New research published in the journal Microbiome, reported that monitoring how microorganisms adjust to the confined conditions on-board spacecraft was important for safety environment for astronauts on long-duration space missions such as a journey to Mars.
The corresponding author of the study, Dr Petra Schwendner, said, "Until now, little was known about the influence of long-term confinement on the microorganisms that live in habitats that may one day be used to travel to other planets, and whether the structure of the microbiota changes with time. Ours is the first comprehensive long-time study that investigates the microbial load, diversity and dynamics in a closed habitat — a mock-up spacecraft — for 520 days, the full duration of a simulated flight to Mars."
The team of researchers found that apart from the main source of human-associated bacteria inside the habitat, confinement appeared to be the strongest trigger affecting the bacterial community (the microbiota) that remained highly dynamic over time.
The researchers said that human-related microorganisms (Bacillus and Staphylococcus species) were the most frequent, indicated that humans were the main source of microbial dispersal.
A group of six male Marsonauts lived inside a mock-up spacecraft to identify the bacterial species which might be present in the air and on the surfaces inside spacecraft and how the composition of the microbiota changes during human habitation.
A core microbiota of the same bacteria was present in all areas of the mock-up spacecraft, but specific bacterial signatures for each area showed that the microbial presence was related to the human presence and the type of activity that an area was used. The maximum numbers and greatest diversity of bacteria were found in communal areas, sleep areas, the gym, and the toilet whereas; inside the medical area the bacterial count was less.
The researchers also observed the impact of cleaning agents. The team found the maximum number of bacteria in a certain area than in other areas, but the overall bacterial counts were within the acceptable limits. Due to appropriate cleaning measures, the microbial community inside the habitat was under control at all times with no or little risk for the team.
A significant decrease in the microbial diversity with time was found that indicated the presence of fewer different bacterial species which might result in problematic developments within the microbial community during long-duration isolation. Normally high microbial diversity associated with systemic stability and health.
Some of the microorganisms along with potential health risks for the group could negatively affect spacecraft, as they grow on and might damage spacecraft material. To ensure the systems’ stability, countermeasures might be required to avoid development of highly resistant, adapted microorganisms, and a complete loss of microbial diversity.
The study findings helped to understand the quality of habitat maintenance and improved the selection of suitable methods to monitor microbial diversity that permitted to develop efficient and adequate countermeasures.
To guarantee a safe environment for astronauts on long-duration space missions such as a journey to Mars, it is important to monitor how microorganisms such as bacteria adapt to the confined conditions onboard spacecraft.