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Without Plutonium, Deep-Space Probe Missions May Sputter Out
cold fjord writes with this excerpt from Wired: "Most of what humanity knows about the outer planets came back to Earth on plutonium power. ... The characteristics of this metal's radioactive decay make it a super-fuel. ... there is no other viable option. Solar power is too weak, chemical batteries don't last, nuclear fission systems are too heavy. So, we depend on plutonium-238, a fuel largely acquired as by-product of making nuclear weapons. But there's a problem: We've almost run out. 'We've got enough to last to the end of this decade. That's it,' said Steve Johnson, a nuclear chemist at Idaho National Laboratory. And it's not just the U.S. reserves that are in jeopardy. The entire planet's stores are nearly depleted. ... what's left has already been spoken for and then some. ... Political ignorance and shortsighted squabbling, along with false promises from Russia, and penny-wise management of NASA's ever-thinning budget still stand in the way of a robust plutonium-238 production system." The plutonium shortage has been deepening for a long time, leading to some creative solutions. The Wired article alludes to the NASA project underway to create more, but leans toward gloom.
We are no longer creating bombs for a nuclear apocalypse.
Two issues
1) You have to get the things into space
2) Stuff still has mass in space and thus a higher mass requires a higher force to accelerate compared to a less massive object.
Hope that helps.
Likely because they need to be wrapped up in so much stuff so they're not killing everyone nearby.
And as far as I recall, you essentially need lead to block the radiation.
Lost at C:>. Found at C.
* Build a moon base
* Setup solarpanels for lots of power generation
* Build infrastructure
* Extract lots of Helium 3
* Build a monorail assisted launch system
* Build space ship parts
* Build a Tokamak in parts, small enough to assemble in space
* Launch all the s#!+ into space and assemble all the parts
* Remember to launch a couple of tons of H3 too
* Go!
Pu-238 is NOT "weapons-grade", and Pu-239 (which is) is NOT a useful substitute for Pu-238.
"I do not agree with what you say, but I will defend to the death your right to say it"
That big yellow ball in the sky is emitting more radiation than that little chunk of P238. You might not be aware of this but without the earths magnetic field and atmosphere in the way that little ball of light would kill you very very quickly.
As others have already noted that P238 isn't really dangerous unless you are going to eat it. Though plutonium is believed to be an entirely a man-made material uranium and all the other naturally occurring radioactive elements exist outside the earth as well as on it. The several ounces on a space probe used as a thermolytic generator is insignificant entirely.
See, this is why people who don't understand radiation shouldn't talk about it.
4.5 billion years of half-life means that the decay rate - the actual process that emits radiation - is so absurdly slow that the material itself is just not dangerous. The dangerous stuff is, almost by definition, the stuff with *short* half-lives. A gram of material with a millisecond half-life will release more radiation in one second than a kilo of U-238 will in a century, assuming they undergo the same types of decay. Secondary decay of the uranium will be a bigger problem, and still not much of one.
In fact, people have incorporated U-238 into everything from building bricks for houses to the glaze on pottery. Let me make that clear for you again: people have built houses out of material containing uranium ore. They have then lived out their natural lives - and sometimes the lives of several generations of a family - in those houses.
Calling it "spewing poison" is bullshit of the first degree. It's probably more dangerous to eat bananas (which contain radioactive potassium isotopes, in tiny amounts, but with much shorter half-lives) than it is to have U-238 all around you. Even pure, enriched U-235, while not something you'd want to hold in your hand, is not particularly dangerous to handle so long as you keep it away from neutron guns or reflectors, and below critical mass.
There's no place I could be, since I've found Serenity...