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Update on Project Prometheus
Aglassis writes "It appears that NASA is not backing down from their nuclear space initiative. Project Prometheus has recently started a new web page (under JPL) and NASA is finishing up a period of public comment (last session today). Currently Northrop Grumman is contracted to begin preliminary design of the spacecraft until 2008 for NASA (the reactor will be built by the Department of Energy's Division of Naval Reactors--the folks who control all US submarine and aircraft carrier nuclear reactors). Early specs are that it will be 60 meters long, have a 30,000 kg mass, use a 100 KW reactor using Brayton cycle gas turbines, be powered by ion thrusters with a 7000 second specific impulse, and have a science payload of 1500 kg. Early mission plans for Prometheus 1 (Jupiter Icy Moons Orbiter) indicate that the spacecraft would orbit Callisto, Ganymede, and Europa individually, and perhaps have a lifespan of about 20 years."
It's spelled Northrop Grumman.
I hope that after I die the one word people use to describe me is "resurrected."
Disclaimer: I am not a rocket scientist.
In Soviet Rush, today's Tom Sawyer gets high on you.
For a large space and aviation company- just awarded a $400 million contract- you'd think they could afford to hire a copy editor.
:)
That was terrible. Cool project though
Thats right the Asgard, come and install their own warp engine
So they finally figured out how to stabilize naquandria...
Actually, funding for JIMO (Jupiter Icy Moons Orbiter) has been cut.
Finally, we can make some real space vehicles. Fission is the most energy dense technology we have.. it's what we should be using in space. When fusion comes along we may well have something better, but until then we should use what we have.
How we know is more important than what we know.
Wow. Am I the only one that thought the JPL must be some license agreement like the GPL, and the wondered why the hell a web page needed to be released with a special license?
Jet Propulsion Labratory
Portland, North Dakota Puppies
"Does it run Linux?" ... yes, it does. The onboard microcontrollers on the craft will run the uCLinux kernel, with Gentoo userspace. I have no idea what the boxen back at NASA supporting this will run though.
... I for one don't want to welcome our angry alien overlords after they get sick of the crashes :-)
It's a pleasant thought that the first software that aliens might encounter from Earth won't be from M$
"Prometheus Nuclear Systems and Technology will focus on enabling NASA missions by researching and developing nuclear sources that will provide power to innovative scientific instruments and robotic systems, large and small propulsion systems that run on electricity and high-speed communications systems. The nuclear power sources would allow us to extensively explore our closest celestial neighbor, the Moon, as well as Mars and other destinations. Eventually, these power sources would support human explorers as they travel through space and explore other worlds.
= mi ssions
The first proposed mission within Prometheus Nuclear Systems and Technology would be a mission to Jupiter, the Jupiter Icy Moons Orbiter (JIMO), which represents a new class of mission capabilities far beyond those possible with current power and propulsion systems. Powered by a space nuclear reactor and propelled by electric ion engines, the spacecraft would make up-close, long-term orbiting visits to three of the solar system's most intriguing moons- Europa, Ganymede, and Callisto. Beneath their icy surfaces, these moons may contain oceans of water that could have provided an environment that may have harbored life."
http://prometheus.jpl.nasa.gov/index.cfm?pageL1
Beats the heck out of me what that has to do with militarizing space. Besides, IMO, nuclear power is a lot less environmentally dangerous than other power sources except maybe solar energy (which might not work when you're x billion miles from the sun).
--- Grow a pair, liberals... stop letting the Republicans bully you!
Looks like runs on Solar power as well, based on the project pictures. Is that for running the experiments or also for running the guidance computers?
I second that!
There are treaties against testing nuclear weapons in space (Or did Bush pull the US out of those? I honestly can't remember). Nuclear fuels are a good choice due to the fact that the potential for use is greatly increased while the danger a mistake leading to an explosion is small and mostly not dangerous to us or anyone with the probe far out in space. This idea has been long proposed, it's nice to see it gaining momentum. And for the record, it would benifit everyone to colonize space. We already have missiles that launch from space (thanks to clinton) which Bush has already used...there's not really much more that could be done with the militarization of space.
Is a possible reason for NASA avoiding nuclear propulsion that the U.S. is worried about giving other countries yet another reason to build nuclear reactors?
http://prometheus.jpl.nasa.gov/contentImages/Blimp _over_Titan211_br.jpg
If that above picture happens in my lifetime, I will drop a load.
I hope they start with something more resonable than this. A big project will get bloated and is less likely to happen. Instead of going to Jupiter, how about getting to Mars with a little more reliability, with people?
Rosco: "If brains were gunpowder, Enos couldn't blow his nose."
Not so dangerous? What exactly happens when a nuke is detonated in space? I know that there would be no pressure wave or firestorm, but there is no atmosphere or ground to absorb the radiation...
For large sets, this will be our guide even unto death, for the LORD will work for each type of data it is applied to...
Just google rorsat
URL to missles that launch from space?
what do you think absorbs the readiation from the sun? (hint, its our atmosphere) that big ball in the sky that is the solar systems largest reactor (although its fusion, not fission). Honestly, do you think it's light that heats the earth? no, it radiation. Any radiation from a little spacecraft up in space is miniscule!
What are we going to do tonight Brain?
Start grunting!
