crew227-experiment

Terrain modelling by Synthetic Aperture Radar

As part of his thesis on the Synthetic Aperture Radar (SAR), Cyril Wain will carry out an imaging campaign. SAR is a form of radar that is used to create 2D images or to perform 3D reconstructions of objects or landscapes. The principle of SAR is that it uses its motion to obtain radar images with very high resolution. This type of radar is usually shipped on airplanes or satellites. The main advantage of SAR is that, unlike optical sensors, it is not sensitive to weather conditions. Indeed, the frequency band used being that of the microwaves, the waves easily cross the clouds and the rain. This kind of tool could therefore be very useful in studying the relief of a planet whose weather conditions (clouds, stormy rains, sandstorms, etc.) would not allow observation via optical sensors. The imaging campaign would allow Cyril to test his image reconstruction algorithm in real conditions.

Study of the efficacy of a potential living-antibiotic, the bacterium Bdellovibrio bacteriovorus, inside and outside a research station in a Mars-like environment

Due to its particularity of killing other bacteria without killing human cells, Bdellovibrio bacteriovorus is being studied as a serious alternative to antibiotics, especially against resistant strains. Moreover, unlike antibiotics, its effectiveness over time does not diminish, which is particularly relevant for long-term travels such as the transport and establishment of a colony on Mars.

 

The project I, Ophélie Remy, would like to lead to the Mars Desert Research Station is about Bdellovibrio bacteriovorus. This small bacterium (max 1 µm) has the particularity of feeding on a wide range of other bacteria. This predator is currently being studied by several scientific teams as a real alternative to antibiotics because the bacteria-prey can’t develop resistance against it and it does not attack the cells of the human body [1]. 

Given the consequent duration of travel and potential stays on Mars, storage and management of perishable products such as antibiotics are significant logistic and biomedical parameters. However, using Bdellovibrio as a future alternative, these problems would be greatly reduced. Indeed, instead of storing various types of antibiotic boxes, useless after 2 or 3 years, only a few tubes of frozen bacteria and medium can generate an infinite number of daughter bacteria. 

There is nevertheless a constraint for its proliferation: prey. That’s why, within the two week time limit, my goals will be to

        • Isolate bacteria from the cockpit space, from the environment (if possible) or directly from the crew (saliva, skin, etc.), grow them, identify them, give them as prey to Bdellovibrio bacteria and observe which strains are thus exploitable as easily accessible resources for this predatory bacterium.
        • Compare the efficiency of the predator Bdellovibrio to kill their preys under various extreme conditions to test if the culture of these bacteria is easily achievable in an environment more hostile than the ideal conditions of a laboratory.

[1]Raghunathan D. et al. (2019) Engulfment, persistence and fate of Bdellovibrio bacteriovorus predators inside human phagocytic cells informs their future therapeutic potential. Scientific reports. 9:4293, 1-16. DOI : 10.1038/s41598-019-40223-3.

Fast assessment of mineral content on Martian-like soil with portable XRF device

This experiment is about testing an innovative way to analyze Martian soil composition. At the MDRS, our goal is to provide a rapid and reliable assessment of Martian-like soil mineral content, which will contribute (i) to evaluate the suitability of these soils for food production and (ii) to study the potential ancient presence of liquid water pathway. To meet this objective, we will use a portable X-ray fluorescence (pXRF) device, already used for terrestrial soil mineral content analysis. Thanks to its portability, its large range of mineral detection or even its rapidity, the pXRF seems to show powerful advantages to tackle questions still unanswered about Martian soil surface composition. Our experiment will implement the guidelines to reproduce these measurements on Mars in coming decades and its actual mineral content, at a small-scale.

 

The experience we will lead at the MDRS is the study of mineral content of Martian-like soils. We would like to test a rapid and reliable method, already use for terrestrial soils, in order to assess the mineral content of Martian-like soil surface.

 This will fulfill two sub-questions we address:

(1)   How suitable the martian soils are for food production?

