KASASpace
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Posts posted by KASASpace
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Didn't it turn that the country they were trying to test the rocket in try to take it over and get missiles or something?
Yes, I have heard of OTRAG, and wasn't von Braun involved?
It's a good idea lost to history, but maybe some small company could do it again?
BTW, mass production is the only "real" way to cheapen space travel. Now, if you use robots, then why must they be complicated? Simple 'bolt that" or "screw this" or "place that" machines can accomplish it, and be cheap enough to maintain. OTRAG is designed for simplicity and thus ease of construction.
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Okay, okay. So basically........ the best system is the one that's not there? Like, for example, if I had a launch vehicle capable of orbiting 10 tons and someone else had one that could orbit 15 tons, but mine was much more simple, then mine is the superior one?
This is kind of like the Saturn I. It's my favorite of all "classic" launch vehicles and was barely used for operational payloads. Now, the design used off the shelf components, like the Redstone tanks and the Jupiter tanks, plus the H-1s, which were based on a previously designed and built engine. So, the S-I stage is kind of a big dumb booster. But it wasn't extremely mass produced. But it was very reliable............
I actually like this concept. Perhaps by putting together multiple sounding rockets, we could have a first stage? But then again, we should probably used something like the Angara rocket family. It's basically a rocket, with the ability to add more boosters (identical to the core) to the side of the core. Only one core stage would be needed for the whole family, and then the rockets would overall be cheaper.
Would you consider arches to be easy to build and thus cheap? I don't why, but I have a strange affection towards arches, they're strong structures and quite simple to construct. The ROMANS built them, for aqueducts, for monuments, the Coliseum, etc. Perhaps alternating arches, made of steel? Wrapping around the first stage.
Now, another thing about boosters, did you know the structure of boosters was moved inside the tanks? This made the rockets lighter, but also a bit harder to produce, as you have to design the tanks to support it. So, perhaps, going back to the not so famous "corset" of the V-2/A-4, we could make rockets even cheaper.
On the reliability note:
Just test it and test it and test it and iron out every bug over a long period of time, get 99+% reliability, because they were only test launches.
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The R-7 missile wasn't exactly slapped together, but it wasn't carefully placed and all that. It took good amount of tests before a success, but then the success rate became higher and higher, the rocket evolved, and finally became the legendary Soyuz rocket. It's reliable all right.
This is a legitimate point, though. Why waste so much on a Ferrari just to drive it once? Why not build a jalopy and then drive it off the cliff? It's cheaper to build something quickly. You just need it to work, you don't need it to be over-complicated. This happens too often. Look at the Space Shuttle, it has so much stuff and equipment on just the orbiter. Now, that is more like saving the front of the Ferrari, but you still lose the back side. So, why overcomplicate? Sometimes you just need to design, build, test, repeat.
It would much simpler if we modularized fuel tank pieces. Then you could just order up a certain number of the pieces and put them together.
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The United States was the second, third, fourth, fifth, and sixth. The question is which nation will be NEXT, or seventh, or whatever.
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Slap a thruster and send it out on a 5-year mission. But before that, re-christen it the Enterprise.
Seriously, though, I would say disassemble and then see what you can do with the parts. Maybe utilizing space fabrication facilities (I know, a lot of stuff) we could break the modules into smaller and smaller components and then build something new. Basically salvage it. I mean, it's billions of dollars of resources, just sitting there. Why not try to recover some of it?
BTW,
the reason for in-space fabrication is that it's easier to send something already in space to somewhere else in space near it than to de-orbit it. (de-orbiting to re-use doesn't make much sense.)
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Succeeds in what? Being efficient and cheap? Or just flying? If it succeeds, then hoorah, a way to get small payloads to orbit. But the only way to make it cheap would be to increase the number of launches a year. If you want a launch a day, you need 366 vehicles (you have to count for leap years). But then you need to pay for maintenance for each one. So make maintenance easy. But then again, they thought maintenance would be fairly easy for the Space Shuttle, but they were wrong.
