> For another view on how this will change things, consider the delta-V map of the Solar System [1]. As an example you need 45km/s to reach Saturn, roughly 20%

> For another view on how this will change things, consider the delta-V map of the Solar System [1]. As an example you need 45km/s to reach Saturn, roughly 20% of that is just spent getting to Low Earth Orbit. Actually, it's 19km/s less than that. You want your destination to be Low Saturn Orbit, not Saturn. You've included the 19km/s that it takes to launch from Saturn to low Saturn orbit. It's even less again if you can aerobrake at Saturn.