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Workable Fusion Starship Proposed
Adam Korbitz writes "A former colleague of Edward Teller — father of the hydrogen bomb — has published a new paper proposing a design for what could be the first practical fusion-powered spacecraft (PDF). As described at Centauri Dreams, the design has certain similarities to MagOrion, a 1990s-era proposal for a nuclear-powered spaceship with a magnetic sail and propelled by small-yield fission devices. The proposal's author also has links to the British Interplanetary Society's Project Daedalus, a 1970s proposal for an unmanned fusion-powered interstellar probe designed to reach 12% of the speed of light on its way to Barnard's Star."
Workable Fusion Starship Proposed
If it's only a proposal, how do we know whether it is "workable" or not?
Colorless green Cthulhu waits dreaming furiously.
Back in the '60s (in stories like those in Niven's Known Space universe), it was always assumed that a fusion rocket would use a ramscoop technology to get fuel along the way. This entire concept seems to have fallen by the wayside. Are ramjets no longer considered a possible technology?
a deuterium fusion bomb propulsion system is proposed where a thermonuclear detonation wave is ignited in a small cylindrical assembly of deuterium with a gigavolt-multimegampere proton beam,
that has to be right up there with back to the future. I mean, it has a frickin' gigavolt-multimegampere proton beam
See here:
http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion)
and here:
http://nextbigfuture.com/2008/12/micro-fusion-for-space-propulsion-and.html
The trailer for "Star Trek" is going to appear in the Stupor Bowl tonight, so this is part of the advance tangentially related news media that the companies use to whip up interest in the movie.
I'm all for ideas like this but we won't be building things like this until we, as a planet, have a permanent manufacturing presence in space.
Moon colony, orbiting L5 colony, whatever it is it must be permanent and able to manufacture using locally sourced materials because building something like this from within the gravity well doesn't make economic sense.
"Bah!" - Dogbert
Edward Teller hired my Dad into the Physics department at UC Berkeley and I remember him as a gentleman - he was occasionally at our house. Once my parents had a costume party and Teller was provided with a bird costume - he did not want to wear the mask so he had these big white wings on. The SF Chronicle columnist Herb Caen ran a story the next day saying that Teller was dressed as the angel of peace. Until Teller died a few years ago, my Dad would occasionally travel to Berkeley to visit with him.
One of my grad school profs worked on a project like this. The concept involved a ship farting (for lack of a more appropriate term) out a series of small fusion bombs. When they went off the heat would cause the shielding at the rear of the ship to sublimate, and this ablation process would drive the ship. As I recall there were only two teensy problems with this: 1) even with the best shielding material available today, the intense heat from the detonation would still cause the maximum heat in the shield to occur at a depth greater than the surface (i.e. the shield would come off in great blobs instead of the slow steady ablation required for thrust) and 2) the amount of anti-matter required for the devices was only about a million times the total amount ever produced on Earth.
But apart from that it worked like a champ.
He took a duck to the face at 250 knots.
http://ida.wr.usgs.gov/fullres/divided/m15012/m1501228a.jpg That is a NASA picture from Mars. Can anyone come with a good explanation what it shows?! To me it looks like some bhuman built biosphere, yet from sci-fi literature. .
It takes a lot of balls to travel several light years without a road-side service plan.
Something I've always wondered about with regards to Project Daedalus and the like is the effects of time dilation as the velocity increases. I suppose at 0.12 * C the time dilation on the probe relative to, say, observers on Earth and Barnard's star is probably minimal. But it seems to me that going faster and faster you reach a point where although it might only take the probe x number of years to reach the star, on Earth it takes significantly more time. Therefore in the case of an unmanned probe, since it's time passage on earth that matters, at a certain point it's not desired to have the probe go any faster.
This line of thought leads to some interesting, paradoxical situations. First, as an object approaches C the time dilation effect becomes such that from a frame of reference of the origin, the object never in fact can reach its destination. Would it not become in essence stuck in time? Secondly there must be some point at which if an object is travelling at x*C, there must be a speed y*C such that another object could reach its destination before the first object, even though the second object is travelling at a lower velocity relative to C. Or maybe not since both objects do experience time dilation.
. . . speeding through their neighborhood whilst "farting out a series of small fusion bombs."
They will come looking for us.
"Hey, Earthling, is this your flatulent spacecraft that fouled our air? We'd just like to return it to you, by chucking it at one of your major cities."
Schroedinger's Brexit: The UK is both in and out of the EU at the same time!
