Slashdot Mirror
Nuclear Rockets Moving Along
AKAImBatman writes "Bruce Behrhorst of NuclearSpace.com recently stumbled across a new engine from everyone's favorite Jet Engine maker, Pratt & Whitney. Unlike P&W's previous engines, however, this engine is not a jet, and is powered by Nuclear Fission.
It seems that P&W has responded to the need for Mars transportation by inventing the first commercially viable nuclear thermal rocket. They have heavily improved upon the NERVA NRX design from the 60's, and have even solved the graphite ablation problem! With this new engine, it seems that an inexpensive trip to Mars is now firmly within our grasp. Will we rise to the challenge?"
Too bad the public fear of anything with the word 'nuclear' in it will grind this project to a halt. :(
I think the only thing that makes sense right now would be: Screw Flanders.
This technology is not already doomed because of politics...
I'd rather be sailing...
Its a bird, NO its a plane, No!! It is a mini-hindenberg!
Ambient [Servlet Based Webapp Engine]
and have even solved the graphite ablation problem
I was just lamenting over the seemingly unsolvable graphite ablation problem!
Trolling is a art,
...this will ever be used. Not because it is dangerous, uneconomical, or anything even remotely having to do with reason. Nay. Rather, because the public has a knee-jerk reaction to the word "nuclear," or "atomic," or "nucular." Fact hardly matters in the opinions of an uneducated, uninformed public.
A blog like any other.
If it's got a nuclear engine behind the cabin, I suggest the pilot wears a lead suit as well as a tinfoil hat...
Perhaps they should solve other problems of being able to visit Mars such as its gravitation and the fact that the surface is quite uninhabitable.
Take off every 'ZIG' !!
"They have heavily improved upon the NERVA NRX design from the 60's, and have even solved the graphite ablation problem!"
Really? I always found that the ablation problems were rarely touched on by my professor. We spent several weeks in the library and online researching this before coming to the conclusion that the vortex efflunziation was inherent with the NRX designs, especially seeing how the rocket designs went from paper to production in 5 months.
So Nuclear subs have been operating in secret? Well, yeah...
Take off every 'ZIG' !!
I was hoping that someone would create a workable nuclear-ion drive. It's the only viable long range engine we have open to us right now that does more than just move the ship :)
Exploration of mars should be second on our list of things to do in the US. Number one should be to have a clear goal on replacing oil as the main source of energy within, say 10 years. Then the US government can shift it energy policy from war to something that benefits us and the world. Why can't we say, ok, first, lets get this urgent problem behind us, and then focus on the next big thing.
This isn't meant as a panicky "omg! nucular!" question. But we have seen a few space craft blow up spectacularly. Now, I assume the designers are bright enough that these engines could not actually produce a nuclear explosion, but wouldn't a conventional explosion at high altitude run a high risk of scattering nuclear material all over the place? Is there a good reason I shouldn't be worried about that?
What's wrong with Project Orion? ;-)
I mean, if we're going to go to Mars, we might as well do it properly - even if it does end up filling the atmosphere with radioactive fallout...
Tedious Bloggy Stuff - hooray?
The only reason we still have so many is because for the most part they're out of the public eye.
But still, the repeated attempts to shut them down are well-documented.
A trip to Mars will be many things, but it won't be inexpensive.
...isn't the exhaust a bitch to deal with?
Everyone get out your wooden clogs and prepare to throw them into the evil machines!
It means they can run the engine and not wear it down from friction. Or at least not wear it down at a rate that is greater than the projected lifecycle of the engine. Having only STFA (Skimmed), I don't know if they are intended for single or multiple use.
We'll at least have some impressive fireworks, when one of these fail.
Was not NERVA somehow proscribed by the NTB? Wouldn't this be a deal-killer? Is it reasonable to believe the rest of the world will rescope the NTB to allow us to run nuclear rockets in space (i.e., why should the world trust the US?).
I'm serious about this.
aside:
I used to work with a cryogenics engineer who designed the Fermilab Tevatron LHe system, who had earlier worked on NERVA. He told some pretty interesting stories about bundle dissasembly during criticality tests. They used a tank with arms to pick up the pieces...
I think they designed it on computer, not pencil-on-paper.
They never ran out of pencils to design with. Hence no "graphite ablation" problem.
yeah - Kerry would kill this project, but at least he can pronounce the word Nuclear... (not that I like either of our "choices")
Nothing is 100% safe; consequently the real question is "what is the acceptable rate of failure?".
have even solved the graphite ablation problem!
... I mean, "well shit outta ammo," so I ran back and the lever thing smashed me and I died....
That's what they think, but then that laser thing that shoots ever few seconds down that tube thing you gotta later run down messes up I think, cuz the room changes color, and you then you get to the other side and see this blue stuff being pumped into this lever gizmo that will smash you so you gotta time your sprint past it, but then these mobs appeared just after I got the health (duh) and I was like "well shit oom"
"All great things are simple & expressed in a single word: freedom, justice, honor, duty, mercy, hope." --Churchill
A nuclear explosion has to push against something, in this case a graphite pusher which would theoretically erode too quickly.
s ion
More info on nuclear propulsion efforts
http://en.wikipedia.org/wiki/Nuclear_pulse_propul
Like those of the recent shuttle crash - with fission material spread from CA to LA.
Not only does it not ablate, but the titanium will melt and scram the reactor long before the reactor itself experiences meltdown.
:-)
In other words, this is an extremely safe reactor design.
Not to sound paranoid, but when the reactor overheats and falls off where does it go? What happens if the reactor falls off over a populated area? Say the reactor falls off on the way to mars. Unless there is a shift in the momentum of the ship or the reactor it'll just melt down beside the ship. Then imagine the case where the ship can separate itself from the reactor. Now how do they get back?
While this is probably an improvement, I'd hardly consider it safe. I'm not saying we should abandon the use of nuclear propulsion. I'm just not convinced it's necessarily safer than current methods of propulsion.
-- john
Has had a nuclear meltdown! ;)
Corporatism != Free Market
It's too bad that silly public hysteria when they started filling the atmosphere with radioactive fallout in the 1950s doomed such projects (at least until those who remember the 1950s die off).
We coulda had Project Orion. We coulda sea-level canal across Nicaragua excavated by peaceful nuclear blasts. We coulda had electricity too cheap to meter.
All spoiled, spoiled I tell you. Just on account of a few dead sheep, some irradiated Japanese sailors, a few U.S. soldiers with cancer, a little bit of fogged film (cardboard cartons made from fallout-tainted woodpulp), and a few "Sunshine Units"-worth of strontium-90 in the milk. And some problems working the bugs out of Windscale, Detroit Fermi, Browns Ferry, Three Mile Island, and Chernobyl.
"How to Do Nothing," kids activities, back in print!
I don't know what Kerry would do about the nuclear stuff.
Build a rocket with a nuclear motor pointing up and a chemical motor pointing down.
Unlike P&W's previous engines, however, this engine is not a jet, and is powered by Nuclear Fission.
P&W rocket engines like the RL-10 are not jets, they are pump fed rocket engines. Jets are air breathing by definition. The main differences between a nuclear engine and a traditional combustion engine is the source of the heat (nuclear vs. chemical) and single exhaust fluid source.
an ill wind that blows no good
And how do you expect to get the nuclear material up into space without risk of the transport blowing up?
I'm sure peak oil will moderate the public's fears of nuclear power.
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
Did you read the article? It has 15000 pounds of thrust, at nominal output. Totally useless for ground-orbit missions. It is designed to fly from orbit here to orbit somewhere interesting.
"I do not agree with what you say, but I will defend to the death your right to say it"
Well, see, there's this graph, and its always bleating about something, so we finally whacked it, and it don't bleat no more.
