.
The late Dr. Max Hunter pointed out that the largest item of space hardware that cannot be disassembled for transport is an adult human being (about 100 kg).
Even giving a reasonably reliable and low cost system, the risks and penalties associated with individual vehicle loses would still be unacceptably high if you have to distribute key components across multiple launches.
You misunderstand reliability. A well-designed (or evolved) system has margin and redundancy. It does not fail simply because one component fails.
If systems worked the way you state, modern industry would be impossible because key components are distributed across tens of thousands of aircraft, ships, and trucks. On any given day, some of those components will be delayed, lost, or fail to arrive at their destination.
Yet, industry continues even though some cargoes fail to arrive. The world does not come to a grinding halt, even when a ship sinks or an airliner crashes.
No one in his right mind would suggest that we could “mimimize risk” by putting all cargo and passengers onto one giant aircraft, ship, or truck. Replacing redundancy with a single point of failure does not, in fact, reduce risk. It magnifies it.
In marked contrast is the traditional space program, with its multiple single point failures. The idea that one can minimize risk by making an entire program dependent on one single launch is foolishness unique to the space industry. The result is that the space program is unable to tolerate most failures, and the entire program is in danger of collapse every time a failure occurs.
Furthermore, because launches are very rare events, the probability of a failure on any individual launch is very large, because there is no learning-curve effect to improve reliability.
Below a certain physical set of dimensions and mass you’d start to find it hard to design things that were worth assembling.
True, but as Max Hunter pointed out, those dimensions don’t demand giant rockets. Even with modest components, we can assemble anything we need to in space. No one has proposed building launchers smaller than the Hunter limit, so your objection is a red herring.
Daveon, you wrote:
Even giving a reasonably reliable and low cost system, the risks and penalties associated with individual vehicle loses would still be unacceptably high if you have to distribute key components across multiple launches.
I don’t see that. If a launch pops, you can squeeze the replacement parts in a future launch.
For example, suppose you need 10 launches of a vehicle with a 2% chance of launch failure. That’s crudely a 18% chance of one or more launch failures with less than 2% chance of two or more launch failures over the ten launches. So if you schedule 11 launches, you cover everything with a 2% chance of needing to schedule more launches on top of that.
If a failure occurs, then build a new payload and put it on a future launch. You lose only 10% of your mission and the schedule doesn’t slip much.
As a layman in these matters, one thing a heavy lifter would be very useful for would be lifting small nuclear reactors which are heavy and really couldn’t be assembled on site.
Also, an asteroid mitigation situation might require getting a lot of material in orbit in a hurry.
Economies of scale would seem to suggest that throwing up a lot of material (to be assembled) would be cheaper than more, smaller launches, but I may well be off base here.
I fully agree that one of the main thrusts of any space settlement program ought to be orbital and low gravity assembly, but I think heavy lift is still a useful capability.
Economies of scale would seem to suggest that throwing up a lot of material (to be assembled) would be cheaper than more, smaller launches, but I may well be off base here.
You are. Way off base.
The economies of scale of large vehicles flying rarely are dwarfed by orders of magnitude by the economies of scale of small vehicles flying frequently.
As a layman in these matters, one thing a heavy lifter would be very useful for would be lifting small nuclear reactors which are heavy and really couldn’t be assembled on site.
Ken, what makes you think a nuclear reactor “couldn’t be assembled on site”?
Construction workers assemble nuclear reactors on site all the time. At least, they did back in the days when we were still built nuclear power plants in the US.
A nuclear powerplant is too big to build any other way. There’s no truck or train big enough to transport a complete plant.
Granted, you said “small” nuclear reactor.
Okay, if you only want a small amount of power, you could launch a reactor in one piece. That may not even require a heavy lifter (if the power you want is small enough.)
But what happens when you need a powerplant that’s 50% larger than the one your heavy lifter can launch? Or 200%? Or 1000%?
At some point, we will need powerplants larger than anything we can build and launch on Earth. (Unless, of course, that we decide to stay on our current no-growth path and never do anything interesting in space.) Those plants might be nuclear, or they might be solar, but either way, they’re going to require that we develop the techiques and experience in space construction.
Also, it’s not certain that the environmentalists would ever let you launch a functioning, fueled nuclear reactor from Earth. It may be that they only way we’ll be allowed to do it is by launching a reactor “cold” and fueling it in space. The good news is there may very well be uranium on the Moon, but we’ll have to find it, process it into reactor rods, and load the rods into the reactor. In other words, we will need to do assembly of reactor components in space.
Also, an asteroid mitigation situation might require getting a lot of material in orbit in a hurry.
In that case, the giant rocket is the wrong way to go. Building a big rocket takes about 12-24 months. What if you don’t have one ready when the asteroid’s spotted? Or what if you do have one ready but there’s an in-flight failure when you try to launch it? Since this is an expendable rocket, you can’t just fly back to the launch pad, fix the problem, and wait for the next launch window. The range safety officer presses the button, and lose your entire mission. Now what?
Here’s a question for you to consider. Which of the following can launch more material in a week? A Saturn-class rocket that can launch a 100-ton payload, once? Or a fleet of 10 reusable spacecraft, which can carry only two tons on each flight, but each of which can fly five times a week?
The answer is that they can both launch the same amount in a week’s time. But the Saturn can only do it if you happen to have a Saturn ready and waiting on the pad. If you don’t, it will take weeks or months to get one ready.
And what happens if you need more than 100 tons? Given the reusable fleet, you can surge the flight rate by calling in mechanics to work on weekends. With the Saturn, all you can do to increase flight rate is call the factory and ask them to start building another one — which they they won’t be able to deliver for 12-24 months.
Economies of scale would seem to suggest that throwing up a lot of material (to be assembled) would be cheaper than more, smaller launches, but I may well be off base here.
Yes, you’re off base. The economics of launch scale weakly with vehicle size. They scale strongly with flight rate. Economies of scale will eventually dictate building larger spacecraft (just as they dictated building larger aircraft), but near term economies of scale call for getting the flight rate up, which calls for modest-sized vehicles. Just as it did in the early days of aviation.
“The economies of scale of large vehicles flying rarely are dwarfed by orders of magnitude by the economies of scale of small vehicles flying frequently.”
I see. That does make sense, thanks.
I still think that there are some capabilities that make HLVs useful.
One other thing does come to mind…
Given the economic problem with heavy lift that you mention, they are not likely to be developed by private industry, so have NASA focus SOLEY on developing a big HLV….and not at all on the sort of Yeoman rockets that would make up the vast bulk of any rational program…Just use things like Atlas and Falcon. It gets them out of the way of industry and still provides capability that might at some point be needed.
if you decide to launch everything on one big rocket, what happens when you outgrow that rocket?
A wonderful question because it contains it’s own answer within itself; however, it remains the wrong question because it’s being applied to NASA.
This question (how big?) is only answered by the economic decisions of multiple private companies.
Earlier Rand posted that NASA doesn’t need a scientist or engineer to lead it. That is closer to the real issue which is…
What should be NASA’s purpose?
That’s a political question.
How should NASA accomplish that purpose?
Not by building rockets or payloads. That’s the point that needs to be driven home. Then those great questions can be properly applied.
NASA could be a single office with a budget and a great leader (I would recommend certain science fiction writers.)
But with NASA being a political jobs program, how do we get there? I believe that is an important question that could use an answer.
I still think that there are some capabilities that make HLVs useful.
Something can be “useful” and still not worth the cost of developing and operating.
“Ken, what makes you think a nuclear reactor “couldn’t be assembled on site”? ”
Eventually, we ought to have factories for manufacturing nuclear power plants on the moon, Mars and perhaps Ganymede, Callisto and Titan.
