4 ms·
A good reason is the lack of availability of the needed isotope (Pu238). The Europa Clipper has a huge array of solar panels instead of an RTG due to the last
by jordanb 2y ago
A good reason is the lack of availability of the needed isotope (Pu238).
The Europa Clipper has a huge array of solar panels instead of an RTG due to the last of the available supply going into the New Horizons spacecraft.
Pu238 was a cast-off isotope from nuclear weapons development so it was more readily available during the cold war. We should be happy that it's scarce now.
Also solar panels have gotten a lot better than they were when Voyager was launched, but even today anything going out past Saturn is not going to be able to use solar energy.
- wffurr 2y agoThere was just an article about a whole array of “nuclear batteries” using all sorts of decent chemistry: https://news.ycombinator.com/item?id=42118306 https://news.ycombinator.com/item?id=42118306 Are any of those candidates or are they just too small or with too poor a mass ratio compared to plutonium RTGs?
- jordanb 2y agoMaybe. I don't know. I'd point out that tritium is a gas, so it may be hard to contain for long periods of time especially in space.