Synergistic Interactions among Vacuum, Solar Heating, and UV Irradiation Enhance the Lethality of Interplanetary Space.

A Planetary Atmospheric Chamber (PAC) was used to create simulations of interplanetary conditions to test the spore survival of three spp. exposed to interacting conditions of vacuum (VAC), simulated solar heating (HEAT), and simulated solar ultraviolet irradiation (UV). Synergism was observed among the experimental factors for all three spp.

Aeolian Biodispersal of Terrestrial Microorganisms on Mars Through Saltation Bombardment of Spacecraft.

A major unknown in the field of planetary protection is the degree to which natural atmospheric processes remove terrestrial microorganisms from robotic and crewed spacecraft that could potentially contaminate Mars (i.e., forward contamination).

Planetary Protection Knowledge Gap Closure Enabling Crewed Missions to Mars.

As focus for exploration of Mars transitions from current robotic explorers to development of crewed missions, it remains important to protect the integrity of scientific investigations at Mars, as well as protect the Earth's biosphere from any potential harmful effects from returned martian material. This is the discipline of planetary protection, and the Committee on Space Research (COSPAR) maintains the consensus international policy and guidelines on how this is implemented. Based on National Aeronautics and Space Administration (NASA) and European Space Agency (ESA) studies that began in 2001, COSPAR adopted principles and guidelines for human missions to Mars in 2008.

Shock-Impacts and Vibrational -Forces Can Dislodge spp. Spores from Spacecraft Surfaces.

Mars spacecraft encounter numerous -loads that occur along the launch or landing vectors (called axial vectors) or along lateral off-axes vectors. The goal of this research was to determine if there was a threshold for dislodging spores under brute-force dynamic shock compressional impacts (i.e.

Advancing the automation of plant nucleic acid extraction for rapid diagnosis of plant diseases in space.

Human space exploration missions will continue the development of sustainable plant cultivation in what are obviously novel habitat settings. Effective pathology mitigation strategies are needed to cope with plant disease outbreaks in any space-based plant growth system. However, few technologies currently exist for space-based diagnosis of plant pathogens.

Microbial Protocols for Spacecraft: 3. Spore Monolayer Preparation Methods for Ultraviolet Irradiation Exposures.

Developing robust microbial survival models for interplanetary and planetary spacecraft requires precise inactivation kinetics for vehicle bioburdens. To generate such data, reliable protocols are required for preparing, testing, and assaying microbial cells or spores on simulated spacecraft materials. New data are presented on the utility of the liquid droplet protocol for applying spores to aluminum coupons.

Microbial Protocols for Spacecraft: 1. Effects of Surface Texture, Low Pressure, and UV Irradiation on Recovery of Microorganisms from Surfaces.

Modeling risks for the forward contamination of planetary surfaces from endemic bioburdens on landed spacecraft requires precise data on the biocidal effects of space factors on microbial survival. Numerous studies have been published over the preceding 60 years on the survival of diverse microorganisms exposed to solar heating, solar ultraviolet (UV) irradiation, vacuum, ionizing radiation, desiccation, and many other planetary surface conditions. These data were generated with diverse protocols that can impair the interpretations of the results due to dynamic experimental errors inherent in all lab protocols.

Diagnosing an Opportunistic Fungal Pathogen on Spaceflight-Grown Plants Using the MinION Sequencing Platform.

Sustainable agriculture in microgravity is integral to future long-term human space exploration. To ensure the efficient and sustainable cultivation of plants in space, a contingency plan to monitor plant health and mitigate plant diseases is necessary. Yet, neither methods nor tools currently exist to evaluate the plant microbial interactions or to diagnose potential plant diseases in space-based bioregenerative life support systems.

Transcriptional response to prolonged perchlorate exposure in the methanogen Methanosarcina barkeri and implications for Martian habitability.

Observations of trace methane (CH) in the Martian atmosphere are significant to the astrobiology community given the overwhelming contribution of biological methanogenesis to atmospheric CH on Earth. Previous studies have shown that methanogenic Archaea can generate CH when incubated with perchlorates, highly oxidizing chaotropic salts which have been found across the Martian surface. However, the regulatory mechanisms behind this remain completely unexplored.