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This is a strange subject. But the real thing to ask is not if it is possible, but if immortality is ethical. Nature set the laws that humans are born, live, and then die. Should we really strive to accomplish this? Yes we can expand the lifespan to 150, 200, 300, 500, 1000 years, but being immortal is not living long (and prospering), rather being immortal would be to see things no one can unsee. Being there when something horrible happens. Given the choice, I would not accept that burden. But whoever will, good luck.
Onto the point, what one must do to be immortal is to find the root cause of aging. And if I remember correctly, there is a small error in the cell replication process that cuts off a small amount of DNA. Very small, but enough that over a long period of time, you start to "age". So, rejuvenating a cell "could" fix this, but remember, we all have the right to die.
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I am a rocket scientist, well, a protégé rocket scientist. Okay, fine, rocket engineer.
(I misspelled over there <--- as a joke)
I understand and know many of the engineering ideas, problems, cost, etc. Notice how I actually know of the handling cost of the fuel, and that the entire rocket is pretty much just accommodations for the fuel, and thus the fuel is the most expensive part via its respective requirements.
I know what NASA does and I know it's not the only LV/rocket development organization. I personally believe NASA is doing the wrong thing. They should have done what NACA did: Make it so that the criteria of rocket engines are easily available, so it takes a year or less to develop engines. Then its all about the design of the LV itself.
Does liquid propane come from KSP? No.
It comes from reality. It has a similar bulk density as RP-1, has better Isp, and needs the same amount of insulation as LOX. So, thinner common bulkhead, the same wall material, and thus it's cheaper (more common components).
NASA should be the pioneering cross feed, not SpaceX. Sure, its great that someone is doing it, but it should be the guys who have more experience with the technologies required for rocket science.
The contractors build the equipment, this I know. But NASA has been known to sometimes build their own things for testing. (it is rare, but it has happened previously)
Plus, when people like Lockheed are only building for NASA, then they have no incentive to develop new rocket tech. They aren't SpaceX, being led by a guy who wants space.
They are more focused on finishing their job, not actual want and desire for space-related equipment.
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The same thing that prevents mud from getting dirty
That it already is as oxidized as it can get without adding another substance, in both senses of the word.Definition 1: Having reacted with Oxygen.
Definition 2: Gave away one or several electrons at least partially to another atom. Since all the atoms are the same, there is no incentive for the electrons to move anywhere between them.
It could form Ozone, but that is a stronger oxidizer than O2 and less tightly bound, and thus a) reduced relative to O2 and
the reaction does not happen on its own.I never said the reaction could happen on its own. It requires energy. Even the heat from the hot exhaust could cause this, but LOX requires good insulation anyways.
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I think he said a wrong thing there. The danger with O2 is that it can react with almost any metal that might be used in spaceship construction: this is what happened to Apollo 13 - a short circuit in a motor used to stir the liquid in a LOX tank heated the motor enough to cause it and the O2 to burn together with an almost instantaneous explosion. But on its own, O2 can't burn with itself, despite that quote.
Incidentally, even his hyperbole that O2 is the oxidiser of oxidisers is wrong - that honour goes to fluorine which is reactive enough it can oxidise helium!
Hmm, well, if even Helium can be oxidized, and it's a Noble Gas, then what is their to prevent LOX oxidizing itself?
Yeah, Fluorine is the best, it's just really expensive and even MORE DANGEROUS.
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And who tell you they don't already do researches in these domains ?
They don't have to make big announcements each time they make experiments.
Nasa made a Swamp Works research center (the name is taken after lockheed martin skunk works)
http://www.nasa.gov/centers/kennedy/news/masters-swampworks.html
They built it specifically to devellop and experiment new technologies on small scales - so they could 'fail' a lot for cheap with experiments, and learn a lot from it. "Fast fail forward".
Maybe they are working on it, but they don't have a cheap, efficient and reliable enough results to share for now.
Because NASA can't exactly just slap rockets together. It's not KSP, not at all. But they may be tied up their as well. I mean, come on, there's a lot of technologies that are experimental that haven't even touched the surface there.