Easy solution, don't use nuclear material for the shuttles. Use it to power the ISS or the mars/moon missions. Mimimize the risk by sending every ounce you plan on using over the next 50 years in one shot and store it on the ISS.
why would i donate to a group that wants to flat out inhibit any technological progression based on a few past failures?
nuclear power can be made and is quite safe today. it may not be perfect, but it is better than the alternatives (ie BURNING chemicals compounds)
With this new engine, it seems that an inexpensive trip to Mars is now firmly within our grasp. Will we rise to the challenge?
There are so many other things standing in our way before we get to Mars, it's not even funny. Do you seriously think that we only need a good rocket to get to Mars? There's no way any trip to Mars in the next 50 years will be considered "inexpensive".
The diagram of the engine is fairly straightforward, but they didn't show the manual ejection system for the reactor core, or the ducts to route plasma and coolent from the engine to the navigational deflectors, or the ducts from the bussard collectors
maybe you should do some research before you buy into the "peak oil" propaganda
Mr. Taco, /. fission reactors to full power!
Or more precisely - what is the acceptable value of (rate of failure * consequences of failure)?
...but it said "For Peter" on it. So you must've thought it was "from" you, so you didn't...you know, it's just easier to call you stupid.
Facts do not cease to exist because they are ignored. - Aldous Huxley
the lesser of 2 evils is still evil
They had catastrophic consequeces for those on board without having a nuclear rocket.
I apologize. I mistook Mars' characteristics with those of Venus. :) -- I'll go back to not doing astrophysics now.
Take off every 'ZIG' !!
ahem, it's pronounced "Nu-Clure". How do these guys expect to get to Mars when they can't even pronounce the word right?
Repant. Thy end is sheer.
What I find interesting is how the Triton combines two great concepts in nuclear thermal propulsion, the LANTR afterburner and the Bimodal power concept.
That was a funny interview. The guy seemed to imply that pornography was keeping us out of space. I wonder if he's a regular church attendant? Hmm, and pro-nuke. What is it with these people?
But anyway it was really long and I bet most people didn't read it, so check this quote
Interviwee: Do you know what ITAR (International Traffic in Arms Regulations) is?
Interviewer: Vaguely, smells too much like excessive bureaucracy an impediment to cooperation with nations that are able in space exploration capabilities such as in space nuclear technology.
Har har har.
Yeah, there ya have it. These damn commie red tape bastards are spoiling all the fun with their senseless prohbitions on trafficking nuclear arms. Curse those fools!
Don't worry, Arnold's on top of it.
"Oh, you hate your job? There's a support group for that, it's called everyone, they meet at the bar."
RTFA
It's for propulsion in Space not for getting into orbit. You can put the powersource in containers that survive being blown up, and fit them to the engines in orbit.
>public fear of anything with the word 'nuclear' in it
We can't start polluting space with all of that radiation. It'll kill all the trees!
(For those of you who went to American public schools, a) space is a big place and b) it's pretty well irradiated already by all those pesky stars. There are no trees in space.)
sigs, as if you care.
If the Challenger or Columbia were nuclear, America's space program would have gone the way of the Soviet Union's Chernobyl program. To say nothing of their "Soviet Union" program. Risk isn't just the probability of failure, it's weighted by the potential damage. Exposing America, and Earth, to the risk of a failed nuclear rocket is not the best alternative to space propulsion. We can do better, so we must do better.
--
make install -not war
Nuclear power generation is self-contained, and only problematic in case of catastrophic failure. The other two are problematic when functioning as designed. Associating the three is precisely what has prevented the use of nuclear power generation.
You of course scare-monger by mentioning nuclear power plant failures, but you'll notice that the world has (shock!) survived just fine. While the death toll from an event like Chernobyl is certainly tragic, there are risks associated with developing any technology. Beyond which, I have the sneaking suspicion that more people have died from the effects of air pollution caused by fossil-fuel power generation than have died due to nuclear reactor failure by orders of magnitude.
I also suspect (based on broad stereotyping, admittedly, so feel free to tell me I'm wrong) that you also buy into global warming as a result of mankind's CO2 production, in which case the death toll from fossil fuel plants will be yet more orders of magnitude higher than would be caused by the occasional nuclear plant failure.
Reality has a conservative bias: it conserves mass, energy, momentum...
The real problem is getting BACK. I mean, once you land, how do you cobble together the resources and facilities to launch a return shuttle? Mars isn't like the Moon, ya know.
-matthew
"THERE IS NO JUSTICE, THERE IS ONLY ME." -Death
Unlike your single processor brain, the U.S. is a big enough country to do more than one thing at a time. If this reduces the amount of fuel needed and the trip time it makes the other problems a lot easier and the whole project a lot cheaper.
... From getting over radiated and killing their tyroids gland before arriving to mars?
I think that is probably the number one obstacle to ever putting this type of propulsion system to work. In the event of an explosion during liftoff, it would become the largest dirty bomb ever conceived. I suppose it may be possible to try to launch the engine components separately and assemble them in orbit. (Similar to what the crew of the B-29 which dropped the atomic bombs on Hiroshima did (because of similar concerns). But you'd still have the possibility of radioactive material raining down in the event of a problem during liftoff.
- dj
discovery wings is at the moment running a show on Project Pluto, the government's project to develop a nuclear-powered ramjet in the 50s/60s. the research got up to successfully running the full-scale Tory-IIC 500Mw prototype for 5 minutes at 35,000lbs thrust. i realize a ramjet design is different from a thermal rocket design, but does anybody know why 'they' can't use the basic design of the tory reactor, homogenous uranium/beryllium oxide fuel tubes, at the heart of the rocket engine? seems an ideal situation, theres no graphite to ablate and AFAIK the oxide ceramics stand up pretty well to hydrogen.
Facts do not cease to exist because they are ignored. - Aldous Huxley
There's a rumor circulating on the Internets about a nukular rocket... I think it's one of those, errr, exagerations!
All excited, the trip takes its toll on your body but you finally get to Mars, severely disappointed because there's nothing to do and the environment is too severe to enjoy, cry and want to go home to earth, go crazy on the way back to earth, have lost your job, get committed to a mental institution.
Fuel enrichment?. Naval reactors are enriched to >90% U235 (from 0.7% natural). The NERVA rocket (and I suppose this rocket) was also enriched to above 90% U235. This would be a significant cost and would produce about 1000 kg of depeleted Uranium.
A realistic actual cost? A 1973 study on testing and building a reactor based on the NERVA/KIWI experience was about $4-5 billion including reuse of some NERVA facilities. Part of the explanation for the increased cost was the additional nuclear safety requirements imposed after NERVA/KIWI started work. This total is a lot higher than the "$1 billion" for a prototype system even not accounting for inflation.
IMHO, P&W have entended the engineering on the NERVA/KIWI but this article is salesman-speak that politely avoids the issues that doomed NERVA. A pleasant fantasy for the /. crowd.
Rename it, like they did with nuclear magnetic resonance, which is now a household word as MRI.
Remember the Russian satellite that broke up over Canada spreading nuclear waste over the arctic? That had to be cleaned up and had a significant cost. Fortunately, the area was uninhabitated. But the Russians had lost control of that one and it could have come down anywhere.
Hell, the correct wikipedia link is in the summary!
If you can figure out how to make the Moron US citizens want to trade in their Escalades and converted school busses for hybrid cars that get 50mpg+ then you will find a solution.
until then rampant stupidity in the general public, espically the affluent public that think they need a Hummer or a 21 foot long SUV let alone the other abortions of engineering called SUV's on the road will continue the spiral of oil dependancy.
what kind of moron buy's a vehicle with less than 20Mpg that is not used for moving Heavy items or large numbers of people?
Sorry, the bullshit response of "how to I transport my family" that always comes up is not acceptable..
Minivans carry MORE than your Escalade PLus with 3 more feet of body length and get 3X the gas mileage.
I am absolutely sure that everyone that drives a large SUV has a 3/4 inch long penis.
add tot hat they they drive like idiots in them.
