Dreaming big: planning a human mission to outer solar system

The problem I see with this mission is that it's essentially another "flags and footprints" mission on a grand scale: yes, the mission time is much longer, so perhaps there would be time to do something valid at Neptune or Saturn, but there aren't many things that could be done on such a mission that would make it cost-positive with an initial cost of $14 trillion. So what happens? We go once, can't afford to go again, and suddenly everything in the inner system is anticlimactic and the public loses interest in space for another 40 years.

50's Orion pulse-detonation combined with a "living off the land" strategy would enable manned exploration of the outer solar system in short order.

MPD thrusters might be good for manned Mars missions, but robotic probes are still a much better deal for the outer system.

I had a thought regarding the radiation shielding issue I'm not sure how they calculated the mass but it seems to me if they focused on shielding the sleeping "pods" and allowed other common activities to be completed with these small areas so the crew could spend upwards of 80% of the trip in these tiny protected areas of the ship then they could greatly reduce the protection material needed...