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I was struck by the comment in your article that NASA officials are confident that nuclear engines can be three times as efficient as chemical systems. Are we talking about nuclear thermal rockets with a specific impulse of 1,500 seconds? I had no idea that ISPs over 1,000 seconds were possible, unless one is using gaseous core fission.
-- RobS
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Hi NuclearSpace!
I knew that nuclear rocketry held great promise for big improvements in Isp (specific impulse), but your post here has really whetted my appetite! I didn't realise how much further potential there was beyond NERVA's achievements. Great stuff!
I remember seeing an article about the "straight through" Americium-242 rocket a year or so back. From memory, it was an Israeli team doing some research on it and there was talk of Earth-Mars transit times of two weeks. (I think I even mentioned it in these posts somewhere). I was delighted at the prospect of such an engine, but it seemed to just fade away and no more mention was made of it.
I seem to remember somebody raising the objection that Americium-242 is too rare and expensive to be a realistic fuel.
Is this true? (Hope not! )
???
The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down. - Rita Rudner
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Nuclearspace, we should post that fusion drive article over here! That's equally impressive.
I wonder if we could sythetically produce some of these nuclear fuels, as we can recycle fission fuels.
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NuclearSpace,
Any luck on getting that fusion drive article over here?
It still burns me up about NERVA being cancelled. Talk about possibilities! If it would've continued, we could possibly have a permanent presence on Mars, Moon, asteroids, and manned deep exploration. We would have over 30-40 yrs of actual nuclear power use in space. :angry:
One day...we will get to Mars and the rest of the galaxy!! Hopefully it will be by Nuclear power!!!
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The main problem with Americium-242 is the cost of producing it, Americium is a man-made element, and its half life in the ground state is only 16.02 hours. This would make it difficult to use as a fuel.
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Source: New Scientist.
19:00 22 January 03
The journey time from Earth orbit to Mars could be slashed from six months to less than six weeks if NASA's idea for a nuclear fusion-powered engine takes off.
The space-flight engine is being developed by a team led by Bill Emrich, an engineer at NASA's Marshall Space Flight Center in Huntsville, Alabama. He predicts his fusion drive would be able to generate 300 times the thrust of any chemical rocket engine and use only a fraction of its fuel mass.
That means interplanetary missions would no longer need to wait for a "shortest journey" launch window. "You can launch when you want," Emrich says.
The principle is to sustain an on-board fusion reaction and fire some of the energy created out the back of the spacecraft, generating thrust. Of course, harnessing fusion is no easy task. Scientists have struggled to contain the super-hot plasmas of charged ions needed for fusion reactions.
Bare nuclei.
To achieve fusion, scientists heat the hydrogen isotopes deuterium and tritium to at least 100 million kelvin. This strips electrons from the isotopes, creating a plasma of bare nuclei. If this plasma is hot and dense enough, the two types of nuclei fuse, giving off neutrons and huge amounts of energy.
Fusion jet.
However, the plasma can only be contained by strong magnetic fields, and creating containment fields that do not leak has proved very difficult. What is more, no one has managed to generate a stable fusion reaction that passes the "break-even" point, where the reaction is generating more energy than it takes to sustain it.
Fortunately for Emrich, the reaction would not need to go far beyond the break-even point to generate thrust. And containment is less of a headache because you actually want some of the plasma to escape, he says. "That's where the thrust comes from."
The problem is 100 million kelvin is not hot enough to generate thrust. At that temperature, the fusion reaction only generates neutrons, which are uncharged and therefore cannot be steered and fired through a magnetic jet nozzle. To produce thrust, you need charged particles.
Bold solution.
Emrich is proposing a bold solution. He wants to use microwaves to heat the plasma to 600 million kelvin, triggering a different kind of fusion reaction that generates not neutrons but charged alpha particles - helium nuclei. These can then be fired from a magnetic nozzle to push the craft along.
Emrich has tested the idea with a scaled-down version using an argon plasma. He found that he could get around many of the containment problems by using a long, cylindrical magnetic field with powerful magnets at each end (see graphic).