Use of NanoSIMS to Identify the Lower Limits of Metabolic Activity and Growth by Exposed to Sub-Zero Temperatures.

is a cold-adapted facultative anaerobic astrobiology model organism with the ability to grow at a Martian atmospheric pressure of 7 hPa. Currently there is a lack of data on its limits of growth and metabolic activity at sub-zero temperatures found in potential habitable regions on Mars. Growth curves and nano-scale secondary ion mass spectrometry (NanoSIMS) were used to characterize the growth and metabolic threshold for ATCC 27,592 grown at and below 0 °C.

as an Opportunistic Fungal Pathogen on Plants Grown on board the International Space Station.

A plant production system called Veggie was launched to the International Space Station (ISS) in 2014. In late 2015, during the growth of cv. 'Profusion' in the Veggie hardware, plants developed chlorosis, leaf curling, fungal growth that damaged leaves and stems, and eventually necrosis.

Salt Tolerance and UV Protection of and under Simulated Martian Conditions.

Ultraviolet (UV) irradiation on the surface of Mars is an important factor that affects the survivability of microorganisms on Mars. The possibility of martian brines made from Fe(SO), MnSO, and MgSO salts providing a habitable niche on Mars via attenuation of UV radiation was investigated on the bacteria and . Results demonstrate that it is possible for brines containing Fe(SO) on Mars to provide protection from harmful UV irradiation, even at concentrations as low as 0.

Addition of anaerobic electron acceptors to solid media did not enhance growth of 125 spacecraft bacteria under simulated low-pressure Martian conditions.

To protect Mars from microbial contamination, research on growth of microorganisms found in spacecraft assembly clean rooms under simulated Martian conditions is required. This study investigated the effects of low atmospheric pressure on the growth of chemoorganotrophic spacecraft bacteria and whether the addition of Mars relevant anaerobic electron acceptors might enhance growth. The 125 bacteria screened here were recovered from actual Mars spacecraft.

A Cruise-Phase Microbial Survival Model for Calculating Bioburden Reductions on Past or Future Spacecraft Throughout Their Missions with Application to Europa Clipper.

During transit between the Earth and planetary destinations, spacecraft encounter conditions that are deleterious to the survival of terrestrial microorganisms. To model the resulting bioburden reduction, a Cruise-Phase Microbial Survival (CPMS) model was prepared based upon the Lunar Microbial Survival model, which considers the effects of temperature, vacuum, ultraviolet (UV), and ionizing radiation found in the space environment. As an example, the CPMS was used to determine the expected bioburden reductions on the Europa Clipper spacecraft upon arrival at Jupiter under two different transit scenarios.

The Hypopiezotolerant Bacterium, , Failed to Grow in Mars Analog Soils under Simulated Martian Conditions at 7 hPa.

The search for life on Mars is predicated on the idea that Earth and Mars life (if present) should be both carbon- and water-based with similar forms of evolution. However, the astrobiology community can currently only investigate plausible Martian microbial ecosystems by using Terran life-forms as proxies. In order to examine how life might persist on Mars, we used a hypopiezotolerant bacterium (def.

Exploring Microbial Activity in Low-pressure Environments.

The importance of hypopiezophilic and hypopiezotolerant microorganisms (i.e., life that grows at low atmospheric pressures; see section 2) in the field of astrobiology cannot be overstated.

Spore Resistance to Simulated Mars Surface Conditions.

In a Mars exploration scenario, knowing if and how highly resistant spores would survive on the Martian surface is crucial to design planetary protection measures and avoid false positives in life-detection experiments. Therefore, in this study a systematic screening was performed to determine whether spores could survive an average day on Mars. For that, spores from two comprehensive sets of isogenic mutant strains, defective in DNA protection or repair genes, were exposed to 24 h of simulated Martian atmospheric environment with or without 8 h of Martian UV radiation [M(+)UV and M(-)UV, respectively].

A Lunar Microbial Survival Model for Predicting the Forward Contamination of the Moon.

