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New Nuclear-powered Spaceship Design Revealed
Posted by
CowboyNeal
on Thu Sep 20, 2007 10:49 PM
from the goes-to-eleven dept.
from the goes-to-eleven dept.
Iddo Genuth writes "A U.S. based company introduced an
innovative propulsion system that could significantly shorten round trips from Earth to Mars (from two years to only six months) and enable future spaceships to reach Jupiter after one year of space traveling. The system, which may dramatically affect interplanetary space travel is called the Miniature Magnetic Orion (Mini-Mag Orion for short), and is an optimization of the 1958 Orion interplanetary propulsion concept."
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Didn't we (Score:5, Funny)
What about the surging nature of the propuslion? (Score:5, Funny)
Re:What about the surging nature of the propuslion (Score:5, Informative)
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Pics (Score:5, Funny)
The best part of the mini-mag design (Score:5, Funny)
Reduces travel time how? (Score:5, Interesting)
How exactly is this supposed to reduce travel time? Current lengths of travel are not due to a lack of available thrust or due to amount of fuel available but rather the path taken to reach the destination. Currently in order to travel to say Mars Hohman transfers [wikipedia.org] are often used. These paths and others like them take a certain amount of time to complete, and stronger engines or more available Delta-V allow only for more instantaneous entrances of the transfers or more allowed change in course once at the ship's destination.
In order to reduce time traveled a different orbital mechanic is needed. Even if a ship were to travel in a straight line toward a destination at a rapid enough speed that it would not have to meet up with it too much further along in its orbit it would have to be able to kill relative speed quickly enough to enter a capture orbit.
Anyone know what orbital transfer method they're saying that this engine makes possible?
Re:Reduces travel time how? (Score:5, Interesting)
Even Hohman orbits are too "spendy" for chemically fueled rockets. Thus the complex back-and-forth gravity-assist paths that NASA probes take on the way to the outer planets, and the use of aerobreaking by Mars probes.
Other, faster transfers are possible. You just enter another sort of elliptical orbit whose path intersects earth's orbit when you leave it, and the destination planet's orbit at a time when the planet will be there. Of course, you have to have a spaceship capable of the much greater change in velocity to enter these orbits.
The linked-too documents suggest that the "mini mag" is not only fuel efficient (read: high Isp), but has a decent amount of thrust. This means it CAN make the drastic changes in velocity necessary.
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Transfer orbit (Score:5, Funny)
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Blog troll. Link to real info here. (Score:5, Informative)
First, this is a blog troll, to drive traffic to some ".info" site. The actual paper, "Proposed Follow-on Mini-Mag Orion Pulsed Propulsion Concept" [aiaa.org] presented at an AIAA conference last year, is more useful.
The basic idea is to create a small fission (not fusion) explosion using magnetic compression. Nuclear weapons use chemical explosives to create an implosion, and during the implosion the fissionable material is compressed hard enough to get a 1.5x to (maybe) 2x density increase. With magnetic compression, a small pellet can be compressed hard enough to get a 10x density increase. This allows smaller explosions, around 50 gigajoules instead of the 20 terajoules of a fission bomb. They want to use curium or californium as the fuel, rather than plutonium.
They also want to use magnetic containment, rather than an Orion-style "pusher plate" sprayed with oil. Unclear if that can be made to work.
The experimental work (they compressed an aluminum cylinder with a big magnet at Sandia) was done back in 2002. This isn't really under active development.
It's not a totally unreasonable idea, but it would be a huge job to make it work. For one thing, the plan is to assemble a large spacecraft in orbit, not to take off from Earth. It doesn't help with the problem of putting mass in orbit.
Re:Blog troll. Link to real info here. (Score:5, Informative)
Ought to be a cake-walk once they've got the field in place to make it go "bang".
The pellet is ALREADY confined in a mag field. The re-expanding plasma from the explosion dumps much of its energy into compressing the field between the plasma and the conductor that created it, making the field stronger (and dumping a bunch of the energy back into the conductor as electricity for potential reuse or consumption).
Should be easy to create a selective leak in the desired direction and more fields to guide the plasma as it makes its getaway. (In fact the compressed field toward the vehicle can be used as a spring to return some of that collected energy to the plasma, further increasing the exhaust velocity. And/or the energy from the compressed field could be used to create or strengthen the "nozzle" guiding fields, just-in-time to guide the burst of plasma.)