In a fusion drive, the fields at the end could easily be controlled to release the highly energetic alpha particles and propel the craft.
If fusion researchers can ever achieve stable, break-even fusion, Emrich believes a full-scale fusion drive - perhaps 100 metres long - could be ready and waiting within two decades. He will reveal his plan in full at a space technology forum in Albuquerque, New Mexico, next week.
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there, i made the effort to get it
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I knew that nuclear rocketry held great promise for big improvements in Isp (specific impulse), but your post here has really whetted my appetite! I didn't realise how much further potential there was beyond NERVA's achievements. Great stuff!
Shaun lives! I'm still somewhat in the dark just to what Prometheus is all about. I wonder if they really are going to bring back great nuclear programs like NERVA or if NASA will just stick to tamer nuclear projects. It seems to be something different to everyone. Anyhow great tagline.
To achieve the impossible you must attempt the absurd
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Hi Phobos!
I just got through saying hello to you over at 'Terraformation'. It's good to be back.
I've got a sinking feeling about this article describing a mission called "Jupiter Tour".
The nuclear-propelled mission 'by 2010', that everyone is hoping might be a crewed Mars mission with NTR propulsion, could turn out to be just a nuclear-electric version of 'Galileo'!
Please, somebody, tell me I'm worrying unnecessarily!!
The word 'aerobics' came about when the gym instructors got together and said: If we're going to charge $10 an hour, we can't call it Jumping Up and Down. - Rita Rudner
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Possibly not, Europa is sometimes considered more important than Mars as a place where life could form. It's very possible that we'd send a probe there to try to make a confirmation. An NTR could aid us with that quite nicely. If anything, NTR means more fast probes before it means human activity, at least initally.
Personally, I don't think that such a race is in the near term, because I think that China has its eyes set on the moon (and for good reason), so if we were to do anything, it would be to beat China back to the moon to set up a base and so on.
Some useful links while MER are active. [url=http://marsrovers.jpl.nasa.gov/home/index.html]Offical site[/url] [url=http://www.nasa.gov/multimedia/nasatv/MM_NTV_Web.html]NASA TV[/url] [url=http://www.jpl.nasa.gov/mer2004/]JPL MER2004[/url] [url=http://www.spaceflightnow.com/mars/mera/statustextonly.html]Text feed[/url]
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The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.
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i said to somebody else, i think its a $1 billion probe with $2 billion for prometheus research. "common costs" was the term he used.
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Josh,
Why do you say that "China has it's eyes set on the moon (and for good reason)"?
One day...we will get to Mars and the rest of the galaxy!! Hopefully it will be by Nuclear power!!!
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Well, I just don't see China participating in what we could call a nationalistic race somewhere. China isn't really like that. China has discussed before the importance of long term planning (indeed, you can read this approach in their Space Policy on the CNSA site), and I don't see them looking at Mars and going to Mars with a short term plan in mind; which undoubtedly, a Race to Mars would be, at least without proper space infrastructure existing to begin with, or massive ammounts of money. When China goes to Mars, they'd probably go ala Red Mars. No fancy one man landings for them.
China wants to go to the moon by 2010, and have a base set up within five years of that date. At China's current rate of space growth, such a timeline is fairly foreseeable. What we can pretty much surmise, is that China wouldn't jump on the Race to Mars bandwagon, since Luna is so close, and affords so much from a practical standpoint.
I've said before that Luna isn't a good place to colonize (it's harder to cut ties from earth), but certainly a great place to start a good business. And it is, really. Since it's so close trade would be much easier, and basic infrastructure could be built without totally new technologies. A month and a half long trip to Mars is still a lot longer than three days. Actually, with NTR's a trip to Luna would be much shorter, probably a few hours or so.
