X-33 Shuttle Problems 131
SEWilco writes: "This AP story points out major problems with the X-33 prototype shuttle. It's out of money and the composite hydrogen tank came apart in a test. The aerospike engine test seems to be doing nicely, but it needs a ship attached. Congress is considering NASA's Space Launch Initiative Program, which apparently includes more X-33 funding along with considering other technologies. The Delta Clipper is my favorite, although the ET Scenario engine-only-return design is interesting."
Re:New Designs (Score:1)
dang it, its an 'merican program with 'merican spelling.
*Wind* power in space..? (Score:1)
Something tells me that whoever wrote this should perhaps not be taken entirely seriously....
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Re:X33 (Score:1)
I live in CA, and I was planning on buzzing on down to Palmdale for the test, I believe it was supposed to be last summer? or was it the summer before? Anyway, when is the test going to be, do y'all have *any* idea?
Re:New Designs (Score:1)
I suspect those booster rockets are subjected to an integrity check as thorough as the one the space shuttles themselves are put through: they're checked literally inch by inch.
)O(
Never underestimate the power of stupidity
Re:New Designs (Score:1)
--- SAVE THE BRITISH LANGUAGE ---
I don't care whether it's an American or a British programme, I'll spell centre as centre.
Well, actually, in British English "center" isn't actually wrong (color and honor are, though). Both ways are allowed, though "centre" is preferred. It's just that "center" is American, so it's Evil. *grin*
)O(
Never underestimate the power of stupidity
Re:New Designs (Score:1)
)O(
Never underestimate the power of stupidity
Re:Everyone is looking to bash NASA (Score:1)
Universal Space Lines bid on NASA SLI (Space Launch Initiative) and lost, then didn't bid on AA (Alternative Access). Much of the USL group of companies' current efforts are focussed on their Universal Space Network spacecraft tracking and communications operation, which has, unlike the low-cost launch business lately, attracted substantial commercial investment.
Kyger is a lobbyist. What he says is probably sincere, but he is still a lobbyist.
Re:Why was this labeled "off topic?" (Score:1)
Re:SSTO will never happen. Get used to it. (Score:1)
Re:SSTO will never happen. Get used to it. (Score:1)
By the way, Columbus was not the first European to reach America (but I wouldn't expect you to know that either).
OK, pop quiz:
1. How long did it take to get from Europe to North America?
2.How long will it take to get to Mars from Earth, using CURRENT rocket technology?
Answer those questions and you'll be quite surprised. Getting to Mars today is no harder than getting to America was 400 years ago (and a hell of a lot easier than it was when the Vikings did it 900 years ago).
-jon
Re:SSTO will never happen. Get used to it. (Score:1)
I'm not going to read the book to you, but it's a GREAT plan. Check it out, if for no other reason than to shore up your own argument.
For the record, the space station as it's designed is a total waste of money. Nobody's going to learn a thing that's worth its cost.
Re:Urgh. (Score:1)
I think that the most cost effective heavy lift transport system is going to be an advanced staged rocket, (maybe you could figure out a way to recover and refurbish the stages, maybe not...) shooting from the equator. If SeaLaunch scales up, it could be very cool.
Re:Urgh. (Score:1)
Let's make the grotesque assumption that developing a new, low cost per pound to orbit spacecraft is the same whether you choose SSTO or "conventional" rocket. (I would argue that the sunk cost of SSTO development is going to be radically higher, since there are SO many technologies that need to be refined in order to make it work) In this case, SSTO is more economical than rocketry IFF the cost to service the vehicle is less than the marginal cost of building one more rocket. Although I agree that the costs to refurbish the Shuttle are more than those of a newer design would be, if you assume similar fabrication technologies for both platforms, I bet that disposable rockets wouldn't cost very much at all. You also would be `ble to use the fuel tanks from the upper stages as modules for your space station, which is an idea I'm terribly disappointed that NASA didn't evaluate further.
With current technology, SSTO vs. rocketry is, at best, a dead heat. I believe (and the industry professionals without a vested interest in SSTO I've talked to agree) that staged rockets will be the cheapest in terms of dollars per pound in orbit.
If you have other mission parameters, like quick turnaround, it may well be that SSTO vehicles have other advantages that can't be enumerated in these simple thought experiments. I don't have the expertise to argue that point one way or the other.
One further note: The other URL referenced in the header hasn't got a lot of attention (probably because the page design is awful...) http://www.atlantic.net/~elifritz/space.htm shows a heavy-lift SSTO rocket, whose engine section is returned to earth, and whose fuel tanks remain in orbit as infrastructure for future development. This seems to me to be the best of all possible worlds. Once we've got a little more expertise doing heavy labor in space (refurbishing the fuel tanks into habitable spaces), this will be a very very attractive proposition. Pretty brilliant idea, that takes the major advantages from both camps. (IE, you recover the expensive part of the rocket, but you don't have to service the whole mess...)
Re:SSTO will never happen. Get used to it. (Score:1)
His rocket math works. I don't know how to estimate the cost of this project, but his figures are a lot more credible than NASA's Battlestar Galactica nonsense.
Getting to Mars is nothing more or less than an act of will. It IS valuable, the only question is whether we've got the balls to do it. I, for one, can't wait. I'll be sure to send you a postcard.
