UPDATE:
Proabably need 4 total starships, with 3 as tankers to get 13km/s for a 15 day transit to Mars. 2 Total Starship only gets us to 10km/s which is 3km/s shy of what’s needed. Original 2 ship idea could probably get us closer to 28 days.
Numbers: https://docs.google.com/spreadsheets/d/1U_pj_0jc53wAgq37A0oYvuiZnMFLptZ3B4N1quCniVo/edit?usp=sharing
Ref: https://www.exploremars.org/wp-content/uploads/2021/09/0914_03-15_Bret-Drake_Trajectory.pdf
According to AI: 15 days to Mars using “conjunction class” orbital transfer with 2 Starships working together. One will be an uncrewed expendible fuel tank with it’s useful payload as additional fuel. The tanker flies in parallel with crewed ship at a safe distance or attached to it.
This allows 15 days transfer to Mars from Earth’s LEO and does not require risky aerobraking on the Martian side as there is sufficient fuel to de-celerate.
Still need to confirm underlying working using rocket equation. This is assuming there is another Starship there on Mars already sent uncrewed or as a robotic mission (with Tesla bots and AI) and fueled up using local resources on Mars. This is for the return trip.
New Mars Forum Thread on this topic:
https://newmars.com/forums/viewtopic.php?id=11019