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Clean Nuclear Launches?
AKAImBatman writes "When it comes to launching millions of pounds of material into space, nearly everyone knows about the Orion Project. Blow up a series of nuclear bombs under your dairy-aire and ride the explosion on up. Unfortunately, the Orion spewed out so much radiation that it just wasn't a feasible launch option. If we want commuter trips to space, we're going to have to find another way. Well, it turns out that NASA's been doing quite a bit of research on Gas Core Nuclear Rockets, an ultra-powerful nuclear rocket that puts out almost no radiation. This research has spurred a fascinating new generation of ideas on reaching the cosmos. Could inexpensive cruises to the moon happen within our lifetimes?"
I think it's great that the we are still seeing innovation in regards to propulsion for space-bound vehicles. I'm especially excited about the new concepts used in the Vostok booster-like series that the Russian space agency is evaluating.
We're definately a long way from the V2 when some simple hydrogen would be ignited, and then Bob would be your uncle.
Radiation can be beneficial and should not be feared. Of course there will be some potential for accidents and some minor radiactive pollution, but it's all worth it in the case of scientific progress. We don't have clean water or clean air, and you don't city inhabitants rioting, or do you?
Could inexpensive cruises to the moon happen within our lifetimes?
I highly doubt it. As the last twenty years have shown, it's not the level of technology that determines how easily we get into space, it's the cost. And concepts such as these, while interesting to think about and develop, are ultimately going to take that many more decades to become proven.
Add to all this that the public would need a near-100% safety record in order to buy into a space tourism industry, and we're looking at more decades added onto the R&D and testing.
However, this kind of engine if developed properly COULD lower costs for putting satellites in orbit. So what's our benefit in the end? Lower satellite TV, telephone, and internet costs perhaps... But that's being optomistic.
But the design itself? Neat.
The environmental whackos go nuts (and let slip the lawyers of war) when you launch a totally sealed reactor, can you imagine what they would do if you wanted to launch something that *gasp* released radioactive gasses into the atmosphere?
Why is it that the proponents of "one nation under God" are so eager to get rid of "liberty and justice for all"?
There's a genuine safety issue with space elevators that ought to mentioned though, which is that if the elevator breaks, the part between Earth and the break point would act as a whip. A few thousand miles probably wouldn't be a big issue, but the closer to the end the cable breaks, the bigger, exponentially, the whiplash. A shockwave that destroys significant amounts of life on Earth isn't impossible.
You are not alone. This is not normal. None of this is normal.
The Project Orion guys believed they could make
the explosions clean and as small as they wanted.
This scared the shit out of them. They
puposefully did not pursue that line of
development for fear of weapons applications.
Ah, but that's the point of stories like this. Trying to explain to the public that *managed* dangers can bring tremendous benefits.
Javascript + Nintendo DSi = DSiCade
Where the reaction begins has no bearing on the danger the reactor poses; again, it's an education issue.
The danger in the event of catastrophic failure comes solely from a possible dispersal of the fissile material.
We have reactor designs now that simply can not result in the reaction going critical. It'd actually be much safer now than it was in the 70s.
The only reason you're not allowed to talk about these things, even to educate the public, is the same reason you're not allowed to promote nuclear power generation. It's simply career suicide for any public official to broach the subject.
Provided the radiation from their rocket stays at what the specs suggest, this is no more inherently dangerous than the operation of any of the dozens of nuclear reactors currently commissioned in the united states. (not counting nuclear naval craft)
The public's irrational fear of all things nuclear is the only opponent that killed nuclear technology. It has nothing to do with actual science or statistical risk.
// "Can't clowns and pirates just -try- to get along?"
You're quite wrong. :-) The Orion was originally intended for launches from some remote area. The nuclear pulsing could blast just about any weight into orbit, then take that same weight around the solar system. When various treaties banned the use of nuclear weapons on the ground, Orion switched to space only mode. Then they banned space-based bombs and Orion became a dead-duck.
Javascript + Nintendo DSi = DSiCade
The space elevator needs equal pull on both sides of the point where it would be at the same distance from Earth as objects in geosynchronous orbit. You can either do that using a counterwieght such as a large asteroid, or by making the elevator exceedingly long, about the same length on either side of that geosync orbit position.
Admittedly, the basic ground-to-counterweight-above-sync-orbit design has great potential. But there are other designs with less cost, extreme materials, and risk.
For instance: A section of cable in low orbit, spinning end-over-end so that each end periodically dips into the stratosphere at approximately the average local wind speed. Fly up to it, hook on as it goes by, and get lifted into orbit. Balance the momentum by bringing back a payload of space-mined material on the other end.
