How complicated is Rocket Science?

Discussion in 'General Science & Technology' started by Captain Kremmen, Dec 10, 2009.

  1. nietzschefan Thread Killer Valued Senior Member

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    Rocket SCIENCE isn't all that complicated.

    Rocket TECHNOLOGY is.
     
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  3. weed_eater_guy It ain't broke, don't fix it! Registered Senior Member

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    Exactly! Just gotta chop open the ol' melon and root around in there with a stick, right!

    Please Register or Log in to view the hidden image!

    My HMO sucks...

    Anywho, it's been said already, I know, but I just dusted off my soapbox, so I'm gonna use it! It's not so much the rocket principles that are so complicated, it's the development of all the stuff you need to make those principles do extreme things. A baking soda rocket is easy enough to be done as an elementary school science project, but to get a man and/or equipment all the way into space, these principles need to be taken to the absolute limit, and a simple baking-soda rocket is, well, not going to cut it. That rocket suddenly needs to be large, the parts need to be light and made out of special materials, the fuel needs ultra-high-end turbo machinery, control systems need to be added, made double, triple, or even quadruple redundant, infrastructure needs to be in place, cooperative development between many, many, many engineering groups needs to be facilitated, and it all has to result in a flawlessly reliable product despite politics, economic conditions, and who the hell knows what else. Like just about any engineering project, the devil's in the details, and when the planet has an escape velocity that demands mankind's greatest technical prowess to achieve, the project's going to have lotsa details! The brilliance behind "rocket science", or any high-end technical field, is being able to identify, comprehend, and manage all these little project details and arrive at a finished product, whether that product be a rocket, a new proof for a physics theory, a cure for a disease, etc.
     
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  5. Uno Hoo Registered Senior Member

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    Beyond a shadow of doubt, I could design and single handedly (although I would greatly prefer, as a time expedient, to use off-the-shelf stuff like nuts and bolts), build a vehicle that would not only "reach space" but would achieve orbital velocity or escape velocity, as preferred.

    If you were offended by the word "retarded" then please hear my apology. I meant to use the word in a generic dictionary way and not in a personal offense way. You have a dictionary, I presume.
     
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  7. James R Just this guy, you know? Staff Member

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    It's more complicated than you might think. Most of the problems are not science problems per se but engineering problems. Any idiot can launch a firecracker, but building something big, capable of going a long way and in the direction you want it to go is a different matter all together.
     
  8. phlogistician Banned Banned

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    10,342
    You just think you can, because you haven't tried yet.

    But if you think you can, do it, prove me wrong.
     
  9. scifes In withdrawal. Valued Senior Member

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    it's very simple in concept, but due to the nature of rockets of extreme speed and high amounts of energy..the margin of allowed error gets 1000times smaller and their consequences multiplied 1000 times, unlike when the same concepts are used to, say, analyze a swinging pandelum.

    so in order for your rocket not to end up in smitheriens and you in jail, you gotta take into account so many freakishingly small details into account, requiring a lot of complicated work, hence the saying you mentioned.
     
  10. Captain Kremmen All aboard, me Hearties! Valued Senior Member

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  11. Uno Hoo Registered Senior Member

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    383
    Amen. The essential physics "problems" are very basic Newtonian physics pretty much straight from the Principia. The trajectory, the amount of propellant versus the initial total weight of the vehicle, bla, bla, bla.

    The practical engineering "problems" can easily become overwhelming. Generally speaking, a higher thrust efficiency means a higher propellant combustion temperature. So you quickly run into enormous engineering difficulties. Not straight from the Principia. What alloy or compound will resist melting at this temperature? How well will it resist being abraded in the exhaust flow? If a cooled propellant is chosen, how will the pumps and pipes react to extreme cold? Bla, bla, bla.

    So, the original post comment or question has to be seen as a kind of two-part thing.

    Basic principle of flight into high space: very simple basic Newtonian physics.

    Engineering technology needed: very complicated mechanical know-how based on many generations of theoretical prediction and hands on trial and error.
     
  12. Uno Hoo Registered Senior Member

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    I mean no unnecessary disrespect to you, but, I must point out to you that I have no imaginable reason to consider your opinion of very much importance to me. Therefore, I find myself bereft of motive to prove anything to you.

    You are free to try to impress me. Go, girl!
     
  13. phlogistician Banned Banned

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    10,342
    So you admit you couldn't do it in practice. You made the claim that you could, so I'm afraid, the ball is in your court.

    See, 'rocket science' isn't just about F=ma on a piece of paper. It's a misnomer to think you can distill the science from the engineering.

    Science performs experiments to gather data, so you actually need to build that rocket to gather your data.
     
