Isn't it smart to invest in Nuclear? Sure, there might be drawbacks right now but if we invest in research and improve it we might find a way to make it "greener"?

Also we seem to be focusing on space exploration again. To take off we're always using fossil fuel. I'm going to take a wild guess and assume that you cannot take a ship into space with wind and solar. Also a wild guess but if we develop nuclear enough we might get smaller generators that are able to help a ship take off and then continue to have energy while in space. I know too little to make these claims but I'm sure the smart people here can help me understand if I am wrong or correct :)