NASA plans to launch a spacecraft to Titan

Re:NASA plans to launch a spacecraft to Titan by bduerst on Friday June 28, 2019 @07:03PM (#20309526)

Probably a dumb question, but how does the nuclear source work? Nuclear powerplants work by heating steam to turn a turbine. This drone won't have heavy water reservoirs so how does it convert the fission heat into electricity? Stirling engine?

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Re:NASA plans to launch a spacecraft to Titan by Gibbon1 on Friday June 28, 2019 @07:22PM (#20309649)

Most nuclear power sources for space stuff works by Peltier effect. See Radioisotope thermoelectric generator.

radio-isotope decay -> heat -> Peltier stack -> electricity.

Advantages: no moving parts, no vibration, infinitesimal mass change, exceedingly reliable. 'Small'

Disadvantage: Efficiency kinda crummy at ~5%. Slowly loses output as fuel decays and the Peltier stack degrades.

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Re:NASA plans to launch a spacecraft to Titan by petascale on Friday June 28, 2019 @07:27PM (#20309670)

Probably an RTG [1], it's what NASA normally uses. It's thermoelectric [2]: Heat (in this case from radioactive decay) is converted directly into electricity without moving parts.

[1] https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...

[2] https://en.wikipedia.org/wiki/Thermoelectric_effect#Seebeck_...

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Re:NASA plans to launch a spacecraft to Titan by ekianjo on Friday June 28, 2019 @07:29PM (#20309689)

Just like nuclear sources work on sattelites. You produce heat with fission or nuclear degradation and then thermoelectric conversion.

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