Some useful links while MER are active. [url=http://marsrovers.jpl.nasa.gov/home/index.html]Offical site[/url] [url=http://www.nasa.gov/multimedia/nasatv/MM_NTV_Web.html]NASA TV[/url] [url=http://www.jpl.nasa.gov/mer2004/]JPL MER2004[/url] [url=http://www.spaceflightnow.com/mars/mera/statustextonly.html]Text feed[/url]
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The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.
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I'm sorry if that post was one of my typical buzzword laden diatribes. The moon certainly offers a lot, though. I have to go work soon, but I can clarify what I meant.
Now might be a good time to read the Mars? Moon First. thread in the Human Missions forum. http://www.newmars.com/cgi-bin....=4;t=25
Some useful links while MER are active. [url=http://marsrovers.jpl.nasa.gov/home/index.html]Offical site[/url] [url=http://www.nasa.gov/multimedia/nasatv/MM_NTV_Web.html]NASA TV[/url] [url=http://www.jpl.nasa.gov/mer2004/]JPL MER2004[/url] [url=http://www.spaceflightnow.com/mars/mera/statustextonly.html]Text feed[/url]
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The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.
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I do believe that the Chinese space program is driven by nationalistic zeal, much as the American and Soviet space programs used to. It remains to be seen whether they will continue with missions to the moon after finally reaching it.
The challenge to the United States, obviously, is to prevent Chinese hegemony over the moon. From a standpoint of national pride, it is disappointing to know that we would reach the moon first but then abandon it so our Chinese "friends" could monopolize it.
Promtheus gives us hope that we, too, can return to the moon in the same period that the Chinese will go. Dr. Stan Borowski and his team at NASA-Glenn have investigated nuclear thermal rockets and lunar applications for them. An NTR shuttle would allow humans to fly to the moon within a day. The team developed this "LANTR" concept to show how an earth-moon infrastructure could be established, using NTR shuttles and lunar oxygen.
Someday America will be forced to go back to the moon. Hopefully, that day will be sooner, not later, and Prometheus will help us to get there.
"I'm not much of a 'hands-on' evil scientist."--Dr. Evil, "Goldmember"
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Hmm, I can't say I'm a huge China buff, but I think nationalism isn't one of their things. I'd have to ask my friend to confirm this, though.
I think the real challenge to the United States, is to act rational for once, and let people do as they will without desiring full control. I mean, China could be saying the same stuff about having to stop the US from having a moon hegemony! And in their case it could be a valid argument.
We in the United States have to face it, we can't control everything. We can't be the police for the world, or space, either.
Interestingly, China's space policy has all these nobal goals, about equal access and so on to space; and like it or not, the moon is a pretty big place, so it's not like they'd have reason to deny people or countries access*. I would honestly rather have China get there first and set up a moon base, before the US. Because then at least we could say, if China didn't allow equal access and had this monopoly over moon resources, militarizing everything, ?Hey, your space policies require that you give equal access! You can't go about policing everything!? With the US this isn't the case. US corporations make no promises, and often times it's in their interest to not allow access, since that could prove to ruin profitablity.
Now, if only I could get clark to make a bet with me that we'll return to the moon before we go to Mars.
* I could get in to this, but I'm not talking, ?free? resources or anything like that. I'm just saying, in a nutshell, if you can afford to get there and sustain yourself through whatever means, be it through trading with the other colonies and paying your way, or being autonomous, you get access. Although China does, in their Space Policy, advocate automony and self-reliance above everything else.
Some useful links while MER are active. [url=http://marsrovers.jpl.nasa.gov/home/index.html]Offical site[/url] [url=http://www.nasa.gov/multimedia/nasatv/MM_NTV_Web.html]NASA TV[/url] [url=http://www.jpl.nasa.gov/mer2004/]JPL MER2004[/url] [url=http://www.spaceflightnow.com/mars/mera/statustextonly.html]Text feed[/url]
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The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.
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You actually think China has a valid argument for "challenging American hegemony" over the moon? When a country has abandoned a place like the moon, it has lost all control over it. After all, territory must be defended if it can be held onto.
