7 ms·

NASA’s Plutonium Problem Could End Deep-Space Exploration

143 points by hereonbusiness 13y ago

jlgreco 13y ago
France has the resources to make Pu-238, though I am not sure if they currently have the facilities/equipment. If the situation really is politically impossible in the US and Russia keeps on flaking out, we could always try buying more from the French again and let them deal with the politics. If we are shitcanning missions because we don't have Pu-238, then why doesn't NASA just take the money they would have spent on those programs and spend it on more Pu-238 instead? Surely that should buy us enough Pu-238 for at least remaining uncancelled missions.
- maaku 13y ago
  > If we are shitcanning missions because we don't have Pu-238, then why doesn't NASA just take the money they would have spent on those programs and spend it on more Pu-238 instead? Surely that should buy us enough Pu-238 for at least remaining uncancelled missions. Requires an act of congress. Need I say more?
  - dalke 13y ago
    To elaborate on maaku's answer, as the article points out, "the Atomic Energy Act forbids NASA to manufacture plutonium-238."
    - jlgreco 13y ago
      The idea is for NASA to buy Pu-238, not make it. I am not sure how much Congress micromanages their budget though, it may very well be the case that money meant for probes cannot be redirected to buy Pu-238.
      - dalke 13y ago
        Buy it from ... whom? As the article points out, Russia "reneged on a deal to sell 22 pounds to the U.S." and might not have any left for sale. There are no other producers of 238Pu. (And for that matter, Russia stopped producing it years ago.) Edit: Here's a link for you. http://www.nasa.gov/pdf/636900main_Howe_Presentation.pdf http://www.nasa.gov/pdf/636900main_Howe_Presentation.pdf . > In the past, the United States had an adequate supply of 238Pu, which was produced in facilities that existed to support the U.S. nuclear weapons program. The problem is that no 238Pu has been produced in the United States since the Department of Energy (DOE) shut down those facilities in the late 1980s. Since then, the U.S. space program has had to rely on the inventory of 238Pu that existed at that time, supplemented by the purchase of 238Pu from Russia. However, Russian facilities to produce 238Pu were also shut down many years ago, and the DOE will soon take delivery of its last shipment of 238Pu from Russia. The committee does not believe that there is any additional 238Pu (or any operational 238Pu production facilities) available anywhere in the world. Full details are in "Radioisotope Power Systems: An Imperative for Maintaining U.S. Leadership in Space Exploration", National Research Council committee report. ISBN: 0-309-13858-2, 74 pages, (2009)
        jlgreco 13y ago
        France could produce it, given time. This is is a situation that has been discused for some time: http://energy.gov/sites/prod/files/nepapub/nepa_documents/RedDont/EA-0841-FONSI-1993.pdf http://energy.gov/sites/prod/files/nepapub/nepa_documents/Re... See the end of that document for discussion of Pu-238 from the UK and France. Notably it was thought in 1993 that France could have Pu-238 production going in a period of a few years ("late 90s" from 1993). To my knowledge the Pu-238 situation in France has not changed one way or the other since then. If the situation is either no more Pu-238, or Pu-238 in several years from France, then I would say that going to the French isn't a terrible idea. We didn't pursue getting Pu-238 from the French at the time because we thought that Russia was going to have us covered.
        dalke 13y ago
        What's the point of referring to a 1993 document when the 2009 document I pointed to says "The committee does not believe that there is any additional 238Pu (or any operational 238Pu production facilities) available anywhere in the world." Yes, anyone with nuclear reactors is functionally able to make 238Pu. The document outlined a possible alternative method to use a 5 MW, licensed TRIGA reactor, available at various universities and in many countries. > "If the situation is either no more Pu-238, or Pu-238 in several years from France, then I would say that going to the French isn't a terrible idea." Why do you think that situation exists when the authors of the National Research Council report on the topic thinks it's not possible? The document says that extensive French facility modifications would be needed, and further discussion would be needed even to establish that that option could be considered. Unlike the UK discussion, there isn't even a mention of how much France might be able to produce. That's your optimism? Is such a facility even still available some 20 years later? So your suggestion is that the US should convince a foreign country to make extensive changes, plus do years of production? Interesting. Why is that better than making it in the US?
zyb09 13y ago