Take is slow
Trackball users will be first against the wall.
Shouldn't we have 'workable fusion' first in order to base the starship's propulsion system on it?
If we don't have to develop a workable fusion engine first, then they should use my idea. It will allow travel at twice the speed of light.
All we need is fairy dust and unicorn piss to power it.
That is how long it will take before someone finally manages to open a sub-space corridor (warp drive).
All the interesting places are either within reach now or too far to go there at ANY speed. What we really need is to find a way to autonomously survive in space for a long time.
...no warp yet?
c'mon, that's lame...
If it's good enough for the geometers, it's good enough for me.
... Edward Teller, the self-described father of the hydrogen bomb.
Other people who worked on the project tend to disagree with that title.
This ain't rocket surgery.
Hmmm, if we can't build lasers and power supplies like that on Earth, even given tens of years and billions of $, how soon will these be doable in outer space, with 100% reliability.
The old project Orion looked into atomic kabang propulsion. There were a few major showstoppers-- two dud impulses in a row and the pusher plate goes flying off into space. No way on Earth to test it. Which is kinda important for a device that has to be 100% reliable with no misfires.
Also the idea of discharging all those Joules in 10 nanoseconds is mighty ambitious-- just the inductance of the objects limits the rate of current rise to a whole lot more than that.
Because they are all dead or going to be soon.
LOL. I was trying to avoid that, but realize the my bloody foot is aching. The "golf-ball surface" is annoying too. Surely, someone has a better resolution image somewhere. The so-called Face on Mars (http://www.space.com/scienceastronomy/060921_mars_images.html) was defaced here http://www.space.com/images/060921_mars_faceB_02.jpg. I am sure this "biosphere" must be defaced too, somewhere.
Somehow, from the very first post, this thread got derailed onto a discussion of the speed of light. The paper assumes 100Km/s. Light is 300,000 Km/sec.
We're talking about trips within the solar system.
only 12 percent of the speed of light? pussies.
Where is the ZPM?
So what would happen if this ship were to explode at take-off, say...somewhere in the lower atmosphere?
The spaceship is driven with a technology like this
If you read the proposal, you'll note that the proposed method of working in space seems to be that the rocket engine actually fires in two directions - first, it fires a very high energy plasma beam AT THE SPACESHIP, which, in the vacuum of space, turns the whole assembly into a Gigavolt capacitor. THEN the spaceship fires a GV proton beam back at the rocket. This proton beam then ignites a classic fission explosion (using Deuterium-Tritium), but "very small", and this DT explosion ignites a second, much more explosive Deuterium-only fusion explosion AWAY FROM THE SPACECRAFT. Repeat one million times per second, or as needed.
What could possibly go wrong?
If that's not exciting enough, the whole plasma/proton beam doesn't work on earth, so, hey, we use a disposable argon laser, which can generate a lot of power, but (sadly), is really inefficient. But wait, we can fix that! All you have to do is set off a small hexogene explosion around your rod of solid argon, and the laser will suddenly work at 80% efficiency. Oh, repeat that every microsecond or so.
Honestly though, if you can get past the insane energies involved, he's come up with a rather brilliant way to use readily available fuel (Deuterium, as opposed to Deuterium Tritium, which is hard to come by), and using a whole chain of events, make the process really efficient (i.e. you need a lot less mass to make all this work). And, since your main burn is fusion (which consumes the fission by-products), not a lot of radiation to speak of (oh, well, there are some pesky neutrons, but who doesn't like neutrons?)
Why would anyone propose a non-functional fusion starship? Duh.
There is a laser bombardment fusion device at Lawrence Livermore which I had the pleasure of visiting in college. The actual yield on the device never got close to break even, and the project was deprioritized in favor of the ITER tokamak. The peper makes no suggestions on how a ship will generate and store the necessary gigajoules of energy to maintain a sustained reaction. We may need a separate nuclear reactor to providing the ignition energy.
Stay skeptical, my friends.
Prepare ship for ludicrous speed! Fasten all seatbelts, seal all entrances and exits, close all shops in the mall, cancel the three ring circus, secure all animals in the zoo! (Colonel Sandurz)
That is fast, but since Barnard's Star is 6 light years away, assuming a constant acceleration and deceleration it would still take 100 years to arrive.