I support Chinese lunar exploration, I'm just saying that America should not back down from the moon after expending so much effort getting there in the first place. We must go back to the moon, for the sake of our scientific and intellectual growth as a society.
"I'm not much of a 'hands-on' evil scientist."--Dr. Evil, "Goldmember"
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I meant potential hegemony... I mean to say that the US has made no strict promises in the way of letting people do what they want (as long as it's not control everyone), whereas China has at least that goal in mind, and explicitly states that space should be free for all. That's all I'm saying really.
I would expect China to challenge the US a lot in the coming years, especially when they reach first world status without the US even realizing.
And I agree with you, the US needs to go back to the moon, this is why I suggest that a moon race will occur before a Mars race. If the US does say they want to go to Mars, China will shrug, and say that's okay, and go to the moon anyway. The US would have visted Mars, but China would have built a moon base. China then, assuming nationalism is their thing (which I don't think their history shows, but I could certainly be wrong here), could be proud by showing off their nice fully functional moon base, with rotating crews, perhaps a small colony, and some American hotels which rent out space within China's base!!
Hopefully by then, people like those in the Mars Society, and those within this forum, will have changed their goal from just going to Mars to colonizing Mars. And by then the infrastructure would be much much better. NTRs should be popular, and China's base could perhaps even become a fueling station.
Some useful links while MER are active. [url=http://marsrovers.jpl.nasa.gov/home/index.html]Offical site[/url] [url=http://www.nasa.gov/multimedia/nasatv/MM_NTV_Web.html]NASA TV[/url] [url=http://www.jpl.nasa.gov/mer2004/]JPL MER2004[/url] [url=http://www.spaceflightnow.com/mars/mera/statustextonly.html]Text feed[/url]
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The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.
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Having a chinese aunt, i can say without a doubt that youre wrong josh. the chinese are fiercely nationalistic, and anything they say about "free space for all" is political crap, at least until they move away from totalitarian oppression.
when a government sends people to work camps for published dissent, i dont think its a safe assumption that they would hold space to a different standard.
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Can you give an example of their nationalism? I just Google'd for Chinese Nationalism, and I can't say that it has changed my mind, really. I've yet to speak to my friend who knows much about Asian countries, but I stand by this assertion. But perhaps our definitions are mixed. In this context I define nationalism as the belief that your nation is superior to another. China does have a sense of national pride, but I do not think that their pride would extend to this petty attempt to beat someone to Mars.
We can get into a discussion about China if you want. Most of my sources come from the Beijing Review, though, so if you'd like I can transcribe for you. What I would argue, though, is that China is getting better when it comes to democracy and wealth, and so on. So their atrocoties (though I would argue not reflective of the Chinese people as a whole- as I can point out atrocities Americans commited which the majority would disagree with) aren't a fair indicator as to their motivations or allowances when it comes to space.
But really, nationalism isn't the central point I was making. I was suggesting that long term planning is above all else. And China has never really said anything about going to Mars. And I see no reason why they wouldn't abide by their Space Policy. The assertion that it's all political crap is dishonest. NASA has held to their policies (even though they've lacked funding or proper management), so there is no justification to suggest that China would not.
Some useful links while MER are active. [url=http://marsrovers.jpl.nasa.gov/home/index.html]Offical site[/url] [url=http://www.nasa.gov/multimedia/nasatv/MM_NTV_Web.html]NASA TV[/url] [url=http://www.jpl.nasa.gov/mer2004/]JPL MER2004[/url] [url=http://www.spaceflightnow.com/mars/mera/statustextonly.html]Text feed[/url]
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The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.
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no, you have completely missed the point. compared with the chinese, american attrocities are nothing. like i said, my chinese aunt experienced it for herself.
they are capitalizing their economy-but they havent really moved to democracy. this is an unbased assessment.
NASA and the Chinese space program are both government agencies. one government is based on freedom of speech, press, etc...and the other is based on the opposite: control, etc. why would this miraculously change in space?
the chinese are extremely nationalistic. especially with the boom in their economy, mainly thanks to capitlisim. nationalism is more than just a feeling your country is better. when i get home later, ill give some big examples.