The risk I worry about isn't Chernobyl. It's waste products that have been stored in metal barrels for decades. This country has an abysmal record on safely disposing toxic waste products of all kinds, and there STILL is not a single site working site for permanent disposal of nuclear waste (which will change with Yucca mountain I know). Too bad many experts say that Yucca mountain is seismically unstable....
The problem with nuclear energy is a false economy. How much expense will running Yucca mountain for the next 10,000 years rack up? How much of its running expenses are currently subsidized by the federal government? That offsets any advantages nuclear fission has in my opinion.
Fusion obviously has none of those problems, and research into it is drastically underfunded. If the government funded a research program on 1/10 the scale of the Manhattan project into fusion I'm convinced it would become a viable power source and overshadow any of the other alternative energy sources being talked about.
I haven't bought into it. Not yet, anyway. I would be happy to see anything that disproves it, however.
The space program is full of good side effects that many never expected. You can get a whole lot more imagination going when you propose magnificent problems to scientist.
Mundane problems generate less interest which usually means they never get solved completely.
* Winners compare their achievements to their goals, losers compare theirs to that of others.
That may be true, but in his first four years, Bush has eviscerated the EPA. Give him another four, and he'll probably have completely dismantled it. We already have the "clean air" act legalizing more air pollution. I don't want to see his "clean water" act - it'll probably call for a 95% pollution-free standard for rivers, which would sound good while allowing businesses to dump raw pollution until 5% of the flow was pure chemicals/sewage.
Yeah, yeah, troll. Go ahead, knock yourself out, my karma can take it.
Just call them the new Nifty Engine, nifty from Non-Fossil Fissle Transportation Energy (NFFTE) or Nifty. Then everyone will think its neat, bang-up, bully, corking, cracking, dandy, good, great, groovy, keen, neat, not bad(p), peachy, slap-up, smashing, swell.
.. how many miles to the gallon does this puppy get?
That being said, to dismiss the fear as ridiculous is unfortunately as narrow minded and confined a view as the fear itself.
Quite simply: People (even the smart ones) are nervous about nuclear power because of two major reasons
Nuclear power has so much potential to assist humanity, but we need to understand the legitimate fears before we can approach those who are afraid of its equally great potential to destroy humanity, and try to convince them to look to the future rather than to the past.
Not that anyone's listening, but it's gotta be said. Who's this "we"? Why not ask, "Will someone rise to the challenge?" The biggest lesson of the X-Prize is that there doesn't have to be a "we" in space travel.
If aspiration is a virtue, achievement cannot be a vice.
Can't we make an airplane engine from this reactor?
It would take the atmospheric air, heat it by the energy of the nuclear reaction and release it for thrust. Same as burning fuel, but the energy source is not chemical.
Such a plane could fly for a LONG time on a single fuel load, and not having to carry excessive fuel weight, would make for quite an efficient design.
Google for Moon and He3 sometime, and you might find that the two policies are more related than you might think.
"Part of what doomed NERVA was possibility of burning up the reactor in the atmosphere."
Something which is perfectly avoidable by launching the fuel in similar containment to the RTGs which have already survived launch explosions and re-entry.
"would produce about 1000 kg of depeleted Uranium."
That is, a whole ton of uranium that is _less_ radioactive than naturally occuring uranium. Wow, I'm scared!
"Part of the explanation for the increased cost was the additional nuclear safety requirements"
Due to anti-nuclear whackos.
"this article is salesman-speak that politely avoids the issues that doomed NERVA"
No, it just assumes that the anti-nuclear whackos can be kept under control this time. Naive and optimistic, I'm sure, but there are no real technical problems, only problems with loons who think the sky is falling any time someone says the world 'nuke-lear'.
Well, if Kerry can't be trusted (Jun 2003) to promote renewable energy, how can we trust him to promote anything nuclear? No, wait a second, this year (Apr 2004) he's conditionally going to wait it out on the results of an environmental report... on a windfarm ... no pollutants, no fuel burning, possible bird hazard...
Honestly, how can we predict how he's going to act? If he wants to wait it out on a windfarm of all things, the odds are he's not promoting anything nuclear based...
Are you serious??? You want the United States to focus on one scientific goal? You are saying, in effect, that even though there are well over 290 million people in the US, each and every citizen should be forced by the government to be focused solely on what you think is the Right Thing(tm). Give me a break!
The US is still (ostensibly) a free market, capitalist country. Each citizen and industry is free to pursue their own interests. And yes, that even includes interests that might not fit perfectly into narrow-minded people's ideas of what is Best For The Country(tm).
Thanks to visionaries pursuing their unique interests in a free market economy, non-conformists have made leaps of creativity and ingenuity that have created some of the most helpful technologies used around the world. Don't ruin it for the rest of us with your command-and-control utopia.
http://www.geocities.com/ussmunchkin7/Star_Trek_IV .htm
http://groups.google.com/groups?selm=BL0zc.107743% 24Qc.4131568%40twister1.libero.it
Here's a design of the spacecraft based on their Footfall novel
I always thought Pournelle to be a bit loony to push for such a technology. I guess I was wrong.
Clem.
Yeah, so a space ship and rockets blow up. That's why it's called rocket science and is dangerous. I know everyone should be concerned with the results that an explosion of such an engine would bring, but then we would still be inside caves scribbling on walls if humans didn't take risks. Heck maybe we should all just stay inside our homes, cause lightning can strike us if we walk outside. Oh, and encase yourself in a plastic bubble cause you just might catch a nasty virus. Come on people. The human race does not move forward by being scared of a little boo-boo. People die all the time and it's a reality of existice. I say shove those engines into space - the sooner we reach the stars, the better. Taking changes and risk is part of the game.
It's "New Clean Hat For Head".
props to The Goodies....
Of course this will make it way into ships.. here's how it works
1. invent new tech
2. put it in a bomb
3. 10 years later, true and realworld beneficial applications make its way(electricity, subs, spacerockets).
Aint that how it's always been ?
I want to know when we're going to have nuclear cars.
Tritium-D is a safe source of nuclear energy. Imagine the effect of putting one of these in a Toyota Prius or other hybrid car:
You could run the car electric only far more often. The Tritium-D could just continuously charge the batteries. Under heavy or continuous usage you'd still use gas, but that isn't the way most cars are used.
It's estimated that 80%+ of car usage is over very short distances.
Tritium-D is easily shielded and contained, and even fairly long term exposure is totally safe.
And yes, it's expensive right now. But that's because it's produced in very small quantities. It doesn't have to stay that way.
Lose Weight and Feel Great with Isagenix
Cragen
I wonder who is running on one processor. Your argument is:
"You simpleton. US is big. It can do many things. A solution to the Mars journey could also produce a solution the energy problem."
The problem with this is that you assume one of the things the US is "doing" is resolving the energy problem. It isn't. While plausible, your idea that space program research will resolve this problem indirectly is naive optimism at best.
what is with the morons that can't read for comprehension, this engine is not designed to propel a craft DURING liftoff, only from orbit to somewhere else.
these idiots just raise the signal to noise ratio on slashdot too high, I really hope you are not voting next week.
Hm, usually people point to schools when they propose cancelling science projects. You seem to refer to greater U.S. dominance and world peace as goals. Make up your mind, are you a left-wing loonie or a right-wing nut?
Shutting down free speech with violence isn't fighting fascism. It IS fascism!
DAMMIT! Please mod this person DOWN! I posted the Coral Cache link SPECIFICALLY SO NUCLEARSPACE.COM WOULDN'T USE UP THEIR BANDWIDTH. Bruce wants this article distributed, but he doesn't have that much bandwidth! It's just a teeny little non-profit site on a single box, and now you're destroy it!
Javascript + Nintendo DSi = DSiCade
I am absolutely sure that everyone that drives a large SUV has a 3/4 inch long penis.
Even the women? *shudder*
I'm not a rocket scientist, or I'd have something more informative to say.
I did skim over the Wikipedia article, though, and I was curious -- the impression given is that these sorts of rocket engines can't escape Earth gravity and would have to be put together in orbit (again -- going strictly by Wikipedia article on subject).
