As you might expect in the doldrums of August, there wasn’t much news on the space policy front last week; good news for me while I spent the week on vacation. A few items of note:
- NASA is looking for more money in its FY2007 budget proposal for the Mars Scout program, an effort to develop low-cost Mars mission analogous to the Discovery program of planetary science missions. Phoenix, the first Mars Scout mission, is scheduled for launch in 2007, with the second Mars Scout mission planned for 2011. The experience from Phoenix told NASA Mars managers that the original cost cap of $325 million is too low, and instead are looking for something at or above $400 million.
- Ongoing cost overruns with the James Webb Space Telescope (JWST) could degrade the telescope’s effectiveness, New Scientist reports. One proposed way to cut $150 million from JWST is to polish the telescope’s mirror segments once instead of twice. That would prevent the telescope from making effective observations at wavelengths below 1.7 microns unless it took much longer exposures. While JWST was designed primarily to observe at infrared wavelengths, astronomers had hoped to use the telescope down to 0.6 microns, in the middle of the visible band. This could lead to pressure on NASA and Congress from astronomers who do work at visible wavelengths to either preserve this capability on JWST and/or ensure that a Hubble servicing mission is restored.
- ATK, which arguably has the most to gain or lose on NASA’s pending decision for new crew and cargo launch vehicles, has enlisted a number of former astronauts as lobbyists. Six former astronauts—Daniel Barry, John Blaha, Charles Bolden, Daniel Bursch, Franklin Chang-Diaz, and Thomas Jones—have registered as lobbyists representing the company. Another former astronaut, Scott Horowitz, already works for ATK; he was pushing for a SRB-derived CEV launch vehicle even before he left NASA last year.
Good find that interview with McCuistion – he’s scheduled to speak at the 1st Sep Mars Rover update news briefing on NASA TV – maybe he’ll say more about how he’s shaping the Mars program.
There is another important space news item today. Katrina and The Waves hit the Michoud plant that builds the external shuttle tanks. The extent of the damage is not clear, but it goes to show that NASA’s human spaceflight program has too many eggs in too few baskets. That’s partly because the the space shuttle and the space station were too monolithic all along. Looking forward, the question is whether NASA finally has an excuse to bury these white elephants.
While I now agree with you that it’s time to give up on the Shuttle (although for entirely different reasons), this statement is wilding unfair, and in its implications inaccurate. No launch vehicle is likely to have more than one facility to manufacture large tanks. Any launch vehicle’s manufacturing or launch facilities can suffer from natural disasters. The Shuttle is no worse and no better than any other vehicle in this respect.
Also, the ET facility may be required for any Shuttle-derived heavy launch vehicle. We may have lost far more than just the Shuttle. . . .
— Donald
No, one of the main shortcomings of the shuttle is that it is a logistical Rube Goldberg machine. The way to cut costs is to simplify launch preparation as much as possible. The shuttle, by contrast, has a proliferation of irreplaceable, vulnerable assets.
Name a launch vehicle with a 29,000 kilogram payload, and a launch system that can lift 100,000 kilograms that isn’t a Rube Goldberg machine? But I don’t really disagree with you that the Shuttle is too complex, only that no large launch vehicle has been built that is not critically dependent on several ground facilities.
BTW, I was always impressed that the Air Force managed to create a launch vehicle after the STS that was even more rediculously over-complex than the Shuttle, cost even more to put a kilogram into orbit, and had a far lower success rate. The name of this wonder? The Titan-IV, which, as I recall, was used to launch Cassini.
— Donald
Name a launch vehicle with a 29,000 kilogram payload, and a launch system that can lift 100,000 kilograms that isn’t a Rube Goldberg machine?
Scaled-up ‘Big Dumb Boosters’ would have been a lot simpler than the shuttle.
Ah, but could or would a “Big Dumn Booster” have been assembled without being vulnerable to natural disasters? It seems to me that if you do the whole thing at one location, you make it _more_ vulnerable. Is it not a basic tenet of chemical engineering that you put each element of a dangerous procedure as far away from every other part as you can?
— Donald
Ah, but could or would a “Big Dumb Booster” have been assembled without being vulnerable to natural disasters?
Some designs would have been very much less susceptible. For example, the first stages of those with high strength steel tanks and pressure-fed engines, especially if designed for recovery after splashing into the ocean.
When somebody builds one (and let you get me wrong I’d love to see it happen as long as it doesn’t come out of the exploration budget), I’ll withdraw my comment.
— Donald
[ Some designs would have been very much less susceptible. For example, the first stages of those with high strength steel tanks and pressure-fed engines, especially if designed for recovery after splashing into the ocean.]
How you thought about how big that that Big Dumb Booster (TM) rocket stack would be, and how difficult it would be to protect the stack from high winds at the launch pad, and how arduous it would be to roll a very big dumb missile stack back to the Vehicle Assembly Building if a storm threatened?
Confucious say, “All rilly cheap and simple panaceas are phoney.”
Boeing, by the way, has offered to recover and re-use its Delta turbopump fed first stage boosters `a la mode Shuttle Solid Rocket Booster: fish ‘em out of the Atlantic, wash them with fresh water, inspect — and reuse. No disassembly and remanufacture of booster segments required.
“Boeing, by the way, has offered to recover and re-use its Delta turbopump fed first stage boosters `a la mode Shuttle Solid Rocket Booster: fish ‘em out of the Atlantic, wash them with fresh water, inspect — and reuse.”
Most clean-sheet designs seem to be trying to reuse their first stage. I believe that SpaceX plans to after their first few flights. Kistler of course does. Anyone know why Boeing decided not to implement this?
And, why not Atlas? Wouldn’t their Russian “big dumb engines” be more durable?
— Donald
[ Anyone know why Boeing decided not to implement this? ]
Because the DOD wouldn’t buy it.
Big Dumb Booster means pressure-fed engines with no turbopumps, using extra large size as compensation. BDB’s are sort of a perpetual alt.space idea.
Does anyone know why JWST didn’t go with any of the less exotic lightweight mirror technologies? A few years ago I saw some cool stuff being done with carbon fiber composite mirrors. Recently I saw some NASA work being done using silicon-carbide foam as the structural part of a mirror. This scheme of folding and unfolding all these hexagonal mirrors, then using an active collimation system to make sure they all focus light on the same spot seems a bit Rube Goldberg to me. Am I missing something?
I don’t think it would fit in any of the available launch vehicles if it didn’t fold.
Dfens: compare the diameter of the JWST with the payload fairing diameters of existing launch vehicles. Draw your own conclusions.
One thing I have not heard discussed is that if the shuttle-derived HLLV does go with a huge payload fairing (9 meters, perhaps) it would be possible to launch monolithic mirrors of the Gemini class (the telescope, not the 60s NASA missions) rather that segmented approaches. Might be interesting to see if the reduced s/c engineering costs would be greater than the (presumed) increased l/v costs by going on an HLLV. Could even get some astronomers willing to support the VSE.
The problem there is designing the mirror to be able to take launch loads without being hugely massive. Usually, especially when you get into larger and larger structures not assembled on-orbit, launch loads are the driving factor in the design. Just my $.02.
I’m sure there is some compelling reason the mirror had to be 21 feet across instead of 16. I’m sure space is probably already littered with 16 footers. No doubt it is more economical to design that whoop-de-do hexagonal mirror shuffle mechanism than it is to design a new payload fairing.
The compelling reason is that the telescope will be that much better if it’s 21 feet instead of 16, not that it has to be. Even though JWST is a small project compared to the space station, it is huge compared to most worthwhile science projects, even most astronomy projects. Two of the best ongoing astronomy missions are WMAP, which cost $145 million, and SDSS, which costs about $30 million. JWST is to more typical projects as the MGM Grand is to a Motel 6. It might still be worth it, but it’s no bargain (except in comparison to the space station).
One explanation for the articulated mirror in JWST is that articulated mirrors and other tricks of active optics are the way of the future for large ground telescopes. (Either that or they were inspired by Diamonds are Forever.) Mount Palomar is the greatest and last large rigid ground telescope. The first ground telescope that decisively surpassed it was the articulated Keck telescope. Doing this in space is of course unprecedented; it is one of several stops that they are pulling out with JWST.
It reminds me of why the target speed for High Speed Civil Transport was Mach 2.4. Of course, had the target speed been 0.4 Mach slower, they could have built it with aluminum leading edges. Had it been 0.6 faster, titanium or steel would have been good candidates. It turns out 2.4M was the optimum speed to provide the most research money to the high temperature composite materials research group. Every year they got just a little bit closer to finding that perfect material, but they never did quite find it. Go figure.