  14. iceaura Valued Senior Member

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    30,994
    When teams of really smart people with lots of money and education dedicate years of effort to doing something, and fail in their first attempts, it's probably a difficult thing to do.

    Most modern rocket launchers are buying a lot of science and math off the shelf - such as mathematics software full of built in theoretical advances - just as they are buying their engineering advances from hardware suppliers and handbook publishers (CD or otherwise). And they are still running into difficulties, still making changes in the basics.

    To say that one can use that bought stuff to build and launch one's own rocket, therefore rocket science is simple, is maybe similar to building one's own laser pointer, and declaring laser science to be simple.
     
  15. Syzygys As a mother, I am telling you Valued Senior Member

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    12,671
    Rocket science isn't complicated, because there is actual science behind it and it is testable.

    Now try Finance, that is complicated....
     
  16. Uno Hoo Registered Senior Member

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    383

    Originally Posted by Uno Hoo
    I mean no unnecessary disrespect to you, but, I must point out to you that I have no imaginable reason to consider your opinion of very much importance to me. Therefore, I find myself bereft of motive to prove anything to you.

    You are free to try to impress me. Go, girl!



    Was your post supposed to be a direct response to my previous post? Do you suffer from some kind of severe attention disorder? Or, perhaps, a severe reading comprehension disorder?

    The ball is in your court. And is laying still on the ground, unmolested.

    Impress me that you are important enough to me, and then I will prove whatever to you. Until then, your ego notwithstanding, I am not motivated to prove anything to you.

    Go, girl!
     
  17. noodler Banned Banned

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    751
    The rocket problem is freshman/high school problem:

    It's about optimizing the height of a varying mass, at which optimal point the rocket's velocity is zero. Then given the weight of a fuelled rocket, and the weight decrease (the tank is full at t-zero and empty at v-zero, h(t)) and knowing the propulsive force and the acceleration due to gravity, away we go with a derivative of velocity wrt time, to find the inflection point.
     
  18. phlogistician Banned Banned

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    10,342
    You claimed you could singlehandedly build a rocket capable of reaching space. Your claim, your burden of proof.

    It's that simple, it really. It really is.

    But you know you can't in reality and now you're playing games and hiding behind your words.

    Please, have the decency to just skulk off and stop embarrassing yourself further.
     
  19. noodler Banned Banned

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    751
    There is way more to rocket science than getting a launch to a highest altitude - you are finding the amount of mass as fuel which, added to the weight of the rocket will at first "commute" with gravity locally.

    What you really want is to get it beyond this local commute, and into the realm of G, where springs of varied weights hang, after they commute locally. You want the route that uses G globally - a global commute.

    But once you are at sufficient v that local g is "vanished" where do you go? You go check out the other local g, it's big and sort of yellow, over there.
    That's two local commutators, that you commute with. Both also commute with each other and the big guy, since G is the acceleration any mass experiences when it has a constant velocity, like at the end of a spring, which absorbs the "weight" stuff. But weight is accelerating mass, and weighing is equivalent to removing (by absorbing the momentum) the weight of some object. Simple huh?
     
    Last edited: Dec 17, 2009
  20. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    How can something at a constant velocity be experiencing acceleration?

    Possibly not...
     
  21. noodler Banned Banned

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    751
    Well, how can you be at constant velocity when you stand still? After all you are also accelerating towards the center of the earth...
    You understand, the "weight" you feel is the acceleration - you can hang from a spring to stop accelerating too but you still accelerate - the stopping is the spring absorbing your momentum.
    If you let the spring go it "recovers" and erases the momentum energy it was storing while you accelerated, but when you stopped moving you didn't stop accelerating - gravity never gives up. After all, a planet accelerates towards itself.

    You can say, if you know how to stand up, or hang from a springy thing (think tree here) you know how to do gravity.
     
    Last edited: Dec 17, 2009
  22. Dywyddyr Penguinaciously duckalicious. Valued Senior Member

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    Er, because there's no change in speed or direction. (That's what acceleration is defined as: a change in speed or direction of motion).

    You stop accelerating but you're still accelerating?
    Very clever.

    Or I could say that you are waffling incomprehensibly.
     
  23. noodler Banned Banned

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    751
    No, if you are on the surface of a dense, massive body you accelerate continuously, even though the surface localizes your momentum you experience an accelerating force, called gravity.

    Think about WHY a weight stops moving, what a spring or balance DOES when you weight anything. The planet "exerts" a force on you because the surface has you balanced against a constant acceleration. Newton's constant is not the force due to g, g is strictly local in F = mg at the surface.
    The local g here is due to a density. The global G is "everywhere", at least between the earth and moon, it is. Once you get to larger distances you need to correct something.
     

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