Probably a non-issue, because more Plutonium-238 can be easily created using existing infrastructure. As demand of this stuff goes up and supplies dwindle, someone is gonna make more of it sooner or later.
- maaku 13y ago
  There are legal constraints on Pu-238. Market forces do not apply, unfortunately...
  - spiritplumber 13y ago
    Maybe they can use a box full of old pinball parts.
    - ballard 13y ago
      Mr fusion FTW.
    - tanzam75 13y ago
      > Maybe they can use a box full of old pinball parts. That would be Pu-239, not Pu-238. Remember, the Libyans wanted him to build a bomb -- not a spaceship.
- sliverstorm 13y ago
  Its production is verboten.
jevinskie 13y ago
> Every so often an atom of neptunium-237 absorbs a neutron emitted by the core’s decaying uranium, later shedding an electron to become plutonium-238. Doesn't it shed a proton to become plutonium 238 and, as a consequence, loses an electron?
- pjscott 13y ago
  Proper description of what's going on: http://en.wikipedia.org/wiki/Beta_decay http://en.wikipedia.org/wiki/Beta_decay
  - jevinskie 13y ago
    Thank you very much, I was under the impression that the electron was lost from the orbital cloud, not the nucleus! Edit: Looking back at my math it was an off-by-one error in the wrong direction. :)
- jlgreco 13y ago
  http://upload.wikimedia.org/math/5/5/7/557cb46ae9126680a7d579dd5e15015a.png http://upload.wikimedia.org/math/5/5/7/557cb46ae9126680a7d57... Basically one of the neutrons kicks out a beta particle and becomes a proton. The atomic number goes up but the mass number stays the same.
slacka 13y ago
Thorium reactors produce PU-238 as a “free” byproduct. One more reason we should be pursuing LFTR reactor research.
- InclinedPlane 13y ago
  Erm, sort of. It doesn't actually help that much. As a short, but helpful, side discussion consider the breeding of Pu-239 in a reactor for use in nuclear weapons. Pu-239 works great in a nuclear bomb but other isotopes of Plutonium cause problems, specifically the high spontaneous fission rate of Pu-240 can create so many background neutrons that having a significant amount of it in a bomb can vastly increase the "pre-detonation" (fizzle) risk, which causes the bomb to have very low yield (on the same scale as the chemical explosives in the bomb). As Plutonium remains in a reactor subject to neutron flux it will naturally breed other isotopes, which is why there is a difference between weapons grade and reactor grade Plutonium. Reactor grade Plutonium can contain any variation of isotopes, essentially all of them are suitable for use in a reactor, but weapons grade Plutonium can only have a very small amount of Pu-240. And for this reason the way that weapons grade Plutonium is made is by removing fuel rods from a reactor on very short time scales and reprocessing it to remove the Plutonium then forming it back into new fuel rods and so forth. This is a very costly and complex endeavor which is why you can't just use ordinary power reactors for generating weapons grade Plutonium. Interestingly, Pu-238 also exists in reactor grade Plutonium in substantial amounts (1% or more of the Plutonium, so nearly an entire tonne per year worldwide). However, because it's mixed up with all of the other Plutonium it would require extremely costly isotopic separation. So, how is this relevant to Thorium reactors? Well, let's go back and look at what actually happens when Pu-238 is produced in a Thorium reactor. You start with Th-232, and under neutron flux you'll breed U-233, which is the reactor's main fission fuel. If U-233 is hit by a neutron and absorbs it instead of fissioning then you can end up with U-234, U-235, U-236, Np-237 (through a decay), and Pu-238 (through another decay). However, it's not as though things don't stop there. Pu-238 will breed into Pu-239, Pu-240, and so on, just as in a conventional Uranium power reactor. So here you have the same problem as producing weapons grade Plutonium, you have a process that you need to stop before it goes too far, and in order to do that you need to pull the Plutonium out of the reactor at regular, short intervals. Otherwise you'll just get a buildup of ordinary reactor grade Plutonium. However, the problem is worse here because instead of being the product of just one neutron reaction (natural U-238 becoming Pu-239) the breeding of RTG grade Plutonium is the product of a long chain of reactions (taking 6 steps between the isotopes in the reactor fuel at the start and the production of Pu-238). This means the amount of production and the time scales of production are very much not helpful from the perspective of pure Pu-238 production, especially if you want to also operate a power reactor cost-effectively at the same time. (Edit: also, there's an additional problem, because Thorium reactor fuel contains U-232, which has a short half-life and has decay products that are prodigious gamma ray sources, making reprocessing and handling even more difficult than ordinary reactor fuel. You can handle Plutonium in a glove box, but with used Thorium fuel containing U-232 you'd need to handle it via robotic manipulators in a heavily shielded area distant from humans, except that gamma radiation kills electronics like nobody's business, which is a bit of a catch-22. This is one of the key technical hurdles of Thorium reactor designs in general.) In short, the fact that Thorium reactors produce Pu-238 isn't helpful, because existing reactors do too, but in either case it's hard to get at.
