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How would you improve current launch vehicles?


Frozen_Heart

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So with all this talk of reusability and SSTOs, there are always plenty of people who say that it will never happen and that multi stage, throwaway rockets will always be the answer.

So my question now is: How would you improve this type of launch vehicle?

Ideas gathered from thread:

Standardised As many components as possible. Should make manufacture and design simpler and cheaper.

Probably use kerosene as its easier and cheaper to handle.

If multi core use fuel crossfeed to improve performance.

If going for reusability:

Advanced nozzles? They have had very little research into them so could potentially offer an improvement.

Composite tanks are more expensive but if they are reused that pays for itself.

Edited by Frozen_Heart
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Standardization of the system. Standard tank diameters, standard engine mounts for a given load, etc.

Then standardize the individual components of the rocket engines themselves. Turbopumps, chambers, the connections in between, etc.

Should help to reduce development time and cost per engine. Might take a whirl to get the ball rolling, though.

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So with all this talk of reusability and SSTOs, there are always plenty of people who say that it will never happen and that multi stage, throwaway rockets will always be the answer.

So my question now is: How would you improve this type of launch vehicle?

Improve how ? There are very little gains to be obtained in chemical rocketry. It's going to be increasingly hard to squeeze more efficiency out of chemical engines.

If you want to increase performance, you would a higher energy density, which means either fantasy unobtanium or nuclear. Nuclear is a no go for plenty of reasons.

If you want to reduce costs, then there are no other choices than to increase demand. A larger market allows economies of scale, lower unit costs, and reusability. A small market increases infrastructure and manpower costs. There is no way around that. The problem is that there are no viable business models that lead to increasing demand for space access. There are a couple of dubious ideas floating around, but none are proven.

In the end, you will always need vast amounts of energy to accelerate a payload from 0 to 27000km/h, and the energy density of chemicals isn't going to change. Handling vast amounts of energy will always be expensive and complicated. That is why, as long as energy is at a premium, and as long as it's dangerous to handle huge energy sources, spaceflight is always going to be a niche business.

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Give up folks. Negativist Nibb figured it all out. It's all impossible to begin with. Just give up on space, and go planting flowers in your garden.

This is not negativity, this is basic physics. A tank of hydro-LOX doesn't suddenly contain twice the energy by thinking positive thoughts at it.

You NEED a higher energy density if you want better payload fractions. And if you aren't allowed to use nuclear power for political reasons then you are stuck with fantasy land methods that are hypothetical at best. Nothing negative about it.

Anyway, provided I had unlimited funding and some idiot decided to put me in charge of worldwide booster design, I'd focus on economies of scale. Design a dirt cheap, ridiculously simple rocket and make sure everyone has to use them. If you launch a few hundred of them a year the mass production will push costs down. Meanwhile I'd work on restarting the NERVA project and gathering political support for nuclear power in space as a long term solution.

If I somehow manage to hold onto my position for several decades and manage to get electrical and nuclear propulsion working. I'd use these to push some miners to Near Earth asteroids and mine them for a LEO fuel depot and structural components. This pushes down costs for launches because now you only need to send up the high tech bits of your spaceships, saving most of the launch weight.

After this its impossible to speculate because technology is hard to predict. Maybe we'll have lightweight fusion reactors by then and an SSTO is trivially easy to make. Or maybe we have the technology to set up a completely separate production line using in situ resources, so we never have to lift anything out of this cursed gravity well again. Or maybe we've had a big world war and we're back to medieval technology.

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Should help to reduce development time and cost per engine. Might take a whirl to get the ball rolling, though.

I think it would hurt the payload fraction though, since standardized gear is generally not as flexible as custom designs are - obviously.

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How would you improve this type of launch vehicle?

Use better chemicals. The performance of a chemical rocket is tied to how energetic the reaction between the propellants are. If you can find a better propellant, you can push the specific impulse a little more.

Current chemical launch vehicles run on either LH2/LOX, Kerosene/LOX, N2H4/N2O4, Aluminium/Ammonium Perchlorate (used in solid rockets), or any combination of them. If the agencies/companies were a little more adventurous (foolish!), they'd probably switch the aluminium fuel in solids with powdered beryllium, which is more energetic. Liquid-fuel rockets can improve their specific impulse by switching to more energetic oxidizers, like liquid fluorine, or better (worse?) yet, chlorine trifluoride. Liquid hydrogen is already tops in being a high-performance fuel in the mix, but the density is rather dismal, so you can replace some of it with a higher-density fuel that is at least as energetic, or possibly more, like liquid mercury or lithium.

Now, if you know a bit about chemistry, you may wince at my choice of propellants, and consider anyone even planning to use these propellants quite a bit nuts. And you'd be right; these chemicals are either highly toxic, corrosive, explosive, or (more likely) any combination of these delightful properties; some of this stuff, like liquid fluorine, has killed people before. Not to mention they smell bad. Really, really bad; the kind of smell that makes one think that pig sheds smell like a perfume shop in comparison.

In conclusion, chemical rockets can still be improved in performance. The question is, is that extra performance worth all the extra safety hazards the scientists and engineers have to put themselves into?

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I wish I really knew how to build better rockets. Rather than merely playing KSP, I'd found my own rocket company and become a bill gates of space industry.

