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Basically a vehicle/space station(s) that continually orbit between the Sun and Jupiter.

Ulysses does that. It's in a solar polar orbit. Luckily I don't have to try and say that.

[FireTrack]

No doubt in my mind that it can be done with some occasional autonomous corrections needed. For such a vessel to be useful would require an orbit in the same plane as the planets instead of perpendicular like the orbit of the Ulysses probe.

I envision an initial formation of two craft. Second craft following months behind the first. Crew from Earth docks with the second vessel and refuels landing shuttle from fuel stored aboard the Deep Space Orbiter (DSO). The crew lives aboard the DSO on the trip out to mars in relative comfort, safety and for a shorter time due to higher speed possible with using the DSO concept.

Upon approach to Mars, crew lands on Mars using the much smaller lander. After several months exploring the Mars surface, crew departs using the lander (refueled from storage tanks left on Mars) and docks and with the first DSO which has completed an orbit around Jupiter and is diving back toward Earth and a loop around the sun. Crew refuels lander from fuel stored aboard first DSO in preparation for return landing on Earth

Crew departs DSO again using lander when in proximity to Earth. Slows from 60,000 plus mph to 25,000 to 30,000 for Earth landing.

Re-supply of DSO vessels could eventually be made primarily from facilities and supply vessels located strategically throughout the asteroid belt.

Numerous DSO vehicles would increase windows of opportunity for voyages to Mars and asteroids as well as providing a superb platforms for scientific research of all types (i.e. optical and radio astronomy, Jupiter and Solar research, jumping off platform for outer planet probes and etc.)