I have 2 questions. First, if you build it in space, and you make it to Mars, would you have enough thrust in the lower gravity of Mars to lift off again with a full payload, say, of people and Mars rocks? Would a Mars lander be required with conventional rockets to get back to a control vehicle?
My second question is -- how the hell would they put this together at a reasonable cost in space? The Russians blew the hell out of their Mir space station at least a few times. And I seem to remember that the new ISS crew nearly rammed the hell out of the space station when they hooked up with the station last week. Feel free to pile on with other minor news stories about lost tools, broken this and that, etc. with the ISS.
And you want politicians with money from taxpayers to approve funding for NASA to build something "nuclear" in orbit with this kind of scary news history? I have full faith that NASA or an international consortium could make it work, but what about Joe Public, the environmentally-motivated voter, who fears a mushroom cloud screwing up astronomy night for his kids?
Finally, and this is most important -- with this nuclear rocket engine, would the guy from Sliders and Gary Sinise be able to save Tim Robbins before he burned up in the Mars atmosphere?
IronChefMorimoto
You simplify this too much. The public tends to fear nuclear power because very specific groups spin nuclear power as the evil demonic force opposed to mother nature. These same groups often use nuclear power as fear-leverage in politics. "Gasp! They want to open up more evil nuclear powerplants and refineries that pollute and readioactivate! Don't vote for them or your child wil grow up with 5 arms! Nuclear waste spill across the highways and nich impreganable underground containment will leak into the ground water, killing us all in several thousand years assuming our technology doesn't advance whatsoever from this point forward. Fear teh nuk3z!"
It's simple to say the public fears it. It's important to know who is driving that fear.
You need a FREE iPod Nano
And it's radioactive, you say? That explains it!
Sometimes seventeen/Syllables aren't enough to/Express a complete
You might want to RTFA then, because it's actually quite fascinating. The engine is designed for reuse, and can even produce ship power while "idling". Oxygen afterburners allow for the engines to produce amazing amounts of power for very short periods of time. Basically, you could build a Mars taxi with these engines. Don't waste your ship, just dock it in LEO when you come back, then send the next crew to Mars. :-)
Javascript + Nintendo DSi = DSiCade
I just use a pencil sharpener.
Assemble the ship in orbit, then fire the nuclear propulsion. Radioactive atmosphere problem solved!*
*completely disregards accident involving transporting reactor/fuel to orbit. But what plan is 100% safe anyway?
That's right. All your base.
Burning coal puts 25 tons of bomb grade Uranium into the air every year and I forget the exact amount of U238. The U238 gets hit by high energy neutrons from cosmic ray impacts and changes into
Launching a little dab of Uranium under highly controlled conditions doesn't seem like such a big deal when you know this fact.
I am very easy to get along with, but I don't have time to waste being nice to people who are being stupid. -Theo
I have it from two reputable sources, one at 742 Evergreen Terrace and one at 1600 Pennsylvania Avenue:
It's pronounced Nuke-you-ler.
Sheesh!
You're right. Building an intriguing project that could get large amounts of public support and is based around a safe and efficient freakin' nuclear reactor has nothing to do with energy.
Sounds to me like the focus is exactly where you want it to be, albeit not (yet) in the form you're asking for.
Dewey, what part of this looks like authorities should be involved?
I think you're all forgetting that if we do build a rocket with a nuclear reactor we're NOT going to be using old-style nuclear reactors.
:-) Reducing the travel time to six-seven weeks has one huge advantage, namely that the amount of space needed for consumables for the astronauts will be drastically reduced, saving considerable weight on the spaceship itself.
We will use the so-called pebble-bed reactor, which is designed to be inherently safe even if the coolant flow is cut off. Also, pebble-bed reactors are quite a bit smaller than the original reactors used in the NERVA program.
The big advantage of a nuclear rocket is that instead of a big burst of power then a long coast, it will just be a steady output of power running for extremely long periods of time. This could mean instead of a six to nine month trip each direction between Earth and Mars we're talking six to seven weeks transit time!
but there are plenty of highly educated nuclear scientists and technicians that pronounce it "Nuke-you-ler." Don't ask me how I know :-)
Not the National Model Railroading Institute, but Nuclear Magnetic Resonance Imaging.
It seems the general public was frightened by the "N" word.
Chip H.
I should be a joke, and a good one, but sadly over the past few years I've actually met people who honestly believe it was a hoax. Sad.
Figuring they have a 'gallon' of nuclear fuel onboard, we can do some cals. Please note that this craft would make 1 round-trip before being reworked, we can't really say if the craft would do multiple trips without being 'refueled' for engineering sakes. So that 1 Gallon might actually be able to make multiple trips. But we wouldn't know. It's like a super efficient car that needs to be overhauld after each week of service. Anywho...
So, taking some rough calculations into effect:
Nuclear 'gallons' of fuel = 1
Distance from Earth-Mars on a good day = 35 Million Miles
So, for a round trip of 70 Million miles, we expend 1 'gallon' of nuclear fuel.
That means, your souped up Nuko-rocket gets a measley 70 Millions Miles per Gallon.
This is simliar to saying that you purchased a consumer road vehicle that gets an astonishing 3000 miles per gallon, but the car cost you in the neighborhood of $14,000,000 dollars.
Kinda stinks either way.
you had me at #!
I guess firing off a few of these is just increasing the market value of non-radioactive steel. Time to do some salvage!
People have almost died by choking on it! People could contract terrible diseases via it (look up "rat parts per million" if you're curious and don't have a weak stomach).
The acceptable rate of death via Breakfast Cereal is certainly acceptable.
-Jesse
Nothing says "unprofessional job" like wrinkles in your duct tape.
Sounds an awful lot like the "no one will ever need more than 640K of RAM" statement. 50 years is a long time for technology.
We won't do that as long as gas is cheap. It's cheaper than anything else out there. Once it goes up to 6 or 8 bucks a gallon, other energy sources begin to become competitive. Of course, we've also been paying for that cheap gas with blood for a while now, but people don't seem to realize or care about that. If they did, there'd be a lot fewer SUVs on the road and a lot more bikes and hybrids.
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
I read about half the article and still was having a hard time making sense of how it works. I have a pounding headache now.
Or it could have been the beer and tequila at the Cardinals rally last night. I'm not sure. It's a toss up.
_damnit_
It's my job to freeze you. -- Logan's Run
what do you mean will "we" rise to the challenge? chances are most of the people reading your post are not going to rise to any challenge of developing new rockets. they will more likely be bribing an 11 year old to buy their sailor moon dvd for them so as not to be laughed at by the clerk in the mall. (including me)
I thought graphite was being used as a neutron moderator for the reactor, not for heat transfer?
What a crackpot.
Anyway, you are suffering from the misconception that uranium is a problem from a radiation viewpoint. It isn't.
Finally! A year of moderation! Ready for 2019?
Why couldn't they just use booster rockets to handle the "high gravity" moments (escaping Earth's atmosphere...)? Isn't that, for the most part, what is done with today's Shuttle?
If the vehicle in question is too large, then it needs to be build in space, anyway.
Cheers,
- slackerman
"...The smart and lazy ones I make my commanders." - Erwin Rommel
I must have a very dull imagination, though: since there's already uranium scattered over Texas, the most exciting thing I can think of is that some uranium fuel might fall on someone and smash their house. I can't even figure out how that one would happen, either, since nobody would be bringing the fuel back down (when the reentry vehicle might fail over populated areas), they'd just be sending it up (when the launch vehicle might fail over ocean).
Relax buddy
Noticeably
Untested
Kinetic
Yellow
Undercarriage
Low-Riding
Antigravity
Rocket
Do some google searches people!
We have already had nuclear fallout from rockets that malfunctioned. Both the (previous) USSR and USA have had fallout hit our citizens from nuclear payloads.
There was something about this on the History channel the other day.
Do such containers exist? If so, then why haven't they been used to solve the nuclear waste disposal dilemma (ie: where the hell do we put this stuff?)
