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Non-Chemical Propulsion Alternatives for Space Launches

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phion
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Jun27-14, 06:52 PM
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I'm attempting to do a term paper about the above title. There are a lot of potential alternatives to chemical rocket launches in the works; some realistic, and some not very. My hope in creating this thread is to gain some insight into what exactly these alternatives are (I'm sure I've missed a couple), which ones are the most promising, and how far ahead in the future these methods might become reality.

Answering questions like economic feasibility, commercial practicality, and comparisons concerning the technical reliability of these alternatives will be central to my paper, along with describing each method in basic, conceptual detail. Basically, I want to gain a simple understanding about where our current capabilities in these areas of engineering are going, if it makes any real sense to switch to something new, and which, if any, alternative methods could take the place of chemical space launches.

Feel free to post links to interesting sources, or elaborate on whatever personal experience and knowledge you have about this topic. I'm all ears.
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jim hardy
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Jun27-14, 07:59 PM
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In the 1960's we built and tested a nuclear rocket engine.

http://pbhistoryb1b3.grc.nasa.gov/as...%281965%29.PDF

Freeman Dyson described it briefly in his "Disturbing the Universe".

A friend who worked on it said the radioactive exhaust was just awful.
berkeman
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Jun27-14, 10:43 PM
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Quote Quote by phion View Post
I'm attempting to do a term paper about the above title. There are a lot of potential alternatives to chemical rocket launches in the works; some realistic, and some not very. My hope in creating this thread is to gain some insight into what exactly these alternatives are (I'm sure I've missed a couple), which ones are the most promising, and how far ahead in the future these methods might become reality.

Answering questions like economic feasibility, commercial practicality, and comparisons concerning the technical reliability of these alternatives will be central to my paper, along with describing each method in basic, conceptual detail. Basically, I want to gain a simple understanding about where our current capabilities in these areas of engineering are going, if it makes any real sense to switch to something new, and which, if any, alternative methods could take the place of chemical space launches.

Feel free to post links to interesting sources, or elaborate on whatever personal experience and knowledge you have about this topic. I'm all ears.
Quote Quote by jim hardy View Post
In the 1960's we built and tested a nuclear rocket engine.

http://pbhistoryb1b3.grc.nasa.gov/as...%281965%29.PDF

Freeman Dyson described it briefly in his "Disturbing the Universe".

A friend who worked on it said the radioactive exhaust was just awful.
Picture an underground nuclear hydrogen bomb test with a carefully constructed tunnel to the surface with some sort of ablative-guarded-rear-end projectile... Calculate the g-forces experienced by the projectile...

berkeman
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Jun27-14, 10:48 PM
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Non-Chemical Propulsion Alternatives for Space Launches

Quote Quote by phion View Post
I'm attempting to do a term paper about the above title. There are a lot of potential alternatives to chemical rocket launches in the works; some realistic, and some not very. My hope in creating this thread is to gain some insight into what exactly these alternatives are (I'm sure I've missed a couple), which ones are the most promising, and how far ahead in the future these methods might become reality.

Answering questions like economic feasibility, commercial practicality, and comparisons concerning the technical reliability of these alternatives will be central to my paper, along with describing each method in basic, conceptual detail. Basically, I want to gain a simple understanding about where our current capabilities in these areas of engineering are going, if it makes any real sense to switch to something new, and which, if any, alternative methods could take the place of chemical space launches.

Feel free to post links to interesting sources, or elaborate on whatever personal experience and knowledge you have about this topic. I'm all ears.
Since this is your schoolwork assignment, what are your thoughts so far? What mechanisms have you found, and what are the associated advantages/disadvantages?
phion
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Jun27-14, 11:49 PM
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Quote Quote by berkeman View Post
Since this is your schoolwork assignment, what are your thoughts so far? What mechanisms have you found, and what are the associated advantages/disadvantages?
My thoughts thus far are that there are a myriad of potential alternative propulsion methods (I'm most interested in the ones primarily utilizing raw electromagnetic power), and that none of them are getting sufficient research. The kind of research required to make it testable, apart from theory.