We don't know what would happen. There is a whole cluster of scientists who believe in SuperString Theory, that we have 10 dimensions but can only percieve 3 of them. Imagine a newspaper comic strip. That character exists in the X and Y plane. What happens if you fire something in Z plane? To him something will appear and disappear quickly. Kinda like how we percieve electrons?? So say we fire off that nuke, and in reality it sends some wave we can't percieve. And that wave hits something else which causes the nuclear action to continue. The whole universe could collapse on itself.
And in those final seconds, I can just hear Bush's voice "Trust me, I know what I'm doing".
Rosco: "If brains were gunpowder, Enos couldn't blow his nose."
The reason it's not an issue for the U.S. to use nuclear power is because we're genuinely interested in only using nuclear power in virtue of its energy-providing capabilities, not in virtue of its WMD capabilities. If Iran had a consistent record of pacifist-endeavors, it, too could be part of this wonderful cause. The minute that NASA workers strap nukes to their chests and run amok in downtime Washington D.C. is the minute I revoke my support for the U.S.
"Nu-cul-ar, it's pronounced, nu-cul-ar."
-Homer Simpson
Well, I was thinking of a nuclear detonation (think meltdown but worse). And, you have a good point. I forgot about the sun :)
For large sets, this will be our guide even unto death, for the LORD will work for each type of data it is applied to...
than the real progress NASA makes.
IMHO, it's a real shame projects like these aren't far more international in scope, open to all bidders, and funded from a futures type trust and traditional venture capital funding, as well as grants and taxes. Heck, most of these projects will pay back in spades if the new technologies were only properly licensed.
It simply amazes me how we have so many business geniuses, but not one of them has even considered space as the next new continent. What ever happened to good old American ingenuity and initiative, eh? Why have we apparently just given up our collective dreams of space exploration and development? Any one care to explain?
Words to men, as air to birds.
"It appears that NASA is not backing down from their nuclear space initiative."
It'll still be lifted off the ground by chemical rockets. What happened to NERVA?
me thinks sun is far worse than a nuke
Yeah cool but please don't call till the Agamemnon is launched.
Goofing around aside. This is cool. Dangerous but cool. Let's face it. This will be the mode of propulsion that will take spacecraft around our solar system for many years to come.
What could possibly go wrong?
LOL!
If that happens I'll eat my hat. I really doubt it will though.
I don't know the ins and outs but I'd imagine that if you have a nice chirpy nuclear-reactor to generate power, taking photovoltaics (solar panels) with you too would be rather pointless. - PVs would cost extra to put into space to start with and would also need trickery to align them with the sun.
Having glanced at the picture, I'd suggest it is more likely that the big flat panels are heat dissipators (heat-sinks) to get rid of the excess heat from the nuclear reactor. I presume that in space there is no conduction of heat away from the vehicle, only radiation. And that you improve the radiation of heat by increasing the surface area.
Ripping an new rectum in the fabric of spacetime.
That's 10 times the best chemical engines ever designed.
We know exactly what would happen because we have already done it. http://www.phy6.org/Education/whtrap1.html
"Truth is much too complicated to allow anything but approximations"
Light is, of course, radiation.
There have been at least three Russian nuclear-powered RORSATs that have fallen to Earth, one into Canada in 1978.
Not sure how big the Russian satellites are compared to this, though.
But if there is a problem on take off, and the craft burns up in our atmosphere...
Not an insurmountable problem, the design of the engine will need to withstand an aborted take off and be launched over an unpopulated area like the sea.
09F91102 no, 455FE104 nope, F190A1E8 uh-uh, 7A5F8A09 that's not it, C87294CE no. Ah! 452F6E403CDF10714E41DFAA257D313F.
>Honestly, do you think it's light that heats the
.
...and most of *that* is in a far more energictic and harmful form that *does* produce gamma rays and other nasties...
>earth? no, it radiation. Any radiation from a
> little spacecraft up in space is miniscule!
Not really... the sun puts out something like 1400 kiowatts/meter^2 before it gets to the surface... and that's mostly *not* in the form of gamma rays
A small 100kw nuclear reactor core puts out a lot more radiation in a smaller form factor (like a cubic meter or so)
----- In Your Cubicle No One Can Hear You Scream...
Great. Let's just hope that the ships don't encounter the Minbari along the way ...
Was I the only one that immediately thought of the ridicious ship that was on ST Voyager? You know, the one that splits up into three pieces?
Ah, nevermind.
Looks like those "early mission plans" have been revised. See the second half of this article. Here's the relevant paragraph:
Oh damn, a nuke in space would turn it into a harsh environment that would kill a person quickly unless they were wearing a special protective suit! Can't let that happen.
Fascism trolls keeping me up every night. When I starts a preachin', he HITS ME WITH HIS REICH!
I would feel sorry for anyone in a space station or vehicle in the vicinity. The sun is a long way away. If a nuke detonated 30 miles from a space shuttle, I bet the crew would still have some serious radiation complications.
For large sets, this will be our guide even unto death, for the LORD will work for each type of data it is applied to...
Some radioactive things are very good ideas.
The best hope of man kind long term is to burn up as much uranium and plutonium as possible - if there are no nuclear fuels, there won't be any nuclear war.This project not only burns up fuel, it gets it off of the planet - where we don't have to deal with the waste.