You would force people to use your product, send some guys to negotate contracts so unclear that after few years FBI would investigate it? :)

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Cheaper solid rockets I think. In theory this design can offer low price, no need for complex engine machinery, and overcome the worse efficiency. In practice the savings don't seem to be delivered, maybe this can change.

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You would force people to use your product, send some guys to negotate contracts so unclear that after few years FBI would investigate it? :)

Well, being a multi-billionaire who knows how to build the best rockets in the world does have some disadvantages. I believe I could live with it.

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You would force people to use your product, send some guys to negotate contracts so unclear that after few years FBI would investigate it? :)

And then, after earning boatloads of money, he'd use it all to eradicate many an illness, reduce poverty and fix education. ;).

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I'll just add that there is a multi-billion dollar industry based around space flight. Some of the smartest people in the world are employed by some of the most capable institutions and corporations in the world to design rockets. These organizations have been continuously innovating and improving technology for decades.

Neophytes on an internet forum are not going to come up with a breakthrough technology. If you've had this crazy idea that might well work, let me tell you: chances are that someone else has already had that crazy idea and if nobody is using that crazy idea, then it's probably for a good reason.

Aerospace engineers and scientists aren't idiots. Believe me, if there was an easy and cheap way to get stuff into orbit, we would be using it by now.

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I'll just add that there is a multi-billion dollar industry based around space flight. Some of the smartest people in the world are employed by some of the most capable institutions and corporations in the world to design rockets. These organizations have been continuously innovating and improving technology for decades.

Neophytes on an internet forum are not going to come up with a breakthrough technology. If you've had this crazy idea that might well work, let me tell you: chances are that someone else has already had that crazy idea and if nobody is using that crazy idea, then it's probably for a good reason.

Aerospace engineers and scientists aren't idiots. Believe me, if there was an easy and cheap way to get stuff into orbit, we would be using it by now.

Exactly my point.

Generally speaking, nobody knows if something really works or not until they try. It's the only reason we need science. So billions of investments would really help. Internet discussions involving professional (and amateur) gamers and students are much less reliable.

There's a guy, Elon Musk, who probably can into space in the most efficient manner possible. Or maybe he cannot. He will be a new bill gates one day, or he won't. We'll see.

More boosters.

Also:more struts.

also:keep jeb away from your rocket at all cost

You sir have the very solid point, too.

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And then, after earning boatloads of money, he'd use it all to eradicate many an illness, reduce poverty and fix education. ;).

And get sued in India, on this year, for illegal experiments on children from poorly educated families?

You can't reduce poverty by giving away even tons of money. If that would be possible USA and Europe wouldn't be in economical crisis, in US there is lots of rich people ;)

You can't fix public education no matter how much money you put in there, no matter what you do in public schools there is always majority that takes vote... and they decide what they want for their and yours children, not a single guy with largest wallet ;)

As for rockets... future is orbital construction and new power sources.

New mix of little more efficient fuels or a bit better engines are not enough it has to be something new like fusion reactors, maybe quantum levitation or some sort of electromagnetic engines.

Nuclear engines would be also nice, but only for crafts that would never have to land on Earth, so dangerous parts would always stay in safe orbit, it shouldn't be so hard to persuade people to make this happen.

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Aerospace engineers and scientists aren't idiots. Believe me, if there was an easy and cheap way to get stuff into orbit, we would be using it by now.

Yeah, If it were possible, people smarter than you would have already invent it in the past. So don't bother... Thinking that way, nothing would be improved ever. We would be still sitting in a cave and chipping stones.

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This is not negativity, this is basic physics. A tank of hydro-LOX doesn't suddenly contain twice the energy by thinking positive thoughts at it.

You NEED a higher energy density if you want better payload fractions.

We could cut the "dead" mass. Or let the payload fraction stay the same but make manufacturing and operating much cheaper. There is no "basic physics" preventing us from doing that. I don't believe that the energy density is the only one parameter driving up the cost.

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In conclusion, chemical rockets can still be improved in performance. The question is, is that extra performance worth all the extra safety hazards the scientists and engineers have to put themselves into?

Unfortunately, rocketry lives and dies with safety. Therefore, for all intents and purposes, the chemicals you mentioned are not viable. It is like designing a car that does 200 kilometre to the litre, though there is a 1 in 5 chance you will lose a part of your body. Great, but nobody is going to (let you) use that.

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Straw man argument much?

Why is it straw argument ? This "if it were possible someone smarter than you would already have done it" reasoning prevents all attempts at improving anything. If it were valid, there would be no improvement in any area.

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Why is it straw argument ? This "if it were possible someone smarter than you would already have done it" reasoning prevents all attempts at improving anything. If it were valid, there would be no improvement in any area.

Because you are misrepresenting Nibb's argument. There are limitations to physics, chemistry, materials science, etc. that set an upper limit to what is possible with rockets. With any mature technology, you reach a point where only incremental improvements are possible. You can't extrapolate out from someone's realistic engineering judgement about a mature technology to accuse them of arguing that all efforts at technological progress are futile.

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Because you are misrepresenting Nibb's argument. There are limitations to physics, chemistry, materials science, etc. that set an upper limit to what is possible with rockets. With any mature technology, you reach a point where only incremental improvements are possible. You can't extrapolate out from someone's realistic engineering judgement about a mature technology to accuse them of arguing that all efforts at technological progress are futile.

This is tautological at best. only small improvements are possible because the technology is mature, but how do you know the technology is mature ? Because you don't think bigger improvements are possible.

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