thangalin 13y ago
Directly related ("U.S. Starts Making Plutonium"): http://news.discovery.com/space/nasa-plutonium-production-space-fuel-130314.htm http://news.discovery.com/space/nasa-plutonium-production-sp...
- ChuckMcM 13y ago
  I was going to supply that link as well. We have been working on a restart for a while. Basically the Wired article is just silly.
  - greglindahl 13y ago
    It's easy to read between the lines: The NASA guys think it's likely there will be problems, and that Congress will fail to act quickly when more money is needed.
guelo 13y ago
Actually DOE has started a production program using $10mil appropriated through NASA, http://spaceflightnow.com/news/n1303/20pu238/#.UjuOO6x3O4B http://spaceflightnow.com/news/n1303/20pu238/#.UjuOO6x3O4B The original plan was to fund $10mil through NASA and $10mil through DOE for a total of $20mil per year, but DOE lost their half of the funding due to Solyndra-related politics.
- dalke 13y ago
  You sound like you didn't read the linked-to article, which details all of that except for the Solyndra politics.
  - sliverstorm 13y ago
    There's no ambiguity here. He didn't.
- deleted 13y ago
  [deleted]
robryan 13y ago
$10 million vs $20 million a year? It probably cost congress more to argue about this than the cut has saved.
molecule 13y ago
> NASA’s Plutonium Problem Could End Deep-Space Exploration > By 2005, according a Department of Energy report (.pdf), the U.S. government owned 87 pounds, of which roughly two-thirds was designated for national security projects, likely to power deep-sea espionage hardware... how about the U.S. government does less deep-sea espionage-- in the name of deep-space science?
- rozap 13y ago
  Wow you must be some kind of terrorist to even suggest such a thing.
  - Asterick6 13y ago
    Useless comment, fade away.
- pintglass 13y ago
  Heck, there's Google (https://www.google.com/maps/views/streetview/oceans?gl=us&hl=en-us https://www.google.com/maps/views/streetview/oceans?gl=us&hl...), Virgin Oceanic (http://www.virginoceanic.com/ http://www.virginoceanic.com/), etc. exploring down there. Nothing wrong with a little deep sea action- even the military contribute. It's much cheaper to explore the ocean than it is to explore space, and many benefits like: OTEC (http://en.wikipedia.org/wiki/Ocean_thermal_energy_conversion http://en.wikipedia.org/wiki/Ocean_thermal_energy_conversion http://cleantechnica.com/2013/05/05/lockheed-martin-to-build-worlds-first-ocean-thermal-power-plant-off-china-coast/ http://cleantechnica.com/2013/05/05/lockheed-martin-to-build...), mining ( http://en.wikipedia.org/wiki/Deep_sea_mining http://en.wikipedia.org/wiki/Deep_sea_mining), etc. Others agree: http://www.forbes.com/sites/quora/2013/01/31/why-dont-we-spend-more-on-exploring-the-oceans-rather-than-on-space-exploration/ http://www.forbes.com/sites/quora/2013/01/31/why-dont-we-spe... http://www.cnn.com/2012/04/09/opinion/etzioni-space-oceans/index.html http://www.cnn.com/2012/04/09/opinion/etzioni-space-oceans/i... But, I personally think we should be exploring space and our oceans. We need to make it a top priority of all countries to fund energy and propulsion research to help make exploration cheaper. That means allocating adequate budget and raising taxes for something that the mass media and our government doesn't seem to give much of a shit about, because they don't understand the part of the world we currently are utilizing is running out of resources quickly and that we are constantly a stone's throw from mass extinction.
hereonbusiness 13y ago
It's actually really interesting what a relatively tiny amount of Pu-238 is needed to power deep space missions for decades, 36lb (16.3kg) of Pu-238 amounts to a sphere with a radius of 5.82cm according to wolfram alpha.
strictfp 13y ago
> 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. Biased much?
runarb 13y ago
According to Wikipedia [0] it isn't all sorrows. There are other fuels available in large quantities at a low price, like Strontium-90 used in many Russian radioisotope thermoelectric generators. Other fuels like Americium-241 are also showing big promise, and are available commercially in large quantities. Americium-241 also has a much longer half-life, and can hypothetically power a device for centuries. 0: https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator#Fuels https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...