However building those will require power. A base will require power….and building nuclear reactors is a complex process that can have nasty side effects if you screw it up. Its something that we probably don’t want to be doing while engaged in the steep (and necessary) learning curve of figuring out orbital and low-G manufacturing techniques.
A reactor might be shipped partially dissembled, but I would think that the reactor vessel at least, would need to be shipped in one piece, at least until one has built a manufacturing capability.
We have to learn to walk before we run.
“But what happens when you need a powerplant that’s 50% larger than the one your heavy lifter can launch? Or 200%? Or 1000%? ”
Well at that point one has a facility powered with nuclear reactors, and has learned all about building in the local environment….so you hire General Atomics or somebody to build a nuclear power plant manufacturing facility….and you put the last Sea Dragon (or whatever HLV you built) in the Smithsonian.
Which of the following can launch more material in a week? A Saturn-class rocket that can launch a 100-ton payload, once? Or a fleet of 10 reusable spacecraft, which can carry only two tons on each flight, but each of which can fly five times a week?
I call straw man… and it’s the wrong question, again.
Straw man because you limit 100 ton to once. Wrong question because it’s not: how much, but what cost?
Which cost more? 50 flights of 2 tons or one flight of 100? What about 4 flights of 25 ton? You can’t rely on historical precedent to answer this question?
We can say that when the government does it, it cost multiple times more than it should.
Well at that point one has a facility powered with nuclear reactors, and has learned all about building in the local environment….
No, at that point you have an International Space Station that’s approaching the end of its design life although it isn’t even finished yet, you can’t afford a full crew, and you’ve had to cancel all the research it was supposed to do just to get the money to keep it in orbit. You’ve learned precious little about working in space, and what you have learned has come at a very high cost.
You can wave all the heavy-lift viewgraphs you like, but the reality doesn’t quite match the viewgraphs.
You say “we learn to walk before we run,” but you want to keep breaking our legs with the same lead pipe that’s crippled us for 50 years.
Increasing the cost of space transportation will not help us to learn *anything* useful.
I call straw man… and it’s the wrong question, again.
Straw man because you limit 100 ton to once.
No, I don’t. Economics does. No one is going to get tens of billions of dollars to build a 100-ton RLV any time in the near future. Not until the launch market develops far beyond what it is at present.
Even if you got the money somehow, all you’d end up with is another Shuttle. A hangar queen that sits on the ground most of the time because there aren’t enough big payloads for it.
Which cost more? 50 flights of 2 tons or one flight of 100? What about 4 flights of 25 ton? You can’t rely on historical precedent to answer this question?
No, you can’t, unless you learn how to interpret historical data properly. That doesn’t mean cherrypicking one or two precedents and ignoring all the other variables involved.
Ken Talton, you wrote:
Given the economic problem with heavy lift that you mention, they are not likely to be developed by private industry, so have NASA focus SOLEY on developing a big HLV….and not at all on the sort of Yeoman rockets that would make up the vast bulk of any rational program…Just use things like Atlas and Falcon. It gets them out of the way of industry and still provides capability that might at some point be needed.
NASA doesn’t even need to do that. Note that the trend among commercial rockets is both greater payload capacity and greater launch frequency. There’s no reason to expect that commercial launch will stop at 25 tons (and 1-5 launches a year), especially with deep-pocketed customers like NASA and the DoD to encourage more investment.
“Well at that point one has a facility powered with nuclear reactors, and has learned all about building in the local environment….
No, at that point you have an International Space Station that’s approaching the end of its design life although it isn’t even finished yet, you can’t afford a full crew, and you’ve had to cancel all the research it was supposed to do just to get the money to keep it in orbit. You’ve learned precious little about working in space, and what you have learned has come at a very high cost.”
Ummmm no….
….because you would have learned a lot from building the base and the base was a success because it had adequate power from its one or more Toshiba mini reactors.
Heavy lift did not derail our space program, bad policies and a non competitive, top down approach to developing the shuttle did.
The space station is not taking more than its design life to build because it was thrown up in one or three big skylab sized pieces…
because it wasn’t…
It was put together piece by piece and suffered budget cutbacks and all the budgetary bloat associated with government programs plus the double secret bonus bloat associated with international government programs.
Getting NASA out of the commercial space business and replacing the “stick” with commercial rockets that have to meet real world cost benefit analysis will lower the cost to space. Developing reusable spacecraft will reduce the cost. Building the sort of orbital propellant depots that John Goff advocates will teach us scads about orbital construction…on this we are in agreement.
However,
A heavy lift booster ought not to increase the cost of transportation to space if it is not (like the shuttle) the only way to fly. It would simply be an expensive but potentially useful fallback capability. And in the case of nuclear reactors it might be the seed corn for being able to manufacture nearly everything off planet…complex components included.
I am not trying to lead pipe the space program.
@ Karl Hallowell Comment#20
That would be a vastly better option IMHO.
BTW, what, exactly IS a generally accepted payload capacity to LEO or GTO for a launcher to be considered heavy lift?
Most of the debate here has been about which rocket is better, a large rocket, or a small rocket? It shouldn’t be a choice like that. What we will ultimately need, is a family of rockets. Not like NASA is doing, but like Spacex is doing. A family of rockets, where they mostly use the same tooling, engines and design.
Look at how little it is costing Spacex to design and build this family of rockets. They will easily have a family of light, medium and heavy lift rockets, for less than it is costing to design and build Ares 1. If their very heavy lift rocket is also of simular design, then it could easily come in at under a billion dollars. Not the around 200 billion that Ares 5 will ultimately cost.
Then you can use the right size rocket for the right job. The US post office doesn’t deliver mail in a tractor trailer truck and they don’t ship mail from state to state, using one of their little trucks.
The right rocket, for the right job, but we need to set them up for low cost production, Like Henry Ford.
No, at that point you have an International Space Station that’s approaching the end of its design life although it isn’t even finished yet, you can’t afford a full crew, and you’ve had to cancel all the research it was supposed to do just to get the money to keep it in orbit. You’ve learned precious little about working in space, and what you have learned has come at a very high cost.”
Ummmm no….
….because you would have learned a lot from building the base and the base was a success because it had adequate power from its one or more Toshiba mini reactors.
Sorry, Ken, but that is fantasy. Look at ISS, and you won’t see any “Toshiba mini reactors.” The reality falls far short of your dreams.
Nor would ISS be a “success” (success at what?) if it simply had “adequate power.” (What makes you think it has inadequate power? What do you think it’s doing that requires more power?)
If Von Braun’s disintegrating totem poles could lead to all the things you predict, we would have had those things 40 years ago.
As Einstein said, insanity is doing the same thing over and over and expecting to get different results.
Getting NASA out of the commercial space business and replacing the “stick” with commercial rockets that have to meet real world cost benefit analysis will lower the cost to space. Developing reusable spacecraft will reduce the cost.
Exactly, and those spacecraft have nothing in common with Ares V, Jupiter 120, etc.
However, A heavy lift booster ought not to increase the cost of transportation to space if it is not (like the shuttle) the only way to fly. It would simply be an expensive but potentially useful fallback capability.
Perhaps in some imaginary world where NASA has an infinite budget. In the real world, NASA can’t afford to build and maintain a heavy lifter just as a “fallback capability.” If they build it, they will use it, and it will be the only thing they use because they won’t have any money leftover for anything else. Aeronautics, science, prizes, and everything else will continue to go down the tubes.
And in the case of nuclear reactors it might be the seed corn for being able to manufacture nearly everything off planet…complex components included.