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Okay, this thread is not going to be hijacked by a discussion about which country is more atrocious than another, because I don't think it's relevant to the current discussion. But if you want, go here http://www.amnesty.org/ and compare the countries directly.
They have moved very much in the way to democracy. This generation of China's children are being taught it. The same generation that will be going to the moon.
Hey, NASA has been quite fair to businesses and people in the past. If NASA did set up a base, I see no reason why they themselves wouldn't allow people to freely set up and so on (what I argue China would do). But NASA in its current state isn't going anywhere, and via American tradition, I suspect they would delegate the powers to corporations and so on, thus making it less likely that any old Joe could go up and set up anything they wanted. The point is that we can hold China to their Space Policy. We can't do that to the US.
One should note, that whoever controls a base anywhere is going to control you. It just depends on how you prefer to be controlled. Myself, personally, like the whole concept of self-reliance and independence. And China's Space Policy convinces me enough to think that I would have that with them. And if not, I can still throw it in their faces.
We are diverging from the central topic, though. The question is whether or not China will join the US in a race to Mars [before setting up a moon base first]. I argue that no, they won't, and that even if the US proposes we go to Mars, China will go to the moon anyway, because their policies dictate long term planning in mind. They would go to Mars, but only after they have convinced themselves that a proper space infrastructure was existing. Not before.
There will be no more Apollo-style missions, where we go, put up a flag, and come home. Climbing a mountain is fine and dandy and all, if you want to throw your superiority around or something. Climbing a mountian and building an observatory on top is what you do when you have true scientific interest.
Some useful links while MER are active. [url=http://marsrovers.jpl.nasa.gov/home/index.html]Offical site[/url] [url=http://www.nasa.gov/multimedia/nasatv/MM_NTV_Web.html]NASA TV[/url] [url=http://www.jpl.nasa.gov/mer2004/]JPL MER2004[/url] [url=http://www.spaceflightnow.com/mars/mera/statustextonly.html]Text feed[/url]
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The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.
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heh, you are very naive. go over to china and tell them about your freedoms.
the USA doesnt control anyone. we abide by laws, but control? look around the world, and see what control is.
yes, compare at amnesty. what happened in tibet is a tragedy. what they continue to do every day is too. children are not taught democracy--not by a totalitarian government. in secrecy maybe, but not in their compulsory education. they are taught money, not freedom.
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Um, so basically your argument is that China is socially bankrupt or something and so that proves that they will join us in a race to Mars, how?
Are we just diverging from the topic or not?
I'm not defending China's political structure even though that's what you're trying to get me to do (since you clearly don't have an argument as to why China would participate in some petty short term race to Mars).
Here's a link to what I was talking about, although a subscription to the Beijing Review has more about the issue: http://www.bjreview.com.cn/2001/CoverStory/FM200118.htm
I guess that's propaganda... lies, all lies. My friend tells me China isn't a good place to visit at the momment. He's quite knowledgable about Asian countries, so I see no reason to defend China on that level. I merely say that progress in that direction is foreseeable. And again, I say that because their Space Policy has the same ideologies I believe in, I can't disagree with it and would embrace it as long as I thought that it was enforcable.
But you really ought to get your head out of your butt with regard to China. (And stop hijacking threads while you're at it, unless you can provide a relevant correlation between China's atrocities and, um, their inablity to progress in to space with long term planning in mind.)
Some useful links while MER are active. [url=http://marsrovers.jpl.nasa.gov/home/index.html]Offical site[/url] [url=http://www.nasa.gov/multimedia/nasatv/MM_NTV_Web.html]NASA TV[/url] [url=http://www.jpl.nasa.gov/mer2004/]JPL MER2004[/url] [url=http://www.spaceflightnow.com/mars/mera/statustextonly.html]Text feed[/url]
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The amount of solar radiation reaching the surface of the earth totals some 3.9 million exajoules a year.
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