Lots of opportunity for cute electric/magnetic/plasma engineering tricks here.
And unlike fusion the time scale, from ignition to completion of the exhaust cycle, is short, so plasma instabilities aren't an issue.
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Re:That's nothing.. (Score:4, Insightful)
Certainly, neither of them has existed in practice -- but one was wild speculation, whereas the other had (and has) actual engineering.
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Re:That's nothing.. (Score:5, Informative)
Orion has already been obsoleted by a similar (but much more effective) design using normal-sized nuclear explosions -- Medusa [wikipedia.org]. Medusa reverses the Orion design, having a parachute in front towing the craft, and detonating the explosives in front of the parachute. It uses structures in tension instead of compression (lighter), it allows the explosions to be further from the craft (less radiation), allows a longer acceleration stroke (smoother acceleration), and captures a larger percentage of the explosive energy.
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Re:That's nothing.. (Score:5, Informative)
I remember that there was some talk of actually launching a small probe based on the concept, but apparently the plan was scrapped. (Probably to help fund manned space travel.) Whatever antimatter confinement technologies they were working on may have led to the development of this new magnetic confinement fission technology. Or it could just be a coincidence.
Either way, nuclear technology of this sort is fairly well developed and is not a pipe dream. At least not from an engineering standpoint. Getting the risk adverse US Government and NASA to actually build one of the many known-quantity engines we have on hand is a completely different ball of wax. They're still trying to get us reliable LEO access (Thank God for Griffin is all I can say), so I doubt we'll be seeing any advanced engines in practice until the CEV/Orion project enters its third phase.
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The solar system is big enough for the moment. (Score:5, Interesting)
The solar system is a big enough place for exploitation, and when we're done with the planets and their moons we can look at the Kuiper belt. That should keep us busy for the next couple of centuries, at least, and also allow us to use technologies to actually analyze nearby star systems without having to send probes there just yet.
And once the solar system gets too small for use, we probably have the necessary technologies, experience and infrastructure to send something on an interstellar voyage (probably a generation ship or even a small planetoid outfitted with propulsion systems).
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Oh dear... (Score:5, Funny)
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Cassini (Score:5, Informative)
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Re:What about manned? (Score:5, Insightful)
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Re:What about manned? (Score:5, Interesting)
Exactly what kind of nerds are they cranking out these days?
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Re:What about manned? (Score:5, Funny)
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Re:What about manned? (Score:5, Funny)
Explains...why...Kirk...talked...like...this. The...future...is...here.
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Re:What about manned? (Score:5, Informative)
Anyway, a 100 metric ton craft would be pretty wimpy. That's 5% of the Space Shuttle's mass, for instance. I suspect this would be an unmanned mission. (For reference, the Apollo Service Module & Lunar Module together were about 40 metric tons and the longest Apollo missions only lasted 12 days).
Also, the 'ignition mass' for the fastest version would be a whopping 1300 metric tons of plutonium. Using uranium prices as a stand-in, that's about $300 million in fuel. That's an awful big price tag for just getting a larger probe to Mars faster.
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Re:jupiter? (Score:5, Funny)
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Re:Not like old Orion (Score:5, Informative)
I'm more worried about Strontium 90 and radioactive iodine.
Given that Hanford deliberately released a BUNCH of radioactive iodine upwind of an indian reservation at least partly to see what its effects would be on the "marginal population" of indians and rednecks downwind (leading to a considerable increase in birth defect constelations and graves' disease), I suspect others are with me on that.
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Re:hopefully (Score:5, Funny)
fixed
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Re:hopefully (Score:5, Funny)
6) Go back to school. Go directly to school. Do not pass Go, do not collect $200.
7) Learn about strange new concepts like Galilean Relativity, Newton's Laws of Motion and Inertial Frames of Reference.
7a) And no, I'm not going to link you to Wikipedia's articles on those. You're going to have to go with step six for that.
8) Now that you understand why step five is no different from step one, you can figure out what step six was supposed to be.
9) For extra credit, write "I will not talk out of my ass about Physics" 6x10^24 times on the chalkboard.
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