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If you pump it down two pipes instead of one, you need twice the flow rate. If your pumps are already used at their limit, then you need two pumps. Or you have to build a pump twice as big.
"Just put two pipes there and pump the liquid anywere for free" dosen't work.
That's why you design the engines in such a way so that the pumps WOULDN'T be at their limit.
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I think it's a bit of a stretch to assume that the two major superpowers haven't conducted a cost benefit analysis of a staging system that's been around since the 30's, having spent billions on research. I think it's intellectually lazy to conclude that because asparagus staging works very well in KSP the only reason it isn't being used IRL is because "it ain't broke don't fix it."
Clearly there is a reason, and I have some serious doubt that those reasons match any of the conclusions in this thread.
I didn't say that was the reason. They don't do it because they're afraid it will cost them. Heck, NASA is supposed to be "stirring competition" but they're still using the same brand SRBs.
The only reason is more that they are either afraid of change, or that they think it might just not go well, and then set them back. But that's why they invented testing. If anything, NASA could do some PHYSICAL research involving crossfeed, like how to pump the fuel around, and also how to separate the stages quickly. It doesn't even need to be a launch vehicle, you can do it on the ground!
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This is KSP people. They observed that asparagus staging works in KSP, and assumed it would also work IRL. The problem is, KSP handwaves some laws of physics to be able to be run on a typical computer, one of them being conservation of momentum. Also, there is no such things as turbopumps in KSP, so people here often overlook that critical component.
You do realize that you can use a turbopump to pump fuel/LOX down more than ONE pipe, right?
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Please share the exothermic reaction O2 has with itself.And third, LOX in its own right is a dangerously volatile chemical because, of course, as the supreme oxidizer of all oxidizers, it can burn on itself.
-How to Build Your Own Spaceship, Piers Bizony
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That doesn't happen because the fuel and oxidizer need to be mixed to ignite. So unless you heat up the first stage enough that the structural section between the oxidizer and fuel tanks are melting this doesn't happen.
Well, do they use LOX? I'm sure they handle it correctly, its just that LOX can burn on itself.......
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LJO is probably one of the least safe orbits in the solar system.
Want a high dose of radiation?
Really high?
Yes?
Than LJO is perfect for you! (or replace LJO with Laythe......... if you want to make a joke about KSP)
Seriously, though. You would need some large mass of radiation shielding. Unless you were using unmanned vessels. But even then, it's a huge amount of shielding. Many instruments are very sensitive.
LJO is the worst orbit for resource harvesting. As you must spend a long amount of time there.
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An intellectually lazy quip.
In 1947, Mikhail Tikhonravov developed a theory of parallel stages, which he called "packet rockets". In his scheme, three parallel stages were fired from lift-off, but all three engines were fueled from the outer two stages, until they are empty and could be ejected. This is more efficient than sequential staging, because the second stage engine is never just dead weight. In 1951, Dmitry Okhotsimsky carried out a pioneering engineering study of general sequential and parallel staging, with and without the pumping of fuel between stages. The design of the R-7 Semyorka emerged from that study. The trio of rocket engines used in the first stage of the American Atlas I and Atlas II launch vehicles, arranged in a "row", used parallel staging in a similar way: the outer pair of engines existed as a jettisonable pair which would, after they shut down, drop away with the lowermost outer "skirt" structure of the booster, leaving the central "sustainer" engine to complete the first stage's engine burn towards apogee or orbit.
I know very well the history of the R-7. I also know very well how the Atlas was developed and the techniques it used.
You seem to have managed to barely address my comment yet at the same time quote it.
If you're satisfied with a launch vehicle, than you don't have to improve performance. Heck, even making it an Onion stage system is advantageous.
The concept was that all engines fire, so less "useless" weight of the engines. They all fired. Now, with the R-7, they made it so it used fuel in the core and gained TWR of the core, which was actually quite heavy alone (thus the need for boosters).