Re:Urgh. (Score:1)
Re:Ram and Scramjets make sense for atmospheric li (Score:1)
X-33 was TERRIBLE engineering from the start (Score:1)
The aerodynamics of the NASP were totally contrary to its mission. Drag forces at high supersonic and hypersonic speeds (from, say, Mach 3 and up) are dominated by the drag induced by the shock wave that develops ahead of the craft. Wave drag is minimized by using small frontal cross section vehicles. The NASP had two major design constraints, dictated basically by the politics of getting the thing funded, that made a slender vehicle impossible. The vehicle was supposed to use slush liquid hydrogen. Although hydrogen releases tons of energy when it's burned, it's density is very low. Other fuels, like propane and methane, would have been much easier to carry in a slender vehicle. The slush hydrogen fuel, however, had technical sex appeal for the people funding it. (Basically, the contractors thought they could make a lot of money developing this fuel technology, so they weren't going to fund the project without it). The aerodynamic chubbiness meant that most of the engines' thrust was used up opposing drag, meaning that there was little net force left over to accelerate the aircraft. Therefore, the vehicle had to fly at Mach 7-15 for about 20 minutes...making cooling the airframe one of the major challenges. Sure you've got a bunch of liquid H2 on board, but piping it to all the places whose temperature is starting to approach that of the sun's surface gets, well, complicated.
The air breathing scramjet propulsion system 0requires a huge engine "bell" (actually, the NASP uses a half-bell ramp), which drives up the cross-sectional area of the ship. The air-breathing nature of the "primary" propulsion system (one of FOUR separate propulsion systems to be carried on the craft!!!) saved the plane from needing to carry liquid O2 to burn with the hydrogen. A neat idea, however modeling the compression and combustion of the engine, operating with high supersonic intake velocities, went from astoundingly difficult to absolutely impossible.
The initial flight profile of the X33 was supposed to go something like this:
From 0 to ~ Mach 1.3: Propelled by a conventional turbojet or rocket engine
Mach 1.3-3: Propelled by a ramjet engine
Mach 3-15: Propelled by a supersonic compression ramjet (scramjet)
Mach 15-orbital insertion: Propelled by a rocket
So right from the get-go, you've got four different engine systems to integrate, three of which are dead weight for any given part of the flight. Never mind the difficulty of actually IGNITING these engines at the proper time...
From a project management perspective, this thing was dead from the get-go. Two separate airframe manufacturers had to coordinate with four separate engine manufacturers, leading to essentially eight different designs. The whole thing was classified, meaning that engineers were not given any information they didn't "need to know", and were not given the opportunity to evaluate the feasibility of their proposed solutions. This is a HELL of a way to run a railroad.
Maybe I'm slow, but for me the most profound insight was into the nature of rockets versus the nature of airplanes. With rockets, your thrust vector directly opposes your weight vector. This means that THE killer feature for a rocket is very light weight. In an airplane, your thrust vector opposes your drag vector, so aerodynamic cleanliness is the most important consideration for airplanes. When your goal is to get up to Mach 25 (LEO insertion velocity) doing so by flying horizontally is just plain stupid.
Anyhow, the moral of the story was, "Don't ever do a project this way ever." Probably the most fruitful hour-long lecture I've gotten so far.
Re:Ram and Scramjets make sense for atmospheric li (Score:1)
Re:The NASP(X-30) and X-33 are two different thing (Score:1)
In that case, since I was confused, it's possible that other people were too. I hope. Or maybe I'm just a big idiot. : )
All my comments above are related to the big doorstop-shaped NASP. The littler reflex-hammer lookin' X33 (which might become the Delta Clipper) was not discussed. Its linear aerospike engine looks interesting, but I still think SSTO is not going to work well. At least it doesn't try to launch horizontally, though...
Well damn. Diggin' the egg on my face...
Re:Ram and Scramjets make sense for atmospheric li (Score:1)
Re:Ram and Scramjets make sense for atmospheric li (Score:1)
Re:SSTO will never happen. Get used to it. (Score:1)
I'm glad that the Spanish didn't take the same idea with the Americas. I mean it takes three months to get there and get back, there's nothing really useful there at all except for gold and silver ore, and it costs a lot to send those gallons across the sea for all that time, they can be put to much better use fighting the English or hauling spices from the Turkish coast. We should just avoid the New World at all costs. It's really just not worth the effort to go at all.
But you see that the possible profit drove them to the New World and the profit will drive people into space. You say that all that's there is ore, well everything around you is just ore. Nothing more. It is what can be done with it that matters. Prohibitive costs in research and development are not going to stop SSTO ships, no more than the prohibitive research costs have stopped cars or airplanes. As long as there is any profit to be made at anything it will be done. It is worth being done. Lowering costs by complete reusing of a spacecraft will cocur. It might not be nasa, esa or the russians. It could be Roton Rockets [rotaryrocket.com]. Quite simply the current needs of space are not being met. It takes too long to set up a launch, it costs too much per pound, and repair is impossible (try replacing a broken motherboard is space, really can't be done so a $50 million dollar satilite has to be splashed for a $1,000 part.) The shuttle cannot do all these things, Soyez is just a orbital taxi, and the Protons, Arians, and Deltas of the world are too few to go around. There is money to be made in space, and we are going to go there, whether you agree with it or not. Developments costs can be divided over time, and there is no testing like putting it to work now.
Re:SSTO will never happen. Get used to it. (Score:1)
Purposefully or not, NASA is killing the space industry. The DC looked *damn* good, and there are plenty of other privately-funded rockets that *don't* cost $1,000,000,000, but can't get any funding because of NASA's promises. Screw that.
better ... (Score:1)
Re:Urgh. (Score:1)
Re:Urgh. (Score:1)
Regardless of the material improvements, the multistage is going to be more effiecent.
As the mass of the tank approaches zero (that is, if we could build the tank out of fuel) we would approach a limit where the "multi-stage" was a continuous function (rather than, say, 3 stages).
Re: (Score:1)
Re: (Score:1)
Re:X33 (Score:1)
If you're not allowed to talk about the NP-19, then you're in violation of federal law mentioning it by name in a public place. Either that, or you're a troll.
I'd have to guess troll. After all, what would someone who, say, builds hardware for training ISS crew or someone who maintains part of JSC's ethernet (which is what the two guys I know who work at NASA do) be able to tell me about some super-secret project? "anyone else working at NASA", indeed.
