From Dr. Zubrin's Reddit AMA:
> for Mars Ascent and Earth return, SpaceX should develop a mini Starship, sized to be an upper stage of an F9. This would create a fully reusable medium lift booster, and reduce Mars propellant making requirements by a factor of 5. A Starsip could lift one of these to LEO fully fueled, after which it could fly to Mars, and return. any full sized Starships that land on Mars should stay on Mars. SpaceX will make plenty of Starships, it won't need any back that go to Mars. A Starship on Mars is much more valuable than one on Earth.
https://old.reddit.com/r/spacex/comments/hgy64k/ask_me_anyth...