Decades to get from Jupiter to Neptune? And this is a “superhighway”? We can get from Earth to beyond Pluto in just a few years.
I’m thinking about Mars in about a week?
Fastest we did it was about 11 years - and that’s just basic straight line to reach the orbit - reaching a specific planet gets more complex if one wants to start today and be where the planet is at a given time. Neptune take about 165 years to make an orbit.
Yeah, but we don’t stop.
It takes as much propellant to stop the vehicle as it does to accelerate it.
So we’re going to need some sort of drive that allows constant, relatively high acceleration over longs periods to bring that number down. Say 1G for weeks, or even months and years...