Re:NASA plans to launch a spacecraft to Titan
by Sharlin on Friday June 28, 2019 @03:28PM
(#20307990)
No fission reaction, just radioactive decay in Dragonfly's case. It will use an RTG (radioisotope thermoelectric generator) not unlike Curiosity and most missions to the outer planets to date.
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Re:NASA plans to launch a spacecraft to Titan
by thatcherc on Friday June 28, 2019 @06:55PM
(#20309478)
Just a note - radioactive decay is is fission, since it involves a nucleus splitting apart.
Re:NASA plans to launch a spacecraft to Titan
by Sharlin on Saturday June 29, 2019 @06:12AM
(#20311744)
No, not quite. One of the types of radioactive decay is spontaneous fission, but it's not relevant in the context of RTGs. Alpha decay (the emission of a 4He nucleus) might in principle be called "fission" but in practice is not. Beta decay involves no splitting whatsoever.
RTGs are heavy; I suppose this means that it'll park itself for a long time to charge its batteries and then do a quick flight and repeat. Which sounds like it could work pretty well for this use case.
On the other hand, a hot-air balloon kept aloft by excess heat from radioactive metal might be a more attractive option if we were selecting proposals based on awesomeness.