Before it is activated the nuclear fuels are not very radioactive so a crash on takeoff doesn't do much.
Most of the immediate damage caused by a nuke, comes from the pressure wave from the blast. In space, no atmosphere, no pressure wave. So, the impact from the pressure wave doesn't exist, so not much is damaged immediately. The chain reaction also lets off a lot of heat, that would definitely effect things in the immediate vicinity, it may even melt them. There will be a localized concentration of radiation for a period, but, there's lots of various forms of radiation in space already, again, will only effect things that cant take it (electronics and such), have little effect on things that can (rocks et al).
This is why i laugh every time the issue of meteor impact comes up here on /., and various folks want to 'nuke it'. A large meteor on an impact trajectory with earth is not going to be affected much by a nuclear explosion, unless the device is detonated well below it's surface. Just landing on it and blowing up, without an atmosphere, isn't going to do much of anything. Blowing up 'in the vicinity' is just going to shower the rock with more radiation, and make it even deadlier when it arrives. The only real solution to an impact trajectory meteor is to adjust it's trajectory, and a nuke the absolute WRONG way to do that. A controlled small expenditure of energy, over a long period, is the best way to adjust a trajectory. A large, uncontrolled expenditure of energy is the worst way to do it.
Project Prometheus has recently started a new web page
Actually, I was trying to figure out how a yet-to-be-built space craft has designed a web page. But, I suppose it isn't rocket-surgery.
Its one thing to have a nuclear reactor down the road with a million to one chance against blowing up...
Its another to be lobbing one up into space where, during launch, there is a 100 to one chance of it blowing up.
Risk = chance of happening x consequences
Here the consequences are catastrophic. Can anyone enlighten me on how this is a good thing?
Yea, I knew that the pressure wave would be absent. But still, if anything (space craft) were in the local (within 100 miles I would say) area the radiation would cause issues. The sun (and other sources of radiation in space) are a loong way away, and we have a large atmosphere to absorb it.
The space craft I mentioned earlier in this post has neither distance or atmospheric shielding. But still, I have never heard of a reactor "Detonating" when it failed and melted down... at least recently. But ships and subs have the scram system. A spacecraft doesn't have a vast supply of cold salt water to drown the reactor in.
For large sets, this will be our guide even unto death, for the LORD will work for each type of data it is applied to...
That said, I'm happy it never really materialized. Having a universe with a human population spreading effectively in it summons an eerie image on a spherically expanding brain-tumor to my mind...
http://isbndb.com/d/book/project_orion.html
Uranium/Plutonium standard.
The Gold Standard used to be the basis for our money. We should go to Uranium and Plutonium as the basis for money. The life of a general that wants to start a nuclear war and bankrupt his country in ten minutes will probably be much shorter than that. It will be a strong disincentive for nuclear war.
Our local observatory (with live night-sky camera) is Gummint-funded. This leads to some interesting effects.
Much of their computing equipment has been scrounged - and doesn't appear on any equipment manifests - because there was no budget for it. They have a Pentium-90 driving (pointing) their main 'scope with a backup P-90 literally sitting on the next shelf in case it dies.
The few pieces of gear that they do get grants for are typically extremely fancy. On the rare occasions when ThePowersThatBe say "yes, you can have a computer to process the incoming images," then the cost of that actual computer system and absolutely nothing else is almost immaterial as long as it fits certain criteria.
So... in the room to the left of the one housing the P-90 sits a you-beauty glow-in-the-dark (well, not literally, it would cause backscatter) state-of-the-art box with double overhead ThermalTakes and all the trimmings. Just one. And I bet they crammed memory and disks into that baby's purchasing spec until the chassis groaned under the weight.
When Mark Shuttleworth gave his amazing talk at LCA2005, one of the things he mentioned was that the Yanks didn't want their astronauts (also going up in the Soyuz with Mark) flying to Baikonur in a rattly old Tupelov transport lest it unexpectedly drop out of the sky en route, but rather than come out and say so directly they came over all clever and simply pointed out that NASA regs forbade their astronauts to travel without seatbelts, which they knew the Tupelov wasn't fitted with. This was a mistake. On the day, the astronauts were marched out to the Tupelov, and aboard - and into a minibus in the cargo bay, where they sat and wore the minibus's seatbelts for the duration of the trip.
BTW, when the video DVD from LCA2005 gets published, bend heaven and earth to get yourself a copy. It's well worth-while for Mark's presentation alone ("Welcome to Khazakstan!"), and there are many other excellent presentations on it (Keith Packard explaining the sport of Window Hurling, for example, or E'dale demonstrating how to collapse a penguin's skull).
The point in that story which I wanted to use as an illustration here was that the minibus wasn't put aboard the transport for the astronauts' benefit. There was a budget for flying the Tupelov - pilots, fuel, landing fees and so on - but no budget for getting from the airport to where they were staying. So the van (which fell under the base's budget, so was financially covered) was fuelled up and driven aboard the Tupelov for use as a taxi while the transport 'plane was prepped for the return flight. In terms of working around bizarre regulations, NASA or not, the Americans really were amateurs playing in a professional field. (-:
Got time? Spend some of it coding or testing
All these worlds are yours except Europa.
Attempt no landings there.
