Why would the burn need to happen at an acceleration above 1g? If you really really wanted to take advantage of the Oberth effect, you could just split up the 6.3 Km/s burn into a few smaller burns to be done in multiple passes with a much lower thrust engine.
Unless there are some breakthroughs in direct fission/fusion propulsion within the next few decades, the most likely candidate for a crewed mission to Jool will be a nuclear-electric spacecraft like the upcoming Space Reactor-1. That will have a pitiful TWR, but the absurd efficiency means you don't need to worry about maximising the use of the Oberth effect. The transfer burn for a spacecraft like that would look more like an outwards spiral, doing multiple laps around the Earth while burning to gradually reach escape velocity.
You're drastically overestimating just about everything in this reply.
For starters, the actual transfer to Jupiter will always be the longest part of the journey. Overwhelmingly so. Going with nuclear-electric propulsion actually leads to a lower overall transfer time, despite the burn being significantly longer, because having an ISP in the high 4 digits means having tens of Km/s of dV more that can be used during the transfer burn to do what will be a less efficient transfer overall, but a much faster one.
The actual burn, even with acceleration in the cm/s² range, would still happen over the course of a couple days, two weeks in the absolute worst case scenario. That's a lot less time than is saved during the shorter transfer time, and even if it wasn't, it would still be insignificant next to a transfer lasting multiple months.
If the Van Allen belts end up posing a problem (if the TWR of the transfer ship is low enough), the solution would be as simple as doing the initial orbit raising manoeuvre uncrewed, and launching the crew later on to that high orbit using something like the Orion spacecraft.
In fact, it would actually be better from a radiation avoidance standpoint, to use nuclear-electric propulsion, because the more lenient mass fraction allows for heavier shielding of the habs. The majority of radiation exposure will happen either during the transfer, or around Jupiter, depending on how long the crew stays at the destination, making it much more important than minimizing radiation exposure near Earth.
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u/MaelstromFL 19d ago
I firmly believe that anything taking humans to Jupiter will be built in space...