re: Sample in situ study
Instead of returning samples back to a laboratory, take the laboratory to Mars.
It makes sense as those "laboratories" become more and more sophisiticated and miniaturized!
Also, that way it would be easier to go everywhere in the solar system, and faster.
It's just that a sample is a kind of relic, a collectible, but if we have a very good remote idea of a Mars rock, we could reconstitute one with earth matter.
Raoul