You sound like somebody who knows that the US has probes all over the solar system already including one on the way to Pluto, whatever you decide to call it anymore, planet, dwarf planet, relatively small hunk of mass that moves like a planet etc.[/quote]
There aren’t really that many probes going around.
Between them, Jupiter and Saturn have over 120 moons. If you’re going to go check out each one, it’ll be a lot more efficient to send probes first.
If a few prove to be particularly interesting later, then you can go for a manned mission.
As cool as it is, sending people is a lot harder.
First, I’d guess that most want to come back. So if you send someone to Mars, he either has to have a way of getting fuel there for the trip back, or he has to bring his return fuel with him. That adds a lot of weight.
And probes don’t need water, air, a nice comfy temperature, etc. Whoever you send need to bring his environment along with him. If it’s six month to go and six months back to Mars, you need 1 year worth of food per person you send.
You also have to shield them a lot better against space radiation; adding still more weight to the whole thing. You have to get them safely down to Mars. Mars has a lot more gravity than the Moon. It also has atmosphere, not much, but enough for it to be a problem for entry.
Then there are the psychological factors of being cooped up in a small space for months at a time, either alone or in a small group. Can you keep them busy enough that they don’t end up killing each other on the way there?
Any accident along the way has to be provided for. Ultimately, you need so many backups that you almost end up bring along a second ship… yet more cost. If you don’t, then you’re hoping for a multi-year space mission where nothing ever goes wrong. Just look at how many Mars probe NASA has lost over the years. Imagine if there had been a crew on each of them…
I like the romantic idea of visiting each planet and traveling to the stars. But at our current technology level, and with the budgets we’re willing to devote to it, space travel is best left to automatic machines for now.
And probes can do a lot more than just photo ops.