No, the JWST people are not deliberately aiming for an R&D quagmire. They genuinely want a great telescope. But they may be overreaching.
Besides, even if JWST does go wrong, you should still credit the spectacular array of 50 unmanned space science missions operating today. That is the real difference between NASA manned and NASA unmanned. It’s not the manned cathedral vs. the unmanned cathedral, it’s the cathedral vs. the bazaar.
Greg is correct (and I must say it is nice to have something to agree about!).
“One explanation for the articulated mirror in JWST is that articulated mirrors and other tricks of active optics are the way of the future for large ground telescopes.”
This will also be the wave of the future for large space telescopes. For obvious physical reasons, the larger your mirror the better, especially at the relatively long wavelengths that JWST will observe. It is worth recalling here that many astronomers were strongly opposed the Hubble, arguing that groud-based telescopes would soon be able to do everything it was capable. Obviously, this proved dramatically wrong and I think that most astronomers today would accept that, while it may not have been the best implementation, the HST was well worth the money.
I expect the same will prove true of the NGST (sorry, I’m falling behind on my acronyms). This telescope is likely to revolutionize astronomy even more than the HST because of its abilities to observe through certain kinds of interstellar dust and see what has to date been hidden. If you believe that science should have the first call on space funds, than this instrument probably should be our highest astronomical priority.
The future beyond segmented mirrors is known, but the technology is a little ways from being practical, and that is the distributed “virtual” telescope using interferometry to synthesize a much larger mirror than you actually have. The technique has been used at radio wavelengths for decades, but is exquisitly difficult at optical wavelengths. It involves taking two or more relatively small telescopes, putting them at a distance, then _exactly_ synchronizing the wavelengths of light captured by the multiple instruments. If successful, you can get the light to behave as if there were a solid telescope between the distributed instruments. At radio wavelengths, telescopes the diameter of the Earth are regularly synthesized, often on a more-or-less ad hoc basis. The Japanese (I think) once launched an experimental radio dish and briefly created a synthetic telescope wider than the Earth.
If we can do it, there is literally no limit to this technique. It is easy to imagine radio telescopes the size of the Solar System using more-or-less existing technology and a lot of money. If we get to the point where we can “time stamp” optical wavelengths accurately enough to synchronize widely dispersed telescopes, optical telescopes the width of the Solar System are at least theoretically possible. Such instruments could do detailed mapping of Earth-sized planets around other stars.
Greg, et al, should root for and hope that the VSE succeeds, it becomes relatively easy to use Solar System resources and move them around, and such grand instruments become possible at least in their children’s lifetimes.
— Donald
Greg: “It’s not the manned cathedral vs. the unmanned cathedral, it’s the cathedral vs. the bazaar.”
Good analogy. However, it is worth pointing out that the European cathedrals still exist and influence us; they are culturally and physically very important artifacts that resulted in great advances in the techniques of architecture in stone reflected in every large building before the beginning of the last century, and in many buildings to this date.
However exciting and vital they may have been at the time, the bazaars of the era have relatively little direct impact on thee and me. They disappeared into the mists of history with narry a trace. Are you sure this is the analogy you really want to make?
— Donald
I know how much you two like to argue about the manned vs. unmanned stuff, but I’m just pointing out the same forces are at work regardless. My personal approch to survival in this industry is to target working on programs funded at about $1B. They have enough clout to evenutally get built, but not enough to allow the program to drag out forever. This Web thing has too much inertia for my taste. Will it perform a valuable mission? Sure. Space station will probably do some good things too. Will either one ever do anything to make them worth the final price tag? Not a chance.
Yes it is. Bazaars made nations rich. Cathedrals bankrupted them. You are conflating cause and effect in crediting cathedrals for advanced stone architecture. The bazaars didn’t disappear either; one of them is the New York Stock Exchange.
But I agree that cathedrals are important cultural and physical artifacts. They make great museums.
I think that an imaginative individual could come up with a method of on-orbit mirror fabrication and the small satellite to dock with it. Launching large mirrors seems a ridiculous proposition to me.
I wonder if there has ever been any effort on this front?
Of course, as Dfens would no doubt point out, once you succesfully do this then the feat is repeatable, and it doesn’t keep the next mission expensive or complicated enough.
Dfens, here I have to disagree with you. You are not looking at things in an historical context. Like those cathedrals, I think there are some things that are worth a significant fraction of the resources of a society. The Space Station is teaching us how to build complex things in space, just like the pyramids taught us how to build in stone and the cathedrals taught us flying butresses. Not one person reading this will live to know the ultimate outcome of the Space Station experiment — but I’ll bet our children’s children see it as at least as significant in the long term than a quick-and-dirty dash to Earth’s moon or robot toys trundling around Mars.
The Space Telescope truly revolutionized our understanding of the universe in a way that very few individual instruments have. In this, I would agree with my understanding of Greg’s arguments that its long-term imporantance to humanity is likely to equal that of any individual set human expeditions, e.g., Apollo. (Where I disagree is that I think the cumulative impact of human exploration has proved far more important to human history and understanding than the cumulative impact of remote observation, and I expect that to continue to be the case.) I suspect (but cannot prove) that the JWST has that same potential.
— Donald
Kevin: “I think that an imaginative individual could come up with a method of on-orbit mirror fabrication.”
Come to think of it, I agree. Many large mirrors today are “spin cast.” The short version of the story is that they are spun at the proper speed for the interaction of gravity and centrifugal force to create the proper parabola. I can’t think of any reason this couldn’t be done in space in a proper natural or artificial gravity field. Creating a perfect artificial gravity field might be a problem, but how about the moon where you could spin a larger mirror with fewer gravity-induced stresses, then launch it more cheaply and without the need for a fairing. . . .
I’m sure there are a lot of problems I haven’t thought of — starting with the need for an established lunar base — but the idea seems worth exploring to this lay eye.
— Donald
Kevin, am I really that transparent? I need to get some new material.
Donald, if you measure the worth of Web against space station, you can make a good case it will be worth every penny. If you look at the fact you could do 90% of the mission with 10% of the funds, it don’t look so hot.
Dfens: I agree one-hundred percent. I didn’t say we did the Space Station the way we should have. What I did and do say is that we need to build complex structures and we need the Space Station or something like it in orbit as what Mr. Griffin says is his “only large market” for the next decade. If I am correct, it makes no sense to abandon what we’ve already done.
Donald wrote: “Where I disagree is that I think the cumulative impact of human exploration has proved far more important to human history and understanding than the cumulative impact of remote observation, and I expect that to continue to be the case.”
Hmm, doesn’t one lead to the other?
Remote observation of the stars lead to a method to navigate the oceans out of view from the mainland. Without this methods, navigators never ventured far from land.
Remote observation of the planets in the sky led to the theory that the Earth revolved around the Sun and thus leading partially to the theory that Earth is round. That led to navigators to eventually discover the American continent.
Remote observation of the moon led to figuring out how to send people to the moon and back.
Fabricating a telescope mirror in space would be like baking a cake while flying a hang glider. But a space mirror shaped by actuators could in principle be more resilient to launch stresses, while an articulated mirror could in principle fold into a smaller launch payload. The only catch is that a good idea in principle might not yet be a good idea in practice.
Bob: Doesn’t one lead to the other.
I have argued that you need both. Too many argue that you can have the one without ever getting to the other and still get real answers about the universe. This is fundamentally counter to the scientific method which requires experiment in addition to observation and deduction. Doing only the one without the other is far too likely to lead you down a wrong path.
“Remote observation of the stars lead to a method to navigate the oceans out of view from the mainland. Without this methods, navigators never ventured far from land.”
Only partially true. First, I wouldn’t call this remote observation, it is part of exploration. Knowledge of the stars was useless (in a practical sense) before you actually navigated on the oceans and a) realized you needed it (don’t laugh, that’s an essential and non-intuitive observation, part of what Dfens said Skylab astronauts told him), and b) fugured out how to make it work with a sextent.
“Remote observation of the planets in the sky led to the theory that the Earth revolved around the Sun and thus leading partially to the theory that Earth is round.”
This was a very late and roundabout realization. The Greeks figured out the approximate diameter of the Earth long before by measuring the shadow at two widely separated points at the same time of day, an application of physical exploration. I believe they did this several hundred years BCE. They had also figured out that the Earth _was_ round simply by watching masts disappear over the horizon and various other methods. (This lesson is especially relevant today because the knowledge was lost to Western civilizations when the Roman Empire started insisting that everyone teach and learn from what would evolve into the Old Testiment instead of the actual science of the day.)
