Replies

I have been thinking about this for some years.
Of course, I am a layman, so I might be totally out of my depth, but here's the gist of what I think might be a practical interplanetary NON-LANDING shuttle's propulsion and power systems.
1. a nuclear powered electrical generator, providing primary ship power and power for the ion drive. The ion drive would be used for sustained acceleration at low deltaV on the long legs between planets.
2. several compact nucler-hydrogen rockets, for use as brute thrusters for large deltaV manoeuvers such as accelerating out of or dropping into specific orbits in gravity wells.
3. redundant plutonium decay "batteries" for emergency backup power.

The shuttles I envision are roughly the size of a small attack submarine, like a Skipjack. They would rotate around their long axis (which is also the thrust axis of the ion drive) to simulate gravity during the long haul between worlds. Payloads and landing vehicles would essentially be bolted onto the frame. These things should be used like tugs. They themselves would NEVER land on a planetary body.