I think we have more pressing issues than bankrolling pointless exercises. I'm curious about the solar system, but am more concerned with dealing with the immediate crises facing us here on the Third Stone.
(%i1) factor(777353);
(%o1) 777353
You know, the "shut down the USB hub because we can, then wonder why we never get a keyboard or mouse interrupt" style of power management? Except that in this case the keyboard is, like, tens of millions of kilometers away and there's nobody around to rip out the power cord for a few seconds when the wheels eventually do come off.
Oh, wait... maybe the aliens can do that for us?
I bet the next major W32 LAN virus author would also be so pleased to know that his software is running a billion-dollar satellite out there, somewhere, although maybe not so pleased at the van-load of scientists who rock up from the nearest earth station shortly thereafter with hot soldering irons in their hands and cold looks in their eyes.
FYI, everything's a module these days. If they forgot an important bit, they'd just rebuild the appropriate module (if necessary), then remove and re-insert it.
Got time? Spend some of it coding or testing
The atmosphere tends to absorb stuff with energy levels equal to or greater than X-rays. That even extends downwards a bit into UV.
There's also an article in this month's Scientific American about how cosmic ray absorption might be triggering lightning cascades.
tasks(723) drafts(105) languages(484) examples(29106)
work is to provide nuclear power capability for military systems in space. Under applicable treaties, the U.S. can't legally develop space-borne reactor technology for military applications using DoD or similar (i.e., 'black') funding sources. Exceptions apply to reactor technology developed for and/or by scientific endeavours, so NASA can develop this technology in the clear. JIMO will be a cool mission, to be sure, but make no mistake, the boys in black are the ones underwriting this and waiting for the results.
exactly which app is that screen shot from? I gotta know! :)
Project Orion is sweet - mod parent up!
I could not find anything about the asgard shields. Can someone post a link to them ? Thanks
Well atmosphere and the Van Allen belts which scoot much of the dangerous radiation around us (Earth).
Of course those outside of our atmosphere and Van Allen belts are exposed to massive amounts of radiation, and without protection they would die.
As to radiation from a Nuke in Space.
1. Nuclear reactors don't explode, to explode (i.e. nuclear bomb) requires particular materials in a very specific configuration. A reactor does not meet the requirements. What you would end up with is a large hot radioactive mass.
2. 100 Miles away wouldn't make much of a difference as there is nothing to stop the radiation in the interim (Vacuum of space), so you just loose exposure geometrically as the sphere of radiation expands. Regardless radiation exposure is kind of a binary system (for you geeks) enough to kill you is enough to kill you. Adding more does not kill you more. Since deep space has enough radiation to kill you the addition of more is irrelevant. Unless it is of a type to penetrate the shielding. That type is already emitted by the Sun, and is not particularly emitted in high numbers from runaway reactors.
As to putting massive amounts of radiation into space. Well we have the Sun which is a big massive nuclear reaction dumping huge amounts of radiation. The sun is 1 million times larger than the earth. Therefore any nuclear reaction we put into space by definition is going to be less than 1 millionth the size of the sun, as a reaction 1 millionth the size of the sun would be the size of the entire earth, and any nuclear mass we put up is going to be less than that. In fact it would be less than 1 millionth of 1 millionth the size of the sun. And this puny mass would be in the solar system which is even bigger than the sun (By definition) in fact it's a lot bigger than that, much much bigger. So long as it's outside of orbit of the earth and doesn't come crashing down on East Philadelphia it would be of so little significance it wouldn't matter.
But regardless. whether it's buried in the ground of Gabon, or floating in space it's just a matter of position. It's still floating around in space, and still emitting radiation. Putting it on a deep space probe just moves it from one plce to another.
bet you don't even know what a meltdown is...
=) You: 0 Science: 1
are you implying that a 100kw fission reactor in orbit presents an exposure concern to personnel? i hope you are joking. assuming average prompt gamma ray energy is 1 Mev, the reactor has NO shielding, 1 Ci of a 1 MeV gamma ray point source produces an exposure rate of 1R/hr at a distance of 1M, all of the energy is emitted from a point source, and the reactor acts as a 100,000 Ci point source(this should be conservative, someone with more knowledge might upgrade me on this?), then(neglecting backscatter buildup): DR @ 1m = 100,000R/hr DR @ 10m = 1000R/hr DR @ 1km = 0.1R/hr DR @ 100km = .01mR/hr
365 days * 24hr * .01mR/hr = 87.6 mRem(assuming 1 as a QF, i can't recall the QF for a 1MeV gamma flux right now).
assume the reactor and craft present 1 tenth thickness of shielding(should be conservative): 8.76mrem
assume the atmosphere presents 3 tenth thickness of shielding(again conservative): .00876 mRem
this craft in orbit(realizing it will not remain there) would, conservatively, increase the average persons natural radiation exposure by less than one thousandth of one percent.
this is simplistic but AFAIK conservative.
i call thirds.
No gods, no demons, and no masters. Secular Humanism!
- Although the mass is higher, the mass per unit power is probably a lot lower. In other words, to provide the same power using solar panels or batteries would likely be a lot more massive.
- There may be a certain level of radiation, but the thing about spacecraft is that they can take up a lot of space. Every time you double the distance from the reactor, you cut the radiation by a factor of four. So, you can put the equipment, or the reactor, on the end of a long boom.