The surface conditions on the Moon are extremely harsh with high doses of ultraviolet (UV) irradiation (26.8 W · m UVC/UVB), wide temperature extremes (-171°C to 140°C), low pressure (10 Pa), and high levels of ionizing radiation. External spacecraft surfaces on the Moon are generally >100°C during daylight hours and can reach as high as 140°C at local noon.

Metabolic fingerprints of Serratia liquefaciens under simulated Martian conditions using Biolog GN2 microarrays.

Microorganisms growing at atmospheric pressures of 0.7 kPa may have a significant impact on the search for life on Mars. Data on their nutrient requirements in a simulated Martian environment are required to ascertain both the potential risk of forward contamination and the potential of past or present habitability of Mars.

Transcriptomic responses of Serratia liquefaciens cells grown under simulated Martian conditions of low temperature, low pressure, and CO-enriched anoxic atmosphere.

Results from previous experiments indicated that the Gram-negative α-proteobacterium Serratia liquefaciens strain ATCC 27592 was capable of growth under low temperature (0 °C), low pressure (0.7 kPa), and anoxic, CO-dominated atmosphere-conditions intended to simulate the near-subsurface environment of Mars. To probe the response of its transcriptome to this extreme environment, S.

The Photochemistry of Unprotected DNA and DNA inside Bacillus subtilis Spores Exposed to Simulated Martian Surface Conditions of Atmospheric Composition, Temperature, Pressure, and Solar Radiation.

DNA is considered a potential biomarker for life-detection experiments destined for Mars. Experiments were conducted to examine the photochemistry of bacterial DNA, either unprotected or within Bacillus subtilis spores, in response to exposure to simulated martian surface conditions consisting of the following: temperature (-10°C), pressure (0.7 kPa), atmospheric composition [CO (95.

Magnesium Sulfate Salt Solutions and Ices Fail to Protect Serratia liquefaciens from the Biocidal Effects of UV Irradiation under Martian Conditions.

The growth of Serratia liquefaciens has been demonstrated under martian conditions of 0.7 kPa (7 mbar), 0°C, and CO-enriched anoxic atmospheres (Schuerger et al., 2013, Astrobiology 13:115-131), but studies into the survivability of cells under hypersaline conditions that are likely to be encountered on Mars are lacking.

Twenty Species of Hypobarophilic Bacteria Recovered from Diverse Soils Exhibit Growth under Simulated Martian Conditions at 0.7 kPa.

Bacterial growth at low pressure is a new research area with implications for predicting microbial activity in clouds and the bulk atmosphere on Earth and for modeling the forward contamination of planetary surfaces like Mars. Here, we describe experiments on the recovery and identification of 20 species of bacterial hypobarophiles (def., growth under hypobaric conditions of approximately 1-2 kPa) in 10 genera capable of growth at 0.

Twenty-Three Species of Hypobarophilic Bacteria Recovered from Diverse Ecosystems Exhibit Growth under Simulated Martian Conditions at 0.7 kPa.

Unlabelled: Bacterial growth at low pressure is a new research area with implications for predicting microbial activity in clouds and the bulk atmosphere on Earth, and for modeling the forward contamination of planetary surfaces like Mars. Here, we describe experiments on the recovery and identification of 23 species of bacterial hypobarophiles (def., growth under hypobaric conditions of approximately 1-2 kPa) in 11 genera capable of growth at 0.

Microbial Ecology of a Crewed Rover Traverse in the Arctic: Low Microbial Dispersal and Implications for Planetary Protection on Human Mars Missions.

Between April 2009 and July 2011, the NASA Haughton-Mars Project (HMP) led the Northwest Passage Drive Expedition (NWPDX), a multi-staged long-distance crewed rover traverse along the Northwest Passage in the Arctic. In April 2009, the HMP Okarian rover was driven 496 km over sea ice along the Northwest Passage, from Kugluktuk to Cambridge Bay, Nunavut, Canada. During the traverse, crew members collected samples from within the rover and from undisturbed snow-covered surfaces around the rover at three locations.