Crawl back under your rock. (Score:1)
Re:X33 (Score:1)
Everyone is looking to bash NASA (Score:1)
"I think the X-33 will never fly, and I'm not alone in that opinion," says Tim Kyger, a former Congressional staffer who now works for Universal Space Network, a company that provides satellite tracking services.
Personally, i would rather have seen a quote from an aerospace engineer or some other profession that actually deals with space flight. I don't know who this guy is or if he even knows anything about the X-33. And it is just his opinion, he even states it! And this is the only quote in the entire article that they use to support the authors conclusion. I was not impressed by this piece of journalism.
What We Really Need... (Score:1)
Of all of the private companies that are developing new, low cost launch vehicles, the most likely to succeed IMHO is Beal Aerospace (BYW I neither work for them or have any financial stake in the company).
Re:New Designs (Score:1)
Those tanks must undergo a tremendous amount of stress, and I wouldn't want to trust one of them after being "used"
Re:What gov't should do... (Score:1)
Re:Forget NASA (Score:1)
about the delta clipper experimental program. (Score:1)
I'll stand by my judgement of vertical landers. Though skips and loops can be used for air breaking, you are sill left with the problem of descent. An exercise for the reader is to immagine how much fuel you would need to land safetly from the roof of the empire state building. I'd rather have a parachute.
It sucks to kill any project, but two half project do not make anything useful. NASA made a good call.
Anyone who is interested in the relative merits of different rockets can read. "Spaceflight Dynamics" by William E. Wiesel. Wings in general are a bad idea, but they alow for controled descent. The space shuttle without wings would reach 9 km/s, but it achieves 7.8 instead. I prefer Orion shuttle combination.
We've gotten lost in pleasant details. My overall point was that politics has not hamstrung NASA with such fine disinctions. Politics have failed to give NASA a clear mission and budget to go with it. If someone like Bill Clinton would have emulated the better characteristics of JFK (not all good, mind you, he feared Orion) instead of chasing interns around the white house, we might have such a mission. NASA is doing well with what they have.
Re:*Wind* power in space..? (Score:1)
A *giant* solarwindplant in orbit!!! (We're talking *really* huge stuff here.)
Re:Why our space program is outta gas. (Score:1)
The human body is a pretty fragile little package as far as equipment goes, it can only handle about 10 gees or so before it breaks. the fact that we showed we could get one to the moon and back showed pretty well that we could put as many A bombs as we wanted on the Kremlin's doorstep.
It wasn't until the shuttle we were really in it for science reasons, and I'm not even sure about that, either, we just needed a reusable elevator to push up a bunch of spy satalites, science was a bonus. it all comes back to `defense'.
but on another note I don't mind living in the country with the biggest stick, since the one with the biggest stick is almost always hitting littler people with it, and I don't wanna be little
'cept canada, we don't tick them off cuz when we do they send busloads of tourists out of Thunder Bay to stone pesestrians to death with their chinsy aluminum quarters
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you're absolutely right (Score:1)
ai yai yai
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Peace,
Lord Omlette
ICQ# 77863057
Re:New Designs (Score:1)
Re:Why was this labeled "off topic?" (Score:1)
Yes, quite intelligent and well-informed, it appears, restoring my faith in /. moderation.
The NASP was the X-30, not the X-33.
Re:Urgh. (Score:1)
It's difficult, but it was done in the 50's by the Atlas and the Titan II second stage, and again in the 1960's by the Saturn V second stage (which was hardly a delicate thing, having the third stage, the LM and the CM/SM sitting on top of it). With appropriate engines (lower thrust to limit the acceleration with a lower payload, and exhaust bells able to operate at sea-level pressure) any of those would be capable of being used as an SSTO with positive payload. They probably wouldn't be reusable but surely materials science has advanced that much in the last forty years?
Regardless of the material improvements, the multistage is going to be more effiecent.
There's your big mistake right there. Efficiency is useless if it costs too much. If you can build something ten times bigger, using ten times as much fuel, but it works out cheaper than the smaller, more "efficient" rocket then the big inefficient guy is what you want for commercial space. This is a different answer than you get if your interest is military space.
It might seem strange that using more fuel can be cheaper, but look at the figures. The fuel needed to provide the energy to lift a pound of stuff into orbit costs maybe $10. Current launch costs are around $10,000 per pound. Where's it all going? Not to fuel.
Re:NASA crowds out real private spacecraft again.. (Score:1)
Re:X33 (Score:1)
And what *is* an NP-19?
Re:New Designs (Score:1)
Tell me what makes you so afraid
Of all those people you say you hate
Re:MEEPT!!!!! (Score:1)
Tell me what makes you so afraid
Of all those people you say you hate
Scientific American (Score:2)
Here is the link:
SciAm Space Exploration Issue [sciam.com]
And, no it isn't a goat sex link.
X33 (Score:2)
Re:Should be 'politics', not 'science' (Score:2)
The funny thing is that, on the one hand, while NASA is doing everything it can to squash privately funded space initiatives in this country (while publicly attempting to appear to "help" them), while on the other hand NASA is held in such high esteem in the rest of the world that if NASA says something can't be done, nobody will even attempt to prove them wrong.
Sometime I expect to hear that Japan or China is building a DC-X style full scale prototype SSTO vehicle and I don't know if I'll laugh or cry.
On the other hand, the Delta Clipper, funded by McD primarily;
Actually, it was funded by the DOD as part of Regan's SDI project. There's nobody in the upper levels of McD management (or Lockheed for that matter) with that much vision.
Wow! (Score:2)
At first I thought that wasn't possible, because the Space Shuttle and Venture Star don't have enough lift for take-off, only for a one-shot landing. But as you said, it won't need nearly as much wing surface to get enough lift to get off the ground, because it can lift off on virtually empty tanks with lots of payload, and refuel in the air.
