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I stumbled across this project while visiting UWash on business back in '99. These guys are progressing slowly toward larger NASA funding. Searched this forum (Interplanetary Trans) and didn't find any other posts on it, so here it is for your edification:
http://www.geophys.washington.edu/Space … /M2P2/]The link.
Synopsis-- These guys propose using the solar wind to push against a ship-generated magnetic field that is 'inflated' via plasma injection. Note the speeds that may be attainable. Note also that the fields can be used to shield the spacecraft against radiation.
I think this is an ingenious idea for interplanetary transportation, as well as for early attempts at unmanned interstellar probes. Beautiful simplicity.
I predict this is how we'll get around the solar system until fusion or antimatter becomes practical.
You can stand on a mountaintop with your mouth open for a very long time before a roast duck flies into it. -Chinese Proverb
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I think this is an ingenious idea for interplanetary transportation, as well as for early attempts at unmanned interstellar probes. Beautiful simplicity.
It would be too slow for a true interstellar probe, transit times to the nearest other stars would be 1000s of years. It might be useful for slowing down at the end of the trip though.
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Not so, Dusty M2P2, if viable, could become one of the fastests ways to transit in the inner solar system.
Some useful links while MER are active. [url=http://marsrovers.jpl.nasa.gov/home/index.html]Offical site[/url] [url=http://www.nasa.gov/multimedia/nasatv/MM_NTV_Web.html]NASA TV[/url] [url=http://www.jpl.nasa.gov/mer2004/]JPL MER2004[/url] [url=http://www.spaceflightnow.com/mars/mera/statustextonly.html]Text feed[/url]
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The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.
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There is a difference between dusty M2P2 and standard M2P2. There is also a very large difference between traveling in the inner solar system and interstellar travel.
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Oh, M2P2 is rather "old" news now.
They have an NIAC-contract since a few years an I read all the tech-pdf's about the M2P2 on the NIAC-homepage.
M2P2 is an nice technology cause it's acceleration does not depend on the distance to the sun, and you can "transform" a mere 20KW of plasma-power into 500times, or 10MW of propulsion. So an M2P2 is really efficient. The highest velocitiy you can reach with the M2P2 is the velocity of the sunwind, or around 800km/sec which is not enough for interstellar travel, but really good enough for stellar travel.
Link1 : http://www.niac.usra.edu/files/library/ … pdf]Plasma Magnet ~ 5.5MB
second link : http://www.niac.usra.edu/studies/ [look for Slough, John]
Thanks for the link to the "dusty" M2P2. I didn't know about that..seems even better than the normal M2P2.
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M2P2 is an nice technology cause it's acceleration does not depend on the distance to the sun, and you can "transform" a mere 20KW of plasma-power into 500times, or 10MW of propulsion. So an M2P2 is really efficient.
What do you mean by that? "Watts of propulsion" does not really have any meaning. Thrust is measured in Newtons (1 Watt= 1 Newton meter/second).
Edit: John Slough seems to be using 1 "propulsion" MW= 2 Newtons. This is somewhat misleading, by this standard the 60% efficient Deep Space 1 ion drive would have actually been 2000% efficient.
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Is it possible that if a photon hits this field that it could generate an electron? If so then I propose that this idea could also be used for energy production. Just have side of the field act as an anode and the other as a kathode. Then the electrons would flow to one side and the could be stored in a battery or consumed directly.
Also it could work as extreme lightweight solar shade.
Waht? Tehr's a preveiw buottn?
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M2P2 is an nice technology cause it's acceleration does not depend on the distance to the sun, and you can "transform" a mere 20KW of plasma-power into 500times, or 10MW of propulsion. So an M2P2 is really efficient.
What do you mean by that? "Watts of propulsion" does not really have any meaning. Thrust is measured in Newtons (1 Watt= 1 Newton meter/second).
Edit: John Slough seems to be using 1 "propulsion" MW= 2 Newtons. This is somewhat misleading, by this standard the 60% efficient Deep Space 1 ion drive would have actually been 2000% efficient.
What do you mean by that? "Watts of propulsion" does not really have any meaning. Thrust is measured in Newtons (1 Watt= 1 Newton meter/second).
I mean, or better Slough means that you need only a 20KW plasma-source to get the same amount of thrust as with an 10MW propulsion unit otherwise. I think he talkes about ion drives here but he does not specify it.
Edit: John Slough seems to be using 1 "propulsion" MW= 2 Newtons. This is somewhat misleading, by this standard the 60% efficient Deep Space 1 ion drive would have actually been 2000% efficient.