“That led to navigators to eventually discover the American continent.”
Nope again. The American continent was probably (but not widely) known to the civilizations of the Medeterranian. We strongly suspect that individual Egyption and Roman ships ended up in the new world; we are not so certain that the knowledge made it back because the currents make deep sea travel much harder in that direction. The Norse certainly know about it, but they discovered it by physical trial and error, not through any knowledge of the structure of the Earth let alone the other planets.
“Remote observation of the moon led to figuring out how to send people to the moon and back.”
So remote observation of the moon led to figuring out how to make a rocket, then make it big and reliable enough to reach escape velocity? Maybe, but I don’t think so.
— Donald
Donald: “The Space Station is teaching us how to build complex things in space”
I think the opposite, that it is teaching us how _not_ to build complex things in space.
As I mentioned many months ago, it is not so hard to extrude large diameter nylon tubes in space starting from a simple ring-shaped extrusion device and a supply of two monomers. Build the modules on-orbit, then fly up the pressurization equipment and furnishings from Earth. Build it in an ad-hoc, modular, astronaut-reconfigurable and non-launcher-specific way.
It was heartening to see NASA last week extolling the anti-radiation virtues of hydrocarbon plastics as building materials in space. With plastics, you can join segments using vibration welding (among other techniques)…
Bottom line: We need the space equivalent of a machine shop up there — just a few robust tools from which we can make many things.
“I think the opposite, that it is teaching us how _not_ to build complex things in space.”
Fair enough, but that’s an important lesson. Would we have figured out the benefits of inflatable modules if we’d not built what we did build? Maybe, but if you wait for the perfect technique, you’ll never build or learn anything. I am in full agreement with the rest of your post, especially the last paragraph!
— Donald
“It is worth recalling here that many astronomers were strongly opposed the Hubble, arguing that groud-based telescopes would soon be able to do everything it was capable.”
No, that is NOT why many astronomers were opposed to Hubble. Even those who were opposed to Hubble recognized that there are some things that ONLY a space-based telescope can do.
The reasons for the opposition were complex, and included the fact that very few astronomers trusted NASA. For most of its first 15 years, the science community (which included astronomers) viewed NASA primarily as an engineering agency. They thought that it would mess up a telescope.
Greg: “Fabricating a telescope mirror in space would be like baking a cake while flying a hang glider.”
Not at all. It would be like baking a cake while riding in a ship. It takes some adjustments, but it’s perfectly possible and maybe even useful if you think constructively instead of attempting to destroy anything that doesn’t fit your world and political view.
— Donald
Greg: “Fabricating a telescope mirror in space would be like baking a cake while flying a hang glider.”
Not at all. It would be like baking a cake while riding in a ship. It takes some adjustments, but it’s perfectly possible and maybe even useful if you think constructively instead of attempting to destroy anything that doesn’t fit your world and political view.
— Donald
Greg: “Fabricating a telescope mirror in space would be like baking a cake while flying a hang glider.”
Not at all. It would be like baking a cake while riding in a ship. It takes some adjustments, but it’s perfectly possible and maybe even useful if you think constructively instead of attempting to destroy anything that doesn’t fit your world and political view.
— Donald
Donald, yes, I agree with you. Once you’ve got these programs in place, it would be foolish not to take advantage of them. I’m sure the Web telescope will find billions and billions of hot, heavenly bodies to check out.
Don’t sell Kevin short, he may already have a manufacturing process in mind for building a mirror in space. If not, I still like his idea of separating the mirror and the rest. You could perch a huge monolithic mirror on top of a rocket if you launched it sideways. If it’s made from something like carbon composite, it will bend and twist a little on the way up but be fine on-orbit. Most of the current approaches seem very, well, terrestrial.
William: “No, that is NOT why many astronomers were opposed to Hubble. Even those who were opposed to Hubble recognized that there are some things that ONLY a space-based telescope can do.”
Maybe, but I recall plenty of congressional testomony by professional astronomers that minimized and belittled those benefits. Fairly or not, it certainly seemed to be the opinion of the “astronomical community.”
“the science community (which included astronomers) viewed NASA primarily as an engineering agency. They thought that it would mess up a telescope.”
Fair enough, but it is also true that there would almost certainly have been no space telescope without NASA. Also, a case could be made that the HST’s costs and problems were largely NASA’s doing, but it would be much harder to make that case about the NGST, which is much more under the management of scientists.
— Donald
Dfens: “Don’t sell Kevin short, he may already have a manufacturing process in mind for building a mirror in space.”
I certainly hope so!
— Donald
Greg: “Yes it is. Bazaars made nations rich. Cathedrals bankrupted them. You are conflating cause and effect in crediting cathedrals for advanced stone architecture.”
Greg, both your and my statements here are fully correct. It’s possible, though unlikely, that the Space Station will bankrupt the United States; it’s very possible that the Station and similar efforts will have the kind of historical importance that I am expecting. The two are not mutually exclusive except in minds like yours.
Likewise, our two statements about the bazaars of the time. They have made nations rich, especially in ideas. They have not in general made the kind of technological developments that made it possible for bazaars to move to new territories and trade new things.
It is worth pointing out that what I am hoping for out of human space exploration is the evolution of exactly the kind of trade and “bazaars” that made nations rich and may me humanity rich in the future. There is plenty of stuff to trade in the Solar System (e.g., water is scarce most places down hear near the sun; it’s in endless supply beyond Jupiter; the reverse it true of heavy metals). But we have to get there to do it, and your route will never get us there; although there are no guarantees in life, mine, and some of the others here, just might.
Trade. You’ve just agreed with me: that’s what its all about. Rather than stating it’s impossible and all a waste of money, let’s figure out how we’re going to make that work. Because, if we don’t, there is no long-term future for humanity and before we know it we will not be building telescopes of any kind.
— Donald
Oops, and as it turns out he did and I skipped right past it.
I like the idea of having a manufacturing capability on orbit. It goes back to the whole thing of why have people up there at all. Plastics sound like a good candidate material too. Right now, everything in space is designed around at least 4g launch loads. Building stuff out of plastic on-orbit would allow you to build for the environment in the environment. You might be able to use pressure to rough out the shape of a mirror, but it would still be tough to get a quality finished surface out of that. We use pressure formed mylar collimating mirrors in simulators, but they don’t have to be too accurate for that application.
In the defense of the builders of the real cathedrals, there would be no western civilization as we know it without them. I know my own ancestors were purely barbarians before the church got a hold of them. Come to think of it, that actually wasn’t too long ago. Well, you know what I’m saying.
There are specific reasons why the mirror proposed for JWST is the size it is, and it has little to do with simply wanting the “biggest” or “best” mirror that they could get. Simply put, they cannot gather some infrared radiation with a mirror below a certain limit. If they set certain scientific goals, then that requires a certain amount of collecting power. You can argue over whether or not those goals are valid or important. But they exist and they drive the design.
As for the speculation about building mirrors in orbit, you people have absolutely no clue what you are talking about. Precision mirrors are some of the most highly-refined objects that have ever been built. They require substantial, expensive, and highly-precise production equipment.
Mostly off topic, but some years ago I went to see the Roman Baths at Bath, an hour east of London. To put what we were seeing in perspective, the archaeologist described it from both the Roman and the native point-of-view.
Roman: An enormous cement-supported, free-standing brick dome with no obstructing pillers. It lasted four-hundred years with maintenance. After the army engineering corps was withdrawn to the continent, it probably lasted at least as long again before seepage undid its foundations.
Native: You’ve never seen anything larger than a mud hut. You walk into a free-standing space larger than your entire village.
The cathedrals worked much the same way. After a long week working the fields you step into a vast enclosed area with colored light and ethereal music.
— Donald
[(This lesson is especially relevant today because the knowledge was lost to Western civilizations when the Roman Empire started insisting that everyone teach and learn from what would evolve into the Old Testiment instead of the actual science of the day. ]
The Old Testament? WE do em-bar-ass ourselves when we expatiate outside our specialties.
William: “you people have absolutely no clue what you are talking about. Precision mirrors are some of the most highly-refined objects that have ever been built. They require substantial, expensive, and highly-precise production equipment.”
Sure, and something as simple as spinning up a bowl of mercury can bypass that cumbersome process you speak of.
Using the way we engineer things on the ground as a starting point for how to make them in space or to guide an estimate of how complex they would be is a mistake.
“but I recall plenty of congressional testomony by professional astronomers that minimized and belittled those benefits.”