You can improve the fuel to payload ratio even further if you put a refueling station in orbit. Then you can take off with enough fuel to reach the tanker aircraft, then top the tanks off - enough to reach the refueling station in orbit, and then take in enough for orbital manuvering and re-entry.
)O(
Never underestimate the power of stupidity
Re:Urgh. (Score:2)
The big problem of a vertical launch is that 80% of what you lift is fuel, and is spent on the way up. Why not put an SSTO craft like the Venture Star as a second stage on the back of a big and fast aircraft, a modified 747, 777 or Beluga for example? Simply fly that aircraft as high and as fast as it goes, maybe stick a rocket on it to gain some extra height and velocity at its ceiling to launch the second stage.
As I said, it's probably been thoroughly researched already - if so, can somebody explain why this isn't done / doable, while it seems so simple and feasable (too simple?) to simpleminded me?
)O(
Never underestimate the power of stupidity
Re:SSTO will never happen. Get used to it. (Score:2)
According to NASA, $50 billion to get there and back on the Mars Reference Design Mission '93.
Hint: there haven't been any realistic estimates below $100 billion, and some have been as high as $400 billion.
Er, you don't think NASA's Mars Reference Design Mission '93 cost estimates are realistic?
Steven E. Ehrbar
Re:Its all physics (Score:2)
There's one very simple way to find out if it will work. One of the goals of Mars exploration is the "Mars Sample Return Mission" - dig up some Mars soil and Mars rocks, put it in a capsule, and send it back. Now, if you used the fuel-making techniques proposed by Zubrin for this mission, you'd get a Mars Sample Return mission done for approximately half the cost of the original mission (because instead of needing two launches and on-orbit assembly to get the mission off Earth, you could do it with one), and validate the technology for a future manned Mars mission.
I'm personally fairly confident that the fuel-making would work (the technology is fundamentally simple, and the Mars atmosphere has already been fairly well analyzed) but this is a great way to find out.
My two damn cents (Score:2)
If you wonder what good an X-15 type plane would be if it could only launch 1 or 2 people at once, then consider that it would be much better than our current cheap launcher which doesn't exist. A cheap launcher that can send a single person up is better than an expensive launcher that can send 7 people up.
Launch your heavy mass on Titan IVs and Energias. Launch people in small launchers. Have then rendesvous in orbit. It's cheaper that way.
Re:X33 (Score:2)
I can't find any reference to the NP-19 on the web, nor to I recall see it in AvWeek. What is it?
And as for running out of money, the problem apparently is that NASA believes that they've given Lockheed enough money; and that Lockheed should pay for the most of the rest of the work themselves, and Lockheed couldn't be less interested in doing that.
I'd be quite interested, and even happy, to be proven wrong, if you can do it.
thad
Re:Should be 'politics', not 'science' (Score:2)
The DCX was really amazing. If it had been built, it could have been the first craft to be able to take off from the Earth, refuel in orbit, fly to the moon & land, refuel there, & come back. And it could land pretty much anywhere on the planet you had a big enough flat space.
It's typical of the government and McDonnell-Douglas's luck at the time. MDC has a proposal based on a previous, successful technology demonstration, then Lockheed gets the contract & fucks it up. Ever heard of THAADS?
Re:DELTA CLIPPER was SUPERIOR, so it was scrapped. (Score:2)
Re:Why our space program is outta gas. (Score:2)
Usually, when a lot of men get together, it's called war.
-Mel Brooks
Re:you're absolutely right (Score:2)
Re:Cheap way to acieve mach 25 (Score:2)
You're not far from another interesting idea though. The nutty geniuses over at Tethers Unlimited want to have a mini-space elevator, whose bottom half is ripping through the upper atmosphere at about Mach 17. You dock with this thing from your hypersonic passenger liner (like the X30 that got canned, and for good reason), and hop on up into space on a great big crane.
How you actually DOCK at Mach 17 is not something I'd care to contemplate. But the idea's there...
Re:Should be 'politics', not 'science' (Score:2)
What do I do, when it seems I relate to Judas more than You?
Urgh. (Score:2)
So it sounds like a great idea... everything is reusable, and if it works on cars and planes, then why not on a spacecraft? But you have to take a *lot* of fuel along. The reason staging works is that what you're pushing gets progressively lighter as you go. Yeah, its wasteful, but it works, damnit. If you want something really nice, design a two stage rocket with both stages reusable.
What you get with current tech is a really big fuel tank, pushing up a comparatively small payload.
What do I do, when it seems I relate to Judas more than You?
Re:SSTO will never happen. Get used to it. (Score:2)
How much would it cost to get from Earth to Mars using current technology?
Hmmm... let's see if I can dig up the GNP of Spain in 1492, so that a relevant comparison can be made....
/.
WWII, Germany, and Coal-Dust Jets... (Score:2)
http://visi.net/~djohnson/lippisch/lip13b.html
BTW - Check out other planes on this site - very strange stuff!
I support the EFF [eff.org] - do you?
Re:SSTO will never happen. Get used to it. (Score:2)
The other issue is turn-around time. The space
Incidentally, having water ice is very important for space exploration, because it removes the need for about half of your consumables. (Water can be drunk and used for hydroponics; cracked water can be used for fuel and to breathe; raw ice, if there's enough of it, makes a good dust shield, etc.)
-_Quinn
The X Prize... (Score:2)
Just a quick link that seems highly relevant to this story but is missing (last I checked, a few seconds ago)...
The X Prize [xprize.com]From their site:
The purpose of the X PRIZE is to promote the development and flight of spaceships able to provide low-cost commercial transport of humans into space.
Thanks for the rant (Score:2)
User Bio
Visual effects programmer/animator/supervisor Developing visual effects tools for Linux
While that's a nice thing for Thagg to be doing, I can confidently say that he's talking out of his ass. NASA has been doing good things with its ever shrinking budget and the directions it is given. If you want to point to politics, look in the mirror.
