Re: Nuclear....
<...few if anyone would support reactors being flown to get to a particularly difficult space science target a little quicker... especially when there are so many cheap nonnuclear missions waiting to be flown.
A reality check is definitely in order here....
Of course, once you HAVE spent the money and developed nuclear systems, then a LOT of targets suddenly become a lot easier to get to, not just one. "Grand Tour" type missions might become more practical without planets having to be in ideal orbital positions.