Cite them.
David: “The Old Testament? WE do em-bar-ass ourselves when we expatiate outside our specialties.”
Oops, you are right, one-hundred percent guilty as charged. That would be the New Testiment.
— Donald
Do you agree with 18th C. historian Edward Gibbon that Christianity was a principal cause of the decline and fall of Rome?
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I don’t think Mike Griffin’s, or should I say ATK Thiokol’s, Vision of Space Exploration is going to happen. I don’t know why it is cheaper or quicker to develop a new medium heavy launcher to send a crew vehicle to the ISS than to use the existing Atlas or Delta missiles. Why couldn’t the heavier version of the Delta IV be used for that? The Delta EELV is fairly far along in development.
Furthermore, I think the quickest, most cost-effective way to return to the Moon soon is to use at least one Atlas or Delta launch to send equipment ahead to the Moon, and then rendezvous two launch payloads in orbit — one payload being a third stage and service module — to get humans to the Moon.
Dr. Griffin is calling for a Shuttle-derived very heavy launch missile that can lift 125 metric tonnes to low orbit. I think a very heavy lifter such as that is nice to have, but it is not essential for returning to the Moon.
Neither of the two launch missiles Dr. Griffin wants are really off the shelf or “proven.” The solid rocket boosters and the Shuttle main engines
have never been operated in the congifurations envisisioned by the new Vision. Developing and testing these new launch missiles will cost beaucoup $$$. I don’t know where NASA is going to find the money.
David: “Do you agree with 18th C. historian Edward Gibbon that Christianity was a principal cause of the decline and fall of Rome?”
I am no friend of Christianity for a lot of reasons that I’ll be glad to discuss off line, but, the short answer to that is, I don’t know enough to know. I suspect it may have been a contributing factor, but I think various individuals and ideologies (including but not limited to Christianity) subverting the system for power probably had a lot more to do with it.
“I don’t think Mike Griffin’s, or should I say ATK Thiokol’s, Vision of Space Exploration is going to happen.”
As I’ve argued many times before, I agree. I _can_ see how Shuttle-derived systems would be cheaper in the long term, but they require too much money up front; they require the nation to maintain an extra set of launch vehicles (because the EELVs are not going to go away, at least not both of them); and they require actually going somewhere to be pushed too far into the future. Many people I respect here disagree with me on this, but I fear it will turn into just another unfinished launch vehicle development project and ten years from now we’ll be right where we are now. (Or worse in the likely event that we don’t have a President that pays at least lip service to a forward-looking human space program.)
I am not pleased to have to argue this, because I like Michael Griffin and I want to support him. But I’ve seen this too many times before.
While I am not an engineer, I fear that using solid rocket boosters for human spaceflight is sheer folly however cheap it is.
I also don’t underestimate the problems with the EELVs. They were not designed for human spaceflight, it will cost significant money to make them work that way, and they probably will be little or no more reliable than the Shuttle (although, with rescue capability, they could be safer). They are also relatively hard to upgrade, though larger designs have been proposed.
The overwhelming advantages of using the EELVs (and possibly the Ariane) is having a capsule that could be launched on all three per the original plan; the fact that we have them already developed; somebody else is paying the bills to keep them in business; they were designed for economies of scale so if we fly them more often everyone benefits, not just exploration; the best way to improve reliability is to launch often and get a good history behind you (witness the reliability of the Delta-II) and no Shuttle-derived system will ever have that, but an EELV system would as a matter of course; and I even see their small size as a potential long-term advantage by forcing us to learn to truly operate in space, at least to the point of assembling prefabricated fuel modules.
“use at least one Atlas or Delta launch to send equipment ahead to the Moon, and then rendezvous two launch payloads in orbit — one payload being a third stage and service module — to get humans to the Moon.”
I like this. It sounds like a small-scale variation on Mars Direct and also like it could be done fast. Didn’t Space Adventures just propose the human half of that with the Russians? Maybe that could be a purely commercial endevor, funded by tourism and used by scientists and others. Does anyone know if it would work mass-wise?
— Donald
So, David, Rome was doing just peachy under Nero, Caligula, etc. then Christianity messed it all up? Such a shame… And you think lobbing a couple of Deltas into the air is going to put a man on the Moon? They are projected to carry, what, 40,000 lbs to LEO? Saturn V lofted 260,000 lbs. I don’t remember it being a luxury cruise those guys took to the Moon and back. I understand the wait staff was very poorly represented.
As for what I know about telescope mirror making, I know most amatures do a better job on those they grind at home than NASA did on Hubble. I wonder how many payload fairings you can buy for $4.5B? It seems to me like a telescope is a tube with a mirror at one end, and a payload fairing is a tube with a point on one end.
[I also don’t underestimate the problems with the EELVs. They were not designed for human spaceflight, …]
But what aspect of a two or three stage Shuttle-derived missile stack is more inherently designed for human spaceflight? Are you going to claim that the Solid Rocket Boosters are “proven” and “man-rated” for human spaceflight?
[ it will cost significant money to make them work that way, … ]
Why will it cost more to plop a space capsule or small spaceplane atop an Atlas or Delta than to develop two whole new missile stacks?
[and they probably will be little or no more reliable than the Shuttle
(although, with rescue capability, they could be safer)…. ]
Those solid boosters: even if there is a tractor rocket to pull the crew capsule away from a malfunctioning Soild Rocket Booster, those SRB’s can’t be turned off. It could be like a RoadRunner cartoon in which Wile E. Coyote thinks he has safely parachuted away from his Acme rocket, only to find that the Acme rocket has turned and is still coming at the Coyote!
[… They are also relatively hard to upgrade, though larger designs have been proposed. ]
Yes, Boeing has proposed getting its Delta IV up to Saturn V size by straping together as many as seven first stage boosters. There’s a small drawing of it here: http://www.nationmaster.com/encyclopedia/Delta-rocket#Delta_IV
The modular missile sales pitch is that missiles can be built in different sizes and upsized as needed in a cost effective manner using additional numbers of the same modules.
By the way, Boeing is advertising that a five meter diameter fairing is avvailable for Delta IV Heavies.
[So, David, Rome was doing just peachy under Nero, Caligula, etc. then Christianity messed it all up? Such a shame…]
I was just making conversation. In real life, I am a Methodist red state-r
[… And you think lobbing a couple of Deltas into the air is going to put a man on the Moon? They are projected to carry, what, 40,000 lbs to LEO? Saturn V lofted 260,000 lbs. I don’t remember it being a luxury cruise those guys took to the Moon and back. I understand the wait staff was very poorly represented. … ]
Two points. One, as I said earlier, Boeing has a plan to upsize the Delta IV to Sat. V size. The Delta IV Heavy is much less less of a paper rocket than the Griffin-Thiokol Shuttle-derived heavy lifter.
Next, let’s suppose we have to make do with the present three-first-stage module Delta IV lofting 40K lbm to LEO. This Delta configuration has already had one test launch. It is not at all a paper or Power Point rocket.
I think a 40k lbm lifting body crew vehicle for three, maybe four humans is feasible, along with a third stage weighing no more than 40k lbm. This small spaceplane would most often be used for trips to the ISS and back. For lunar expeditions and space platform servicing missions, the spaceplane would mate with a crew habitat module and airlock. Granted, it’s possible that giving the lunar explorers the comfort of the additional room afforded by this habitat module would require an extra launch.
We also budget for a least two prior launches that would mate a third stage with a Lunar excursion Module and Moon dune buggy, Moon shack and other supplies. This payload would be sent to lunar orbit ahead of the human flight. This prior non-human lunar mission would also be part of the human safety of flight test program.
I think a very heavy lift launch system would be good to have. I’m not opposed to the idea, except that I don’t want our Return To the Moon program to have to wait until a very heavy lift missile stack is developed. … espcially a Shuttle-derived stack that ain’t no mo’ tekno-futuristic than an EELV.
Seriously, and I hate to be the bearer of bad news, but no company is going to strap together 7 boosters. I can make a picture like that on my CAD machine right now. It doesn’t make it a serious proposal. It just means I know how to use the “Detail, Ditto” function.
The last item Jeff listed in his summary of last week’s news was an item about NASA enlisting astronauts as lobbiests. It occurs to me that’s the reason unmanned space doesn’t get any money. No astronaut PR people.
David, I’m on your side. I just don’t underestimate the difficulty. Also, I am _not_ opposed to a heavy lift vehicle. I think it should be developed ASAP. However, I strongly agree with you that the lunar program should not wait for that.