143 points by hereonbusiness 13y ago

France has the resources to make Pu-238, though I am not sure if they currently have the facilities/equipment. If the situation really is politically impossible in the US and Russia keeps on flaking out, we could always try buying more from the French again and let them deal with the politics. If we are shitcanning missions because we don't have Pu-238, then why doesn't NASA just take the money they would have spent on those programs and spend it on more Pu-238 instead? Surely that should buy us enough Pu-238 for at least remaining uncancelled missions.

maaku 13y ago
> If we are shitcanning missions because we don't have Pu-238, then why doesn't NASA just take the money they would have spent on those programs and spend it on more Pu-238 instead? Surely that should buy us enough Pu-238 for at least remaining uncancelled missions. Requires an act of congress. Need I say more?
- dalke 13y ago
  To elaborate on maaku's answer, as the article points out, "the Atomic Energy Act forbids NASA to manufacture plutonium-238."
  - jlgreco 13y ago
    The idea is for NASA to buy Pu-238, not make it. I am not sure how much Congress micromanages their budget though, it may very well be the case that money meant for probes cannot be redirected to buy Pu-238.
    - dalke 13y ago
      Buy it from ... whom? As the article points out, Russia "reneged on a deal to sell 22 pounds to the U.S." and might not have any left for sale. There are no other producers of 238Pu. (And for that matter, Russia stopped producing it years ago.) Edit: Here's a link for you. http://www.nasa.gov/pdf/636900main_Howe_Presentation.pdf http://www.nasa.gov/pdf/636900main_Howe_Presentation.pdf . > In the past, the United States had an adequate supply of 238Pu, which was produced in facilities that existed to support the U.S. nuclear weapons program. The problem is that no 238Pu has been produced in the United States since the Department of Energy (DOE) shut down those facilities in the late 1980s. Since then, the U.S. space program has had to rely on the inventory of 238Pu that existed at that time, supplemented by the purchase of 238Pu from Russia. However, Russian facilities to produce 238Pu were also shut down many years ago, and the DOE will soon take delivery of its last shipment of 238Pu from Russia. The committee does not believe that there is any additional 238Pu (or any operational 238Pu production facilities) available anywhere in the world. Full details are in "Radioisotope Power Systems: An Imperative for Maintaining U.S. Leadership in Space Exploration", National Research Council committee report. ISBN: 0-309-13858-2, 74 pages, (2009)
      - jlgreco 13y ago
        France could produce it, given time. This is is a situation that has been discused for some time: http://energy.gov/sites/prod/files/nepapub/nepa_documents/RedDont/EA-0841-FONSI-1993.pdf http://energy.gov/sites/prod/files/nepapub/nepa_documents/Re... See the end of that document for discussion of Pu-238 from the UK and France. Notably it was thought in 1993 that France could have Pu-238 production going in a period of a few years ("late 90s" from 1993). To my knowledge the Pu-238 situation in France has not changed one way or the other since then. If the situation is either no more Pu-238, or Pu-238 in several years from France, then I would say that going to the French isn't a terrible idea. We didn't pursue getting Pu-238 from the French at the time because we thought that Russia was going to have us covered.
        dalke 13y ago
        What's the point of referring to a 1993 document when the 2009 document I pointed to says "The committee does not believe that there is any additional 238Pu (or any operational 238Pu production facilities) available anywhere in the world." Yes, anyone with nuclear reactors is functionally able to make 238Pu. The document outlined a possible alternative method to use a 5 MW, licensed TRIGA reactor, available at various universities and in many countries. > "If the situation is either no more Pu-238, or Pu-238 in several years from France, then I would say that going to the French isn't a terrible idea." Why do you think that situation exists when the authors of the National Research Council report on the topic thinks it's not possible? The document says that extensive French facility modifications would be needed, and further discussion would be needed even to establish that that option could be considered. Unlike the UK discussion, there isn't even a mention of how much France might be able to produce. That's your optimism? Is such a facility even still available some 20 years later? So your suggestion is that the US should convince a foreign country to make extensive changes, plus do years of production? Interesting. Why is that better than making it in the US?

zyb09 13y ago

Probably a non-issue, because more Plutonium-238 can be easily created using existing infrastructure. As demand of this stuff goes up and supplies dwindle, someone is gonna make more of it sooner or later.