- Nuclear subs prove that humans can live beside reactors for long periods of time without undo difficulty. (See above comment about lowering the radiation hazzard.)
- Failed launches do not spread nuclear waste anywhere. Nuclear fuel is specially contained to survive launch accidents, as has been shown in the past. Also, NASA's launch facilities and direction guarantees that any debris will fall into the Atlantic.
- Automating a nuclear reactor is probably less complex than operating the craft itself. The reactor has only one task to do: produce power. Automating the spacecraft involves orienting sensors, buffering data, performing course corrections, monitoring the AE-35 unit [grin], etc.
Fusion does have a long way to go, and I'm pulling for the He3 fusion mentioned on Slashdot before. Cold fusion is likely a statistical error. At least most nuclear physicists seem to think so."I'm not impatient. I just hate waiting." - My Dad
So by all means launch them (from over the US, don't follow you previous nuclear plans and do it in the Southern Hemisphere for 'safety reasons', I live here - you take your own risks) - but once they're up use them outside earth orbit, I don't want them coming back down years from now
I thought you might like to know that nucleotides are those cool little thingies in your DNA that make up the genetic code.
The current plan is for fission reactors to be used outside of an earth orbit. Earth is close enough to the sun that solar panels are still a good choice for energy, so reactors aren't needed. It's on the deep space probes, like the Jupiter Ice Moons Orbiter (if it ever happens) where this becomes useful. It could also potentially be used on a manned Mars mission since the extra power it produces could be used to run an ion propulsion system.
Of course, the efficiency is related to the temperature of the cold reservoir being used and the temperature of the working fluid when it is heated. If you can heat it to 800K (typical for a HTGCR) )and then cool it to 3K (sometimes called the temperature of space), you'd have nearly complete efficiency (apart form the inefficiency of the turbines, that is). Obviously, on the earth there are practical reasons you cant get the temperature that low (you're pretty much stuck with 300K), but in space if you angled the radiators correctly and were relatively far form the sun, you could probably get it down to say 150 K, and have maybe 70% efficiency, rather than the 50% you'd get with a HTCGR on earth.
I used to run "Operation Cyber Prometheus", at ocprometheus.org, a tech web portal (circa 1996) featuring links to any tech material that existed on the net, which I left to die when search engines started getting more popular and updating links manually grew too tedious a process :)
;)
If you check that url, you'll see someone else registered it to capitalize on the name, it still exists. And guess where hardOCP got their name from too
And now Project Prometheus? Coincidence? I THINK NOT! They stole my name! Well I guess Project Prometheus is a rather generic name..
Did I mention how I got Google started too? Well I'm kidding about that, former is 100% true however. Oh well, maybe someone cares somewhere.
I'm not worried about that - what worries me is if something carrying long-life nucleotides reenters and breaks up in the atmosphere
I have some VERY bad news for you; your body currently has litterally BILLIONS of nucleotides in it at this very moment. I suggest you seek a medical professional and ask that these nucleotides be removed as soon as possible, for both your safety and the safety of the human race.
IT'S NOT GOING TO HAPPPEN, YOU WHINEY DUMBASS PUSSY!
We will not solve the miseries of human nature for thousands of years. It's not going to happen. Not in your lifetime. Not in yout great grandchildren's lifetime. To put progress on hold because thee Earth is filled with morons who can't get their acts together is completely insane.
..and look it up yourself, you ignorant, demon-haunted fucktard.
I mean "radionuclides" ....
I was under the impression that a meltdown was an uncontrolled reaction (that incedently melts its way out of wherever it was reacting). A detonation would be something more... explosive. I don't think that can happen accidently, but meltdowns still are not pretty.
The true badness of a nuke going off in space is that the Xrays (I think) ionize everything they hit - including metal sattellite skins, wiring traces, etc. The resulting surge of "static" electricity kills the entire electrical system.
I don't think humans would be bothered too much - we are pretty much transparent to Xrays - though they probably wouldn't survive too long afterwards with no electronics...
You can harden electronics against this of course.
while (sig==sig) sig=!sig;
On a related note, a few words about nuclear rockets. Back in the 50s and 60s some people, mostly science fiction writers, fantasized about nuclear powered rockets. In the 60s there was an actual prototype engine called NERVA. The idea was simply to use the reactor as a heat source to superheat a gas which would shoot out as rocket exhaust. The main drawbacks were the weight of the reactor core, the maximum temperature of about 3500 degrees C, and the radioactivity of the exhaust.
Here's a really interesting article that describes a design for a 100% reusable, non-polluting nuclear rocket based on the Saturn V form factor, capable of lifting 2 million pounds of cargo into orbit and returning to a soft landing. Just like in the old sci-fi movies. The design involves a gaseous core reactor, sometimes called a "nuclear lightbulb." It consists of a quartz bulb containing a cloud of uranium gas such as uranium hexafluoride, confined the center of the bulb by a buffer gas swirling around it. By adjusting the movement and pressure of the buffer gas, the compression of the UF6 can be finely regulated. When it is compressed to a critical state it heats up to about 25,000 degrees C, glowing intensely in the ultraviolet. Liquid hydrogen propellant pumped around the outside of the quartz bulb absorbs the ultraviolet light, becomes superheated, and shoots out of the nozzle. There is no leakage of radioactive fuel and no irradiation of the hydrogen. Completely clean burning. Such a rocket could burn for immensely longer times than any chemical rocket, providing the speed to get a manned mission to mars in a couple months. And not a skimpy mission, a spacious vehicle carrying 1000 tons of equipment, supplies and radiation shielding. Building a rocket like this wouldn't require any far-fetched technology, just some dedicated engineering.
