131–140 of 176 posts
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I'm about 80% sure leni536 is right, from playing Kerbal Space Program.
i think you are right based on a similar feeling from that game, but be careful with that intuition. how much delta-v do you spend lifting the orbit so that lowering the periapse is cheap?
http://en.wikipedia.org/wiki/Ulysses_(spacecraft)#Jupiter_sw...
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>Besides, nuclear waste is still mostly unburned fuel which could be reprocessed and burned for power in special reactors. That was my reaction. Future generations will want to use that stuff for fuel. There's no reason to launch it into space.
Well yes, it could be fuel in the future. But at current in the US it is stored in holding pools all over the country. None of those are getting any larger, although they are frequently reworked to allow better use of the volume available. Very little of it is 'weapons grade' and not many people have access to the equipment to weaponize it into a nuclear weapon. But turning any of it into a dirty bomb is trivial if y…
Every time the question of nuclear waste disposal comes up, someone is sure to say, “Why not shoot it into the Sun?” It seems so obvious. Or we could get over our stupid fear of recycling. The stuff's only hazardous because we haven't taken all the energy out of it yet. Nuclear fuel reprocessing is performed routinely in Europe, Russia and Japan. http://en.wikipedia.org/wiki/Nuclear_reprocessing
The reason for its cancellation? The belief that any nuclear reprocessing is bad for "nuclear proliferation". I cannot even comprehend the mental gymnastics required to justify shutting down vital research which didn't even produce isolated plutonium when the country possessed thousands of nuclear weapons and tonnes of weapons-grade plutonium. How the fuck would this have any affect at all on "nuclear proliferation"?
Every time the question of nuclear waste disposal comes up, someone is sure to say, “Why not shoot it into the Sun?” It seems so obvious. Or we could get over our stupid fear of recycling. The stuff's only hazardous because we haven't taken all the energy out of it yet. Nuclear fuel reprocessing is performed routinely in Europe, Russia and Japan. http://en.wikipedia.org/wiki/Nuclear_reprocessing
One of the downsides of reprocessing is that it makes plutonium easy to separate out in a form that is good for making nuclear bombs. Therefore it represents a nuclear proliferation risk.
Form the wikipedia page: "Ordinarily (in spent nuclear fuel), plutonium is reactor-grade plutonium. In addition to plutonium-239, which is highly suitable for building nuclear weapons, it contains large amounts of undesirable contaminants: plutonium-240, plutonium-241, and plutonium-238. These isotopes are extremely difficult to separate, and more cost-effective ways of obtaining fissile material exist (e.g. uranium enrichment or dedicated plutonium production reactors)" http://en.wikipedia.org/wiki/Radioactive_waste
As the wikipedia article points out a very good approach to deal with nuclear waste would be burn the waste in pyrometallurgical fast reactors like the proposed Integral Fast Reactor. (For background on the Integral Fast Reactor: http://en.wikipedia.org/wiki/Integral_fast_reactor)
Trying to throw the waste in the sun would be one of the worst possible imaginable ways of dealing with nuclear waste.
I'm not rocket scientist, but it seems like the author is calculating a decreasing spiral into the sun rather than an impact. Why not slingshot around a planet and barrel into the sun with all of the orbital velocity still intact.
So, getting to the sun is actually really hard, the earth is moving around the sun at ~30km/sec. For comparison, a satelite in low earth orbit is only moving about 8km sec. 30km/sec is a LOT of velocity change, and you'd need to cancel practically all of it to actually fall into the Sun. Way harder than getting to any of the planets.
How about exiting planetary orbits retrograde? It seems like larger planets would have escape velocities that are larger than their orbital velocity. Why couldn't our space barge leave Jupiter's orbit on a trajectory that would intersect with the sun?
> To reach the Sun you need to subtract 100 percent of Earth’s orbital velocity; to reach solar escape velocity you need only add 41 percent to it. You could send the waste with near solar escape velocity to travel on a really long ellipsis trajectory, at the furthest point you can get rid of the remaining kinetic energy with minimal fuel and let the waste fall back straight into the Sun. Subtracting Earth's orbital…
To what end? To spend literally decades, perhaps centuries, with nuclear waste floating around the solar system? Why not just leave it in deep space to start with? Why bother sending it into space in the first place? Meanwhile, if you succeed in sending nuclear waste into the Sun what do you think happens to it? It doesn't go away, it just gets vaporized and then scattered into the solar wind.
We can make it to Mercury. In fact, putting a spacecraft in orbit around Mercury is made more difficult because of the need to decelerate against the Sun's gravity. If you look at the Wikipedia page for the MESSENGER mission, you'll see they tackled that problem by using gravity assists from Earth, Venus, and Mercury to reduce MESSENGER's relative velocity with Mercury and allow it to go into orbit. These gravity ass…
I'm not sure how much I like the idea of using the Earth for a gravity assist on a nuclear waste payload. Getting that one wrong (anyone remember the meters vs. feet debacle with a Mars probe?) wouldn't end well...
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> When the Shuttle was first commissioned, my concern at the time was that America's most reliable rocket was the delta, which failed every thirty launches. You were right to be concerned. The shuttle had "a 40% vehicular failure rate and a flight failure rate of 1.5%", killing more people than any other space vehicle. [1] [1] http://www.forbes.com/sites/carolpinchefsky/2012/04/18/5-hor...
And the space shuttles carried many more people than other space vehicles except for the current generation of Soyuz. You don't measure failure rate by number built divided by number crashed. You measure by how much it's used. The more often something is used the more likely it it that it will fail one of those times.
Also it's a great target for sabotage for radicals.