Posting this ahead of Kris Zacny's discussion on analog field sites.
Microorganisms swept up from the Earth's surface are floating in the stratosphere (about 17 to 50 km above sea level); an environment that is extremely dry, frozen, irradiated, and hypobaric. Sound familiar?
Both Mars exploration and balloon-based stratospheric microbiology experiments must detect microbial signatures without false positives (i.e. contamination) on flight hardware that operates autonomously in harsh conditions. Moreover, balloon-based stratospheric microbiology research can improve our understanding of UV-resistant microbial species. Post-landing irradiation on Mars is an often-cited kill mechanism for contaminated spacecraft, but we may discover viable stratospheric microbes that can tolerate more UV than currently known ground species.
For these reasons, I would like to see the stratosphere included in the Mars analog discussion. Programmatically, it seems reasonable to require future astrobiology missions with life detection instrument payloads to demonstrate technology readiness in the upper atmosphere (e.g., instrument sensitivity, in-flight sterilization or contamination containment).
I would also suggest that a review of existing planetary protection methods be evaluated and the risk quantified for contamination of actual Mars missions by airborne microbes.
I agree. Even if we don't land in "special regions" on Mars, the microbial hitchhikers could very well be blown over to one. More work needs to be done measuring & modeling long range microbial dispersal from spacecraft.
I was thinking one way to test the concern and gain some attention would be to gain some samples from the outside of the ISS (EVA) and see if any microbes can be grown in a suitable media. I see a solicitation for student experiments on the ISS. Are there any solicitations for non-students available?