Okay, in the first place, NASA isn’t going to have the money to develop those nuclear reactors, either, if they put all their money into building der Great Big Rocket.
In the second place, it’s strange that you say it’s too hard to assemble things in space then say NASA can “manufacture nearly everything off planet.” Which is it?
In the third place, economics matters. The cost of goods produced by any factory has to reflect the cost of building and operating the factory. There have been numerous studies of space manufacturing, and all of them show the same thing: For space manufacturing to be viable, we need significant reductions in space transportation costs.
In a way the ISS is evidence of the counter argument. There was so much extra cost and complexity to design it so it was stable at each stage of assembly, and the extra problems of on orbit integration and testing – plus issues where stuff lunched with out on the ground integration testing didn’t work together in orbit – that the program could have been done years faster, and cheaper (even including the cost of a custom HLV in the station budget) if it had been assembled no the ground and launched intact.
>> Jupiter 120 and Jupiter 232. NASA will never ever need anything bigger than that.
> Rand
> Those are bigger than NASA will ever need. NASA does not ever
> need to develop another launch vehicle. The fact that they decided
> to regardless may be the death of the VSE.
That’s three questions. Will they ever need anything bigger then X craft (especially extremely small boosters) is certainly yes. Trying to build something big out of tiny parts “on site” is expensive and a real safety hit – and could well not be possible for other reasons. Foe example early space station freedom designs had the struts almost completely assembled pipe by pipe by astronauts assembling them in space from piles of parts. The astronauts pointed out that NASA did have enough astronauts, since it would require so much EVA time, the entire career lifetime radiation dosage limits of the astronaut cor would be exceeded. NASA reluctantly launched pre assembled modules.
Should NASA ever build their own launch vehicle again? (Or more correctly custom order one since NASA doesn’t build them.) That certainly depends on what your doing , others are doing you can use, and of course political whims and needs. The constellation architecture at $30B>$40B..$50B?? Isn’t that big a chunk out of the projected $170B budgeted up to the return to the moon. Obviously you could do the same for a laughable fraction of that, but NASA couldn’t, and likely wouldn’t be allowed to return to the moon if the costs dropped too much.
> Edward Wright
> The late Dr. Max Hunter pointed out that the largest item
> of space hardware that cannot be disassembled for transport
> is an adult human being (about 100 kg).
One hopes Hunter knew (and you know) better then that. That not really even enough to launch a single person, and a hell of a lot of parts for things don’t break down that far (Hubbles Mirror, an upper stages engines, etc). Imagine trying to build a airliner or similar sized craft out of parts cut to fit the truck of a medium sized car. Nor would you want to break a whole ship down to such tiny peaces if you could avoid it. That forces you to effectively first construct the factor in orbit to build whatever it is you want up there.
>> Even giving a reasonably reliable and low cost system,
>> the risks and penalties associated with individual vehicle
>> loses would still be unacceptably high if you have to
>> distribute key components across multiple launches.
> Edward Wright
> You misunderstand reliability. A well-designed (or evolved)
> system has margin and redundancy. It does not fail simply
> because one component fails.
Actually you missed it Ed. Things often do fail missing one part. Your car, certainly space craft, etc.. More then that, the point is for systems like VSE everything has to launch simultaneously, and link for a mission. So the Ares 1 and V joint launches were projected to be far less likely to be able to complete a mission, then if both cargos launched, or didn’t launch, together no one big LV. Otherwise if one launches and the other can’t. Pretty soon the launched one is space junk.
Similarly for the ISS things had to launch on time ni order. If certain extra modules didn’t launch on time – at some key points, the rest of the station would be lost.
> Robert Simko
> Most of the debate here has been about which rocket is better,
> a large rocket, or a small rocket? It shouldn’t be a choice like that.
> What we will ultimately need, is a family of rockets. Not like
> NASA is doing, but like Spacex is doing. A family of rockets,
> where they mostly use the same tooling, engines and design.
That can make sence, but has limits. NASA likely could never get funding for families of craft due to political issues. Even if they could, what really is the advantage of carrying extra smaller craft in a family? Normally it’s a big advantage because smaller craft are hceaper to build and maintain, but with the current virtually nil flight rates, that doesn’t matter. All your costs now are in the R&D and fixed overhead. So multiple craft carry multiple R&D and support. SpaceX has cut that down a lot, but its still a extra. In contrast if you just build the biggest craft you’ll need for any of the loads, and fly it for all of them, the cost per flight is minimized since you’ve minimized the total overhead and R&D costs.
I know this sounds like buying a 18wheeler and having it do everything from taxi up a 2-3 folks, to carrying a 30 ton module. But with the per use costs negligible when compared to the overhead and development (such as was the case with even the shuttle, and we know how to cut the per use costs down 3 orders of mag for a craft like that), the cost of the overhead of a second class of craft cost more then the inefficient use of the big one.
Its not intuitive, since were not used craft where the global market for all “flights” of all craft is low tens per year. I.E. where the fixed overhead per flight is over a billion a launch, and much of it is insensitive to the size of the craft being launched.
> No, at that point you have an International Space Station that’s
> approaching the end of its design life although it isn’t even
> finished yet, you can’t afford a full crew, and you’ve had to
> cancel all the research it was supposed to do just to get the
> money to keep it in orbit. You’ve learned precious little about
> working in space, and what you have learned has come at a very high cost.”
Ah but Ken, none of that was what ISS was built for. Its mission was to be a joint international construction project ni orbit. Specifically to get Ex-Soviet Russians focused no building station – not building weapons for export. That’s what Clinton – Gore promoted it as. So the fact we did no R&D in orbit, and are about to throw it away as soon as we finish building it, makes perfect sense. It’s served it mission, since we built it together.
I’ld suggest not thinking about it to hard. It helps avoid screamnig and pounding your head no a wall.
> ken anthony Says:
December 15th, 2008 at 8:33 pm
> Which cost more? 50 flights of 2 tons or one flight of 100?
> What about 4 flights of 25 ton? You can’t rely on historical
> precedent to answer this question?
It is a complicated question, and you also must add in the extra cost of breaking down the 100 ton – whatever – into 2 ton parts, and design it for inspace reassembly.
Given NASA and its contractors agree it would cost NASA $1B – $1.2B to develop SS1 and $40?B to develop a new 25 ton RLV. Its likely your 2 ton RLVwould cost $10B-$20B? (Orion carrys nothing but crew, and is fully expendable and less safe, but still cost much of the cost of a new shuttle.) Plus a couple billion a year to care and feed for its KSC and JSC overhead – pretty much for either. In a good (not pork maximized) design the per flight maint and other costs can be ignored.
So if you’re 2 ton craft needs $15B to develop, 5 years to lift all the parts and integrate them together (lots of space walks) – that’s $15 + 5x$3B? or $30B total.
If your 25 ton cargo craft needs $40B to develop, and 1 year to launch and integrate. $40b + 1×4 = $44B total. Course 4 years of program costs and simpler building of 4 25 ton parts vrs 100 2 ton assemble able parts, and the much higher safety of using the more integrated parts — that $14b could easily be recovered.
I’m not talking about the ISS or some ISS follow on when I’m taking about nuclear reactors. I’m talking about the moon and possibly mars. I think the follow on to the ISS should be a series of Bigelow type stations…most privately owned. HLVs shouldn’t be necessary in any way for them.
“In the second place, it’s strange that you say it’s too hard to assemble things in space then say NASA can “manufacture nearly everything off planet.” Which is it?”
Both, I don’t say NASA can go out and build a nuclear reactor in space right now. It is, however, an eminently attainable goal once we have the proper infrastucture there.
We don’t have a great deal of space manufacturing expertise now.