Decade One: Give up on Shuttle now and supply current Space Station with commercial vehicles. Possibly launch remaining modules (which weigh a bit over 10,000 lbs empty) with EELVs. Bare bones lunar presence with EELVs or Ariane or Proton. Get the ball rolling and a presence back in deep space.
Decade Two: second generation lunar presence with cargo delivery via uprated EELVs and/or new rockets. Concurrent relatively slow development of heavy lift, maybe clean sheet amybe commercial since there would now be an established maret.
Decade 2.5 – 3: Martian moons using heavy lift; commercial cargo with second-generation of whatever the commercial world has come up with to the supply the Space Station and lunar base.
Post Decade 3: Martian surface.
Whole thing should be possible within something like NASA’s current human spaceflight budget. However, it would be politically very tough because it means abandoning the Space Shuttle infrastructure and labor force right now. I don’t think Mr. Bush cares enough about space to risk that kind of political price to his party’s prospects in the next Presidential election (though I hope otherwise, of course!).
Dfens: “most amatures do a better job on those they grind at home than NASA did on Hubble.”
This is neither fair nor accurate. Failing to catch the HST problem was spectacularly stupid, but the mirror was polished with exquisit precision, albeit to the wrong figure. If that were not the case, the additional-lense-in-front-of-the-mirror repair would not have been possible.
BTW, did anyone catch the story in yesterday’s Space News that Mr. Griffin may cancel the deorbit part of any Hubble repair? Apparently, NASA thinks its post-repair orbit would last until at least 2020. I consider this entirely good news. It saves money in the short term (several hundred million dollars, I think) while potentially preserving a wonderful facility for the long term. It buys time to develop new repair methods with the CEV and potentially provides additional market to whatever rocket ends up launching the CEV.
— Donald
“Possibly launch remaining modules (which weigh a bit over 10,000 lbs empty) with EELVs.”
I just did a Mars oops, to coin a phrase. That’s 10,000 kg. empty, but still about half the payload of the Delta-IV (21,892 kg. to Space Station, according to Boeing’s Web site).
— Donald
Donald: “Bare bones lunar presence with EELVs or Ariane or Proton.”
I believe that would be the political death kneel of VSE. Imagine using launch vehicles with a payload to LEO capacity of only 20 tons to go to the Moon once. That would require at least 4 launches, at a cost of around 250 million each. It would likely take at least 2-3 months to get all the equipment off the ground, assembled in orbit and ready to go. And then you would most likely only be sending 2-3 astronauts to the lunar surface for a period of less than a week. At a cost of at least a billion dollars per mission you would only be recreating Apollo, or maybe a fraction better. That IMHO provides entirely too much anti-manned space fodder to those who will do anything to kill VSE.
On the other hand we will from the very first mission using heavy lift be able to do the below (in Dr. Griffins words):
“They will be able to carry larger and heavier cargos into space, allowing more people to remain on the moon for longer periods of time. Even on the initial missions, we will take the entire crew of four astronauts to the surface instead of two, remaining on the surface for a week instead of a few days, while the crew exploration vehicle remains unoccupied in lunar orbit. Going well beyond Apollo, we will have the ability to land and conduct exploration activities anywhere on the moon, including on the far side or in the polar regions.”
Donald: You talk about the Hubble Space Telescope like it’s the Great Temple of astronomy. It is a great telescope, but it’s longer that great. The Chandra telescope is comparably versatile and comparably important. You can see for yourself by doing restricted searches for HST and Chandra, respectively, in the astro-ph archive for 2005 using Google Scholar.
In order to move forward, astronomers need to keep launching completely new telescopes. Even telescopes on the ground are trending in the same direction as silicon chip factories: Expensive but temporary. (This should be interpreted carefully: Ground telescopes still aren’t all that temporary, but the trend is in that direction.) If that is the trend on the ground, there is all the more reason to do it in space. Astronomers don’t want the vintage automobile model for their instruments.
Cecil, we’ve been over this before and I think we have to agree to disagree. I hope you are right since that appears to be the way we are headed.
However, I’ll state a couple things again. First, I think David’s idea was dismissed far too easily. Pre-positioning equipment on the moon can be done at our leasure and by almost any launch vehicle. Even if we don’t send a crew right away, you’ve got a visible (probably literally, even from Earth!) base to aim for and a visible market for supplies.
Second, let us assume that you are right. Say you spend a billion dollars and get three astronauts on the moon for a week. You can do that three or five times for what developing even the cheapest Shuttle-derived vehicle will cost (let alone two, which is what Mr. Griffin’s plan actually calls for). You’ve got nine or fifteen astronauts visiting the moon without spending a penny on new launch vehicles. If you plan their activities correctly, they’re spending their time learning how to extract oxygen, aluminum, and glass out of typical lunar soil, and / or searching for polar ice, rather than finding and returning samples.
Now, we’ve got something visible on the moon for our money and some knowledge that may reduce the heavy lift requirement. If some of the pre-positioned supplies include semi-permanent shelters and a commitment from NASA to go forward, you’ve got suddenly got a market that may allow somebody else to develop a clean-sheet HLV off of NASA’s budget. Some of the new Internet bazillionairs seem willing to blow their money on rocketry with a lot less demonstrated market than that. They won’t blow their money on yet anothe promise from NASA that once they have developed the perfect rocket they’ll establish a perfect lunar base.
Once again, I am not arguing against an HLV. I am arguing that, if we’ve learned nothing else from history (both NASA’s recent history and the history of exploration in general) we should have learned to use what we’ve got _while_ developing something new. If we’ve proved anything in the last thirty years, its that developing new transportation without building somewhere for it to go first or concurrently does not work, economically or politically, however technologically elegant it might or might not be.
— Donald
Greg, I’ll agree when I see astronomers stop using Palomar or when Hubble time is under-subscribed. No matter how many disposable super-telescopes you’ve got in orbit or on paper, astronomers are still signing up for the one large visible-light mirror that is actually in orbit. Same lesson as the Space Station: just because it’s not perfect and cost far too much does not mean you throw it away for something that may be better or cheaper, especially if it only exists in some CAD drawing somewhere.
“You talk about the Hubble Space Telescope like it’s the Great Temple of astronomy.”
Isn’t it? In the same way Palamar was and is?
You argue that fifteen years on, a new instrument is more preductive. As Cecil might say, “Wow, Mr. Holmes.” Does that mean you throw away the old instrument, especially when the new one operates at a different wavelength?
Repairing the HST is likely to get cheaper over time especially if we don’t insist on using the Shuttle. If you can keep it in orbit until 2020 at less cost than you can deoribit it, and especially if it remains over-subscribed, I say let’s do it and see how the cards fall.
— Donald
Sounds good on paper Donald
A
But the problem with your plan, as I see it anyway, is that you won’t be able to have those 9-15 astronauts do much on the moon other than gather samples using the 20 ton at a time piecemeal approach. To do something productive with the medium lift approach I believe you would then have to go to 6 or 8 launches per mission rather than the 4 I wrote of above. The 4-launch scenario is just a bare minimum to get there; more would be required to build a base and create a destination as you say.
Sure you could put a few folks on the Moon for the HLV development costs. But you then proceed at an agonizingly slow pace, creating a perfect target for those politicians who lust after every NASA dollar. Whereas if you take the “first 3-5 medium lift scenario missions” equivalent in funds and you use that to instead build the HLV you can proceed at a pace such that in the first two HLV launched Moon missions you’ve built more Moon infrastructure than you would have with those 3-5 medium lift launched missions. And with each new HLV launched mission your Moon infrastructure grows at an appreciably greater pace than it would via medium lift. That would be much more politically attractive than the ISS-like glacial creep that would be possible otherwise.
Another consideration is if you design a lunar lander vehicle that could be launched, assembled etc. by medium lift and then build an HLV later, the lander design that you are then stuck with in all likelihood will be one that grossly under utilizes the HLV’s lifting ability. That would then handicap you from the very beginning until such time as a new lander is created to take advantage of the HLV’s lifting abilities. And considering how much such things cost to design/create you’d likely be stuck with the small lander for a long time.
Cecil, you could look at it the other way around: if you learn to get buy with EELVs, think of what you’ll be capable of if and when the HLV comes along.
I hope you are right, Cecil, but my doubts remain.