The X-33 was a risk, but not nearly such a stunt as the Delta Clipper, which had a marked tenedncy to explode. Think about vertical landing for a minute. Parachutes and gliders can be made stable much easier than the DC. Vertical landers are also the least efficient of rockets. If it took a Saturn 5 to get to escape velocity, it will take a Saturn 5 to stop a vertical lander at escape velocity. Now what would it take to get a fully loaded Saturn 5 to escape velocity? Orion [quilt.com], that's what.
The X-33 was not all worked out when it started, what is? The technologies being tried are mostly involved with new materials. They have benifits that could greatly reduce weight and that equals cost to put things in orbit.
Carbon fiber technology has great promise and has worked it's way into all sorts of parts already. Fiber is to aluminum what aluminum was to steel. Parts can have 1/5 th the mass of their aluminum equivalent. I'm not sure why they have been having so much trouble with those tanks, but I know from a friend that works at Michaud that there have been problems like this for the last three years. I suspect heat curring just induces too much strain for cryrogenic tanks, and I wonder why they have not tried to use E Beam curring [ornl.gov] another Lockheed Martin technology. Oh well.
As for politics, we could have used Appolo technology to get to Mars by now, or Orion to get even further. But, we the public are full of bad advice.
To learn more visit and or join:
AIAA [aiaa.org]
SPE [4spe.org]
Re:New Designs (Score:2)
Re:New Designs (Score:2)
Tell me what makes you so afraid
Of all those people you say you hate
Re:about the delta clipper experimental program. (Score:2)
Okay, slow down for a minute and calculate exactly what you've proposed; make sure you account for the fact that the vehicle is very lightweight and almost empty (hint: W/[Cd*S] is not large).
What you'll find is that the vehicle is its own parachute! Depending on the exact details, terminal velocity turns out to be around a couple of hundred feet/second -- it only takes a few seconds of thrust at a reasonable level (say 2 gees) immediately before landing to bring that to zero.
This is actually quite well-known -- I don't know why you aren't aware of it, unless you're just ignoring it. DC-X was a damned fine project, and it met its goals; only when NASA took the reins with DC-XA did things go to hell. I leave it to you to speculate on the reasons...
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Re:you're absolutely right (Score:2)
The moonshot was just an expensive way to thumb our noses at the Soviets.
If going to the moon had any intrinsic value, why haven't we been back since the early seventies?
Re:SSTO will never happen. Get used to it. (Score:2)
Do they not teach math at the University of Kansas? Try looking up the distance to Mars next time you toss around your useless anecdotes.
By the way, Columbus was not the first European to reach America (but I wouldn't expect you to know that either).
Prohibitive costs in research and development are not going to stop SSTO ships,
You're right, physics is.
Soyez is just a orbital taxi, and the Protons, Arians, and Deltas of the world are too few to go around.
Thats garbage, you have no idea what you are talking about. From refurbished SS-18s, to Sea Launch, to Arianne, there are numerous ways to put your satellite in orbit, and they're getting cheaper all the time. The X-33 was never intended to be used as a satellite ferry anyway - NASA knows it will never be the cheapest satellite delivery service, and they aren't even in that business anymore.
Re:SSTO will never happen. Get used to it. (Score:2)
Ok, pop quiz:
How much did it cost to get from Europe to America?
How much would it cost to get from Earth to Mars using current technology?
Hint: there haven't been any realistic estimates below $100 billion, and some have been as high as $400 billion.
Comparing a trans-atlantic journey to a Martian journey is a stupid comparison, and it would behoove thinking people to drop it asap.
Amen (Score:2)
SSTO will never happen. Get used to it. (Score:2)
The real question you have to ask is why bother at all. We can already put up satellites cheaply - there is no need to create new technology to meet this need. The shuttle or the Soyuz capsule can meet all the needs of manned orbital flight and the ISS (another boondoggle) for the forseeable future.
What else is there? Mars? Newsflash folks, its a rock floating in space with some ice on it. Waste of a trip. Until we develop drastically advanced propulsion technologies that in no way resemble anything we are even thinking of now, space is simple a gigantic lonely space that is off limits to us. Astronomy is a far more useful and realistic way to explore the heavens.
Its all physics (Score:2)
747s never have to attain escape velocity - they need only to become airborne. They can also make use of lift - which is mostly meaningless with regards to current and proposed orbital designs.
Attaining escape velocity means going fast - very fast - the shuttle hits 17,000 mph in order to achieve orbit. This take fuel, and a lot of it, per pound of payload. But the tricky part is that your fuel becomes part of your payload - the more fuel you carry, the more you need to propel it. Staged designs have typically been a solution to this problem - each stage is only powerful enough to get the stages above it to a certain point in the atmosphere - when this point ius reached, the stage falls away (reducing the weight of the vehicle).
There's nothing stopping us from getting to orbit, or Mars for that matter, it's just the price that would be involved doing it safely enough to prevent disaster and maintain NASA's reputation.
Not true. There are some serious opinions claiming that SSTO is simply not workable given the technologies we are developing - the physics simply cannot be overcome unless we develop dramatically lighter materials and more effective propulsion.
As for Mars, we do not have the technology available right now to get there. Zubrin and co. may have designs which seem workable, but they are only designs. No one knows if generating return fuel on the Martian surface will actually work.
Re:SSTO will never happen. Get used to it. (Score:2)
Yes, but the development costs are sunk. Lowering the cost per pound must consider the cost of development. So far it is cheaper to simply continue with what we have - multistage rocketry.
Incidentally, having water ice is very important for space exploration, because it removes the need for about half of your consumables. (Water can be drunk and used for hydroponics; cracked water can be used for fuel and to breathe; raw ice, if there's enough of it, makes a good dust shield, etc.)