We don’t have a facility to cast reactor vessels in space.
We don’t have the knowledge or the expertise to mine, smelt, or machine the components of a reactor on the moon.
Therefore it is currently unfeasable to start building large component items like reactor vessels, big mirrors and such. We can certainly learn to do so and indeed must if we are to do anything meaningful with the program. But we are not there yet.
The ISS was put together bit by bit and is a mess. Skylab was thrown up in one piece and despite some problems was a success. This does not mean that space construction can’t work (it saved Skylab after all)
However, it also doesn’t follow that because we developed an HLV and subsequently pissed it away, cut NASA’s budget, and designed the shuttle in a non-incremental fashion that insured no lessons could be learned and applied during its development….that the HLV was the crux of the problem. Bad decisions were.
“For space manufacturing to be viable, we need significant reductions in space transportation costs.”
I agree totally, but that is vanishingly unlikely to be solved via NASA and seems to really be a separate issue.
(This whole argument may be moot, if the little Toshiba reactors and their competitors have major components within the lift capacity of a Falcon 9H.)
> Ken Talton Says:
> December 16th, 2008 at 10:53 am
>
> == I think the follow on to the ISS should be
> a series of Bigelow type stations…most
> privately owned. HLVs shouldn’t be necessary
> in any way for them.
I’m not clear what you want that ISS successor to do? NOre am I clear what you’re assuming is a HLV? Currently 25 tons (like the shutle) is considered a HLV. It sounds like you are thinking 100 tonish?
” Ah but Ken, none of that was what ISS was built for. Its mission was to be a joint international construction project ni orbit. Specifically to get Ex-Soviet Russians focused no building station – not building weapons for export. ”
Ha! LOL Yes I know. I wasn’t talking about the ISS
but some future project that would focus on developing the proper skillsets…as opposed to the ISS which is such an incoherent mess as to be inapplicable on a policy basis except as a terrible terrible warning. (Though I certainly hope that SOME hands on skill lessons have been learned(
)
I think Ken and Kelly are getting mired into the design of an ideal space transport as the key driver to a successful space industry. The design is important but, to borrow from Rand, it is focusing on markets that is of primary concern to lower the cost of launch $ per pound. Letting multiple markets compete will eventually shake out which methodology is best to insure a successful launch industry.
Saying what is and isn’t heavy lift is purely semantics. What is considered heavy lift today could be just another launch vehicle later on down the road. That leads up back to the crux of the original conclusion to address the argument that, eventually you will need to do some type of on orbit assembly.
A perfect space transport flying every once and while is never going to out perform a 2nd rate launcher flying often.
The money one saves in developing, ‘the ideal space transport’ could be invested in technologies that allow for efficient assembly of components on orbit — perhaps in an automated fashion. Getting there to space is half the battle, building a sufficient infrastructure will insure market growth in the latter half.
As someone who builds PC computer systems for a living I can tell you that the most robust systems have a modular design. Laptop computers will never be a server because one controller or bus channel goes out and the whole system has to be replaced. Server systems are highly modular systems that just require the replacement of specific failed parts instead of having to scrap the whole system. They often are not built at a facility and shipped in whole to the site ready to go. They are partly assembled at a factory and built in place at the final destination. This also allow for scalability to address the power needs of an individual customer instead of forcing them all to adopt a one size fits all mentality. After all, a truly computer driven society doesn’t exist today with everyone dependent upon a handful of data centers scheduling and sharing computational time. The power of the computer was realized when the price per FLOPs was reduced to a reasonably attainable dollar figure that everyone could afford. I don’t think I should have to point out how computer markets have matured up unto this point.
The ISS didn’t cost more because of its modular in-orbit construction design. It cost more because NASA’s customer, the government, kept changing the design requirements to accommodate international partnership. Having to do integration design over and over again as modules were added and taken away led to the runaway development costs. If you keep moving the ball when it comes to project scope and goal then of course something is going to give — most notably time and budget.
Ah, I’m getting too long winded.
Here I suggest that Ken and Kelly just go read Rand’s lengthy thesis to get a better perspective.
http://www.transterrestrial.com/papers/The_Path_Not_Taken_Directors_Cut.html
> Ha! LOL Yes I know. I wasn’t talking about the ISS
> but some future project that would focus on
> developing the proper skillsets…as opposed
> to the ISS which is such an incoherent mess
> as to be inapplicable on a policy basis
> except as a terrible terrible warning.
> (Though I certainly hope that SOME hands
> on skill lessons have been learned)
Pork to district is the coin of the relm.
AAAAAAAAAAHHHHHHH!!!!!!!!!!!!!!
I keep remembering coming to work everyday on the SSFP program, past the paintings of the dual keel config on the walls with on orbit sheltered assembly bays, labs, free fliers….
8(
Really, were past the point where yuo can justify a station just to practice on buildnig and working in stations. I can see building one as a space opperations center where you assemble, service, or fuel deep space craft. Or a big industrial platform. Or a space port where commercial mini platforms come for cargo trans shipment, shielded residential / medical support, etc.
A station to study being on a station? (Much less show how many buracracies working together can make the most trivial effortimpossible.) Don’t think so.
The funny thing is that Apollo used orbital assembly, it just so happened that the LM and the SM were launched on the same rocket and the rendezvous and “assembly” occurred on a trans-lunar trajectory. We have the technology, it’s not that complex. If you can begin with breaking a vehicle into 2 or 3 pieces then many options open up which weren’t there before, and you lay the ground work for yet further improvements in orbital assembly.
@Kelly Stark
Yes, I was thinking BIG… uprated Saturn 5 or even Sea Dragon big. I had in my head of some of the big projects associated with the SPS proposals. If it can’t put up big unitary things like a reactor vessel and such then it’s probably not worth displacing commercial rockets and would, in fact be a retrogade step for the reasons others have mentioned.
Your comment also answers my earlier question about what the actual definition of an HLV is. Thank you.
Regards the function of a follow on to the ISS, a I’m not sure what function its serving now other than to give internationalists woodies. If there were a government run follow on, I’d hope it would be mainly a staging area/ shipyard for steps farther out…
Thank you all for the responses.
> Josh Reiter Says:
> December 16th, 2008 at 11:50 am
>
> I think Ken and Kelly are getting mired into the
> design of an ideal space transport as the key driver
> to a successful space industry. The design is important
> but, to borrow from Rand, it is focusing on markets that
> is of primary concern to lower the cost of launch $ per
> pound. Letting multiple markets compete will eventually
> shake out which methodology is best to insure a successful
> launch industry.
I think your mixing terms here. One – there is no real market for space launch now. Total global launch rate is about 50 flights a year and declining. Hence really no market to support enough flights to generate economies of scale.
Also markets don’t compete. Now if there were enough markets to support multiple launch vendors, those vendors could compete – but really now there isn’t enough to keep any of them from starving.
> The money one saves in developing, ‘the ideal
> space transport’ could be invested in technologies
> that allow for efficient assembly of components
> on orbit — perhaps in an automated fashion.
> Getting there to space is half the battle, building a
> sufficient infrastructure will insure market growth
> in the latter half.
I don’t follow your “building a sufficient infrastructure”? If you mean fielding a low cost reliable launch system will allow a market to grow – that’s arguable, but that seems to contradict your dismissing developing the ideal space transport?
Also really in contrast to the “break it all down to couple hundred pound peaces folks – you really don’t want to try assembling complex sats and the rest out of very small parts – then try to do the work of factories, quality testers, etc in orbit. It just costs too much.