Building a starship is the least of our concerns. It baffles me that we are discussing building a fusion spaceship when it seems that very little is being done to get fusion working for making our energy here on earth. Our priorities are all mixed up. While we are spending billions on wars to give money to banks so they can use it to by their yachts, we desperately need to be spending that money on fusion and clean, environmentally friendly energy sources NOW. We cant afford to wait any more on this.
It amazes me there is not a more strong and powerful call from scientists globally to rapidly expand fusion research adn development. We should be funding not one but many different technologies via government funding, having a sort of competition with different designs being tested. With several projects development different designs and with funding to new designs that can do fusion better, cheaper and smaller, such as the Polywell, we have a better chance of getting something that will work.
With our destroying our planets environments with CO2 and toxic fossil fuel related wastes and set to totally deplete the entire supply of oil in 40 years, and with a supply that simply cannot bring electricity to everyone on planet, such as those in Africa, to alleviate the poverty and suffering there, our energy crisis for producing energy for use here on earth is the greatest challenge we face. If fusion is feasible for a spaceship, why the hell are we not building fusion plants right now or at least spending billions on development of this. We need to stop dilly daddling around here, we cant afford to sit around longer and wait for markets to somehow come up with a solution. Its clear that government funds most nuclear fusion development and corporations are not doing what we need to be doing to solve our worlds problems.
If we can develop fusion, global warming is solved and we dont have to worry about it anymore. Then why are we not doing it. Why is it sometimes I get the feeling that while everyone moans about global warming, no one wants to take the initiative and actually fix the problem? There needs to be a strong call from the scientific community to expand funding for fusion development and research as well as other renewable, environmentally friendly technologies. We need to tax the oil companies as well so that we can fund these projects with the money that consumers are struggling to pay at the pump. While we have a planet in crisis it makes me FURIOUS that oil company CEOs are using money wrenched from hardworking people via their monopoly to fund their yachts when we desperately need this money to be put into fusion research. Its like these wealthy CEOs are saying to the people of the world "screw you all, Im going to spend all of the money on my yachts and let this planet go to hell". That we see so little priority on this energy crisis in government policy, in regulating oil company profits and through a democratic and science directed process regulating their research and development priorities around goals of eliminating fossil fuel dependance ASAP? We cant afford inaction and the same old same old with oil companies wanted to pollute the environment and oceans with their rigs, to spend all of their money on yachts and oil exploitation, and for fleets of wasteful fuel inefficient 20 mpg cars when we can have 80 mpg NOW. Is it because they want their to be a global warming crisis, for whatever political agenda they have?
it may be the lead in for stargate universe.
Alpha Centauri A and B are more likely to harbor an earth like planet... not to mention are almost 2 LY closer.
If you want some red dwarf action, swing by Proxima on the way.
I am very small, utmostly microscopic.
whatever... Shotgun !
Dont Judge The situation by the Misfortunate. Goga.
There's water on the moon. There's solar power on the moon, easily convertible to electricity. With the two and a couple of pop bottles you could get escape velocity. It's really not that big a deal.
Although a good first step would probably be some sort of LEO recycling facility. Lots of space junk could park and be recycled rather than reenter. Solar powered ion drive scavenger robots should do the job just fine.
Help stamp out iliturcy.
The delta v between your typical Amor class earth crossing asteroid and the Earth-Moon system is on the order of a few meters per second. In other words if you could stand on it and chuck a rock, you could hit the Earth.
Existing propulsion technology could easily move one of these rocks around. It would be expensive and take time, but it could probably be done without requiring the invention of any fundamentally new technology.
A 100 meter diameter rock like Apophis would mass on the order of a gigaton or so. It would take a good bit of work, but it isn't at all unrealistic.
"Malo periculosam, libertatem quam quietam servitutem." -- Jefferson
Whatever may be the reason, on most of the paper, his calculations and figures are in the obsolete CGS system (Centimeter, Grams, Seconds). Forces are in dynes, pressures in g/cm^2, etc.
And then you see later in the paper Amperes and Watts (which are SI units).
CGS and SI (or MKS) don't mix.
Zippy, is that you?
Is this a new Jazz ensemble tribute to Jefferson Starship? In which case, God-speed my acid-trad-jazz-fusion-combo. May your riffs light up the galaxy
If he's the Walrus then can I be a penguin please?
Sounds like you're talking about something like this. I couldn't agree more. But keep in mind, our butts need not be all that collective after all. These days the idea of a few hundred mostly private entities between them getting humans established on the moon and with a diverse range of launch capabilities from the earth looks more practical all the time.