Really? Don't you forget that the M2P2-propulsion has an far higher specific impulse as the simple ion drive like in DS1. You cannot only count Thrust, you have also include the specific impulse here. Slough imho uses an virtual "exhaust velocity" of around 800km/sec or ~80000 sec for the M2P2 [this is an guess, I have not checked the slides, but the equations work] but the DS1 has an specific impulse of only 3000 sec AFAIR.
Theoretically if you would decrease the specific impulse of the M2P2 from 80000 sec to 3000 sec the Thurst would increase from 2 Newton to ~53,3 Newton. This an simple and crude calculation only using the equations Wkin=m/2 * v² and F = m*v with v= exhaust velocity so the result is not correct but should be in right ballpark.
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Let me get this straight these things are able to absorb photons or refeclect them right?
If so why no reflect those photons and aim them to heat up something and that will then drive a turbine?
Waht? Tehr's a preveiw buottn?
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Slough imho uses an virtual "exhaust velocity" of around 800km/sec or ~80000 sec for the M2P2 [this is an guess, I have not checked the slides, but the equations work]
I can understand how he gets this, but it still seems kind of arbitrary to use an exhaust velocity when there is no propellant. It really would be more helpful for comparing with other propulsion systems if he used force instead of virtual energy for his measurements.
Let me get this straight these things are able to absorb photons or refeclect them right?
No, they use a magnetic field to deflect the solar wind (made mainly of protons and light atomic nuclei).
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Ehhh i've got big doubts about the whole contraption... its a neat idea, but not a panacea of spaceflight...
-Its still a sail, so acceleration probably won't be that great if you have a payload of substantial mass
-Its still a sail... so how do you turn around?
-Course corrections? Maneuverability?
I think the performance for the thing is a little dubious... trying to sell it to Nasa too hard.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Yeah, it's mostly just talk. But if all the physics were real, it would be astonishingly fast, I mean, the more sail you have, the faster you go (unless it's a heavy sail, of course). We're talking about sails many miles across, if it could be thousands, tens of thousands, hundreds of thousands, I'd be hard pressed to think anything else could beat it from a fuel/speed ratio in the inner solar system. Sure, it's one way, but by golly would it be a fast one way.
Some useful links while MER are active. [url=http://marsrovers.jpl.nasa.gov/home/index.html]Offical site[/url] [url=http://www.nasa.gov/multimedia/nasatv/MM_NTV_Web.html]NASA TV[/url] [url=http://www.jpl.nasa.gov/mer2004/]JPL MER2004[/url] [url=http://www.spaceflightnow.com/mars/mera/statustextonly.html]Text feed[/url]
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The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.
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-Its still a sail... so how do you turn around?
-Course corrections? Maneuverability?
I believe that you can alter the magnetic field it so that the thrust does not point directly away form the sun. This allows you to turn around the same way you do with solar sails, you use thrust from the sail to reduce your orbital velocity, and then you let the sun's gravity do the rest. I am not sure how the maneuverability would compare with that of solar sails, but it would certainly not be able to match the versatility of other methods of propulsion.
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The dusty plasma idea looked pretty interesting, I just wonder about the layers of complexity it would add. In solving problems associated w/ the dust confinement, they kept adding more equipment. And what kind of funding is it getting, how far along is it? I don't see anything on the net later than 2002. It appears the dust has to be ionized in order to be deployed... so what happens to it after being bombarded by the charged particles of the solar wind? How much of the dust would become neutralized and no longer controllable? The potential additional payoff by using reflective properties of the dust is certainly huge though.
One drawback for the magnetospheric idea (dusty or not) seems to be limited payload size. I wonder how well such a system would scale up to payloads a couple of orders of magnitude larger than 100kg? Is there a point where increasing the size of the fields wouldn't be able to provide enough acceleration for the increasing ship mass.
I was a little overzealous w/ that interstellar statement. Depends on what kind of speed you could build up before passing the heliopause... getting up to 50 km/s, according to the m2p2 calculations, was based on an acceleration period of only 3 months. What if you could accelerate all the way to the heliopause? 100 km/s still takes roughly 10kY to Alpha Centauri. So not great for long distances.
I did read somewhere that it could be used to 'tack' against the solar wind but couldn't re-find the place I read it. So I don't think maneuverability is a huge issue.
You can stand on a mountaintop with your mouth open for a very long time before a roast duck flies into it. -Chinese Proverb
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