Think of it as building a server farm, where everything’s shipped to you chip by chip in shrink wrap, and you have to assemble it in the parking lot while wearing gloves, and you can only survive so many hours in the parking lot per lifetime. The result likely will not be as good as one shipped in some big peaces (racks, blades, etc), and assembling the robot to assemble the server chip by chip, just moves the issue to the one time use assembly platform.
Or another example often quated is delivering a airliner to a customers hanger in boxes of parts sized to fit in a car truck sized UPS box.
Where a lot of small flights can give you a edge is where your lifting fuel and supplies. It doesn’t mater if you fuel comes up a buck at a time ot a 100 tons at a shot (give or take some issues) and “reassembling” the full propellant load in a tank requires no no-orbit assembly issues.
“Here I suggest that Ken and Kelly just go read Rand’s lengthy thesis to get a better perspective.”
I read it and agree in large part, particularly with regards to incremental approaches.
Regards Mr. Simbergs recent update, I simply think that heavy lift is a complementary asset for enabling colonization (and as he pointed out not necessarily an enabling one). I agree that it should not be the linchpin of a program as it does not reduce cost to orbit. A really heavy lift capability ought not detract from the larger goal of reducing cost to orbit.
The problems being raised seem more policy oriented than engineering oriented.
I was not saying that NASA should build a family of rockets. That is already being done and NASA would never be able to build a cost effective family of rockets. They should buy them as they need them, from a company like Spacex. I know many will say, that Spacex has only had one successful launch. But once they get the kinks worked out, they will be able to do much more, than work on goverment contracts. They will be able to compete prisewise, world wide for satellite contracts and space tourism.
NASA needs to go back to concentrating on R&D and qualifying rockets built by our commercial space companies. NASA needs to also drive research by American commercial companies, through setting goals and awarding X type prizes to the company that achieves that goal. Like a new type of rocket engine. They can also continue award COTS type contracts, that pay for performance.
> Robin Goodfellow Says:
> December 16th, 2008 at 12:00 pm
> The funny thing is that Apollo used orbital assembly,
> it just so happened that the LM and the SM were
> launched on the same rocket and the rendezvous and
> “assembly” occurred on a trans-lunar trajectory.
> We have the technology, it’s not that complex. If you
> can begin with breaking a vehicle into 2 or 3 pieces
> then many options open up which weren’t there before,
> and you lay the ground work for yet further improvements in orbital assembly.
That’s not really what folks are talking about her as to assembly. Its more docking autonomous parts. On the other hand, that’s likely a better model for no orbit assembly for the near future. Not breaking everything down into 10’s or a hundred launches worth, but a couple major prefabricated “lifts” that are docked and assembled in orbit.
The ISS was a crappy station and program, and assembling it when you had to get everything no orbit at the time and in order is a major problem and program risk – but it does offer a lot of advantages if you can organize better and don’t make an international forum out of it.
> Ken Talton Says:
> December 16th, 2008 at 12:02 pm
> Yes, I was thinking BIG… uprated Saturn 5 or even
> Sea Dragon big.====
Oooo Sea Dragon.
8)’’
Though really, Star Raker probably makes more sense. But unless your going to need millions of tons of uplift for something- its hard to justify.
>== I had in my head of some of the big projects
> associated with the SPS proposals. If it can’t put
> up big unitary things like a reactor vessel and such
> then it’s probably not worth displacing commercial
> rockets and would, in fact be a retrogade step for the
> reasons others have mentioned.
Yeah unless your going to build SPS fleets or O’Neil colonies – its hard to keep something that big busy. I mean Star Raker was sized to lift 100 tons a flight, with possibly 3 fights a day! A single ship could lift everything lifted in the last 30 years in a couple weeks! Then it collects dust, and over head eats you alive.
> Your comment also answers my earlier question
> about what the actual definition of an HLV is. Thank you.
Opps, I ment to check if anyone answered you..
> Regards the function of a follow on to the ISS, a
> I’m not sure what function its serving now other
> than to give internationalists woodies.==
Yeah, that’s about it.
And really it reinforces the myth that space is to expensive even for nations to do – so OBVIOUSLY, commercial projects in space are rediculas.
>8[
>==If there were a government run follow on, I’d hope
> it would be mainly a staging area/ shipyard for steps farther out…
Yeah, a central urban core supporting fleets of commercials, and deep space projects.
What I expected we’ld be building with shuttle by now.
:{
> Thank you all for the responses.
😉
Heavy lift (STS infrastructure) is how NASA funding bills get through Congress.
Back in the day when Sean O’Keefe was NASA administrator and Admiral Steidle was in charge of exploration systems, advocates of smaller launchers, on orbit assembly and propellant depots were perhaps positioned as well as they had ever been, from a political perspective.
Griffin’s attitude towards such things should have been apparent to all given his participation in that Planetary Society study and yet advocates of on-orbit assembly and fuel depots somehow failed to assure that a supportive choice was named to replace O’Keefe.
Going forward, cancellation of NASA’s human spaceflight budget (except perhaps for a modest ISS taxi capability) is more likely than a re-direction of NASA’s human spaceflight budget to a propellant depot centric architecture for the Moon and beyond, especially given Senator Nelson’s support (for example) of STS.
Also of note, Christopher Columbus wasn’t born in Spain.
Perhaps devotees of Henry Spencer shall need to emigrate to somewhere like Singapore and attempt to implement that approach there, thereby avoiding inflated BoLoMart prices and gaining access to an equatorial orbital inclination, simplifying launch window issues associated with the several dozen or more rendezvous events that replace a single large launch.
In a way the ISS is evidence of the counter argument. There was so much extra cost and complexity to design it so it was stable at each stage of assembly, and the extra problems of on orbit integration and testing
Yes, you’ve learned another of the “false lessons” Rand talks about.
– plus issues where stuff lunched with out on the ground integration testing didn’t work together in orbit – that the program could have been done years faster, and cheaper (even including the cost of a custom HLV in the station budget) if it had been assembled no the ground and launched intact.
ISS did have a custom HLV. The largest rocket the US ever built, after the Saturn V. It was called “Shuttle.”
early space station freedom designs had the struts almost completely assembled pipe by pipe by astronauts assembling them in space from piles of parts. The astronauts pointed out that NASA did have enough astronauts, since it would require so much EVA time, the entire career lifetime radiation dosage limits of the astronaut cor would be exceeded.
Kelly, you’re accepting all of NASA’s assumptions. 1) That anything built in space must be built by NASA. 2) That we should never be more astronauts we do at present. 3) That construction work should be done by NASA’s PhD astronauts instead of actual construction workers. 4) That it’s impossible to build a hangar so astronauts can assemble things inside instead of having to do everything via EVA.
Actually, 4) wasn’t even NASA’s assumption — the original Space Operations Center design included a pressurized hangar.
> The late Dr. Max Hunter pointed out that the largest item
> of space hardware that cannot be disassembled for transport
> is an adult human being (about 100 kg).
One hopes Hunter knew (and you know) better then that. That not really even enough to launch a single person, and a hell of a lot of parts for things don’t break down that far (Hubbles Mirror, an upper stages engines, etc).
Laugh. I’m pretty sure Max knew better, Kelly. He was the project manager for the Hubble!
http://www.maxwellhunter.com/Biography/spacetelescopeandMax_large.jpg
There are numerous concepts for building space telescopes with launching large mirrors, Kelly. Astronomers have proposed segmented mirrors, folding mirrors, optical interferometry (the current favorite), even manufacturing large mirrors on the Moon.
Astronomers are no longer satisfied with apertures the size of Hubble’s. Even on Earth, big telescopes are now built with segmented mirrors that are built in pieces and shipped to the construction site for assembly. In the future, they’re going to want apertures that are hundreds or even thousands of meters. Do you think NASA’s going to launch those in one piece?