Personally, I think we really NEED to get on with building space colonies. We could do it together like we did the International space station. Each nation involved could build sections. Working together we can do it!
how about a giant laser..
Looks like you need to brush up your relativity, also.
It doesn't "shorten" the trip for the passengers. Time is what passes slower. So the trip may take 50 years from the point of view of observers, and the passengers only perceive a 5 year trip. So the passengers age five years while the observers age 50. Meaning that while the passengers could do a round trip in 10 years, everyone they know would likely be dead, or really old, by the time they got back.
The concept of the solid ablative shield for this type of propulsion is probably too limiting. Once one of these physicists realizes that they can baste it with a layer of something else between blasts (water, or hydrogen, or mercury) the designs will improve. The challenge of building the physical shield is reduced, as it doesn't need to double as the fuel, and it won't matter so much it doesn't erode with perfect smoothness each pulse.
If you mod me down, I shall become more powerful than you could possibly imagine.
I wondered why many fusion drive proposals are the slightly absurd mini-bomb machine gun kind, then realised perhaps it is because the Orion program really was that awesome in a nuclear-steam punk fantasy kind of way. However ludicrous it is to detonate 1000 nuclear warheads sequentially to reach orbit, you had to admit it'd be super-cool. http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) "This extreme design could be built with materials and techniques that could be obtained in 1958 or were anticipated to be available shortly after."
Yet these equivalent fusion-based proposals seem to be only plausible with some assumptions of technological advancement, rather than with assumptions that people wouldn't mind the irreparable damage to the earths biosphere.
I think the approach is all wrong by many proposals so far. Thing is, we can create and contain fusion right now, and you can do it your backyard (no kidding - see lower). I think a plausible fusion drive would be something like a Bussard electrostatic confinement based drive. Essentially you are accelerating ions to high enough velocity for fusion, but allowing some to escape by a neutral charged nozzle.
We don't have fusion reactors right now that break even in any practical generative fashion, however that is absolutely not necessary. Give up the need to generate power from fusion, for example use an existing fission pile to power the thing, and you start to get results. The high-velocity fusion products become a nice boost to your specific impulse, along with your exhaust velocity much higher than any Ion or VASMIR thruster for any high-energy fuel leaking out the rear.
Ditch the perfectionist science and apply practical engineering and tune the thing for efficiency. Go to the stars.
Interestingly, electrostatic inertial confinement in a hard vacuum doesn't even need reactor walls .
What makes this even more exciting is that hobbyists build electrostatic confinement devices, and even get fusion reactions. Oh, OpenSource too.
http://www.fusor.net/
http://en.wikipedia.org/wiki/Inertial_electrostatic_confinement
Now figure out how to make a drive out of a Fusor, strap some solar cells on it, and convince a private space launch company to put in orbit.
After logging in slashdot still does not take you back to the page you were on. It's been that way for 20 years.
if gravity waves do exist, then a space craft could theoretically create an interfearance pattern in all direction except for the direction of motion. thus able to accelerate using waves from other celestial bodies.
So if "swimming" isn't the right approach, how about those little handheld fans that they always give out at trade shows?
It's all about the information. And what we do with it.
You're right that 70ly is a long, long way. But three things counter that:
1.) Suspended animation is getting closer to real all the time and most of the supposed problems with that (such as radiation exposure in transit) are actually just matters of cost, not absolute limits.
2.) Generation ships.
3.) Yes, but what about getting to the nearer stars in part in the knowledge that the next generation would take the next step further away?
Perhaps the first two are examples of what you meant by "survive in space for a long time".
And keep in mind that what we can already see of a solar system is very far from complete. We may not be able to see anything orbiting Alpha Centauri yet but our resolution is rough indeed. In fact, our current techniques are in large part not even direct viewing but just imperfect means of derivation. I think that it's safe to say that we would find something there beyond just a ball of plasma.
As for your "they would go mad" absurdity, citation please. People have gotten by without contact with "civilization" for years on a regular basis for most of history. Look into how most of the Pacific islands were first settled. Or at some of the long duration nuclear sub cruises, which were shorter but still in very cramped spaces. Just bloody well watch Master and Commander or anything decent about 1500's to 1800's sailing ships.
People are tough. They adapt. Many of the proposals for ships to other solar systems have long proposed crews of several dozen or even more, quite enough to create a small society of their own. And if we were to choose to do it that way, we could send ships in clusters so that they would not all be at risk from one point of failure but could still communicate across the ships in transit and know that others would be there by the time they reached their destination.