Build it so that if the orbit decays it will break up on reentry rather than crashing, keeping its own mass low enough that it won't create another Cretaceous event by spreading tons of red-hot debris throught the upper atmosphere if it comes in. (But if you get your spin right you can design it so that it tends to be pushed UP if the active guidance fails.)
Use a near-circular orbit if you want to lift a lot of payloads to near orbit (where you can use slower engines - like ion or light-sail - to achieve high orbit or escape), or an eliptical orbit for fewer payloads to a higher initial launch.
Lots of ways to do the active guidance:
- Control the spin with currents through the cable to electron guns and collectors at the ends working against the earth's mag field.
- Small attached light sails - For orbital elements, spin, attitude, AND killing vibrations.
- Ion thrusters ditto - and you can collect reaction mass each time an end dips into the atmosphere.
- Control, solar power plant, etc. at the center, which never enters the atmosphere. (Elevator/cable-crawler to get there from the ends.)
Lots of other systems are possible, too.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
It has nothing to do with the tonnes of nuclear waste produced for which the only solution seems to be "put it down a large hole, that'll do" then?
Or perhaps my irrationality extends to thinking that when the pigeons around the UK's nuclear waste processing plants are so radioactive they would be classed as nuclear waste themselves if they were inert. Internal contamination of the pigeons was found to be beyond safety levels set by the EC in the aftermath of nuclear accidents.
The problem with nuclear power is that it is made by humans and they have a habit of fucking up on a grand scale.
In theory it's all safe and dandy.
In theory, theory and practice are the same.
You should read some of the US Nuclear Inspectorate documents.
Our own inspectorate says that "British Energy's downsizing has seriously compromised nuclear safety."
I could go on and on and on. But you know that already.
There are places where the networks are not touching,and there are places where they are-Boeing's Lori Gunter
Actually, a SE makes a significantly better, safer and cheaper inter-solar-system-transportaion-system than dirty bombs. It's not just a tool to escape orbit - it can take us to other planets. That's what's so genious about the idea.
There are two reasons for making it 91000km long when all you technically need is 35000km.
One: because you need a very large and unfeasible mass at the top if you want to balance 35000km of cable hanging below GEO with a weight located, say, 1 meter above it. You need a significantly smaller weight at the top if you want to balance it at 91000km.
Two: (which brings us back to our point of discussion) If you go as far as 91000km, you can slingshot payloads as far as jupiter and its moons. If you build even higher, at 140000km you can get as far as pluto.
Of course, the first thing you'd want to send to your destination is a pre-fabricated and spooled SE to deploy there, so you can send stuff back...
-
The kind of stuff we have to deal with from nuclear power plants is nasty. WAY nastier than anything which comes out of a traditional power plant.
Which is why we have to figure out how to get the stuff into space cheaply so we can jettison it into the sun. No geology to think about. No tectonics or water flow, just pure fusion energy cooking the bejesus out of our toxic waste.
"Not to mention the fact that your average coal burning plant simply doesn't have the potential to cause a catastrophe on the scale of Chernobyl"
Not all at once in one place.
Coal and Petrochemical based air pollution has killed tens of thousands to hundreds of thousands at younger ages than they would have otherwise died, and cars and tobacco have killed TENS OF MILLIONS of people this century, and yet you think that the HUNDREDS of reactors in current operation in North America whom haven't killed a SINGLE HUMAN BEING yet - are a bigger badder threat.
Stupid dumb public. And they bitch like hell when we try and keep their asses in High School all the way through until grade 12.
Actually, going critical and melt-down are two different, yet slightly related events.
"going" critical: All nuclear reactions (not nuclear decay) are critical. In order for a self sustaing nuclear to occur, a critical mass of fissible material must be present. If the mass falls below critical the reaction will extinguish. Decay will still occur and generate heat, abliet much less.
Melt-down: A melt-down happens when a reaction goes out of control and produces sufficient amounts of heat to cause the core the liquify (melt down). When a core melt-down happens, there is not a damn thing on this planet (that I know of) that can the molten (and getting hotter by the second) glob that used to be the core.
It has been theorized that if this happens, the molten core will burn through the earth until it reaches water. Upon contact with the core the water will turn into steam and create what is in effect a steam cannon, blasing the core back up the hole and showering bits of the core for miles around.
Pure carbon nanotubes have the required strength-to-weight ratio. The only question is how long before we can develop a composite that binds CNTs together into a material that retains enough of the strength of pure CNTs. Steady progress is being made. Keep an eye on LiftWatch.org for regular updates on this and related techs.