As for rocket engines, a modern engine typically has a thrust-to-weight ratio of 100-200 to one. So, even a large engine does not weigh all that much. And if you can’t disassemble an engine into components, as you say, then you’re going to be in big trouble because you won’t be able to maintain that engine. If you can’t disassemble something into components, then you can’t replace components when they fail.
You’re arguing that we should never change the way we work in space or redesign anything to take advantage of cheap access to space or reduce costs.
Why is that?
Imagine trying to build a airliner or similar sized craft out of parts cut to fit the truck of a medium sized car.
That’s pretty much how we do it, Kelly. I can drive down to the Boeing surplus store and buy metal ingots and sheet metal — the same basic components used to build airliners. All of which fit easily into the back of a pickup truck.
Boeing doesn’t start with 200,000-pound ingots. Why would they?
Nor would you want to break a whole ship down to such tiny peaces if you could avoid it. That forces you to effectively first construct the factor in orbit to build whatever it is you want up there.
So???
You’re arguing that we should build a giant rocket so we never have to do anything ambitious in space, like building a factory in orbit.
I don’t accept that building factories in space is a bad thing. If we’re never going to build anything more ambitious than a 3-man Skylab stations (which you seem to regard as the role model for all future stations), why should we bother doing anything at all? We’ve learned about all we could from Skylab. Now, we should move on to bigger and better things — or just pack up, go home, and forget all this space stuff. Historical reenactments are not worth the cost.
Actually you missed it Ed. Things often do fail missing one part. Your car, certainly space craft, etc..
My car has enough redundancy and sufficient margin that it seldom fails because of one part. And the ground transportation system has massive redundancy — it does not fail because one car has problems. This is called a fault-tolerant system.
The same is true of sea and air transportation.
The National Space Transportation System, on the other hand, is large non-fault tolerant. Every time there’s an accident, the system comes to screeching halt, for years. The same thing happened in Apollo. What’s going to happen if you build a Moon base and your heavy lifter has to stand down for two years because of an accident investigation? Do you close the base down? Leave the crew there to starve? Worse still, what if it’s your lunar lander that has to stand down? Now, you have no way to get the crew home at all.
More then that, the point is for systems like VSE everything has to launch simultaneously, and link for a mission.
No, it doesn’t. Components could be launched over a period of months, even years. Look at the South Pole station as a model. Or even ISS.
So the Ares 1 and V joint launches were projected to be far less likely to be able to complete a mission, then if both cargos launched, or didn’t launch, together no one big LV. Otherwise if one launches and the other can’t. Pretty soon the launched one is space junk.
Well, that’s what you get for making VSE dependent on Ares. Now, if you had a reusable, high-flight rate launcher, all you’d have to do is refly the mission the next day. The same way Fedex or Air Mobility Command do, when something unexpected like an ice storm forces them to scrub a mission.
> NASA needs to go back to concentrating on
> R&D and qualifying rockets built by our commercial
> space companies. NASA needs to also drive research
> by American commercial companies, through setting
> goals and awarding X type prizes to the company that
> achieves that goal. Like a new type of rocket engine.
> They can also continue award COTS type contracts,
> that pay for performance.
We’ld all love that, but that’s not what they ever did, or what congress and voters want them to do. NASA was warped by Apollo into a mega project agency used to justify huge space centers, with 100’s of thousands of jobs in them. So you get shuttle not fixed because the fixes would save to much labor hours per flight – I.E. lay-off to many folks; and you get Ares.
When we look at Ares we see a bloated, engineering mess serving no real need. But when congress looks at it (until recently perhaps) they see a brilliantly designed system “utilizing” as many of the shuttle “team” as could wildly be conceived for a program that flies so few fights and does so little.
Adding in SRBs may be a safety and performance night mare, but it keeps costs up and keeps the money going to Utah. Using SSMEs keeps that team funded. The throw away capsule will employ a lot more people then the partly reusable shuttle or (horrors) a well designed fully reusable system like those the aerospace firms and space advocates have been proposing. The Ares-V big tank keeps the New Orleans facility fully funded.
All in all a masterful design to maximize costs in the proper districts.
..now if the damn thing actually worked, and that misbegotten SpaceX didn’t make it look laughably overpriced.
COTS was supposed to show the commercial could do anything! Now SpaceX is actually delivering!!!
…Yes follow the dark path into the mind and soul of “the district”…. Ignore the screaming of tortured libertarians and space advocates. Each scream is another useless job in your district.
I’m not talking about the ISS or some ISS follow on when I’m taking about nuclear reactors. I’m talking about the moon and possibly mars.
So? What makes you think building an ISS on the Moon or Mars would turn out any different? With affordable space transportation, it doesn’t matter what the view is like out the window.
Both, I don’t say NASA can go out and build a nuclear reactor in space right now. It is, however, an eminently attainable goal once we have the proper infrastucture there.
And NASA will never be able to develop any infrastructure, if they spend all their money building Great Big Rockets. Look at ISS, and you will see all NASA can afford with current transportation costs.
“For space manufacturing to be viable, we need significant reductions in space transportation costs.”
I agree totally, but that is vanishingly unlikely to be solved via NASA and seems to really be a separate issue.
No one said it would be solved by NASA. That’s why NASA should be required to use commercial space transportation *as the Launch Service Purchase Act requires* and not build an HLV.
I thought of a couple of observations. First, a reasonable development of a heavy launch vehicle would involve constructing smaller prototypes to test designs and ideas. If you are doing that anyway, it’s not unreasonable to turn those prototypes into viable launch vehicles. It only makes sense, if those other vehicles can compete in their launch markets. SpaceX, for example, can do that. NASA, with Ares I and V, cannot since the Ares I is competing with the EELVs.
Second, while the launch market collapsed in 2001, it has been steadily growing since then. Last year, in 2007, there were 23 commercial launches and 45 non-commercial launches (according to the Office of Commercial Space Transportation). Non-commercial launches aren’t really going anywhere (at least by number of launches, it’s been near 45 for the past ten years), but commerical launches have gone up since 2004 where there were only 15 launches. It’s still well shy of the years, 1998-2000 when there were 35-36 launches per year.
Now maybe the downturn will cause another reset of space launch demand, but it’s not just a story of uniformly dropping demand. The demand creeps up when the economy gets better.
Another thing to keep in mind. Virtually everything made on Earth is composed out of stuff that can fit in a standard tractor-trailer or railcar, in other words a “TEU” or “twenty-foot equivalent unit”. A growing number of rockets can launch a TEU with almost the allowed mass (24 metric tons including container mass, 21-22 metric tons, ignoring container mass). This seems a reasonable base unit in the future for space launch infrastructure.
> Bill White Says:
> December 16th, 2008 at 12:41 pm
> Heavy lift (STS infrastructure) is how NASA funding bills get through Congress.
> Back in the day when Sean O’Keefe was NASA
> administrator and Admiral Steidle was in charge
> of exploration systems, advocates of smaller launchers,
> on orbit assembly and propellant depots were perhaps
> positioned as well as they had ever been, from a political perspective.
Griffin’s attitude towards such things should have been apparent to all given his participation in that Planetary Society study and yet advocates of on-orbit assembly and fuel depots somehow failed to assure that a supportive choice was named to replace O’Keefe.
Going forward, cancellation of NASA’s human spaceflight budget (except perhaps for a modest ISS taxi capability) is more likely than a re-direction of NASA’s human spaceflight budget to a propellant depot centric architecture for the Moon and beyond, especially given Senator Nelson’s support (for example) of STS.
Also of note, Christopher Columbus wasn’t born in Spain.