I understand water can keep you alive on Mars - but why would you want to be there in the first place? I haven't heard one useful reason to go to Mars. The cost of extracting ore from the crust is prohibitive. There are no useful materials to extract beyond ore. Even if you just wanted to go so you said it could be done, the cost is so high that making more than one trip isn't realistic.
Re:SSTO will never happen. Get used to it. (Score:2)
Uh huh, and ISS was only supposed to cost $5 billion. Zubrin is a scientist, not an accountant.
Going to Mars is going to cost $100 billion, minimum.
Larry Niven on private ventures and economics (Score:2)
Also, for the political and Economic musings related to getting in space, check out this article [space.com], also on space.com.
-------------
on the moon for a few days at a time, come home, and stop.
We saw our space station built in Houston,
orbiting too low and too slow, at ten times the cost.
Thirtieth anniversary of the first man on the moon,
celebrated by grumbling.
My tee shirt bears an obsolete picture
of Freedom space station and the legend,
"Nine years, nine billion dollars,
and all we got was this lousy shirt,"
and it's years old and wearing out.
Now is economics interesting?
-------------
---Mike
harlock@raindrop.com
What we need is a really good war. (Score:2)
Martian Valuables: (Score:2)
List from the top of my head:
In short, the attitude that Mars is just a ball of dirt and ice is exactly equivalent to the French and the Russians regarding Louisiana and Alaska as a lot of worthless wilderness. (Until recently, the Russians thought that way about Siberia as well, but they wised up before they sold it to anyone.) Had a realistic value been set on either of those territories, the United States would never have been able to afford either.
The obvious answer ... (Score:2)
Cheap way to acieve mach 25 (Score:2)
Drastic problems require drastic solutions
Okay, so we won't be having orbital transit soon. (Score:2)
Physics, politics et cetera - read this book (Score:2)
Why our space program is outta gas. (Score:2)
Funding is a pain (Score:2)
The fact that it could lead to a place for their great-great...grandkids to live other than on a burned-out, over-crowded planet means nothing. It doesn't put money in their pocket now, that's all that matters. What they don't realize is that we are where we are today because of advances made in the space program of the 60's. Computers, plastics and myriad other things we have benefited enormously from that program.
The money spent today on the space program primarily benefits specific people in specific congressional districts. I don't see how we can get back to the way things were in the 60's space program in today's culture. Advances will almost certainly have to come from the private sector. I still have a certain amount of respect for NASA, but as the saying goes, "lead, follow or get the hell out of the way." If they aren't allowed to lead us into space then they should get out of the way of private industry.
Re:Urgh. (Score:3)
Fuel is cheap. Maintenance is expensive. There is a certain amount of energy you have to dump into one pound of stuff in order to get that stuff into space. The least expensive vehicle is the one that weighs the least.
What makes a single stage craft horribly wrong is that it WILL weigh more than a staged rocket. End of story.
There's nothing magic about SSTO that makes it cheaper than the Shuttle (whose alleged cost savings have NEVER been realized). The economies are supposed to come from simplified servicing and maintenance. Therefore, IF you can service the thing for less than the cost of a similar capacity rocket, it's economical. This has not proven to be the case.
And before you start hollering about people who don't know what they're talking about, let's discuss this "fuel per square pound" idea you've got in your post. I'm REALLY sure that this measurement has nothing whatsoever to do with rocketry.
Re:Urgh. (Score:3)
I'm saying the technology for an efficent SSTO rocket isn't here yet. First off, you need to have an extremely light rocket, or its not even going to matter. Consider this:
To lift the mass of a single stage launcher using hydorgen/oxygen rockets (currently our highest conventional specific impulse fuel), you have to carry along eight times the unfueled weight of the rocket in fuel.
You must now have an extremely light, large rocket. So, it pretty much has to be built out of composites. You now have a really big fuel tank with a payload. So let's consider the engines.
You need some damn powerful engines, and damn adaptable engines. Bell rockets won't cut it- the Aerospike is the only concept that even comes close. So, you have a rocket made out of emerging materials on top of a semi-proven rocket design (I say semi-proven since the Aerospike has never been used, to my knowledge, on an actual rocket). Quite a bit of stuff to develop. Quite a bit of unproven technology.
And now, since you have 8 to 1 propellant to spacecraft, you don't have a real lot of room left over for the payload.
What I'm saying is that SSTO is quite the challenge. It's something that I'm not sure that is feasable, as yet- theres a lot of unknowns. To this date, the best alternative is staging- you drop weight as you go. Since you drop significant weight with each stage, you have less rocket to keep going. The (as promised) VentureStar might be uber efficent, but I suspect that when it hits the cold, hard light of reality, that tenfold reduction of cost argument will fall through, just as it did with the Space Shuttle. If they even get it into orbit- there is yet to be a rocket built capable of a single stage insertion into orbit.
What do I do, when it seems I relate to Judas more than You?
The NASP(X-30) and X-33 are two different things (Score:3)
X-30 info: er, I can't find any in three minutes of searching. However there are some pretty pictures. [nasa.gov]
--
"I have also mastered pomposity, even if I do say so myself." -Kryten
Re:Urgh. (Score:3)
It's a good idea, but it has problems. You're severely restricted in the size you can make the spacecraft by all sorts of things. You've got to be able to support the fully-fuelled spacecraft on top of an aircraft not originally designed for that, which means extensive modifications. Look at how much trouble NASA had to go to with the Shuttle transporter aircraft, and the Shuttle rides empty. As well as structure, that impacts takeoff speeds and runway lengths. Note also that tthe maximum takeoff weight of aircraft such as the 747 is far more than the maximum landing weight -- if they have to abort early in the flight then they normally have to dump lots of fuel. That's tricky if the weight is in a spacecraft.
There are also operational problems. It takes time and special equipment to mount the spacecraft on top of the carrier aircraft, which means expense. You've also got to be careful not to land the spacecraft anywhere that the carrier can't fly out of.