— Donald
Going to the Moon 5000 lbs at a time is possible, but is way too success oriented. Let’s say you have a mission success rate of 0.95, which I think is optimistic, but let’s assume that’s your success rate for putting the building blocks of your mission on the Moon. If it takes 8 launches to build your mission, you have a total probablility of success of 66%. I agree with Cecil, you’d be hanging out a mile, and spending lots of money doing it. With a shuttle-c vehicle, it still takes three launches, you assemble the mission in LEO and have a more realistic probablility of success of 86%, which is not great.
One of the things I think we need to do is get a realistic idea into our heads of how difficult successfully colonizing the Solar System will be. It’s entirely possible that Americans are too risk-averse to pull this off. Many frontiers on Earth were probably colonized at a success rate of sixty-six percent or far less, especially those that involved deep-sea transit. While no real evidence exists either way, examples might include the Polynesians; North Atlantic islands immediately after the retreat of the last glaciation; or the first colonization of the American mid-West. (One of my archaeology professors once pointed out that the Native Americans who colonized the American continent, while essentially neolithic, actually had quite an advanced level of technology and that there are very few places on our continent where a nakid human being could survive more than a few hours in winter. Colonizing this continent was a difficult and amazing achievement.)
There is no reason to expect colonizing Mars to be easier, even for us. If we want to do it, we have to face the facts and take real risks to do it affordably. If we don’t, then someday somebody else will — I hope!
— Donald
[ Let’s say you have a mission success rate of 0.95, which I think is optimistic, but let’s assume that’s your success rate for putting the building blocks of your mission on the Moon. If it takes 8 launches to build your mission, you have a total probablility of success of 66%. ]
But if Pgood of each launch = 0.95, each launch is, in the Bayesian sense, independent of prior launches and only the last of the eight launches carries humans, then the probability of a successful human round trip = 0.95.
In fact, since the the first seven launches would consitute a test evolution of the same spaceflight system, the probability of success would increase for each sucessive launch.
Let’s compare this to your bigger rocket. How many trans-lunar, non human-carrying test launches of your bigger rocket system do you plan on?
[ With a shuttle-c vehicle, it still takes three launches … ]
I think Shuttle-C is a worthwhile option to discuss. I am not insisting on Atlas or Delta EELV’s. I am just not sure that the one big launch method of August 1969 is the way to return to the Moon. Maybe a golden oldie re-run of summer 1969 is not what we need now. Uh, anybody going to Woodstock?
Good points, David. I think we often forget the “practice” effect which I also brought up above in a different context. If we fly anything often, it will get more reliable with time, especially the EELVs that were designed for that. If it takes us eight launches to deploy a human mission (which I’m accepting for the sake of argument, though it seems high to me), but only the last one contains a human crew, then just call it nine launches. With the Shuttle-C three launch model, you get less practice, reliability doesn’t go up as much, and if you lose one flight use lose one-third of your mission and you have a 33.3 percent chance that it’s the human flight. I’m no statistician, but is this _really_ that much more reliable?
— Donald
[ … That would require at least 4 launches, at a cost of around 250 million each …. ]
Bur how much will development and testing of a very heavy launch missile cost, compared to the cost of four launches of the the current heavy version of the Delta EELV, which has already had one test launch?
That is THE question and comparison to make.
Oh, I am guesstimating that six or even eight EELV lunar expedition launches might be needed, allowing for two to four launches for pre-positioning stuff. So let’s use your $250M per EELV launch number and multiply by eight. Again I ask, how the heck much do you think it wilkl cost to develop, test, and then launch just one time a Shuttle-derived Very Heavy Lift missile?
Don’t forget the cost of modifying the launch servicing tower and the flame trench for the Shuttle-derived lifter, as well as refurbishment of the upper regions of the Vehicle Assembly Building?
[ … It would likely take at least 2-3 months to get all the equipment off the ground, assembled in orbit and ready to go. ]
If this equipment consists of nonperishable pre-positioned items and a lunar landing vehicle pre-positioned in orbit, there’s no hurry. This stuff could be dispatched many months ahead of the human launch.
Let’s schedule six or eight EELV launches during eighteen to twenty-four months. To keep the public interested, we’ll have a robotic rover sending video back from Luna before the astronausts arrive. Sorry if that deflates the romance of man in space, but it’s not 1969 anymore.
We’ll also pre-position tanks of lunar landing vehicle propellant in lunar orbit, and make our lunar lander robotically smart enough to re-fuel itself in orbit. What propellant to use? Something non-cryogenic, maybe kerosene and H2O2.
Our lunar lander will be smart enough to autonomously land on the Moon, then re-ascend to lunar orbit and re-fuel itself as needed. This series of events would also test our lunar lander. The culminating event of this series would be: humans using this same lunar lander, with the option of a human piloting the vehicle if desired.
Assuming we have pre-positioned a shelter and ample supplies on the Moon ahead of our astronauts’ arrival, our astronauts should certainly be able to stay on the Moon for several weeks, instead of no more than one week.
Let’s allow two launches to send to LEO the compactly-sized three or four person crew vehicle, a service module containing extra electrical power supply and extra life support perishables, a third stage, and perhaps an expendable “bonus room” for humans. Once assembled, the sequence would be: crew vehicle, bonus room, service module, and third stage.
Let’s suppose that our third stage will also use propellants that won’t boil off, hypergolics or kerosene/H2O2 or maybe a Shuttle-derived Soild Rocket Booster, ha ha. Why couldn’t this third stage and another module be launched two or three months ahead of the human launch?
The service module and third stage and maybe the bonus room could evolve into a Space Tug that would stay in space. That’s a subject for another post.
One again, I think having a Saturn V-sized heavy lifter would be nice. However, I suggest that it would be a mistake to put Very Heavy Lift Missile development in the critical path of human return to the Moon.
Maybe a great big launch missile will be needed to put people on Mars.
But Moon return next and sooner, Mars later is what I say.
If it’s just you and your backpack, and you want to hike into unknown territories with an unknown chance of success it’s one thing. If you’re risking billions of someone else’s money, I can tell you from personal experience you’d better have a darn good story to tell them as to why you want to do that. Maybe Hubble found out the Moon was made of platinum. In that case, let’s start launching tomorrow, who cares about a little chunk of foam here and there. If it’s just made from titanium, let’s think about it a little bit.
Risk is fine. Everyone should have to risk something to get a reward (except, of course, aerospace companies sucking away your tax dollars). Risking billions when there are better solutions easily within your grasp simply doesn’t make sense.
As for NASA, they need to start succeeding before I will advocate giving them another dime. Shuttle is a failure. Station is a fiasco, and I’m an idiot for giving them even one more chance, but given they will probably get it anyway, they’d better succeed if they want a second opportunity. I need food, shelter, clothing, and a means of defending my home. NASA I do not need. They should start from that assumption, check their damn egos, and start earning their money.
As for your reliability model, David, it is wrong. The launches are all in series for success. You can have redundant launches (backups) which increase your probability of success, but which also increase the probability of an embarrassing failure.
So, Dfens, what was the reliability of all those sailing ships that supplied San Francisco by sailing the hard way around South America, through the world’s roughest seas where there’s no land to stop waves going round-and-round-and-round? I haven’t a clue, and I’m not sure where to find out, but while it was probably way above sixty percent, it was nowhere near one-hundred percent. They were spending someone elses money.
Again, we need to get real about what’s realistic on a new and difficult frontier.
— Donald
David: “Sorry if that deflates the romance of man in space, but it’s not 1969 anymore.”
I don’t see why it deflates the romance. As long as it’s leading directly to a human mission, I don’t see why you couldn’t launch many prepratory flights beforehand. It shouldn’t be any harder than sustaining political support for an HLV while (once again) nothing is on the moon!
— Donald
Davenport on a lunar base: “perhaps an expendable “bonus room” for humans”
…yeah, and put me down for a “breakfast nook” – something like that nice coffee lounge window the Italians made for the Space Station.
David: “Don’t forget the cost of modifying the launch servicing tower and the flame trench for the Shuttle-derived lifter, as well as refurbishment of the upper regions of the Vehicle Assembly Building?”
And don’t forget that if we want to launch more than one “heavy” EELV per month another pad or two will need to be constructed.
Hey, Cecil, just had an idea for a compromise on our EELV versus Shuttle-derived debate.
How about:
1). Stick with the original plan to develop a twenty metric ton capsule that can launch on anything.
2). Use Delta-IVs to launch capsule (with Russian-engined Atlas and European Ariane as backup). EELV launched capsules and cargo containers would be used to support station, Hubble, future LEO infrastructure.
3). Meanwhile, the cheapest possible Shuttle-derived heavy vehicle (probably side-mounted to avoid pad redesigns) — and ***not man-rated*** beyond what it already is to keep it cheap — is used to launch trans-lunar stage.