I have never been a fan of nuclear reactors, but this thing sounds really good to me. The gaseous core has tremendous safety advantages over a solid core. The criticality of a cloud of gas is much easier to control and is to some extent self-regulating. For example, the problem of "hot spots" would not exist, because in gaseous form any part of the UF6 that overheated would expand, losing pressure and quenching itself instantly. The author describes several safety features, both active and passive, for letting the gas depressurize into a storage container extremely fast. Even if a gas core nuclear rocket exploded in the atmosphere, it would release a small fraction of the amount of nuclides from a single 1950s H-bomb test.
that's right, George, there's rivers and rivers of LIQUID HYDROCARBONS down there, and America's got the mineral rights!
Like LSD: the only way it can kill you is if you'd be hit by a truckload of it.
This unique sig is intended to make this user more recognisable.
Hm it's also interesting how the concept of a family in the society and changes in it affect attitudes here. Since we generally don't see our families now as clans going on for centuries across generations any ROI that is likely to happen after your death is not worth much trouble. I guess people who have kids have a slightly different view, but even then, I think most people concentrate at things that will happen within the span of the life they're living now. It has also much to do with the assumption, deeply rooted in our culture, that we have only one single life.
If you sum all that up there are a lot of psychological incentives to concentrate rather on stuff that would bring fast, tangible results within one's lifespan so that he can enjoy them.
Research this some. You may be forced to conclude that the decision actually saved tens of thousands of American lives and literally millions of Japanese. I once tried researching the possibility of writing and SF novel predicated on Truman deciding not to use atomic weapons. I concluded that it could never be published. Too grim and no one wanted to read about the Soviets as the single surviving super power.
------ The only greater hazard to your liberty than n politicians is n+1 politicians.
It's the politicians who make the spending decisions you should blame, and more generally, the voters who elect those politicians...
You have that right. I have talked with people who literally seem to think "all the money we have shot into space" is somehow really in orbit out there. Arguing that "all that money" was really spent right here on the ground and that we are all benefiting from the knowledge it paid for often falls on deaf ears.
------ The only greater hazard to your liberty than n politicians is n+1 politicians.
The reason that it can be true that 1+1 > 2 is that very peculiar nonzero value of the + operator
...is wait for it to be finished (chopped, possibly remixed from different audio if needed, possibly direct video from the screen pasted in - a job I don't envy in this case since Mark had OOImpress set for automatic advance and kept going back, rendered into a compressible format) and released. (-:
Let the organisers know that you care. Conf delegates and speakers get a CD/DVD set snailmailed out automagically, you may be able to buy and/or download a DVD (or just the video) later as well.
Got time? Spend some of it coding or testing
...is also dumb enough to make the watchdog timer a USB device.
Got time? Spend some of it coding or testing
Except that uranium is so common material, that it would be akin to basing the currency on iron. (or something...)
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Make sure any treaties have an exception for the sun. Idiot.
Sometimes at night I imagine the darkness is filled with horrible things with too many teeth, like Julia Roberts.
That's one heavy mothership to be pushed by shooting out tiny amounts of ions!
At a first approximation, the acceleration's gotta be somewhere under 0.00001G's, which makes the whole scheme rather slothful and boring.
And if there's going to be pumps and turbines involved, how're they going to keep the thing from spinning wildly in several axes? Surely not with reaction thrusters. The more I think about this thing, the more it looks like some gigantic delayed April Fools joke.
http://en.wikipedia.org/wiki/Project_Orion
There's some thing much coooler about the idea of riding into space on top of a series of A-bomb explosions. Bit of a public relations nightmare of course but you can't have everything.
"Physics is to math as sex is to masturbation." -R. Feynman
Where did the name come from?
Are they:
a) planning on stealing fire from the Gods?, or
b) expecting it to get it's liver ripped out?
Geee, doesnt life itself cause death, lets outlaw life then.
Why is everyone turning into pussy little gay girls, get some damn guts. Life is cheap, risk is easy, payoff is huge.
Just think of all the badass pollution/lead contamination, especially in LA/Sanfran where they build new condos over old waste disposal sites from the 60s that have tonnes of crap burried, but no one cares because local govts get some good cash from land taxes and banks get more sales and builders build more houses.
Liberty freedom are no1, not dicks in suits.
We're missing an opportunity here. This isn't about nuclear space propulsion, this is about:
Permanently removing nuclear material from the Earth
Look at what a wonderful service is being provided, nuclear material is being made to Go Away Forever. The minor factor that it opens up exploration of the solar system is a minor side-effect, we don't need to talk about that. Just think of the nuclear material elimination aspects.
The hurdle is to convince skeptics that it's "Challenger-proof", not "Columbia-proof". Remember that this stuff is never intended to re-enter, only launch and leave, forever. From a materials durability point of view, that's quite a difference. Much more of Challenger was recovered than Columbia, and in better shape. That suggests that nuclear containment might well better survive a launch problem than a reentry one.
