>>10936534>Why don't we explore them?We've done, and continue to do, some pretty extensive explorations by robotic probes.
Manned flights come with some challenges.
First, they are a long way away on any sort of reasonable approach trajectory. We do not have, nor have we ever had, a spacecraft that would carry a crewman on that sort of journey, and ideally you want a crew of more than one, unless you just want to claim "First Man at Jupiter" as you fly by and head home.
Missions of such long duration expose you to all sorts of hazard from Solar and Cosmic radiation. On short jaunts to the moon, you can play the odds (and watch the solar weather before launch) and miss the worst of it. But A mission to Jupiter would last for YEARS, to the other giants much longer -- the chance of getting clobbered by solar of cosmic ray flux higher than you can survive begins to approach a certainty. You can carry shielding against all that, but every pond you take means more reaction mass, and makes your ship more expensive, complex and difficult.
Plus at some of them, the local radiation situation is sort of what scientists like to call "bad."
IF we expand out away from Earth, we'll have to at least figure out Jupiter: it has a shit-ton of useful stuff in orbit, and down in the atmosphere if you can figure a way to go get it. The others might get a Armstrong visit some day, but I'm not sure they'll ever be worth more than a quick nod and wave, unless tourism to Saturn, maybe.