4). Centaur-derived, J2-derived, or clean-sheet trans-lunar stage and lander developed and used in two ways:
a). Cargo flights go one-way, Shuttle-C launched, direct landing.
b). Human flights launch on EELV-derived vehicle, dock with Shuttle-C launched trans-lunar stage in Earth orbit, procede to moon with fuel for two-way flight. (Later, maybe lunar-derived O2 replaces terrestrial oxidizer.)
Advantages = minimum possible up-front development costs; available in a few years; human-rated hardware uses smaller and possibly more reliable and cheaper launchers; diverse launches provides inherent backup and systemic reliability at little extra cost since most of these launchers will be maintained anyway; global commercial stake makes political backout less likely even though US maintains full control; more frequent flights of the Delta-IV should reduce costs for everyone in the near-term; and replacing the Delta-IV with a fully commercial, much lower cost vehicle is more likely to be within reach than a commercial heavy lift.
Longer term, an up-and-running lunar base provides a market for commercial development of a clean-sheet (third generation, after Saturn and Shuttle) HLV.
What do you think?
— Donald
Sounds good Donald. I thought all along that the CEV would be launched on an EELV, but evidently NASA’s thinking is that the SRB launcher will be cheaper. And although I am no fan of the SRB launcher idea, and I have no real figures to back this up, the simple single stick SRB does “look” cheaper than say a 3 core Delta IV Heavy.
Even so, NASA has committed to using EELV’s where appropriate and affordable. But if the SRB is cheaper to use as a CEV launcher (assuming this to be true just for the sake of the argument here) you have to wonder in what circumstances NASA would actually use the EELV? Why not use SRB derivatives for anything say 15-30 tons?
I’d really like to sit in on some of those brainstorming meetings to here ALL the pros/cons.
And as far as the side mount SDV idea, I’m betting that after all is said and done that is what NASA will go with. Inline may be too expensive for Congress/OMB to buy I’m afraid.
Doing it on the side gets you a lower payload, but it also allows us to get started faster, I would guess much faster. Then, by the time we’re ready to build the Mars infrastructure, there may be enough of a market supplying the lunar base to justify commercial development of a clean-sheet design. This would fit in with Mr. Grifith’s professed preference for commercial supply, at least of bulk cargo — though I have seen little practical evidence of that so far. . . .
— Donald
[ The launches are all in series for success. You can have redundant launches (backups) which increase your probability of success, but which also increase the probability of an embarrassing failure.]
No, the launches are not stict-sense in series for success because afailure of a prior unmaned launch will not endanger the safety of flight of a human launch to be performed later. The human flight can be postponed until the necessary non-human equipment is pre-positioned.
Furthermore, he human launch is, in a heuristic sense, the launch that really counts. All the prior n-1 unmanned launches get much less weight in the scale of importance. If you don’t kill an astornaut, it doesn’t make headlines.
“The launches are all in series for success” also applies to your very heavy lifter system. It’s first manned lunar launch is not going to be your big rocket’s very first launch, is it? How many prior launches of your big rocket will there be before the first manned lunar expedition on the big boy?
[ And don’t forget that if we want to launch more than one “heavy” EELV per month another pad or two will need to be constructed. ]
Why one EELV launch per month? Plan on one EELV launch every two or three or even more months, and try to increase the tempo as we go along.
…
Accomplish a lunar expedition using two or more launches of an EELV: is this a novel idea? No! Just five or so years ago, this was NASA’s vision for lunar exploration. I’ve been waiting for someone to recall that. Since Dr. Griffin came in, EELV’s are out for human launches.
But something I’ve noticed since I started in the aerospace business in the 1980’s is that plans can change. I remember when it was sure and certain that the USAF was going to buy at least 132 B-2 bombers. Will this new, Shuttle-derived Vision for Space Exploration come to fruition? Who knows. The future remains to be seen.
PS: How has that ATK Thiokol has taken over NASA? Is paying off some Shuttle “astronauts” all it takes?
PPS: This so-called single stick launch missile: is a four segment SRB powerful enough, never mind avant-garde enough, to serve as the first stage to deliver a large, six person capsule to LEO. That’s apparently what Dr. Grffin’s Planetary society wants, a six person capsule.
Once again, I agree with you David.
BTW, I think it’s time to remind everyone of the good ol’ 1992 General Dynamics proposal to do the lunar mission with one Shuttle launch and a Titan-IV launch, after two to pre-position cargo on the lunar surface.
Here is the text from my contemporary article (published in Astronomy magazine) on the subject.
In 1992 and early 1993, General Dynamics conducted a study on what a near-term mission to place astronauts on Earth’s moon might look like. The ground rules were simple. To keep costs low, the project must use hardware already developed for other purposes. The missions must be “meaningful.” That is, they must accomplish science that had not already been done by Apollo. And the missions must pre-position supplies and equipment, test technology, and obtain knowledge useful for a later lunar base.
According to Dave Caudle, a design engineer involved in the study, the project started in the marketing department at General Dynamics. They wanted to propose a human lunar project to NASA that could be done cheaply enough to fit within realistic NASA budgets, yet could be done within a decade, like Apollo. “They came to me, as someone who knows the hardware, and said, `This is what we want to do. We want to use the Space Shuttle and the Titan to go to the moon. Come up with a vehicle that will do it.’ So I came up with a vehicle that could do it,” says Caudle.
The project was to begin in 1994, and culminate in the year 2000. The principle launch vehicles are a slightly uprated Space Shuttle, and a Titan-IV with larger and lighter fuel tanks or a European Ariane-V with two extra solid rocket boosters. The Single-Engine Centaur is used to get to the moon, and a capsule shaped like the Apollo Command Module returns the crew to an ocean splashdown. The capsule would have a modern interior, but the old Apollo shape and size was retained to avoid having to do extensive new wind tunnel tests. The only vehicle that has to be developed from scratch is the lander. To reduce the weight that needs to be sent to the moon, and to avoid having to refuel on the moon, the lander must be a far more efficient vehicle than its Apollo counterpart.
After two cargo missions to pre-position supplies on the Lunar surface, the third mission starts with a Space Shuttle orbiter in a low parking orbit around Earth. The orbiter’s payload consists of the lunar lander, the return capsule to take the crew back to Earth, and a lunar crew of two.
The lander and return capsule are prepared for flight in the Shuttle’s payload bay. Once they are ready, the lander with attached return capsule is deployed from the Shuttle’s bay, and the crew transfers from the Shuttle to the lander’s crew cabin.
Meanwhile, a Titan-IV or a Ariane-V has been launched from Earth with a fueled Single-Engine Centaur. The Centaur approaches the waiting lunar lander, and docks to become a complete lunar spacecraft, which is checked out by the Shuttle’s crew.
The Centaur’s engine begins the long burn to send the vehicle toward the moon, then the Centaur falls away. A little over two days later, the lander’s rockets fire and the spacecraft lands directly on the lunar surface, without first orbiting the moon. After three weeks of surface operations, the crew blasts off, again aiming directly for Earth. Their capsule reenters and splashes down in the ocean.
But before the crew can be sent, the two 8.5 metric ton cargo flights were used to test the entire system. To provide early science, an optical telescope is mounted on the automated lander. With the moon as a stable platform, and no atmosphere to see through, such a telescope could provide major scientific advances. Other cargo consists of automated scientific equipment, a habitat and supplies, an unpressurized rover, and lunar mining experiments.
A second cargo flight sends more hardware and supplies, including a closed life support system.
After the third mission demonstrates sending a crew, this lunar transportation system would be declared operational. A fourth mission could then send equipment for extended science and the beginnings of a lunar base. All for far less money than has been assumed in the past, according to General Dynamics.
Unfortunately, the company’s initial proposal underestimated the project’s weight. Wendell Mendell, A NASA planetary scientist who has spent years studying lunar bases, said, “When General Dynamics came [to NASA Johnson] with their presentation, [NASA engineers] were going crazy, because they had worked the problem every which way and had not been able to do it. So they wanted to find out what in the world the secret was.”
Caudle admitted that there was a problem, but said, “So we re-did the calculations and said, we can still do it. But you would have to make a lot of modifications. You would have to have the new [Advanced Solid Rocket Motor] boosters for the Shuttle and the new solid boosters for the Titan.” The Titan’s fuel tanks would need a somewhat larger volume and would be made out of a light alloy called Aluminum-Lithium. The Shuttle’s external tank also would be made out of Aluminum-Lithium. Caudle emphasized that all of these changes either are in development or are being considered for other missions. [Note that two of these items have in fact been developed in the intervening years.]
