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Difficulties of the Nuclear Powered Prometheus Project
brandido writes "Space.com is reporting on some of the technological difficulties facing the nuclear powered Prometheus Project. In particular, it is focusing on the fact that the Prometheus project promises to represent a paradigm shift in the capabilities of interplanetary probes. Such a large shift in capabilities entails the development of new technologies and designs, a process that is often full of mishaps and setbacks."
What happens when something like the Challenger disaster occurs to a launch vehicle carrying a nuclear reactor?
Further detailed exploreation of the solar system is something that needs to be done, if only to give us humans more things to chew on.
Personally, I hope we don't find any sort of lifeforms beyond the microsopic, at present Humans have enough trouble dealing with other humans, let alone a compleatly differnt being from a vastly differnt evolutionary chain.
But I do hope that this technology gets up there, and gets used, one more step in the refinement of space tavel, even if it doesn't work, at least it was tried.
Unless you buy into the notion that all the Mars probe failures were due to xenophobic Martians, we've recently witnessed several examples of unmanned, robotic craft turning into expensive piles of junk for reasons ranging from the sublime (legs bounced harder than expected) to the ridiculous (meters? feet? what's the difference?).
Contrast those catastrophic failures with events on human-occupied craft. Fires and collisions on Mir, and of course Apollo 13 for those who get their science from the local multiplex -- yet the craft kept flying, due to human involvement and ingenuity. The conclusion is clear: the more complex the system, the more likely you need a non-silicon-based intelligence to keep it from self-destructing.
To address the issue at hand: NASA wants to send a nuclear-powered spaceship to Jupiter? Cool, but you'd darned well better include a crew compartment, unless you *want* to see what happens during a space-based meltdown.
The bottom line is that there is no way to predict everything that can go wrong with any complex system. That's why we need more manned missions. Spend less money on absolutely "perfect" systems, and more on systems to support a human presence to fix it when it breaks.
After all, Captain Cook explored the south Pacific with nothing more than boats of wood, and men of iron. He also had a whip, and generous quantities of very strong beer...
Stressed? Me? Of course not. Stress is what a rubber band feels before it breaks, silly.
Firstly, unused nuclear fuel is not very radioactive relatively speaking and is not very toxic.
Secondly, the fuel can (and is) built into very strong and resilliant "cans" and can be further protected to the point that even a fall from a great height such as earth-orbit will not result in any radioactive release.
Thirdly, any engineer woth their salt will design the darned thing such that it will not start its nuclear reactor (when the nasty fission products start to be produced) until the craft is either a significant distance away from earth already, or has achieved escape velocity and can not fall back to earth.
I am a qualified nuclear engineer with several years reactor physics experience at a nuclear power station.
Stick Men
IIRC, Prometheus' story didn't exactly have a happy ending. (obSlashjoke: This project will surely open a Pandora's Box)
Maybe we could call it Magellan Mark IV or something a bit more optimistic?
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If the nuclear reactor is meant to provide energy to the ion thrusters, what fuel will the ion thrusters be using? If the project is meant to last for decades thanks to nuke, it would take a lot of xenon to supply the ions. Surely the decaying ions would not provide enough for thrust, if re-used in that way? Or can solid fuels be vapourised by the heat of the reactor? I quite like the idea of the reactor rods (or whatever) blasting themselves into space with electricity they've just generated.
Could be Icarus
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Manned missions are vastly more expensive than any automated probe, for obvious reasons. What's the loss of a few million dollars due to miscalculations or unpredictable conditions compared to the potential for loss of life, or the reduced frequency of missions? And anyway, is sending a human up with your probes only for purposes of maintenance really worth the added expense? It would be cheaper to just send two or even three probes at once than to design the mission to support human travellers.
Sure, we'll send astronauts to Mars, and eventually even colonists, but I think it would be more for political, rather than scientific purposes.
Your comment is accurate, but depressing.
The early explorations of the Americas, IIRC, were intended to 1) find a shorter route from point A to point B, 2) exploit the resources, and 3) establish settlements. Unfortunately, none of these lead directly to getting more manned missions:
1) Space, like the American continents, isn't a shortcut to anywhere (although communicaions satellites do provide a "shortcut" for information -- but not people).
2) It's still cheaper to rape Earth-bound resources than it is to mine an asteroid (unless it's made of solid gold, of course).
3) In the countries that currently have the ability to launch manned rockets, life just isn't miserable enough to leave -- at least, not on a rocket.
I'm very encouraged by the development of manned rocketry by countries like China and India -- where there *are* conditions miserable enough for people to make a Mayflower-like pilgrimage to the stars in search of a better life. I don't see boatloads of US citizens lining up to launch into space to avoid road rage.
Stressed? Me? Of course not. Stress is what a rubber band feels before it breaks, silly.
These craft typically use heat to make electricity, and then use the electricity to power a thruster of some kind; the thruster accelerates propellant. Ion thrusters have been made to use a great many different things as reaction mass (propellant), ranging from argon to bismuth to Buckyballs to xenon. The Deep Space One probe which was so phenomenally successful used xenon in its ion engine.
Scientists restrict study to entire physical universe; creationist
...and just in time for me to go home, too.
Here's a NASA page on Project Prometheus.
Have a good weekend, all.
-Carolyn
Like Daddy always said: if you can't dazzle 'em with brilliance, baffle 'em with bullshit.
Prometheus has been on the drawing boards at the Jet Propulsion Lab since the early eighties. The reason it didn't get anywhere then is the same reason it won't get off the ground now. It's nuclear. Let's give an example. Recently, there was a major press blow-up (no pun intended) in Michigan about allowing the transport of used fissile material across the state. Never mind that said material was cast in the center of rain barrel or bigger sized pieces of concrete. Never mind that you could drop the damn containment vessels off a five story building and they wouldn't break. Everyone was screaming about the possibility of radiation getting into the water and air. The poor NRC guys had a public relations nightmare. And all because Ralph Nader and his merry bunch of marauders has made "nuclear" anything the scariest thing in the public imagination since Anthrax. You can't build new nuclear reactors and there is no chance you can get a nuclear powered craft whether propelled or simply powered by radiation off the ground. Too many people are too dumb to understand how infitesimal the possibility of disaster is, because all they remember is Chernobyl and Three Mile Island. Sad but true my friends. And now we get treated to the same feast of ignorance about cloning or genetically modified foods by people who let ignorance and fear rule their imaginations. [-)
What would Richard Feynman do, if he were here right now? He'd do some math and he'd follow through!