maaku 13y ago
There are legal constraints on Pu-238. Market forces do not apply, unfortunately...
- spiritplumber 13y ago
  Maybe they can use a box full of old pinball parts.
  - ballard 13y ago
    Mr fusion FTW.
  - tanzam75 13y ago
    > Maybe they can use a box full of old pinball parts. That would be Pu-239, not Pu-238. Remember, the Libyans wanted him to build a bomb -- not a spaceship.
sliverstorm 13y ago
Its production is verboten.

jevinskie 13y ago

> Every so often an atom of neptunium-237 absorbs a neutron emitted by the core’s decaying uranium, later shedding an electron to become plutonium-238. Doesn't it shed a proton to become plutonium 238 and, as a consequence, loses an electron?

pjscott 13y ago
Proper description of what's going on: http://en.wikipedia.org/wiki/Beta_decay http://en.wikipedia.org/wiki/Beta_decay
- jevinskie 13y ago
  Thank you very much, I was under the impression that the electron was lost from the orbital cloud, not the nucleus! Edit: Looking back at my math it was an off-by-one error in the wrong direction. :)
jlgreco 13y ago
http://upload.wikimedia.org/math/5/5/7/557cb46ae9126680a7d579dd5e15015a.png http://upload.wikimedia.org/math/5/5/7/557cb46ae9126680a7d57... Basically one of the neutrons kicks out a beta particle and becomes a proton. The atomic number goes up but the mass number stays the same.

slacka 13y ago

Thorium reactors produce PU-238 as a “free” byproduct. One more reason we should be pursuing LFTR reactor research.

InclinedPlane 13y ago
Erm, sort of. It doesn't actually help that much. As a short, but helpful, side discussion consider the breeding of Pu-239 in a reactor for use in nuclear weapons. Pu-239 works great in a nuclear bomb but other isotopes of Plutonium cause problems, specifically the high spontaneous fission rate of Pu-240 can create so many background neutrons that having a significant amount of it in a bomb can vastly increase the "pre-detonation" (fizzle) risk, which causes the bomb to have very low yield (on the same scale as the chemical explosives in the bomb). As Plutonium remains in a reactor subject to neutron flux it will naturally breed other isotopes, which is why there is a difference between weapons grade and reactor grade Plutonium. Reactor grade Plutonium can contain any variation of isotopes, essentially all of them are suitable for use in a reactor, but weapons grade Plutonium can only have a very small amount of Pu-240. And for this reason the way that weapons grade Plutonium is made is by removing fuel rods from a reactor on very short time scales and reprocessing it to remove the Plutonium then forming it back into new fuel rods and so forth. This is a very costly and complex endeavor which is why you can't just use ordinary power reactors for generating weapons grade Plutonium. Interestingly, Pu-238 also exists in reactor grade Plutonium in substantial amounts (1% or more of the Plutonium, so nearly an entire tonne per year worldwide). However, because it's mixed up with all of the other Plutonium it would require extremely costly isotopic separation. So, how is this relevant to Thorium reactors? Well, let's go back and look at what actually happens when Pu-238 is produced in a Thorium reactor. You start with Th-232, and under neutron flux you'll breed U-233, which is the reactor's main fission fuel. If U-233 is hit by a neutron and absorbs it instead of fissioning then you can end up with U-234, U-235, U-236, Np-237 (through a decay), and Pu-238 (through another decay). However, it's not as though things don't stop there. Pu-238 will breed into Pu-239, Pu-240, and so on, just as in a conventional Uranium power reactor. So here you have the same problem as producing weapons grade Plutonium, you have a process that you need to stop before it goes too far, and in order to do that you need to pull the Plutonium out of the reactor at regular, short intervals. Otherwise you'll just get a buildup of ordinary reactor grade Plutonium. However, the problem is worse here because instead of being the product of just one neutron reaction (natural U-238 becoming Pu-239) the breeding of RTG grade Plutonium is the product of a long chain of reactions (taking 6 steps between the isotopes in the reactor fuel at the start and the production of Pu-238). This means the amount of production and the time scales of production are very much not helpful from the perspective of pure Pu-238 production, especially if you want to also operate a power reactor cost-effectively at the same time. (Edit: also, there's an additional problem, because Thorium reactor fuel contains U-232, which has a short half-life and has decay products that are prodigious gamma ray sources, making reprocessing and handling even more difficult than ordinary reactor fuel. You can handle Plutonium in a glove box, but with used Thorium fuel containing U-232 you'd need to handle it via robotic manipulators in a heavily shielded area distant from humans, except that gamma radiation kills electronics like nobody's business, which is a bit of a catch-22. This is one of the key technical hurdles of Thorium reactor designs in general.) In short, the fact that Thorium reactors produce Pu-238 isn't helpful, because existing reactors do too, but in either case it's hard to get at.

thangalin 13y ago

Directly related ("U.S. Starts Making Plutonium"): http://news.discovery.com/space/nasa-plutonium-production-space-fuel-130314.htm http://news.discovery.com/space/nasa-plutonium-production-sp...

