[TaylorAlexander]

I think the very big rocket planned for launch in a few days will, if successful, help a lot with this. Chemical rockets aren't the best but if we can launch much larger payloads, we can design deep space rockets that consume a lot more fuel to get there faster. Imagine a multi stage rocket which is assembled in orbit from multiple Starship launches, and then blasts off to the outer worlds.

[mdorazio]

I don't think you would need to assemble anything in space. Starship's planned LEO payload is about a third of the entire mass of the Ariane 5 rocket that launched Juice. If you have that kind of mass budget at orbit, your delta v capability is pretty massive for a space probe.