I am the maverick of Slashdot
Oil and the trouble-some source of where we buy it (Middle East) is a BIG problem. I'm tired of dealing with that part of the world because we are so dependent on oil. I'm dependent on it too and I'd gladly trade in my SUV and sports car for something that ran on a compeltely alternative (hybrids still need gas) source of fuel, hydrogen perhaps?
How much $$ are we spending on the war? Oil is the root of a lot of problems today, and this country and the world itself, needs to find another source of consumer energy.
I'd risk driving around with a nuclear reactor in my car if I didn't have to hear about the Middle East anymore.
While your response is poorly written and borders on completely incoherent, you're absolutely right.
You really might want to work on the spelling and grammar. People will take you more seriously in the future.
Boycott everything - they're all trying to fuck you one way or another
To hell with plant failures.
You of course convienintly forget about the waste disposal problem. Including up to the entire plant after X number of years of service in which huge sections of the plant has become radioactive from use.
There is still tons of radioactive waste material sitting at nuke plants the world over because there is still no acceptable way of disposing of it.
These plants were built at a time when no one knew how they were going to dispose of it, the idea then was "by the time it becomes a problem, we'll think of something" well 30 years later... we've thought of nothing. (Well there have been a few hundred half-baked suggestions, none of which has passed much serious inspection)
How about taking care of that one little (giant fscking...) problem before we go off half-cocked again and double or triple an already daunting problem shall we?
Haven't you heard? The "clean coal technologies" are the future! LOL! This is the most irritating commerial of the entire presidential campaign.
When will the gov'ts step up to the plate and actually fund fusion research? The problems with the test reactors are now well known (size being one). Why not just spend some money and build a prototype of a *real* fusion reactor. Something that actually *produces* energy on a sustained basis.
Having a fusion reactor solves not only the energy problems. It also solves the nuclear weapons problems. There would not be an excuse for countries to start building fission reactors or mining uranium if fusion is available unless their goal is to build nukes.
The 15000 pounds figure is actually the low end of the estimate for one of their three operation modes - the engine can also be used just to supply electrical power for ion drives (much lower thrust, more efficient) or with an "afterburner" of LOX added to the hydrogen (45,000-60,000 pounds thrust, less efficient).
60,000 pounds thrust isn't nearly enough to be useful as a launch vehicle engine either, though. The only possible use in ground-to-orbit missions might be as an orbital tug: a chemical rocket puts your satellite in LEO; the nuclear rocket docks with it, moves it to GEO (or whereever else you want), then comes back for the next satellite. Even that's kind of a stretch.
However, you got the patents on the Rocket and the Airplane.*
Obscure Richard P. Feynman reference. Hopefully some on slashdot will get it.
Try to hack my 31337 firewall!
i would like to read this article but it is dead dead dead.
What newsroom? Nuclearspace.com is the personal rantsite of known space fetishist Bruce Behrhorst, space forum goon extraordinaire. And absolutely none of his claims can be backed up by the P&W web site. Maybe you should call them instead? Ask them about their Triton nuclear rocket. See what they say.
If guns kill people, then CmdrTaco's keyboard misspells words.
n the event of an explosion during liftoff, it would become the largest dirty bomb ever conceived.
WRONG! We have launched rockets and satelites using nuclear reactors that blew up during launch. We had the material safely contained in a case (ready to use without any modification at all for power) and it survived the explosion and impact when it hit the ocean/ground. It was re-used in a later satelite. We have ALREADY built containers that can survive explosions so THIS IS NOT A PROBLEM.
Fly me to the moon Let me sing among those stars Let me see what spring is like On jupiter and mars
Note that the engineering term "intrinsically safe" has a substantially different meaning than "inherently safe". Although the terms are used interchangably by some, those who live by the "law of milspecs" never confuse the two.
In any case, it'd be wise for P&W to rename it something other than a nuclear engineer. That's dumb marketing. Hell, they don't call the Army's M1 tank the "nuclear tank", despite its use of depleted uranium.
And anyhow, many jet engine parts use radioactive materials for hardness and during the manufacturing process. This is not news.
Most of the solar system is toxic anyways. When they're done they can throw it at the sun.
I guess some people might be upset because its not an oil based product.
Honestly, how does this crap get posted?
VASMIR seems like a far more generally useful form of space propulsion. The basic premise is the use of radio and magnetic fields to accelerate propellants. Its also inline with the general plan for societal advancement. It is rooted in many of the same technology we'd use to build Fusion reactors, relying upon superconductors, magnetofluid-dyanmics and plasmas. It was derived from plasma manipulation techniques discovered in fusion experiments.
Whereas a nuclear rocket will aid one given form of space travel: moving to mars and back, VASIMR systems are useful from launch to interplanetary, using extremely dynamic engines which consume virtually neglidgible reaction mass (aka fuel). They do, however, require a power source, which could well some nuclear variety, particularly for takeoff. VASIMR's fuel is hydrogen, which is a) readily available anywhere in the galaxy (including mars) and b) the most effective radiation shield we know.
This guy said one nuclear engine should cost about $1 Bil to produce. ITER is estimating $10 Billion for the first working Fusion power plant and will indirectly aid useful space travel more than a nuclear rocket. The ITER project aims to create a 500MW sustainable power plant. Compare this to JET, our current Tokamaka, which bursted at a world record 16MW. Yes, this is an apples to oranges comparison.
We need to stop dumping cash at quick easy bandaids to solve the next problem and begin evaluating our long term priorities as a society. We are wasting money on a hydrogen economy which will make coal plants burn the fuel our current cars would be burning anyways. We are wasting money building nuclear rockets. There is an energy crisis at hand and a environmental problem looming. We need reknewable resources. If we're going to be dumping billions in to space flight again, we might as well research two things which will go hand in hand.
Harness plasma. Make fusion go. Learn how to D-T react, and then get D-D reactions as fast as possible. Miniaturize.
Finish cleaning up the mess your old toys made before you ask for new toys.
Then it might be a bit easier to convince the public that new applications of nuclear power are safe and cost effective.
The primary craft would remain in Mars orbit. There would be a separate landing craft for traveling between Mars orbit and the surface.
"how the hell would they put this together at a reasonable cost in space? The Russians blew the hell out of their Mir space station at least a few times. And I seem to remember that the new ISS crew nearly rammed the hell out of the space station when they hooked up with the station last week."
They are working on this problem right now:
http://www.wired.com/news/space/0,2697,65272,00.h
Whenever the offence inspires less horror than the punishment, the rigour of penal law is obliged to give way...
...or they might really freak.
If an 800,000-mile ball of nuclear fusion sitting just a few light-minutes away isn't enough to scare the bejeebers out of anyone, I don't know what is!
-- Slashdot: When Public Access TV Says "No"
The main reason that people fear nuclear technology is because our leaders (yeah, the fools we elect) are too damn short-sighted to understand the implications.
Let's see - we intentionally nuke our troops (even though we knew what it would do to them). We expose people (who are poor and black) to hazardous radiation, just to see what it would do to them. Rather than concieve of a way of make nuclear power stations safe, we just say "store it off-site, someone will let us bury it near them". And on and on and on.
There is nothing demonic about nuclear power. It is what runs all life on this planet (you can see it - it's this giant ball that's very, very bright). What is demonic is how it seems people progress from "oh, this would be good for humanity" to "oh, this would be great to wipe out those folks that crack the eggs on the wrong side".
If you disagree, look at what our leaders fear... others with nuclear power.
