Water and microbial monitoring technologies towards the near future space exploration

Space exploration is demanding longer lasting human missions and water resupply from Earth will become increasingly unrealistic. In a near future, the spacecraft water monitoring systems will require technological advances to promptly identify and counteract contingent events of waterborne microbial contamination, posing health risks to astronauts with lowered immune responsiveness. The search for bio-analytical approaches, alternative to those applied on Earth by cultivation-dependent methods, is pushed by the compelling need to limit waste disposal and avoid microbial regrowth from analytical carryovers. Prospective technologies will be selected only if first validated in a flight-like environment, by following basic principles, advantages, and limitations beyond their current applications on Earth. Starting from the water monitoring activities applied on the International Space Station, we provide a critical overview of the nucleic acid amplification-based approaches (i.e., loop-mediated isothermal amplification, quantitative PCR, and high-throughput sequencing) and early-warning methods for total microbial load assessments (i.e., ATP-metry, flow cytometry), already used at a high readiness level aboard crewed space vehicles. Our findings suggest that the forthcoming space applications of mature technologies will be necessarily bounded by a compromise between analytical performances (e.g., speed to results, identification depth, reproducibility, multiparametricity) and detrimental technical requirements (e.g., reagent usage, waste production, operator skills, crew time). As space exploration progresses toward extended missions to Moon and Mars, miniaturized systems that also minimize crew involvement in their end-to-end operation are likely applicable on the long-term and suitable for the in-flight water and microbiological research.

Planetary protection classification of samples returned from the martian moons: Summary of a review by the European Science Foundation and the National Academies of Sciences, Engineering and Medicine

This work summarizes the review undertaken by a joint committee of the European Science Foundation and the National Academies of Sciences, Engineering and Medicine into the transfer of viable organisms from the surface of Mars to its moons-Phobos and Deimos-as a consequence of a giant impact on the martian surface. The possibility that viable organisms could survive ejection from Mars and subsequent deposition on Phobos and Deimos is an important consideration in determining whether samples returned from the moons by spacecraft missions be classified as restricted or unrestricted Earth return in the consensus planetary protection guidelines maintained by the Committee on Space Research (COSPAR) of the International Council for Science. Having reviewed recent research undertaken in Europe and Japan, the joint committee recommended that samples returned from the martian moons be classified as unrestricted Earth return. This paper is not intended to be a standalone work. Rather, it should be regarded as a summary of, and advertisement for, the material presented in the joint committee's formal report, Planetary Protection Classification of Samples Return Missions from the Martian Moons (the National Academies Press, 2019).

Planetary Protection and Mars Special Regions--A Suggestion for Updating the Definition

We highlight the role of COSPAR and the scientific community in defining and updating the framework of planetary protection. Specifically, we focus on Mars "Special Regions," areas where strict planetary protection measures have to be applied before a spacecraft can explore them, given the existence of environmental conditions that may be conducive to terrestrial microbial growth. We outline the history of the concept of Special Regions and inform on recent developments regarding the COSPAR policy, namely, the MEPAG SR-SAG2 review and the Academies and ESF joint committee report on Mars Special Regions. We present some new issues that necessitate the update of the current policy and provide suggestions for new definitions of Special Regions. We conclude with the current major scientific questions that remain unanswered regarding Mars Special Regions.