4 ms·

They didn't shoot nuclear reactor cores into space. RTGs are still dangerous but people do stand next to them. https://en.wikipedia.org/wiki/Radioisotope_therm

by pvg 4y ago

They didn't shoot nuclear reactor cores into space. RTGs are still dangerous but people do stand next to them. https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator#/media/File:RTG_radiation_measurement.jpg https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...

perihelions 4y ago
Believe it or not, lots of nuclear fission satellites in the 1960's-70's. https://en.wikipedia.org/wiki/Nuclear_power_in_space#Fission_systems https://en.wikipedia.org/wiki/Nuclear_power_in_space#Fission...
- pvg 4y ago
  You're right, I didn't realize they fired quite that many (31?!) BES-5s into space and those are really the only non-experimental ones. Still, the chances of one of those falling out of orbit as a functioning reactor are about nil.
  - perihelions 4y ago
    The posterior probability, given that you've already found a very rare piece of space debris, would have been high. https://xkcd.com/795/ https://xkcd.com/795/ (By the way, there's an documented instance [0] mentioned in the sibling comments. The hazard is much worse than you'd think: the space reactor didn't simply fall in one piece, but left a trail of fragments 600 km long, some of which were lethally radioactive. It's pretty lucky this one happened in an uninhabited wasteland). [0] https://en.wikipedia.org/wiki/Kosmos_954 https://en.wikipedia.org/wiki/Kosmos_954
    - pvg 4y ago
      Yes but those dangers are the dangers of radioactive material - it's naturally 'hot', much of it also chemically toxic, etc. It's not core-at-criticality-that-murders-you-as-you-stand-next-to-it type of dangerous. I think that's still an essentially hypothetical danger of nuclear space junk.
      - robonerd 4y ago
        As a general rule, it's not reactors functioning inside design parameters that are cause for concern, but rather failed reactors that have spew their guts and stopped working. Those are the reactors that will fuck you up.
Teknoman117 4y ago
Some of the Russian satellites had full-on liquid cooled nuclear reactors, not RTGs. https://en.m.wikipedia.org/wiki/TOPAZ_nuclear_reactor https://en.m.wikipedia.org/wiki/TOPAZ_nuclear_reactor The flight profile did indeed have the reactor core being ejected into a graveyard orbit before deorbiting the satellite: https://en.m.wikipedia.org/wiki/Kosmos_954 https://en.m.wikipedia.org/wiki/Kosmos_954 The US ran a couple of experiments but otherwise didn't officially use them: https://en.m.wikipedia.org/wiki/SNAP-10A https://en.m.wikipedia.org/wiki/SNAP-10A

by pvg 4y ago

perihelions 4y ago

Believe it or not, lots of nuclear fission satellites in the 1960's-70's. https://en.wikipedia.org/wiki/Nuclear_power_in_space#Fission_systems https://en.wikipedia.org/wiki/Nuclear_power_in_space#Fission...

pvg 4y ago
You're right, I didn't realize they fired quite that many (31?!) BES-5s into space and those are really the only non-experimental ones. Still, the chances of one of those falling out of orbit as a functioning reactor are about nil.
- perihelions 4y ago
  The posterior probability, given that you've already found a very rare piece of space debris, would have been high. https://xkcd.com/795/ https://xkcd.com/795/ (By the way, there's an documented instance [0] mentioned in the sibling comments. The hazard is much worse than you'd think: the space reactor didn't simply fall in one piece, but left a trail of fragments 600 km long, some of which were lethally radioactive. It's pretty lucky this one happened in an uninhabited wasteland). [0] https://en.wikipedia.org/wiki/Kosmos_954 https://en.wikipedia.org/wiki/Kosmos_954
  - pvg 4y ago
    Yes but those dangers are the dangers of radioactive material - it's naturally 'hot', much of it also chemically toxic, etc. It's not core-at-criticality-that-murders-you-as-you-stand-next-to-it type of dangerous. I think that's still an essentially hypothetical danger of nuclear space junk.
    - robonerd 4y ago
      As a general rule, it's not reactors functioning inside design parameters that are cause for concern, but rather failed reactors that have spew their guts and stopped working. Those are the reactors that will fuck you up.

Teknoman117 4y ago

Some of the Russian satellites had full-on liquid cooled nuclear reactors, not RTGs. https://en.m.wikipedia.org/wiki/TOPAZ_nuclear_reactor https://en.m.wikipedia.org/wiki/TOPAZ_nuclear_reactor The flight profile did indeed have the reactor core being ejected into a graveyard orbit before deorbiting the satellite: https://en.m.wikipedia.org/wiki/Kosmos_954 https://en.m.wikipedia.org/wiki/Kosmos_954 The US ran a couple of experiments but otherwise didn't officially use them: https://en.m.wikipedia.org/wiki/SNAP-10A https://en.m.wikipedia.org/wiki/SNAP-10A