Sometimes. Sometimes not. On my college campus there was a small (6 MW IIRC) nuclear reactor, used for instruction in the Nuclear Engineering courses. I took a tour of it once (I was in Chem E, not Nuc. E, so I never got to do any actual work with it) and heard an interesting story from one of the professors there.
They were doing a scheduled test one weekend of some of the safety systems, so they were expecting some alarms going off. One of the students walked in the door, and suddenly all of the radiation alarms went off. They got out their gear and traced it down to the student who had just walked in. Specifically, they tracked it down to his head. So they got a 55 gallon drum of water and started washing his head. After a little bit of that, the water was radioactive, but his head wasn't. After they were finished, he told them what he had done. He had gone to WalMart and bought a wick for a coleman propane lantern. He took some scisors and cut it up into fine pieces, and sprinkled it on his head (The wicks are coated with a chemical which gives it a cleaner, whiter light, and also happens to be slightly radioactive).
The amusing thing about all of this is the contrast between normal use and a nuclear power plant. 99.99999% of the coleman wicks that are sold are thrown away in the trash (or littered with near campsites) because they really are not a hazard to anyone, and no sane person would say they are. However, because he brought the one he bought into a nuclear power plant, the plant had to classify the whole 55 gallons of water as potentially dangerous nuclear waste, and they had to spend a fairly large amount of money to have it disposed of "properly". How much of the nuclear waste that's being encased in concrete and buried under miles of rock is more (or less) dangerous than what you can buy in the local WalMart?
Pound! Bang! Bin! Bash! is this a shell script or a Batman comic?
A lot of people claim that the reason why the US doesn't use nuclear power everywhere is because of environmentalist whackos. This is not true. The reason is economics.
Back in the 50's when nuclear power was first proposed, people talked about having electricity too cheap to meter. The thing they did not consider is that a nuclear power plant costs much more to build than a coal/oil/natural gas plant. I want to make sure everyone understands why.
First of all, the radiation given off by fission destroys inorganic materials just as happily as it destroys human tissue. Very high quality metal must be used in all parts of the reactor to prevent degradation and to prevent it from becoming highly radioactive. This is even more of a problem in fusion reactors which have a much higher flow of neutrons, and in those, the only solution will be to replace the pieces every so often.
Second, the plant must be extremely highly reliable. One reason for this is draconian public safety regulations. However you have to keep in mind that even an accident that is contained within the plant and poses no risk to the public (a la Three Mile Island) can still destroy the reactor and put the plant out of commission.
This is true because of a property of the nuclear chain reaction. Dropping all of the control rods (scramming) does not instantly shut down the reaction in the way that dousing a coal fire would extinguish it. The reactor will continue to produce heat for around an hour after it is shut down. This means that it must be cooled for that hour, otherwise it will melt and flood the building with radioactive chemicals. The Chernobyl accident was caused by an attempt to test what happens if the cooling system is disabled.
So the system has to be very highly redundant, in part to protect the public, but mostly to protect the plant.
The last problem is that if the coolant is radioactive, you can't just call in a plumber to fix the leak as you might in a coal plant. See the movie K-19 Widowmaker for the effects of radioactive coolant on humans. You better make damn sure that system doesn't leak in the first place.
So the plants are expensive. This means you want economy of scale and build one large plant instead of many small ones. This means you don't want to build these plants in the Midwest where that much power just isn't useful. You want to build them near population centers. That explains why there is no nuclear power in sparsely populated places.
The other thing is that even though uranium is much cheaper than coal per joule (because you need so much less of it), the cost of the nuclear plant makes the whole process expensive enough that it has to compete with coal for the market. This means that in places where coal is cheap (as in the United States) building nuclear plants is only sensible up to a point. As the nuclear plants drive down demand for coal, the coal gets cheaper, so there is a natural feedback mechanism.
In the United States, we are a little bit below the optimal balance. We could economically build more nuclear plants but not that many. This difference is in part accounted for by the public perception of nuclear power.
It is also accounted for by the fact that it takes ten years to build a nuclear power plant, so if you have an energy crisis NOW, building a nuclear power plant is no good. California had to go with building natural gas power plants after their energy crisis because they are cheap and fast to build. Natural gas is more expensive but that's life.
Now it should be clear why France and Japan, two countries that use nuclear power for most of their needs, are able to do so while the US cannot. It has nothing to do with progressive governments or the lack of environmentalists. It is simply that France and Japan are small, densely populated countries (compared to the US) that have expensive coal (compared to the US). So they have a lot of nuclear plants (compared to the US).
I hope that explains a few things. Now as