Perhaps devotees of Henry Spencer shall need to emigrate to somewhere like Singapore and attempt to implement that approach there, thereby avoiding inflated BoLoMart prices and gaining access to an equatorial orbital inclination, simplifying launch window issues associated with the several dozen or more rendezvous events that replace a single large launch.
> Edward Wright Says:
> December 16th, 2008 at 12:46 pm
>> In a way the ISS is evidence of the counter argument.
>> There was so much extra cost and complexity to design
>> it so it was stable at each stage of assembly, and the
>> extra problems of on orbit integration and testing
> Yes, you’ve learned another of the “false lessons” Rand talks about.
It’s a real issue, and a real cost and danger of building stuff up from lots of little parts.
>> – plus issues where stuff lunched with out on the
>> ground integration testing didn’t work together
>> in orbit – that the program could have been done
>> years faster, and cheaper (even including the cost
>> of a custom HLV in the station budget) if it had
>> been assembled no the ground and launched intact.
> ISS did have a custom HLV. == It was called “Shuttle.”
I – and JSC – was talking a Sat-V cargo class “Shuttle C” lifting 2 skylab like cylinders.
HLV in the old school definition.
> early space station freedom designs had the struts almost completely assembled pipe by pipe by astronauts assembling them in space from piles of parts. The astronauts pointed out that NASA did have enough astronauts, since it would require so much EVA time, the entire career lifetime radiation dosage limits of the astronaut cor would be exceeded.
> Kelly, you’re accepting all of NASA’s assumptions.
> 1) That anything built in space must be built by NASA.
It wouldn’t serve any purpose otherwise. And helping to develop a low cost, or even high cost, commercial launch space astronaut core would be NASA founding its own competitors.
Again, like with CATS, you’re offering NASA the chance to hire hit men to kill the agency – they are not going to do it, nor will congress pay for it.
They are not there to make space advocates dreams come true Ed. I spent 15-16 years in NASA programs and had that lesson beat into me over and over.
> 2) That we should never be more astronauts we do at present.
> 3) That construction work should be done by NASA’s
> PhD astronauts instead of actual construction workers.
Hell, they get so many resumes they throw out the non PhD candidates just to cut down the stack. They have a limited # of job slots, and have no reason to expand it. So they hire the most over qualified and insanely desperate to get the job at any cost candidates.
> 4) That it’s impossible to build a hangar so astronauts
> can assemble things inside instead of having to do everything via EVA.
> Actually, 4) wasn’t even NASA’s assumption — the
> original Space Operations Center design included a pressurized hangar.
Not big enough to build SSFP or ISS sections in it.
>>> The late Dr. Max Hunter pointed out that the largest item
>>> of space hardware that cannot be disassembled for transport
>>> is an adult human being (about 100 kg).
>> One hopes Hunter knew (and you know) better
>> then that. That not really even enough to launch
>> a single person, and a hell of a lot of parts for
>> things don’t break down that far (Hubbles Mirror, an upper stages engines, etc).
> Laugh. I’m pretty sure Max knew better, Kelly.
> He was the project manager for the Hubble!
Yup. I’m sure he had a lot of folks rib him for that it all can be reduced down to a 200# person.. quip.
😉
It really does get to be a cost reliability nightmare – and in some cases you just can’t build it.
.
>==
> Astronomers are no longer satisfied with apertures the
> size of Hubble’s. Even on Earth, big telescopes are now
> built with segmented mirrors that are built in pieces and
> shipped to the construction site for assembly. In the future,
> they’re going to want apertures that are hundreds or
> even thousands of meters. Do you think NASA’s going
> to launch those in one piece?
Hell they don’t even plan to ever replace Hubble when it dies in a few years.
That’s all part of what Griffen figures was what NASA never should have done over the last 30 years.
There were designs for fleets of free flying arrays of Hubble or smaller then Hubble sats that precisely measure their inter-sat location and range and ground computers integrate it; but that was all dropped.
> As for rocket engines, a modern engine typically
> has a thrust-to-weight ratio of 100-200 to one. So,
> even a large engine does not weigh all that much.
With The Altair/Orion stack weighing ni at close to 200 tons on orbit., and engines usually should be integrated in with their support electronics etc, you still likely talking a couple tons.
> And if you can’t disassemble an engine into components,
> as you say, then you’re going to be in big trouble
> because you won’t be able to maintain that engine.
> If you can’t disassemble something into components,
> then you can’t replace components when they fail.
The point of the Shuttle was everything went up in major assemblies – even full LEO to lunar LEMs – and it was all landed together for sevicnig. Nopw the idea for NASA is its all thrown away after every use.
Really, you can’t service a big ship, by taking it apart peace by peace and shiping it down. You really need a few big assemblies for a lot of the major stuff. Trying to do factory level rebuilds ni space is a waste.
Really, rather then all those on orbit space walks to repait Hubble, it would have been cheaper to land it ni noe peace and send it all back to the factory for refurb and later relaunch.
> You’re arguing that we should never change
> the way we work in space or redesign anything
> to take advantage of cheap access to space or reduce costs.
No I’m saying doing things the way your suggesting raises costs, and makes even less sense if you have a CATS system. Rather then training huge numbers of astrounants to do dangerous no orbit repairs and assembly, put it back in the space truck, fly it down and send it back to the manufacturer, then fly it back up and re dock it.
Yeah if you have a 2001 space odyssey wheel station you take out major parst like in a building and send those down for rework, but talking about breaking it down unnecessarily into hundreds of parts to unnecessarily increase flight rates, just increases your costs unnecessarily. The point of the exercise should be to develop a holistic, low cost system.
Ok, if your NASA you do NOT want a low cost system, but I’ll assume you and I are referring for something more significant then gov pork driven designs.
>> Imagine trying to build a airliner or similar sized craft out
>> of parts cut to fit the truck of a medium sized car.
> That’s pretty much how we do it, Kelly. ==
No, we don’t. I’ve been on programs like that. You order wing beams the size of a pair of SRBs stacked one no the other, milled out of a single block of aluminum. Engines the size of UPS trucks, fuselage panels or hull segments the size of a 747 fuselage carried in 747’s built up like supper guppies. Banks of seats, etc, etc
All that goes into assembly buildings you could slide foot ball fields into intact. And all that is linked to hundreds of folks assembling, integrating, and testing all that.
>> Nor would you want to break a whole ship down
>> to such tiny peaces if you could avoid it. That
>>forces you to effectively first construct the factor
>> in orbit to build whatever it is you want up there.
> So???
> You’re arguing that we should build a giant rocket
> so we never have to do anything ambitious in space,
> like building a factory in orbit.
No, I’m saying do something ambitious in space THAT’S USEFULL. Building a city in space so you can avoid building a 25 ton lift craft as apose to a 2 ton lift craft is nuts given the orbital city platform to support the factory would be thousands of tons and a hundred times the cost of the larger RLV its replacing.
The point isn’t to build a factory in space for its own sake damn the crippling costs (ISS uselessness raised to levels even the feds would blush at) – its to build a viable economical SOMETHING in space that’s worth its cost and getting you usefull results. I.E. starting a viable space industry and settlement.
> I don’t accept that building factories in
> space is a bad thing. If we’re never going to
> build anything more ambitious than a 3-man
> Skylab stations (which you seem to regard as
> the role model for all future stations), ==
My point was ISS vers Skylab showed you can really save a ton of cost and trouble building things out of biger assemblies. There are limits. Unless your building a O’Neil or fleets of SSPS a 100 ton HLV likely isn’t cost effective – though for ISS it would have been due to the crippling constraints on shuttle.
