Mars Sample Return Concepts and References

(It may be important to note: sample return is not a necessary precursor to human exploration,
and, some robust sample return missions are proposed as follow-ups of on-going
human settlement.)

Gorgeous 2020 MSR Concept by Corby Waste for NASA JPL

Earlier MSR Concepts also by Corby Waste for NASA JPL

Even Earlier Concepts by Corby Waste for NASA JPL