Why rescue? Colonize from the start!
The first manned mission to Mars should be a real pathfinder:
The establishment of a permanent colony right off the bat!
Otherwise you run the risk of another Apollo, where we pick up
a few rocks, leave some footprints and flags, and then don't go
back for another half century.
You know there are plenty of people who would like to start a
new life on a new world, with no turning back. The first missions
to Mars with humans aboard should plan on staying there. They
can always ships surface samples back to Earth on a robot craft.