If you possibly can fly SSTO -- even with a very small payload -- then you're probably better off to do that than to use a piggyback carrier aircraft. See however Len Cormier's Space Van [tour2space.com] concept, which looks quite interesting.
Other alternatives for a 0th stage include KellySpace's [kellyspace.com] concept for using a 747 to tow a spacecraft (already tested by towing a jet fighter), and Pioneer Rocketplane's [rocketplane.com] concept of the spacecraft and a tanker taking off seperately (possibly from different locations) and doing aerial refuelling.
Both these concepts have advantages over a piggyback arrangement, through reducing the loading on the 0th stage aircraft's structure. I think the Pioneer proposal is the best. It allows a lightly-loaded spacecraft to take off from almost any commercial runway where the payload is, while the tanker takes off from a longer strip possibly hundreds of miles away. The undercarriage of the spacecraft doesn't have to carry the fully fuelled weight (giving a weight saving) and the wings only have to be big enough to carry the fully-fuelled vehicle when travelling at 500+ mph, not when at a 100 - 150 mph takeoff speed, for a huge weight saving.
Pioneer have done detailed design of their intitial aircraft, right down to the point of getting fixed price quotes from the likes of Boeing to actually build it. What they haven't been able to organise is the funding. I don't think anyone seriously doubts that their idea will work, the question is whether an investor will make money in the current environment, especially with Iridium having gone bust and Teledesic cutting back their plans drastically.
... and America is just a heap of dirt in the sea (Score:3)
I often try to decide whether space exploration is comparable to the sea voyages undertaken by 15th to 18th century mariners. These voyages were comparable in risk to today's space flights, even flights to the moon and to Mars. Back then, I guess, the motivation for these explorative voyages was partly commercial, partly just human curiosity. Admittedly, they did know that there were spices to be found in India. We (pretty much) know there's water on Mars - let's go there and see what we can do with it!
But no, we don't need to invent new technology. It's all been done before, so why bother? The Commissioner of the U.S. Patent Office declared in 1899, "Everything that can be invented has been invented." For this reason, he wanted his office closed. "No, no - you can't go farther than you can look, it's no use leaving here."
Re:SSTO will never happen. Get used to it. (Score:4)
How do you think those magical propulsion techniques will be invented?
I'll give you a hint. We're not going to sit around on Earth for the next hundred years until somebody says "Hey guys, I just realized, with that space engine sitting in your back yard, we can get to Mars in two hours, so let's go!" The first trip there will be horribly, painfully slow, and then people will come up with better techniques.
Mars is in reach of current technology NOW if anybody wanted to do it, and had the money. Of course, why go to Mars? There are better things out there: asteroids. The metals in the average mile-long asteroid would supply our industries for something like fifty years at the current rate.
People who sit back and wait for things to happen only get away with it because other people are not content to sit and wait.
Forget NASA (Score:4)
$1,000 per pound (Score:4)
The real issue is that many of the private sector solutions to low cost to orbit have either chosen the wrong launch weight, run out of venture capitol, or just not proven to be as affordable and reliable as a NASA launch.
The other thing that needs to be considered about the X33 is that if you can afford to keep it feuled and on the pad, it can be looking down on anywhere on the planet in less than one hour! That's revolutionary.
From the article:
"In the wake of last year's back-to-back Mars mission failures and repeated delays in constructing the space station, a high-profile success would help rehabilitate NASA's tarnished reputation. The X-33 could have produced that success, but for almost a year the space agency has kept the project out of the limelight."
*Nowhere* in the article did they mention the complete *success* of NASA in deploying the ISS. This is hardly a fair reading of the facts.
NASA is attempting to solve hard problems that take time and money to solve and NASA should be given the funding and time to succeed. When completed, this will put our countries space capabilities leaps and bounds ahead of everyone else, and will make projects like LEO comunication constellations finacially feasable.
Over budget, Under thought (Score:4)
Tell me what makes you so afraid
Of all those people you say you hate
Should be 'politics', not 'science' (Score:5)
SSTO systems are, in some ways, extremely simple to evaluate. To get a payload to orbit without staging, you have to have both an extraordinarily efficient engine and a remarkably high mass ratio (fuel:everything-else ratio). It was obvious that the X33 prototype wasn't going to get to orbit very early; the mass ratio just wasn't there; even with rediculously risky materials and structures were specified. So, there were two obvious things to do at that point:
1) Kill the project
2) Lower expectations to a technology demonstrator, and cut way back on the risk.
They, of course, chose the insane third option, maintain the (extremely expensive) exotic materials, but still give up on the the idea of going to orbit. So, they ended up with failed tanks, and nothing to demonstrate whatsoever.
The aerospike engines really are a great idea, it would have been extremely useful to see them fly. As it is, there is absolutely no question that the project will be killed. Lockheed even wants it dead. And why not? They got all the money that they could ever get from the program, and they didn't actually have to produce anything at all.
It's very likely that almost every part of the alleged rocket wouldn't have worked; the tanks were just the first thing to fail spectacularly. The engines had very serious problems too (the ramps that are the key to the aerospike concept were much harder to fabricate and cool than 'expected').
On the other hand, the Delta Clipper, funded by McD primarily; was a system that could be tested in stages, and in that testing they took some actual risks; but measured ones. The first test when they flew the rocket and landed it vertically was a big step -- but they managed the risk to the point where they made it happen. The engines, tanks, and almost everything else in those first tests were off-the-shelf items (the aeroshell was a unique thing, but contracted out to Scaled Composites, a company with a sterling record for this kind of thing.)
So what happens to the Delta Clipper approach. It's killed, of course.