IANAL, but I've seen actors play them on TV
i am sorry but your method of thinkingg is the problem, not the 'common man' worried about chornobyl 2.
as soon as the 'geek community' wakes up and realizes that it has to respond to peoples concerns legitimately, and not just as an excuse to 'get their geek on', or build their new toy.... at that time is when nuclear will really come into use.
until then, we cant trust you, we dont trust you, we shouldnt trust you, because of what you have done in the past, and your flippant attitude towards human life.
and fortunately, most real nuclear scientists agree with the 'common man'.
you are rude, arrogant, and blow off legitimate concerns. nuclear reactors have had many accidents in the past, even after the public has been told hundreds of times by people just like you , using language just like you use, that there was nothing to worry about. thats what they told people in the soviet union, thats what they tell people at 3 mile island, the bikini atoll, and on and on. and its not just nuclear. its places like love canal, or erin brokovich.
you keep yellin about the 'dumb people' who dont trust you. sorry, but why should they trust you? you and your kind have lied so many times before, or been mistaken. your memory is short. the peoples memory is long.
unfortunately, you do not care about history, or about any of this. you just want to light your candle.
fortunately, we live in a democracy, not the old soviet union. so the people have control over nuts like you.
what kind of crack are you smoking?
freedom of speeh does not come from capitalism, nor does freedom of assembly, freedom to choose politicans, freedom of press, freedom from oppressive government police system, etc etc etc.
there are plenty of 'capitalist' societies where there is no freedom. especially when you consider things like capitalist monopolies. british east india company? now we have multinational capitalists who can override governments trade laws, laws which are made by legislators who are elected by a free people.
absolutely none of freedom comes from capitalism. i dont knwo what you have been eating but you need to try a nice little diet of a history book. capitalism has often been an impediment to freedom. ever heard of microsoft?
While this may be an improvement on traditional rocket designs, it still has one major flaw for distant space travel:
It needs a propellant.
That's right boys and girls, if you want to travel long distances on this rocket, you'll need to carry a lot of propellant - most likely hydrogen.
We need to work on non-propellant based propulsion if we are to ever get out of our solar system.
Oh yeah, we also need to work on the speed of light thing as well if we are going to get anywhere in our galaxy in a reasonable time.
-ted
Actually, I think we *have* thought of something, called the Yucca Mountain National Storage Facility.
Why is it that the media complains when we want to transport the fuel from the nuclear power plants to the storage facility, but it won't complain when the same highway and railroad networks are used to deliver fuel to the plants?
It's pronounced it nu-q-lar Mr. Senator. Message approved by, GWB
AKAImDopey wrote:
Will we rise to the challenge?
It seems someone is straining to slip the bonds that "tie" him down.
Somehow I don't that is a "rocket" in your pocket, so maybe you should cool your jets.
No.
When will people learn that 300 million people can have more than one focus.
Patrick Doyle
I mod down every jackass who puts his moderation policy in his sig. Oh, wait a sec....
then when people say we aren't ready, we can go over the checklist:
do we have a way to get there? (check, engine)
do we have a way to come back? (check, engine with scram for fuel reload)
are we physcologically ready?
enough food?
etc, etc, etc....
these ideas are great, I'm not scared that people are having them. I would be scared if they stopped!!!
This is completely false. This is not a sig.
Dumbass
With this new engine, it seems that an inexpensive trip to Mars is now firmly within our grasp. Will we rise to the challenge?
Define 'inexpensive'.
"Anyone that has ever gotten an idea based on any of my work and done something better with it-good for you."--J.Carmack
Lisa has a rocket with a message tied to it that breaks into Mr. Burns's office and lands in his suit
Burns: I've got a rocket in my pocket.
Smithers: You don't need to tell me, sir.
I'm not sure whether you're ignorant, illiterate, or just a dumbfuck, but please fix whichever it is before posting again.
Reality has a conservative bias: it conserves mass, energy, momentum...
I think that most of our ideas are that we'll become rational about it at some point and either recycle the waste for usage in the then current reactors or actually dump it in a subduction zone, probably some combination of the two.
It's not really necessary to wait until the stuff reaches ambiant radiation levels.
I don't read AC A human right
Death reports for coal
Indeed, which is why I propose we build one of these plants in your back yard. You can put your money where your mouth is.
Actually it'd be more like you putting your money where my mouth is, as you'll be buying power from the plant where I work in that case.
I don't read AC A human right
I have full faith that NASA or an international consortium could make it work, but what about Joe Public, the environmentally-motivated voter, who fears a mushroom cloud screwing up astronomy night for his kids?
The people who are scared about a mushroom cloud resulting from this venture are unlikely to care enough about astronomy (not to mention rationality) to even have "astronomy night". They're more likely to be planted in front of the TV watching moronic reality programming and "news" broadcasts that have about as much intelligence and substance as the latest Danielle Steele novel.
God ! i wish i had Mod points now. I would have modded you up...
"Doing what i can, with what i have." ~ Burt Gummer
Well, you posted this article with a link that does not work. If you do not want people to go to the real source maybe you should have anticipated the demand /. will bring and made other plans.
Otherwise stop your bitching. I want to read the article, and am too lazy to find it myself. But since you have posted quite a bit of the comments on this thread you are apparently a god, one who likes to whine like my six year old daughter.
Ah hah!
See, this Batman dude is a bud with the author of the article. No wonder he's so enthusiastic. And Hemos?
Hmm.
So what's the deal on the pro-nuke scam on Slashdot anyway? That's pretty lame.
You encapsulate the burnt fuel in ceramic modules, and dump them into tectonic subduction zones. Fairly cheap, fairly simple, and very safe.
I think Gas Core is the way to go. As the article mentions, a solid core reactor engine is expected to have a specific impulse of only 800-900 seconds, compared with 1500-2000 for a Gas Core engine of the closed loop type (no radioactive emissions). This translates into heavy lifting capability. As the article says, the solid core engine weighs to much it is only useful for vehicles already in orbit, so it would have to be lifted up in pieces by other ships. For really grand-scale work, like putting factories and hotels into space and hauling significant loads to Mars in a reasonable time, we need the big kahuna lifting power of a gaseous core engine.
Here is a highly detailed 12-part article that discusses a Saturn-V size gas core rocket that would lift a payload of 1000 TONS from the ground to orbit and return with an equal payload to a powered landing. Skip the first 5 parts (author's justification of why to build it) if just want to know how it works.
Kudos! This is the first post that makes sense. Oil Peak is just a few short years away. Pretty soon all space missions will end if a solution to oil isn't found real soon.
However, I am on the pessimistic side that we will not be able find a solution to oil. I've looked at all of the alternative options and none of them can remotely replace oil. At best we can convert all Ngas and Oil fired Electrical Plants to Fission Plants or Coal, where fission is vastly perfered over Coal because it produces no CO2 emissions. CO2 sequesting might work on the small scale, but it can't work on global or even national scale. The only major draw back to fission is long term storage of contaminated materals (liquids, clothing, equipment that becomes exposed to radioactive materials). Fuel Rods could be permenment contained in fused glass, but are probably more valuable if recycled. As it stands Fusion is a Pipe Dream. I would want to gamble on a fusion breakthrough anytime soon. Plus Fusion still would produce some radioactive waste anyway.
Alternative Fuels are complete failure. All current alt. fuels are made by buring oil to distill or refine them. Biodiesels or other synthetic oil based fuels also need large supplies of hydrogen which costs a heavy premium to manufacture. The Canadian Tars Sands project (oil from tar sands) will never be able to meet current demand, because of time and expense required to extract and refine fuels from these deposits.
Hydrogen is not a feasible as a tranport vehicle fuel because it is explosive, a very bad green house gases, and requires a substantial volume compared to gasoline and diesel (has less energy content per cubic meter). Fuel Cells won't work because there is insufficient availablity of precious metals, required for manufacturing them. Only the very rich will be able to afford Fuel cell powered vehicles. Hydrogen production also requires vasts amounts of energy if its produced from renewal resources.
We also use Oil for agraculture (fertalizer). The last study done in the 1970's shows that one calorie of food production consumes about 10 calories of oil. Oil is used every Manufactured good that uses Plastics (which is just about everything today). The list goes of issues goes on and on. The bottom line is that when global oil production goes into terminal decline, our living standard will fall drastically and there is a good chance that WW3 will break out as world's leading economies battle to get the last few drops.