What you seemed to be arguing was building up ISS or bigger platforms out of hundreds of 1 ton parts assembled in orbit – which would be VERY expensive, and unsafe.
>>Actually you missed it Ed. Things often
>>do fail missing one part. Your car, certainly space craft, etc..
> My car has enough redundancy and sufficient margin
> that it seldom fails because of one part. ===
Really? Try flattening a tire, , kinking a fuel line, killing your battery, crack a water pump, remove a head bolt, etc.
You cars a collection of critical parts – all need to be precisely integrated and tested as a whole. Or at least in major sub assemblies.
> The National Space Transportation System, on
> the other hand, is large non-fault tolerant. Every
> time there’s an accident, the system comes to
> screeching halt, for years. ==
Right. NO demand for launches, so no ability to support multiple redundant craft. Course that’s unrelated to the lots of little parts, vrs a few big parts discussion. Nor does filding a wildly uneconomical orbital infrastructure project help.
>> More then that, the point is for systems like VSE
>> everything has to launch simultaneously, and link for a mission.
> No, it doesn’t. Components could be launched
> over a period of months, even years. Look at the
> South Pole station as a model. Or even ISS.
I was refernig to ISS, before, but Apollo on steroids is worse since you can’t park either of the 2 launched craft ni orbit. If either stays in orbit for more then a couple days in orbit without the other the missions a scrub and you dispose or the launched part.
ISS AT SOME POINTS ni its assembly could be left in orbit for moths or years without the next part coming up. But at other points it was critical that the next part get up no time or it starts to unravel. Like the South polar stations – if the years build isn’t pretty much finished by the winter – it will be trashed by spring.
>> So the Ares 1 and V joint launches were projected
>> to be far less likely to be able to complete a mission,
>> then if both cargos launched, or didn’t launch,
>> together no one big LV. Otherwise if one launches
>> and the other can’t. Pretty soon the launched one is space junk.
>
> Well, that’s what you get for making VSE dependent
> on Ares. Now, if you had a reusable, high-flight rate
> launcher, all you’d have to do is refly the mission the
> next day. The same way Fedex or Air Mobility Command
> do, when something unexpected like an ice storm forces
> them to scrub a mission.
But theres nothing else for your high-flight rate launcher (big or little really) to do. I agree that a fast turn around craft would allow you – MAYBE – to swap out the cargo into a new LV and boost it up the next day (assuming you can unload/reload it quickly), but then if your NASA such a craft doesn’t support the thousands of ground support workers, which eliminates the reason and political support for the return to the moon program. Also you don’t save much money, since the high flight rate capable craft just collects dust the rest of the time.
I would STRONGLY agree a NASA should build a CATS supper shuttle and field it. If it ate the cost of fielding it and the overhead of the centers, the low cost per flight could foster a explosion of onorbit development. But that’s not what NASA is funded for.
You have to laugh at some of the ideas here. Probably the most laughable is the Hunter limit, “the largest necessary component launched into space in one piece that cannot be disassembled is a human being.” Guffaw guffaw.
Or how about Edward Wright riding that silly trajectory all the was down to “r(t)< Re”? I doubt the shivering members of the South pole station would be too excited about their habitat being delivered in 3 lb alumninum and glass ingots.
Come on, guys. Deal in the here and now, not in a theoretical fantasy world of Heinlein’s fashioning. There is a context to the current space environment, and that, unfortunately, is one that still is within the scale of DOD space and NASA’s budgets.
Any kind of plan, NASA or commercial, that depends upon the expansion of large markets outside of the scope of NASA and DOD space is currently speculative at best. That’s why you’ll notice already the majority customer for SpaceX is Nasa and DOD space. That’s just a reality.
There really is a minimum practicable size for components in space, just as there is a minimum practicable size for seagoing vessels. Yes, technically you can ship computers one at a time on a series sanpans from Xianjing to Oakland (in fact Cocaine is shipped into Oakland from remote Columbian villages in just this manner) but the reality is that the smallest size of anything really shipped from Xianjing to Oakland is a freight container.
There is good reason to suspect that the minimum practicable size for discrete launch of space exploration components to LEO at current technology levels is somewhat larger than the capacity of space shuttle. (I know, this is heresy, right?)
I offer as evidence the following:
1. Generic human support equipment has redundancy and QA requirements that generally mandates pre-launch assembly and a minimum practical weight somewhere between 2-4 tons per person, with a minimum size of about 4-6 tons
whether it is 1 or 5 people you are supporting.
2. human support equipment that connects together has to have certain components including: -docking ring and docking systems
-sufficiently sized RCS, navigation, and propulsion equipment. This stuff has a definite minimum size. For a capsule like Dragon, assume 1 ton.
3. It is extremely difficult to separate propulsion components like the engine from their fuel, or at the very least their empy fuel tank. That stuff has a minimum size as well. For a large propulsion requirement like TLI or TMI, etc, you are going to need a sufficiently large engine and fuel tank. For the 6-7 tons you already need, assume another 2-3 tons of engine and fuel tank.
4. The fuel fraction effect. Add up #1,#2 and #3. Then realize that whatever you got dry for TMI or TLI, you’re going to need either 3 or 5 times that amount in fuel (depending on whether you have LH2 or RP-1 as your fuel) and oxidizer.
Ok, so now you’re at shuttle-sized minimum launch weights. This can be cut quite a bit by
using a fuel depot as many have mentioned — but of course, now you’re once again relying upon a required infrastucture that just doesn’t yet exist. Pretty soon you’re looking at building an ISS-sized fuel depot on orbit in order to get anything done. Good luck justifying that to congress.
What matters for the NASA budget is not taxpayer return on investment (taxpayer ROI), but Politician Return on Political Capital Expended. (RPCE). Since RPCE for space projects will always follow years after appropriations, RPCE for Space will always be lower than RPCE for wealth redistribution.
Edward Wright Says:
December 16th, 2008 at 12:59 pm
==
> And NASA will never be able to develop any
> infrastructure, if they spend all their money
> building Great Big Rockets. Look at ISS, and
> you will see all NASA can afford with current transportation costs.
ISS’ problems are not related to space access costs. Even for it – launch costs were not huge factor, and really building a big HLV (100 to lift) would have cut ISS costs compared to the small HLV (25 ton lift) shuttle. So its not really supporting your point.
Again, given my druthers, I’ld see NASA pay to have a commercial team/firm field a low cost RLV, eat the overhead, and let the team market the rest at margin cost etc (worked this up in some detail if curious, but you get the idea). That could cut costs to orbit of a fully loaded craft down below $100 per pound to orbit. However none of this would suit the needs of NASA or its masters in congress, or get public support. I.E. congresses votes would not secure them reelection.
> # Karl Hallowell Says:
> December 16th, 2008 at 1:09 pm
> I thought of a couple of observations. First, a reasonable development
> of a heavy launch vehicle would involve constructing smaller prototypes
> to test designs and ideas. ==
Not really. For a 25 ton lift, very low operating and servicing cost, RLV; all the areo firms have said its pretty much a low risk efort. The subscale prototypes of concepts and designs were done long ago. (The DC-X program was the most well known.) so unless your going really exotic like a Star Raker, the bids for commercial (not gov) development is for $5B-$10B and 5+ years for a 25 ton ish RLV with a thousand fold labor cost per flight reduction. No takers from DOD, NASA, or anyone else though.
> Second, while the launch market collapsed in 2001, it has been
> steadily growing since then. Last year, in 2007, there were 23
> commercial launches and 45 non-commercial launches
> (according to the Office of Commercial Space Transportation). ==
Thats still so low there is nothing like economies of scale. Hell competician actually raises prices all things being equal. Which show how nasty a economic corner were into with space launch.