I don't know if this is meant as humor, or not.
The living have better things to do than to continue hating the dead.
With a nuclear source and/or solar panels we can get lots of energy. The problem is always getting enough mass to check away to get momentum. There is not a lot of stuff out in space, but there is enough to drive a solar sail. If we can trap a bit of this, then we can use this as propellant. I dimly remember a proposal for a craft with an electromagnetic scoop for interstellar hydrogen (the Daedalus, I think it was called). If we can scoop enough to keep a gaseous core reactor busy, then we would be cruising indeed.
PS.
If it blows up in the atmosphere, the uranium might not be a huge problem, but the fluorine you get when the UF6 splits up in the UV would do in the ozone layer something rotten. Be prepared for considerable community service slapping factor 30 suncream on angry emperor penguins.
and not just today, either.
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Dude, look at the M3 money supply, how much trillions is lent out each year just for housing/credit cards. (http://financialsense.com/resources/fed/moneysupp ly.htm)
Those old farts who own pension funds dont mind lending out trillions to teenagers credit cards and 20somethings home loans that might never be paid off, just so grandma can keep living cheaply. But if you want real investment, nooooooooo, because all those old people will die before they see a return, pitty, trillions of wasted money all going on immediate returns just so grandma can get her titanium hip.
Dont forget, the FED creates tonnes of new money out of thin air, they could easily say, "well lets print 1000 billion in Tbills , sell em at 5% and give the cash to NASA"
Liberty freedom are no1, not dicks in suits.
On Earth, we use water to cool fission reactors (right?). So in space, would they use diffusion of heat into the void to cool systems?
I hope they've played with this stuff in gravity free environments. What would happen if you had the reactor on before breaking free of gravity? Would the change be disruptive to the plasma?
( I'ld rather have the Prometheus from SG-1 )
Marques Johansson
From NASA's overview:
"Prometheus brought down the gift of fire from the heavens to humanity".
That will go down well with the environmentalists... it does not inspire much confidence about keeping this (nuclear) fire up there instead of down here, does it?
It's much slower than traditional orbital transfers, but so much cheaper that it's worth using. It's already been used on SMART and Galileo:
http://www.sciencenews.org/articles/20050416/bob9. asp (even mentions using it for Jupiter moon exploration!)
http://www.ufoindia.org/news_intsuperhighway.htm
PHEM - party like it's 1997-2003!
Who will develop the reactor? The Naval Reactors (NR) program.
Will they release the design to public examination? No. NR spent several months arguing with NASA and even with some engineers within NR about classification. In the end much of the reactor design will be secret. Therefore the public will have an insufficient basis on which to question the safety of the system. Instead safety for launch and flight will be determined by a panel whose conclusion will be public, but whose basis for conclusion will be secret. This is no way to run a civilian space program.
The current plan is for fission reactors to be used outside of an earth orbit.
All reactors used in space up to today have been used in low earth orbit. The USSR used about 40 such reactors to power spy satellites in low earth orbit. The US ran 1 such reactor in low earth orbit; this reactor is now in a 1000 year orbit of earth.
For those dreaming of a 10 or 20 year JIMO mission, it's worth noting that the US was able to run a reactor in space for just over 1 month before it broke. The record of the USSR is 1 year, but most of their reactors also ran on the order of a month.
Despite the weight (or was that mass?) of immemorial tradition, the units of specific impulse are not seconds. Pounds force are not pounds mass. Giving them the same name does not allow one to cancel them, any more than one can cancel the "d"'s in a derivative.
The units of Isp are lb-f*s/lb-m, or better yet, N*s/kg. lb-m isn't even a good Imperial unit--it ought to be slugs.
Isn't it about time rocket scientists got with the 21st century?
--Tom
Blasphemy is a human right. Blasphemophobia kills.
What exactly happens when a nuke is detonated in space?
If in earth orbit, large numbers of energetic charged particles are released, wrap around the earth's magnetic field, and fry satellites in reachable orbits. This has been studied as an anti-satellite weapon. It is very effective, but not very specific.
. . . the solar system with RADIATION!!!
Damn you Chimpy Bushitler!
Your original question, while not related to nuclear reactors (yep, they can't detonate), is a good one. The sun is very big, but very far away. A nuclear weapon up-close can exceed the sun's apparent output for a short time. The radiation from a weapon is different, too - there aren't any nuclear reactions at the sun's surface.
Check this out for more info on what a nuclear blast in near space can do: http://science.howstuffworks.com/e-bomb2.htm/. People don't die, but computers do.
Guys, I'm here to tell you that this project is doomed to failure. Nothing to do with the science involved...
It's the name.
PROMETHEUS? Why not name it the Titanic Initiative while you're at it? Or the Pandora Project? Or maybe pay some homage to the Kobayashi Maru? (You know: that one ship that was TOTALLY FREAKING DOOMED and there was NOTHING you could do about it.)
This is the problem with scientists: they fail to think *dramatically*. It is only sensical that a project of this type will open a dimensional rift to Hell, mutate the human race, and/or ignite the core of the Earth in a catastrophic conflagration that will blow the Moon out of orbit.