I've also been discovered that the Middle East probably has far less oil than they're reporting. Back in 1987 OPEC switched to a quota system. Over night all Opec nations had doubled their proven reserves in order to increase production (Quotas were bases upon reserves). Despite 17 years of heavy oil productions their reserves have not fallen below their 1987 estimates. OPEC would have you believe that Oil is a renewable resource. Amazing!
Sooner or later the news will get out. There are only a few new Oil projects in the pipeline to increase global production. Two come online in mid 2005 and three in 2006, only one in 2007, and no new projects beyond 2008 (It usually takes 10 years of planning to develop new fields). Its unlikely that beyond 2008 production will keep above demand. Oil Companies are no longer investing in new discoveries. Most are buying up the smaller fish that have oil and other are simply dumping record profits into stock dividends. Is the Oil Industry telling us something here?
This year's rise of Oil is only the begining of issues with oil. China has gone from a Oil Exported in 2000 to the second largest Oil importer (the US is number one). If Demand from China and India does not decline, the demand for oil will exceed oil production and prices will continue to rise. High oil prices will likely triggler a global recession, which in turn will cut demand. Its possible that a global recession could hide the oil problem for a decade, but that depends on how deep the recession becomes.
"and have even solved the graphite ablation problem!"
Wow, can long-lasting space pencils be far behind?
(I'm getting really tired of my pencils evaporating into the vacuum of space.)
-- thinkyhead software and media
True, but it does accomplish decoupling the power source from the reaction mass, which is definitely a step in the right direction.
Reality has a conservative bias: it conserves mass, energy, momentum...
You dont need a mushroom cloud to cause immense damage.
Imagine a failed rocket spreading a few kilograms of uranium for miles around. Thats a very dirty bomb
(MOD PARENT DOWN)
More proof moderators are sheep.
I think in the early 60's, NASA and the Air Force were considering building or built a nuclear powered variant of the B-36. If anyone has any links with information about this project, post away, I'm interested, just as a comparison. My guess was that it simply used a PWR with the steam driving turbines in the engine pods to provide power to the propellers. I'm sure the greatest challenges were cooling and weight, but the benefit would be practically unlimited range.
It's pretty safe to say that the likelihood of a nuclear reactor crushing into a critical configuration despite the normal measures taken to keep it "off" (neutron-absorbing control rods inserted, etc) is vanishingly small. In that you are correct.
In a gun design you only need to move one mass. This only appears to be feasible with U-235. Faulty thinking; the temperature and radiation (which turns the bomb core into high-pressure gas and pushes it apart again) are caused by the reaction; they are not separate from it.One point you appear to be missing is that the nuclear reaction takes a certain amount of time; neutrons are not infinitely fast, nuclei do not fission instantaneously, the exponential change rate of the reaction (whether growth or decay) is controlled by the composition of the material and its geometry. The geometry controls whether a splitting atom has a > 1 or < 1 probability of causing another fission. If the probability is >>1, you've got an explosion in progress; if it is < .5, you've got a lump.
The goal of the bomb designer is to turn the sub-critical mass into a prompt-supercritical mass before a chain reaction can begin and take the mass apart again; to this end they design implosion mechanisms and neutron generators to make everything happen when desired and not a microsecond before. The goal of the reactor designer is to make certain that the chain reaction is always under control. We can see that this isn't overly difficult; even Three Mile Island had a nicely-controlled reaction (its problem was lack of coolant), and only the Russians appear to have been careless enough to have a major incident (and without any containment building either, tsk tsk).
Sustainability and energy independence essay
in fact, i'd say mars is way too short-sighted, i want to see probes going into deep space to find our alien friends :)
Seriously, though, NERVA was always a good option for space travel - it's not as though you can 'pollute' space with radiation, as it's already full of the stuff. The only problem was that NASA tested it in the atmosphere, where people could rub their chins and go, "Y'know, is spewing all that radioactive reaction mass directly into the air a good idea?"
Maybe we've finally found an actual, worthwhile use for the ISS: assembling NERVA drives in orbit! If nuclear rockets were good enough for Moonbase Alpha's Eagles, they should be good enough for any half-assed, budget-strapped, politically-crippled interplanetary craft that gets developed in the next 25 years...
You must think in Russian.
Through in your sabots!
_____________
Huh?
Unlimited growth == Cancer.
Once it got there it wouldn't hang around long; Pu-238 decays into U-234 with a half-life of less than a century. Ten thousand years would see it gone.
Sustainability and energy independence essay
YES! (they're all fake, didn't you know?)
Don't flame me for saying the engine in the article is for in-orbit use only. That was based on the Wikipedia article.
The Pratt & Whitney engine looks like a very interesting concept, still underpowered compared to a gas core design but at least do-able right now. They talk about a 180 to 200+ day trip time to get to Mars. Gas core proponents think in terms of half that.
Sustainability and energy independence essay
In a nutshell, the Americans were afraid that if they armed the bomb before takeoff and the plane crashed, they would have nuked themselves.
So they made the decision to arm the weapon after takeoff.
Read more here:
http://www.acepilots.com/usaaf_tibbets.html
- dj
To reach earth escape velocity requires 11 km/s, to get to mars an additional 5 km/s (really really rough calc). Since the energies add, the delta-v required to reach mars orbit (it gets worse if you want to land safely) is about 12 km/s, so the vast majority of the energy to reach mars is expended leaving the atmosphere. A nuclear rocket could reduce fuel mass fraction to 50% (optimistic, but not overly so) which would reduce launch costs significantly - The launch fraction of the space shuttle is approximately 82%, with usefull payload being much less, and the space shuttle only goes to LEO (delta-v ~ 8 km/s less than half the way!)
Using nuclear rockets it is possible to buid practical vehicles for the trip to earth orbit. Much better technologies already exist for the transfer to mars orbit (where lack of atmosphere and freefall mean exhaust velocity is more important than raw thrust).
A schoolbus sized vehicle would only be twice as big as a regular schoolbus as opposed to the space shuttle's many times the size of a schoolbus despite its being functionally equivalent to a cramped one.
To the most important question, If the mass fraction is low enough, it may even be possible to bring significant amounts of extra fuel for crazy orbital maneuvers. or plan for a much shorter trip..
think space-swimming as opposed to space-bobbing_for_apples
In order to deploy it, you have to get it into space (using a conventional rocket).
The problem there sir is that if there is a Columbia type accident, you may have just created the world's largest dirty bomb.
Now some here have suggested that the technology exists to make the radioactive material safe enough to survive the explosion in one piece.
The question I think most folks are asking themselves is whether they want to take that chance. It's entirely possible that the radioactive material would not be spread across a wide area in the event of a rocket explosion.
I'm just not sure I'm on board with that belief.
- dj
http://www.nuclearspace.com/A_PWrussview_FINX.htm is correct link. Bush spends money on space, kerry wants to give the money to the poor.
I don't think I'll visit NASA that day to watch the lift off, the glow in the dark side effect is annoying!
Building ultra-high altitude blimps is within the means of technology we know how to do and materials we know how to make, and building blimps to go to high altitude carrying cargo isn't all that big an extension of this.
Like the Space Elevator, I see nuclear powered rockets for use within Earth's atmosphere as just another blind alley. Outsise Earth's atmosphere, they might be a good idea.
Tech Public Policy stuff
Remind me...HOW many nuclear subs are rusting at the bottom of the world's oceans?
They have got to have far more radioactive material in them than one of these rockets would.
On top of that, the Hanford nuclear waste dump up in eastern Washington has been leaching a radioactive plume into the groundwater - and into the Columbia River - for years now. Portland, OR and Vancouver, WA are two cities that have not been affected by this.
I thought they shoot rockets out over the Atlantic especially for mitigating these kinds of dangers. Let's get some rockets up there!!
A different user, but one with response to both false fears and nationalist agenda you have expressed. Severe difficulties with posting system, response in segments.