In the end, I have no question that the next-generation launcher will be built by private industry either in the US or more likely overseas. Sad, but that's the way it is.
thad
Re:Thanks for the rant (Score:5)
The Delta Clipper was an orbital vehicle that was never built. Perhaps you're thinking of the DC-X? That was a subscale demonstrator of vertical landing and low-Mach terminal maneouvering. It was a near-perfect example of what a focussed research and development project *should* be. It tested one thing and one thing only, on a very small budget and short time-scale. And it worked perfectly. The only real thing wrong with it was that research projects should really build two or three, not one. It's only a little more expensive to build several copies than to build one, and it protects against losing the whole project if you crash the vehicle. If a research project is really a *research* project then it must be investigating something that you're not 100% sure you know how to do, which means that if you don't crash a vehicle then you probably weren't pushing hard enough.
The vehicle which burned was the DC-XA. The DC-X safely completed its test program with the Air Force/BMDO, and NASA took it over for a test program of their own devising. They put in a composite tank similar to (but simpler than) the one which is giving so much trouble on X-33 and then a technician forgot to reconnect a hydraulic hose to the landing gear before a flight, resulting in one leg failing to deploy and the vehicle tipping over, cracking the NASA tank and destroying the vehicle in a fire.
Think about vertical landing for a minute. Parachutes and gliders can be made stable much easier than the DC.
But DC-X showed how to do it. That's the whole reason for it to exist.
Vertical landers are also the least efficient of rockets. If it took a Saturn 5 to get to escape velocity, it will take a Saturn 5 to stop a vertical lander at escape velocity.
This is not correct. All reentering rockets rely on friction with the atmosphere to get rid of 99% of their speed. Parachutes, wings, or rockets are used only for the last 1%. If you're bringing the engines back in the vehicle anyway then a little fuel for landing might weigh less than wings (and the extra fuel to lift them into space), or it might not. You need really detailed design work to find out, not just some halfbaked suposition.
Re:$1,000 per pound (Score:5)
Part of the X33 design is to respond to the many threats NASA faced from private industry, over the past 8 years or so, that promised to reduce the cost to orbit by a factor of 10
NASA doesn't face threats from industry. NASA's job is to explore space, not to build launchers. As long as no one else builds launchers commercially then NASA has no choice but to build their own, but they are required by US law to use commercial services where available.
The threats go in the opposite direction. As long as NASA can get near unlimited funds to build things that they will then provide (near enough) for free to those they judge to be worthy, no businessman in his right mind would invest in a private launcher. You can't compete with the government, even when they're worse.
They've done some truly revolutionary work on the linier aero-spike engine
Aerospike engines are probably great, but no one actually knows for sure because none have ever been flown. There was a project called LASRE which was supposed to fly a small linear aerospike attached to an SR-71. This project got rolled into X-33 and killed. The X-33 engine looks quite good, but they've crippled its chances of ever flying by putting it into a vehicle with huge problems. They should have build something conventional and cheap and low-risk to test the aerospike engine in first, just as they should have build a dedicated vehicle to test the new thermal protection system, and a dedicated vehicle to test the aerodynamics and the multi-lobed tanks.
By rolling everything into a single high-risk vehicle they not only probably spent more money than they would have building specialised vehicles (because of the inter-dependencies and constant redesigns needed -- the DC-X cost $60m, the X-33 has eaten $1b already), but they have ensured that if any single part of the vehicle has problems then the other parts can't be tested at all.
The real issue is that many of the private sector solutions to low cost to orbit have either chosen the wrong launch weight, run out of venture capitol, or just not proven to be as affordable and reliable as a NASA launch.
In what way has this been proven? X-33 doesn't fly at all, let alone affordably and reliably. Shuttle flys barely half a dozen times a year, at a cost of billions of dollars each year. All of the public money was put into one basket. The eggs are broken. For the same money, *all* of the private sector companies could have been funded. Surely one of them would have worked. In fact, probably all of them would have, because they are in general very low risk plans using off the shelf technology.
Wrong launch weight? There are very few large heavy payloads that need to go up in one go. Most of those are military. The shuttles fly twice a year each. A small, cheap, vehicle that could fly every day -- or even twice a week -- would lift in aggregate far more in a year than the shuttle fleet can, and far more flexibly. What is needed right now is a DC-3, not a 747. There is not yet anywhere for the 747 to go, and it will sit half a year waiting for enough cargo to make it worthwhile taking off. That's not good economics.
The other thing that needs to be considered about the X33 is that if you can afford to keep it feuled and on the pad, it can be looking down on anywhere on the planet in less than one hour! That's revolutionary.
Actually, X33, if it ever flies, won't go anywhere near orbit. It was designed to get all the way from Nevada to Montana, but now looks as if it might only make it to Utah. VentureStar is the hypothetical orbital follow-on to X33, but NASA hmade it clear from the start that LockMart would be expected to finance VentureStar themselves. At this moment LockMart don't appear to even want to put up the money to finish X-33 -- why should they when it has been incredibly sucessful at its primary mission: preventing other companies from developing cheap, reusable, launch vehicles so that LockMart can continue to sell the government expensive throw-away rockets?
Even this "can afford to keep it fuelled and on the pad" shows the wrong attitude. Air New Zealand's B747's spend an average of more than 18 hours a day in the air, year round, not on the ground. (I'm sure it's the same for QANTAS or any other long-distance carrier) An aircraft on the ground is costing you money. An aircraft in the air is making you money. That's the difference between NASA and a for-profit company. NASA looks at the cost side of the equation. A private company looks at the difference between costs and revenues.
*Nowhere* in the article did they mention the complete *success* of NASA in deploying the ISS.
You're going to have to define "success" for me. Looks half a decade late and way over budget to me. No one has died, so far. But no one is living there, either, unlike the working space station the other guys deployed fifteen years ago which has had several hundred different people living in it to date.
NASA is attempting to solve hard problems that take time and money to solve and NASA should be given the funding and time to succeed.
NASA has had hundreds of billions of dollars since the last moon rocket flew. There is precious little to show for it. Every indication is that NASA would rather work on solving hard problems and never fly than do things the easiest way they can find and actually put people into space.