ChuckMcM 13y ago
I was going to supply that link as well. We have been working on a restart for a while. Basically the Wired article is just silly.
- greglindahl 13y ago
  It's easy to read between the lines: The NASA guys think it's likely there will be problems, and that Congress will fail to act quickly when more money is needed.

guelo 13y ago

Actually DOE has started a production program using $10mil appropriated through NASA, http://spaceflightnow.com/news/n1303/20pu238/#.UjuOO6x3O4B http://spaceflightnow.com/news/n1303/20pu238/#.UjuOO6x3O4B The original plan was to fund $10mil through NASA and $10mil through DOE for a total of $20mil per year, but DOE lost their half of the funding due to Solyndra-related politics.

dalke 13y ago
You sound like you didn't read the linked-to article, which details all of that except for the Solyndra politics.
- sliverstorm 13y ago
  There's no ambiguity here. He didn't.
deleted 13y ago
[deleted]

robryan 13y ago

$10 million vs $20 million a year? It probably cost congress more to argue about this than the cut has saved.

molecule 13y ago

> NASA’s Plutonium Problem Could End Deep-Space Exploration > By 2005, according a Department of Energy report (.pdf), the U.S. government owned 87 pounds, of which roughly two-thirds was designated for national security projects, likely to power deep-sea espionage hardware... how about the U.S. government does less deep-sea espionage-- in the name of deep-space science?

rozap 13y ago
Wow you must be some kind of terrorist to even suggest such a thing.
- Asterick6 13y ago
  Useless comment, fade away.
pintglass 13y ago
Heck, there's Google (https://www.google.com/maps/views/streetview/oceans?gl=us&hl=en-us https://www.google.com/maps/views/streetview/oceans?gl=us&hl...), Virgin Oceanic (http://www.virginoceanic.com/ http://www.virginoceanic.com/), etc. exploring down there. Nothing wrong with a little deep sea action- even the military contribute. It's much cheaper to explore the ocean than it is to explore space, and many benefits like: OTEC (http://en.wikipedia.org/wiki/Ocean_thermal_energy_conversion http://en.wikipedia.org/wiki/Ocean_thermal_energy_conversion http://cleantechnica.com/2013/05/05/lockheed-martin-to-build-worlds-first-ocean-thermal-power-plant-off-china-coast/ http://cleantechnica.com/2013/05/05/lockheed-martin-to-build...), mining ( http://en.wikipedia.org/wiki/Deep_sea_mining http://en.wikipedia.org/wiki/Deep_sea_mining), etc. Others agree: http://www.forbes.com/sites/quora/2013/01/31/why-dont-we-spend-more-on-exploring-the-oceans-rather-than-on-space-exploration/ http://www.forbes.com/sites/quora/2013/01/31/why-dont-we-spe... http://www.cnn.com/2012/04/09/opinion/etzioni-space-oceans/index.html http://www.cnn.com/2012/04/09/opinion/etzioni-space-oceans/i... But, I personally think we should be exploring space and our oceans. We need to make it a top priority of all countries to fund energy and propulsion research to help make exploration cheaper. That means allocating adequate budget and raising taxes for something that the mass media and our government doesn't seem to give much of a shit about, because they don't understand the part of the world we currently are utilizing is running out of resources quickly and that we are constantly a stone's throw from mass extinction.

hereonbusiness 13y ago

It's actually really interesting what a relatively tiny amount of Pu-238 is needed to power deep space missions for decades, 36lb (16.3kg) of Pu-238 amounts to a sphere with a radius of 5.82cm according to wolfram alpha.

strictfp 13y ago

> 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. Biased much?

runarb 13y ago

According to Wikipedia [0] it isn't all sorrows. There are other fuels available in large quantities at a low price, like Strontium-90 used in many Russian radioisotope thermoelectric generators. Other fuels like Americium-241 are also showing big promise, and are available commercially in large quantities. Americium-241 also has a much longer half-life, and can hypothetically power a device for centuries. 0: https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator#Fuels https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...