Coincidentally, when Astronomy interviewed him, Wendell Mendell had just completed a study with International Space University students on establishing a relatively low-cost interferometric observatory on the lunar farside. They reached conclusions very similar to General Dynamics’, and their method of getting to the moon was almost identical. The only real difference was use of a very large launch vehicle, like Russia’s Energya, rather than the Titan-IV. “If you are not going to do a lot of assembly in low Earth orbit, or if you are not going to obtain fuel on the moon, you need a very large launch vehicle. That,” said Mendell, “is where the General Dynamics study is most likely to be unrealistic.
General Dynamics’ scenario “does not use existing launch vehicles,” says Mendell. “It uses upgraded versions of existing launch vehicles. And once you talk about upgrading, upgrading always sounds very simple. Quite often the word `upgrading’ is applied to something that” would cost almost as much as a new vehicle. Mendell maintains that to return to the moon, a new, much cheaper way of getting to orbit is almost essential.
General Dynamics thinks otherwise. Using their plan, how long would it take to return to the moon? “That depends on how badly you wanted to go,” said Caudle. “If it was an Apollo level of effort . . . if it were a race with Japan or something . . . we could get there in five years. If it was a normal process with some Skunk Works [management] and they kept the politics out of it, probably seven to eight years.”
How much will it cost? “All of these new things [needed for the company’s lunar mission] are not trivial,” admitted Caudle. They will cost millions to do, and you combine them and they become billions. But they are all much cheaper than building a new rocket, far cheaper.” How cheap? $7 billion to $8 billion, according to Caudle, including the required up-grades to the Shuttle and Titan-IV.
[Note how “modern” this debate sounds!]
— Donald
David: “Why one EELV launch per month? Plan on one EELV launch every two or three or even more months, and try to increase the tempo as we go along.”
A years worth of launches to enable 3 astronauts to spend about a week on the moon, such a program would never survive politically. Nor should it.
“…five or so years ago, this was NASA’s vision for lunar exploration. I’ve been waiting for someone to recall that. Since Dr. Griffin came in, EELV’s are out for human launches…”
I recall it very well. For nearly two years, there has been an organized effort from the NASA/contractor/SDV cabal to suppress and thwart the thought of using EELVs for human flight and it has intensified under Griffin. Some of these activities have been:
– Refusing the presentations of EELV papers at conferences
– Sitting on large amounts of information generated during OSP that showed the viability of the EELVs for manned operations
– Inaccurate statements, actually lies, from the SDV community to policy makers concerning the capabilities and reliabilities of the EELVs. The EELV community (government and contractor) has been unable to respond for being gagged.
– Changing requirements just enough to exclude the EELVs.
These activities beg the question, “What is the driving fear of the HQ/JSC/MSFC/ATK community when considering EELVs?”
“…so-called single stick launch missile: is a four segment SRB powerful enough, never mind avant-garde enough, to serve as the first stage to deliver a large, six person capsule to LEO…”
The “single stick” (some prefer to call it the “shaft”) plans to use a five segment SRB with a J-2 (variant) based second stage.
The five segment SRB is not a normal SRB with an additional segment. Different skirt, different throat equals a different vehicle with no flight tests.
The J-2 has not been in production since the 70s. Some estimate it will be a 3-4 year development to get a J-2 variant into production. Basically, it will be a new engine.
Furthermore, the SRB configuration was not designed to have a 40 tonne load on top. Is it possible? Unknown. Some conversations with the SDV proponents lead me to believe the engineering is not developed enough to support the choice of this vehicle.
This vehicle bothers me far more than the SDV in-line or side-mount. This “shaft” is planned as a manned vehicle, but has no flight experience. While it will have some heritage to the present SRB and the Apollo era J-2, one must remember that this will be a new vehicle and “shuttle derived” in name only.
You both make some good points regarding the SRB vs. EELVs. You are, of course, correct in stating that a 5 segment SRB with a payload stacked on top is a new vehicle. I think the shuttle-c is a good way to quickly get a heavy lift capability, but the rest of the evolutions from the current shuttle make me nervous. Every one of them is a new vehicle. So if you’re going to pay for a new vehicle, why not start from a clean sheet of paper? I think this is another good argument for taking launch vehicle procurement away from NASA and giving it to the USAF. NASA can launch payloads on top of USAF vehicles. They do it all the time. Why should this be different?
Ok, I’m equivocating now but on the other hand, the prospect of being able to launch on a single stick solid booster is very attractive, and especially so with astronauts in a space station. It’s got the same appeal solids always have had. They require little maintenance and are always ready to go. Also, I can imagine the pressure loads from the propellant burn probably drive the structural design, so adding to the stack may not be significant. Maybe everything looks rosier to me after I’ve eaten?
Eaten what, Dfens? Did Mr. Walker’s HQ / JSC / MSFC / ATK cabal finally get you on the phone over dinner? .
Seriously, this SRB idea might make sense if the escape system is really, really good, I suppose, and it could be cheap. That astronaut office seems to support it and its their skins on the line. Who am I to argue? But, all my instincts are crying that it still seems wrong, very wrong.
— Donald
Donald: “But, all my instincts are crying that it still seems wrong, very wrong.”
I agree; my instincts don’t like it either. But logically it makes sense. But that doesn’t convince my instincts.
Good Mexican food always puts me in a better frame of mind, or it may have been a post hypnotic suggestion. I’m not sure any more. My bias is against NASA these days, but I’m trying to give them a fair shake. I wish I had a little more confidence there was some actual analysis behind that 5 segment booster concept.
Dfens: “I wish I had a little more confidence there was some actual analysis behind that 5 segment booster concept.”
Have they not actually test fired a 5 segment SRB, or just an “advanced” 4-segment SRB?
Even if they had fired one, the point Mr. Walker was making is the load path is completely different, and he is correct. On the other hand, a solid, unlike a liquid booster, is pressurized along it’s entire length, with part of the thrust coming from the top bulkhead. I don’t know about them having tested one. I haven’t been following closely enough to know.
I understand what Mr. Walkers concerns were and also that, as you state, the SRB structural loading is a bit more simple as compared to a liquid fueled vehicle. I was simply wondering if the 5-segment SRB was a completely paper idea or if any hardware had been built. Since my post above I’ve found a few “references” to a 5-segment test firing by Thiokol, but nothing really definitive.
I thought we’d started out with more segments and reduced them in the post-Challenger redesign, but maybe my memory is wrong.
Haven’t we been launching heavy nuclear weapons on top of heavy second stages on top of first stage SRBs for decades? It seems to me that the loads from a liquid second stage plus CEV would be differrent in magnitude but less so in degree.
Am I wrong?
— Donald
Why not use the existing 4 segment SRB as the CLV and eliminate some of the risk?
“Why not use the existing 4 segment SRB as the CLV and eliminate some of the risk?”
Simple, a 4-segment SRB doesn’t have the lift capacity NASA has determined it will need.
No, Donald, the redesign of the shuttle SRBs was limited to a redesign of the joints, which is the part that failed on Challenger. CSD makes (made?) some 7 segment solids for Titan IV. If I remember correctly either a 34 or IV flight had to be terminated because of a joint failure. I seem to recall at least one friend and a paper perhaps citing this as a reason fewer joints are better.
I would think the advantage of the SRB approach would be not having to deal with cryo-fuels. It would seem to me, if the first stage was solid, the thing to do would be to make them all solid.
If I remember correctly either a 34 or IV flight had to be terminated because of a joint failure.
‘Had to be terminated’ in the sense of ‘had to watch all the pretty burning fragments crash to the ground after it catastrophically spontaneously disassembled.’
It was a Titan IVA with the 7 segment CSD solid. It seems they decided it was a case burn through, so the number of segments really wasn’t an issue. None the less, they went to a 3 segment composite case with the B model. Wasn’t that the one that got to about 90 degrees of yaw before the range safety officer hit the button? It was 100 seconds into the launch, so it must have been going pretty fast, and probably didn’t need any help. It’s amazing how many unmanned vehicles have failed just in the ’90s. There were at least 3 Titan missions that failed, one due to the IUS upper stage. Not an IUS I worked on. Mine all worked very well, thank you very much, which got me into lots of trouble with the program manager. It got me into lots of trouble with those Aerospace Corp. weenies too. Every time I’d find something the USAF would call them on the carpet for not finding it first. Then they’d start stabbing me in the back. Too bad they couldn’t take up the slack after I left.