A lot of research is happening at universities regarding propulsion, but none of it seems to scream out that it could or will replace chemical based rocket propulsion, or that anyone is actually interested in reducing the risk of exploding human beings into orbit and beyond via chemical means. While curious, I don't question the motivation for innovative research, especially with engineering feats so edgy and "new" as far as being put into practice. The way I see it is that the alternative most likely to be handed over to the business world or government are what I can safely put an umbrella over.

I believe I've reduced the important research down well enough to a list of four sub-topics:
  • Laser/Microwave Propulsion
  • Launch Loop
  • Orbital Ring
  • Rail Gun

The differences between these more rational methods (compared to the Orion Project) are fairly obvious. Some require a vast geography to work, advances in nanotechnology, and innovative control systems. These are my focal subjects I want to integrate into my paper, but I'm still uncertain about a lot of technical details, or if I'm missing something big regarding professional research in this area.

I'm reminded of a video where Freeman Dyson talks about his work at Princeton. Even though he did a great deal of work in astrophysics supporting the nuclear propulsion paradigm, the idea ultimately failed because the engineering just wasn't there. I suppose I'm trying to avoid including those methods that will meet the same fate, but I have no idea how to see ahead.

Link: http://www.webofstories.com/play/freeman.dyson/117
MrSparkle
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Jun27-14, 11:55 PM
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I found Ion Drive engines to be pretty interesting. They are for movement in space tho, not breaking earth orbit.
phion
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Jun28-14, 12:41 AM
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Quote Quote by MrSparkle View Post
I found Ion Drive engines to be pretty interesting. They are for movement in space tho, not breaking earth orbit.
Thanks for the suggestion!
sophiecentaur
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Jun28-14, 04:59 PM
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Quote Quote by MrSparkle View Post
I found Ion Drive engines to be pretty interesting. They are for movement in space tho, not breaking earth orbit.
Yes. These have low thrust but, because of the very high velocity of the ejecta (what gets pushed out of the back) they will provide thrust at very high rocket speeds - much better than chemical rockets. Also, they do not require a large mass to be lost - unlike conventional rocket engines. Ideal, once you are well on your way - having been launched by conventional means.
ythamsten
#9
Jun29-14, 03:34 PM
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This might be of interest: http://erps.spacegrant.org/uploads/i...C-2011-261.pdf

And for some other alternatives, take a look at the wikipedia page (http://en.wikipedia.org/wiki/Electri...aft_propulsion) for a start...
The Jet Propulsion Laboratory may have some interesting material for you about the subject as well: http://www.jpl.nasa.gov/

I'm not too much into the subject, hope that helped a little bit.
phion
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Jun29-14, 09:26 PM
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Quote Quote by ythamsten View Post
This might be of interest: http://erps.spacegrant.org/uploads/i...C-2011-261.pdf

And for some other alternatives, take a look at the wikipedia page (http://en.wikipedia.org/wiki/Electri...aft_propulsion) for a start...
The Jet Propulsion Laboratory may have some interesting material for you about the subject as well: http://www.jpl.nasa.gov/

I'm not too much into the subject, hope that helped a little bit.
Much appreciated, thank you!
D H
#11
Jun29-14, 10:37 PM
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In the end, you should find that we can't do that. Not a single one of the techniques you are investigating, or that others have suggested, is technically or economically feasible.

Mankind has been putting stuff into space for over 56 years, and we're still using chemical propulsion to do that, and nothing else. Why? The answer is simple: It is the only viable option.
phion
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Jun29-14, 10:56 PM
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Quote Quote by D H View Post
In the end, you should find that we can't do that. Not a single one of the techniques you are investigating, or that others have suggested, is technically or economically feasible.

Mankind has been putting stuff into space for over 56 years, and we're still using chemical propulsion to do that, and nothing else. Why? The answer is simple: It is the only viable option.
Right. However, the purpose of the writing this paper is to be argumentative. While I understand and agree with what you're saying, my intent is to present a clear cut explanation of the most promising alternative(s), and if nothing else convince you which avenue may be most worth while in the long run, whether or not the application leads to some type of aerospace, commercial, or experimental breakthrough.

There's a lot of good information on the web already, it's just too bad the best stuff costs money to read.

Link: http://arc.aiaa.org/loi/jpp


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