When are we going to learn? Never, *never* name a first-of-its-kind endeavor after any legend that concludes with the high price of human hubris. Likeways after anything that will be considered ironic when it inevitably goes down in flames.
You're speaking of the Bernard ramscoop. EM funnel several light-seconds across funnelling hydrogen and other fuseable elements into a scoop to use as a reactor mass.
It's called a "Bussard Ramjet" after the guy who dreamed it up.
Better still, was an idea for a variation on the Solar Sail, which creates a magnetic field from an onboard power-source. Solar-wind drag on this magnetic field is what then propels the craft - which solves the propellent problem. As with a "conventional" solar sail - accelleration is very low (as compared to the very low accelleration of today's ion-drive technology, akin to the weight of a sheet of paper) - but top speed is limited by the speed of the solar-wind, which is higher than the top speed attainable by ion-drives by a couple of orders of magnatude. . . which is also, higher than the top speed attainable via chemical rockets by another couple of orders of magnatude (ie. you can't travel any faster than the speed of the stuff you're chucking out the back).
These are my friends, See how they glisten. See this one shine, how he smiles in the light.
We already have missiles that launch from space (thanks to clinton) which Bush has already used
Please provide link to source for missles in space. Could not find any information on space bassed missiles, much less any that were launched.
Fly me to the moon Let me sing among those stars Let me see what spring is like On jupiter and mars
The US hasn't made a nuclear weapon in over a decade. Read the list. We just keep up maintainence on the current ones.
Fly me to the moon Let me sing among those stars Let me see what spring is like On jupiter and mars
But if the computers die, the people die shortly, right? So it is still a bad thing unless we shield the electronics.
For large sets, this will be our guide even unto death, for the LORD will work for each type of data it is applied to...
30 miles still vary close when your talking about objects in space
0 rads = No Apparent symptoms
I think the main advantage is there would be almost no fall out and you would be protected by the hull of your space ship / hull.
Anyway, 3d space so...
Looking at www.hiroshima-is.ac.jp/Hiroshima/radiation.htm
1
100 rads = Changes appear in lymphocytes produced by bone marrow
2,500m from hiroshima would you got 12 rads now at 700 you are going to die but 12 is more a small long term risk. But at 30 miles you get (1 / (48 / 2.5)) ^2 of that dose which would be 1 / 368.64 of that or 0.03 rads which is fairly safe.
And yes I am skiping alpah and beta rays but:
A single piece of paper can stop an alpha ray effectively
Depending on its energy (i.e., speed), a beta ray can traverse different distances in water--less than 1 mm for tritium to nearly 1 cm for phosphorus-32.
Their might be some fallout stuck to your space ship with out gravity to pull it down and consitrate it on you your geting a lot less fallout than you would normaly. Your also not going to injest any radio active fallout which will help a lot. Now clearly there are larger bombs something 1000x that would fall into the 32 rads range which would increase your risk of canser over the long term but with a little shielding from the space ship your probably going to be fine.
PS: Once again this is in space at 30miles on the ground you get stuck eating / breathing fallout at that range which greatly increases your risks.
"when you take a small mass of radioactive material that gives off lethal amounts of radiation and spread it over a large geographic area you cannot get a lethal exposure. "
It really doesn't work that way. Highly-radioactive chunks of metal of various sizes hit the ground after Cosmos 954 crashed. Several of them could have delivered a lethal dose to a person whio handled them without proper protection.
Here's one reference
And another reference
That talk about the potential lethality of some of the recovered fragments from the satellite. Keep in mind that nobody knows how many of the fragments that hit the ground were actually recovered.
That's probably why they're using NR for the source. You know, Naval Reactors, those reactors that sit in the US submarines and surface warships and operate nearly without break for years between refueling? If they were to put a Soviet-designed and built NR in there, I think I would not be so confident, though.
"The generation of random numbers is too important to be left to chance."
.. yes.. but when it all goes to hell you know there's always a group of people waiting to fish you out of the deep water/fire/space
It's a pity they don't care at all.. for all the power/s they have.
Much like any government really..
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Am I the only one to remember that Prometheus after giving the fire to the humans was punished by the god.
From Wikipedia:
"Zeus [...] had Prometheus carried to mount Caucasus, where a vulture or an eagle named Ethon [...] would eat out his liver; it would grow back each day and the eagle would eat it again"
It would be quite easy for any opponent to the subject to make a similarity that after sending it the economyy would have to suffer for 30'000 years.
Nils
with the distances involved
Just like real world military aircraft need "homes", either land bases or aircraft carriers, military space fighters will need "spacecraft carriers" or space stations (either orbiting planets, or deep space, a la Star Trek).
and the lack of a "top" speed there is not going to be much dog fighting.
Lack of "top speed"??????
Huh?
Anyway, this is all moot until the requisite power source is discovered.
It's moot anyway, I think. Space is just so hostile, building small fighter craft would just be too expensive.
"I don't know, therefore Aliens" Wafflebox1
The US dudes making the decisions thought they were, which is what matters. They also thought they'd be cute about it, which was not a particularly bright approach to people who have been immersed since birth in a culture where multi-level messages and indirection are the norm.
I think the Tupelov-fearers would have had massive coronary palpitations when Mark got to the fuelling-tech anecdote, though. (-:
Got time? Spend some of it coding or testing