Not only that, there are always some people out there who find the idea of near total isolation a feature rather than a bug. Just look at the history of forest service fire watch towers or lighthouse personnel. The travelers have plenty of ways to deal with human factors. Hell, maybe some of them would use up most of the trip smoking pot and playing video games. Add in a "real doll" and plenty of people would find it an improvement on their current level of social interaction. And if you think that I'm joking you're not paying attention.
It's all about the information. And what we do with it.
Hey, man, welcome to the 21st century. Private companies do space stuff now, too. Since when do we need to get everybody to "work together" to do such a thing? Anyway, we could create a station faster than it takes most proposals to get written these days by using approaches like this one.
And fwiw, the ISS is famously a boondoggle whose costs are grotesquely outscale in no small part because of how well it worked to have "each nation...work together". For the amount of money and time that was blown on the ISS we could have gotten a colony built on the moon by now. Seriously. Maybe two of them.
So if you want to see us working together like that my question becomes, so, what are YOU doing to help, cobber? It's real easy to say what others should or could do, not so easy to do it.
It's all about the information. And what we do with it.
I mean really, anyone can propose anything. That doesn't mean that it'll work.
Mind you, I didn't read the article or the other posts.
I could be wrong.
Why go to Banards star? It's not the closest, it doesn't seem to have planets and it flares so if it does they definately won't have life. It's so old there are probably not a lot of heavy elements in the system either. I would go to Alpha Centauri. 3 Stars for the price of one! And a huge habitable zone(s) to boot!
___
No power in the 'verse can stop me
this is so hilarious.
serious something like this could only
come to mind during a time like the cold war.
-
bit early for 1st april post, non?
The Queller Drive!
The aliens will want revenge!!
Not even Martin Landau could sweet talk them out of it!
fusion-powered spacecraft (PDF)
"PDF" is a moronic abbreviation for "fusion-powered spacecraft". I propose "FPS".
History calls him the father of the hydrogen bomb, but it ought to call Stansilaw Ulam the stepfather. Teller was the whiny "my way or the highway" guy who wouldn't believe everybody else when his design was shown to be fatally flawed. Without Ulam, who knows what would have happened. Anyway, after Teller was pushed out for being a chronic a-hole, Ulam got the job done, for better or for worse.
Oh, and don't forget what Teller did to Oppenheimer. Man, talk about some egos at work...
Just a sidenote to history, of course. Richard Rhodes has written two very good books about the fission and fusion bombs.
Hyper moralizing == a cult. Hopefully you'll age gracefully and latter laugh about the "activist" days. Or, you'll continue to wrap yourself in dogmatic ethics and call out the "heretics". You are living the lie of a cult -- wake up and think for yourself!
... provided you can solve the technical problems involved in maintaining a self-contained, artificial ecosystem over a relatively long period of time - far from a sure thing. But it's not economically viable. The cost of doing even step 1 is beyond exorbitant. And what's the payoff? We do large scale interplanetary transport... to what end?
Until you can answer the questions of who could make money at this, how do they make it, and how much they could make, this is going nowhere. You'd never get anyone to invest.
... but the explosions in my car aren't from NUCLEAR FRICKEN' BOMBS! Yes, I think we need to worry about this.
He's talking about charging up the ship to GeV potentials. I envision severe side-effects of this practice, particularly with electronic control equipment. (The words that popped into my head were "play holy havoc.")
jim frost
jimf@frostbytes.com
Only if you travel at a constant speed of 0.12c the entire journey, which is impossible. It requires you to accelerate to 0.12c instantaneously and decelerate to 0 at the destination just as quickly. Such enormous acceleration would destroy the craft; it's comparable to a meteorite impact - and even if it didn't, it would take vast amounts of fuel.
Feasible interstellar travel works by accelerating at a constant rate until the midway point, then reversing thrust and decelerating at the same constant rate until you are there. While I don't know the formulae that would prove this, doing it this way should minimize travel time for a fixed amount of fuel.
To reach v=0.12c by the midway point of s=3 lightyears, you must accelerate at a=(0.12)/t, where 3=0.5*a*t^2 (t in years, s in lightyears, v in c).
Substituting a yields 3=0.5(0.12/t)*t^2, simplificating to 6=0.12*t, which comes to t=50.
There you go, 50 years to accelerate to the midway point. The second half of the journey takes the same amount of time, which comes to a total of 100 years. :)