The supposedly legitimate fears you describe are based on poorly designed and over engineered contraptions that attempt to alleviate the faults of a poor design rather than correct those faults and the only partial decay of heavy elements that produces waste requiring hundreds of years rather than a few decades to decay to levels equal to background radiation. The joint project of Tsinghua University's Institute of Nuclear and New Energy Technology and Chinergy has developed the pebble bed reactor, using graphite sphere embedded with uranium, that is incapable of meltdown and will shutdown if excess heat is not carried away from it-cooling down on its own. This reactor will, within 10 years, be available in module form that can be easily shipped, assembled, and operated with a fraction of the requirements of fuel rod reactor the US Navy forced upon the US. Half-life of waste is measured in decades.
Precision manufacturing is not limited to a specific country, and manufacturing technology of the equivalent US 1940's is no almost the minimum for competitive production; nearly every nation can already make a fission bomb if that becomes a goal for any reason. Consider the actual reasons that the type of group you are implying would be interested has not acquired nuclear weapons-namely that they do not need them and for the cost much more can be accomplished using conventional attacks.
Aside, the US Army is more a high ranking terrorist group in the world. What else is called a mass of undisciplined youths that will beat prisoners, and assault or murder members of the civilian populace of occupied areas if they are not in the midst of continuous battle? It is the threat of invasion by this group that is a greater deterrent against a nation than its overt reliance on flimsy technological backing, and inadequate forces for the occupation of 2 or 3 nations at the same time over the long term. A quickly written response, excuse language errors.
there is already a nuclear testing and usage ban on earth and in space if im not mistaken. As stated before, P & W will probably have to change nuclear to something friendlier. Not only will the shuttle have to be launched from space due to radiation, but the shuttle would have to carry fuel to get off mars if they are hoping to land and not release a large quantity of radioactive materials on the planet. So far, i feel that the mag-beam propultion system http://science.slashdot.org/article.pl?sid=04/10/1 5/1223222&tid=160&tid=126 is a better sounding idea to people. Unfortunately its some ways off, but possible if only a few billion out of the hundreds of billions that the military recieves went to this program.
I thought what I'd do was, I'd pretend I was one of those deaf-mutes. - Catcher in the Rye
Useful site in English language, remove space: http://www.inet.tsinghua.edu.cn/english2/academics .htm
Um, no, that's not what I said at all. I didn't say anything about what the U.S. was doing. No statements tying this rocket to an energy solution. In fact I don't believe this rocket will lead to an energy solution. Let me be more clear ... The U.S. could have an energy policy as its primary goal AND have a manned Mars mission. This rocket could make a manned Mars expedition technically easier and more economical. An easier and cheaper mission is more likely to happen and would be one of many other things happening if we chose to have a primary national focus on solving the "energy problem." Sigh.
I hate to puncture all your Mars Mission fantasies, but I should point out one little thing to all you red, white, and bluers...
Your country is broke. Flat out busted, no money... Living on global welfare.
Trillions of dollars in debt with no real potential of every paying it off.
A third of your tax revenues goes just to pay the interest on the massive debt.
And....
Your country is addicted to war. You can't go ten years without sneaking off to some worthless third-world shithole to blow things up and kill thousands of people because they were just hanging around. You are a psychopathic people and you have been ever since you murdered most the natives originally in your land.
We had hope that you would get some kind of treatment for the national mental disorder. But it doesn't look like that will happen. We are not sure how long we can avoid bringing this problem of yours out into the open. We're not sure what to do about it either. Since you're violent and crazy it's usually best to pretend that you don't have a problem.
And...
Your political system is frozen in absolute corruption and you no longer have the ability to make the changes that you need to do to regain your health. By the way, this absolute corruption of your political system have led to select leaders that are certifiably insane. But they look good so we don't say much about it.
Therefore....
We caution you against to caught up into these Mars Mission fantasies. You run the risk of pissing off the people who are picking up the tab for your illusions and games. They might pull the plug on your reality-distortion machine. They might even cut off your medication.
Things could get ugly. You're nowhere as strong as you think you are. And your people are a lot dumber than they used to be.
Best just to let things continue as they are.
Helloooooo? In case you haven't a grasp on history, Bush won just barely half of the votes cast, when just barely half of the registered voters bothered to show up, or were otherwise dismissed by hanging chads and crap.
3/4 of Americans are against Bush, if we weren't complacent to begin with, he would have lost in a landslide.
So please (enter your country here) stop shitting on the rest of us because of 1/4 of the assholes who make up the balance of the US. We're on your side, but can't just casually grab every gun and march on the guy who's finger rests on a goddamnned nuclear trigger, let alone commands that military power everyone says is so powerful.
Sucks when a country the size of the US is expected to be able to overthrow a corrupt government like Chile or whatnot.
Just because you can mod me down, doesn't mean you're right. Shoes for industry!
Are they now going to nuke mars? Will we be responsible for starting first ever interplanatory nuclear war? Who is responsible if all marians die because of radioactive material that they would dump on mars to lighten up the return journey? Somebody stop these guys.
Just build a spacecraft with a very thick
lower metal hull, and explode a series of
nuclear bombs underneath. Guaranteed that
it would be a bumpy ride into orbit, but
just think of the payload you could lift.
You don't mention the many leaps of creativity that have been made in the pursuit of government mandated projects - from satellites to TANG to velcro. You comment implies that the government should not decide that something is the "Right Thing(tm)" to do, but our history has a long history of deciding things were the "Right Thing(tm)" to do:
- War of Independence
- Apollo program
- Vietnam War
- WWI/II
- Space Shuttle
- United Nations
- Eradicating Polio
- Invading Iraq
- Social Security
- etc etc etc.
I have deliberately made a list that include items that are inarguable worthwhile and some that inarguable worthless, and others that are debatable - the point is that inarguably, our government will decide somethings are the "Right Thing(tm)" to do, and do them. It is our responsibility to try and offer up possibities of what these endeavors might be.Arguing that the U.S. Is "(ostensible) a free market capilist coutry" is just an idealistic statement used to avoid debating the merits of the parents statement. As I mentioned it seems that the parents post has a fair bit of validity, and I think that it is deserving of a response of reasoned creitique instead of a miguided rant.
The person that you are responding to is talking about long term goals for the United States as we move through the 21st century. What I read a proposal from the parent advocating trying to free ourselves from dependence on foreign oil. The dependence that the parent is addressing is currently subsidized by our government and tax dollars in the form of wars and political clout. If it weren't for our dependence on oil, significantly less money would be flowing into the middle east, which would probabaly result in significantly less violence radiating from the middle east. In addition, providing for multiple sources of energy would help to prevent decreases in availability of one energy source would not have the ability to drag on the global economy, as oil currently is at $50+ per barrell.
I think that is is particularly ironic that the parent post was advocating redirecting some of our military expenditures towards a commendible goal that would potentially lift all the pies higher. Yet you are complaining about the parents "command-and-control utopia", when he is advocating moving our focus away from the military, the ultimate command-and-control utopia, and moving that focus to what are technologies that will free of us from economically and ecologically damaging energy sources.
First Falcon-1 to orbit, then Falcon-9. Then I can die a happy man.
I'm no expert, but I would imagine the problem set of making something that can survive high temperatures and a 200mph impact on the ground is quite different to making something that shields against radioactive particles for 20 or 100 or 1000 years.
Sometimes I wish there were an edit button, but I imagine the containers used for ferrying fissionable material up to orbit are nowhere near the standards of stuff dumped on earth, given the amount of gamma radiation that exists outside of the atmosphere, i'd assume the difference between 99% block and 99.8% block would be marginal.
Sustainability and energy independence essay
Why in Gods(or ahlah or what not) name are we not generating free electricity from those tons and tons of radioactive waste? (If something has value people tend to care about it)
So? any answers kiddies?
(Shake hands with beef)
(Tink Der4 U is....... Alien8ted
We all must band together against the asome power of cheese
You guys might want to tone down the quality of information in here..Or else the terrorists might win. And the government will shut down slashdot ;)