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The probes get their power from the decay of a plutonium isotope. The question is why can't we find applications for this technology on earth, for example to po

The probes get their power from the decay of a plutonium isotope. The question is why can't we find applications for this technology on earth, for example to power your house or something?

allisvancity 4y ago
They evidently used to use radiothermal generators (RTGs) as the power source for some pacemakers. https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator#History https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge... Plutonium is nasty & expensive stuff, however. That puts some pretty severe limitations on its usefulness for domestic purposes.
- 1letterunixname 4y ago
  RTGs in humans: not for a long time.
deleted 4y ago
[deleted]
neaden 4y ago
It's a very small, but stable, amount of power generated given the amount of plutonium and the costs/risks of it it's not really worth it for anything else. Geothermal for instance for a home would make much much sense.
speed_spread 4y ago
The USSR did that for a while. It didn't end well for some people. https://en.m.wikipedia.org/wiki/Lia_radiological_accident https://en.m.wikipedia.org/wiki/Lia_radiological_accident
- FridayoLeary 4y ago
  Thanks for that source. Maybe it's impractical for domestic use but it looks like they found uses for it in isolated locations for industrial purposes. Obviously it needs to be handled responsibly.
  - speed_spread 4y ago
    > needs to be handled responsibly. Yes, for the next 10000 years. Plutonium's half life is annoyingly long.
    - mlyle 4y ago
      RTGs don't use things with 10,000 year half lives, because they need to have meaningful amounts of decay happening to make heat. 238Pu is pretty common, because it produces just alpha decay and has a half life of 87 years. Within 1000 years, the main remaining activity is 234U with a half life of 240,000 years: still an alpha emitter but much, much less active.
- Tade0 4y ago
  > Around the canisters there was no snow for about a 1 m (3.3 ft) radius, and the ground was steaming. I recall a discussion on HN about securing radioactive waste sites so that future, possibly illiterate, generations would understand the danger and keep off. Reading this I'm starting to doubt it's possible. I mean, no snow and steaming ground? Clearly suspicious. And this was the 21st century - these people must have been at least vaguely aware that nuclear power exists.
magicalhippo 4y ago
The problem is not finding applications. The problem is cost and safety. In space they make sense because as you go far enough away from the sun, solar power is negligible. Since it costs a lot to launch, the cost of the RTG itself isn't such a big deal. And you only have to worry about safety for a little while. Relying on the thermoelectric effect, they're horribly inefficient. Here on earth we have other options that are more efficient, cost less and is way safer.
- sgtnoodle 4y ago
  The heat may be inherently useful for keeping the spacecraft warm enough to operate, mitigating some of that inherent inefficiency.
creatonez 4y ago
They have a lot of advantages, but they are extraordinarily expensive, screamingly radioactive, require nuclear weapons technology to manufacture, and are inefficient in the amount of energy you put in vs. get out. Even for space missions, the tradeoff of just using solar panels (which have a ton of problems in space) is often worth it. It's not easy to get an RTG approved for your multi-billion dollar space mission.
OkayPhysicist 4y ago
Forget all the minor concerns about nuclear proliferation and cost. RTGs just have a very small niche of useful applications RTGs are basically just a thermocouple stuck to a chunk of radioactive material, which gets hot. They are dramatically less efficient than a nuclear power plant, so it really doesn't make sense to use them in situations where a nuclear power plant is an option. That limits them to relatively small things (because your submarine or ship or whatever can have a proper power plant), that can't be connected to a power grid (because you could just have your power plant elsewhere), even periodically (because you could just use batteries), that can't harness more easily available sources of power like the sun or wind, and can carry the shielding necessary to make them safe. Ultimately, that narrows down their applicability greatly.

The probes get their power from the decay of a plutonium isotope. The question is why can't we find applications for this technology on earth, for example to power your house or something?

allisvancity 4y ago

They evidently used to use radiothermal generators (RTGs) as the power source for some pacemakers. https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator#History https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge... Plutonium is nasty & expensive stuff, however. That puts some pretty severe limitations on its usefulness for domestic purposes.

1letterunixname 4y ago
RTGs in humans: not for a long time.

deleted 4y ago

[deleted]

neaden 4y ago

It's a very small, but stable, amount of power generated given the amount of plutonium and the costs/risks of it it's not really worth it for anything else. Geothermal for instance for a home would make much much sense.

speed_spread 4y ago

The USSR did that for a while. It didn't end well for some people. https://en.m.wikipedia.org/wiki/Lia_radiological_accident https://en.m.wikipedia.org/wiki/Lia_radiological_accident

FridayoLeary 4y ago
Thanks for that source. Maybe it's impractical for domestic use but it looks like they found uses for it in isolated locations for industrial purposes. Obviously it needs to be handled responsibly.
- speed_spread 4y ago
  > needs to be handled responsibly. Yes, for the next 10000 years. Plutonium's half life is annoyingly long.
  - mlyle 4y ago
    RTGs don't use things with 10,000 year half lives, because they need to have meaningful amounts of decay happening to make heat. 238Pu is pretty common, because it produces just alpha decay and has a half life of 87 years. Within 1000 years, the main remaining activity is 234U with a half life of 240,000 years: still an alpha emitter but much, much less active.
Tade0 4y ago
> Around the canisters there was no snow for about a 1 m (3.3 ft) radius, and the ground was steaming. I recall a discussion on HN about securing radioactive waste sites so that future, possibly illiterate, generations would understand the danger and keep off. Reading this I'm starting to doubt it's possible. I mean, no snow and steaming ground? Clearly suspicious. And this was the 21st century - these people must have been at least vaguely aware that nuclear power exists.

magicalhippo 4y ago

The problem is not finding applications. The problem is cost and safety. In space they make sense because as you go far enough away from the sun, solar power is negligible. Since it costs a lot to launch, the cost of the RTG itself isn't such a big deal. And you only have to worry about safety for a little while. Relying on the thermoelectric effect, they're horribly inefficient. Here on earth we have other options that are more efficient, cost less and is way safer.

sgtnoodle 4y ago
The heat may be inherently useful for keeping the spacecraft warm enough to operate, mitigating some of that inherent inefficiency.

creatonez 4y ago

They have a lot of advantages, but they are extraordinarily expensive, screamingly radioactive, require nuclear weapons technology to manufacture, and are inefficient in the amount of energy you put in vs. get out. Even for space missions, the tradeoff of just using solar panels (which have a ton of problems in space) is often worth it. It's not easy to get an RTG approved for your multi-billion dollar space mission.

OkayPhysicist 4y ago

Forget all the minor concerns about nuclear proliferation and cost. RTGs just have a very small niche of useful applications RTGs are basically just a thermocouple stuck to a chunk of radioactive material, which gets hot. They are dramatically less efficient than a nuclear power plant, so it really doesn't make sense to use them in situations where a nuclear power plant is an option. That limits them to relatively small things (because your submarine or ship or whatever can have a proper power plant), that can't be connected to a power grid (because you could just have your power plant elsewhere), even periodically (because you could just use batteries), that can't harness more easily available sources of power like the sun or wind, and can carry the shielding necessary to make them safe. Ultimately, that narrows down their applicability greatly.