Now, if you could improve a rocket further (there is a limit to what you can do without going into advanced staging) than you can actually get a better cost per unit payload. That gives you a better rocket.
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If it is so easy to asparagus the Soyuz to make it more efficient while maintaining its stellar reliability, I have to wonder why the Russians haven't done so. They're not exactly dolts when it comes to rocket science.
Maybe their analysis, with full access to all the flight data, schematics, actual hardware to test, and staff of engineers and rocket scientists, has reached a different conclusion.
They haven't considered because they're satisfied with its current performance.
"If it ain't broke, don't fix it."
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Asparagus staging is the only reason SSTOs that can carry 500 tons is possible. Period.
It wouldn't be a SSTO if it was asparagus........
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The problem is, turbopumps is the single most expensive part of a rocket engine (up to 55%)
Before even thinking about asparagus, we need cheap, lightweight & ultrareliable pumps
and the combination of the 3 is extremely difficult to get.(Heck, the RL-10 engine is the single most expensive part on rockets that use it - excluding the payload)
So the gains of building 'smaller engines' would soon be offset by the additional turbopumps needed to transfer fuel - because you'll need to drive the pump with the rocket engine, you'll also lose efficiency (more kinetic energy lost due to the need to drive the pumps), and thus ISP, so the thrust / fuel savings are even more diminished at greatly increased costs.
I know it is the most expensive part. The Russians were actually quite ingenious in their engine clustering techniques. Just use one turbopump for them all.
The RD-180 uses one turbopump. So does/did the RD-170. Those were large engines, and are typically counted as only one engine. I personally think it's how they managed to weasel their way into getting the most powerful liquid engine. But it really is an ingenious technique, and should be used more often.
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Let me ask you this N_las:
How many separation events occur on the Soyuz Launch Vehicle?
First it launches
Then after it burns out the fuel in the boosters, it jettisons them
Then the core goes on alone
Then the upper stage is activated after core separation.
At least 2 for the first/second stage alone. Yet it's one of the most reliable LVs ever created. How much of an impact would adding some limited crossfeed capability do? You can use all of the present pumps, you just need extra piping. That adds at most a few hundred kilograms. But the payload increase would be very worthwhile.
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Hydrogen? Expensive? You can get the stuff from water! Heck, you can get the Lox from water, too! If anything, Nasa should work on a cheap way to separate water into it's base components. That way, it can make its own fuel AND make the integration of fuel cell car infrastructure easier.
Oh, you can get H2 easy. It costs large amounts of energy and thus money to cool it down to it's boiling point. Then you have to actually STORE and transport the thing.......
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And, you only have to remember half of the entire LM. Makes the mental workload easier. Plus, I wouldn't want to be lost and alone on the moon.
That it already is as oxidized as it can get without adding another substance, in both senses of the word.
the reaction does not happen on its own.
How would anyone actually build a space elevator?
in Science & Spaceflight
Posted
Simple, you don't. This is one of those ideas people think are good. But they aren't. Building a space elevator? The stress on the structure would be too much to bear for anything but carbon-nanotubes, and even then it's hard to tell. You would experience what makes orbits even possible, and that's the force created when rotating around a common axis, centripetal force. Many may, and may not know that this force keeps you in orbit. That's why orbits are the shapes they are. The elevator would have problems because the force applied is too uneven, it would end up getting pointed in the opposite direction of rotation if not perfect, and how would you maintain GEO? Satellites use engines, but a fixed structure can't change it's orbit. It would be cheaper to go to the moon, build a decent mining colony, and build what you want in space on an orbital fabrication facility with resources from the moon. We have the technology to do it, just not the will. You see, eventually the in-space resources will be so cheap to maintain that you just park it in a garage, "open the hood, find the problem, fix it somehow, and be on your way." Then, you could get the resources to the fab-fac easily.
Now, what would the cargo pod on the elevator be powered by? Electricity? Probably not, if you want decent sized payloads (~10 tons at the least) then you would need rockets still. So what's the point of the elevator? And what if you want a lower orbit. Wasted Delta-v.
So, no-go.