Because of their essential role in Human survival, soil quality on Earth is highly studied all around the world. Indeed, soil contamination with metals or toxic components may have dangerous consequences on Human health. In a context of Mars colonization, if someday people are expected to live on Mars, could they rely on a “local” food production? Do those soils contain the minimal required concentration of essential plant nutrients? Do they contain too high concentration of toxic elements (such as Pb, As, Cd, ) making the food production unsuitable for human alimentation?

(2)   Can we identify ancient preferential liquid water pathways?

By studying the element distribution at a soil-profile scale, we will be able to highlight the mineral element mobility through a soil profile. On Earth, mineral mobility is driven by water and wind transport, vegetation cycling, etc. As Martian environment does not present any current vegetation or life, liquid water transport seems to be the only potential driver of minerals mobility through vertical and lateral fluxes. According to their solubility, specific elements are more relevant to study because they are more susceptible to dissolve and be taken away by the liquid water. By studying the element concentration distribution along soil profiles at different locations, their variability will allows us to observe their mobility and assess the potential presence of liquid water fluxes. The aim is to imagine a transposable protocole on future Martian rovers, in order to reproduce it up there and study the potential ancient presence of  liquid water…and therefore potential ancient Life!

How is working a pXRF device and what are its advantages ? 

The portable X-Ray Fluorescence device relies on the X-ray fluorescence principle to quantify the concentration of mineral element in a sample. It allows to detect every element from the periodic table from Magnesium up to Uranium, even to heavier elements depending on the calibration of the instrument. This device has already been used to assess element content from Wallonia soil, to more remote areas such as Siberia and Alaska (permafrost region). While laboratory standard methods can be quite expensive and time-consuming, the pXRF device offer a faster and cheaper method, and can also performs in situ measurement. Using this device on Mars would avoid to have to bring back any sample on Earth and measurement would be directly stored in onboard computers.

Data collection and transmission over low-powered devices for station monitoring.

By installing a series of low-powered sensors and transmitters, it will be possible to model the MRDS’s environment and extra-vehicular activities (temperature, humidity, pressure, brightness, etc.) in order to detect variations in the habitat, the greenhouse and along expeditions. The objective is to collect, transmit and analyze the data as efficiently as possible as we try to adapt to the harsh Martian conditions. The data can be used to prepare and monitor other experiences.

 

A Martian mission involves a lot of risks and hardware must therefore be extremely reliable. To check the reliability of certain objects used during the mission, we will use a series of Zigbee transmitters capable of transmitting information about the status of the monitored devices. Zigbee transmitters are low-power, low-cost radios that can transmit data over long distances through a network of intermediate transmitters in order to reach more distant ones. Such radios are currently used for home automation, data collection in medical devices, etc.

The low-power transmitters could be extremely useful in a hostile environment like Mars where batteries cannot be changed frequently or where low power consumption is of high importance.

In addition, the data collected by sensors, and transmitted through the Zigbee devices, will provide insight about the status of the EVA suits, the rovers, the GreenHab, etc. The data would then be analysed to understand the condition of the monitored equipment. Data anomalies would thus result in warnings which would inform the crew that repairs are required.

Study of the survival of human flora bacteria as well as efficacy of several antibiotics under Martian environmental conditions.

When humans will colonizes Mars, they will not come alone: the microorganisms of the intestinal, oral, cutaneous flora… will accompany them. It is therefore essential to predict what type of microorganisms in these floras would be able to survive and colonize Mars.

As a bacteriologist, Audrey Comein will focus on studying the survival and growth capacity of bacteria collected on the crew and exposed to the environmental conditions found on the MDRS site. These harvested bacteria will be identified by proteomic analysis. The exposed bacteria will be compared directly to their unexposed analogues based on CFUs (Colony-Forming-Units) analysis. This analysis will allow us to determine the number of bacteria per millilitre of sample for each collected bacteria. Comparison of this value between exposed and non-exposed bacteria will reveal what types of bacteria in the human flora could potentially colonize Mars.

If some of our bacteria are able to survive on Mars, they could potentially cause infections in the human colony. Therefore, the question to be asked is: which antibiotics would remain sufficiently functional under such conditions?

In order to answer this question, Audrey will evaluate the efficacy of antibiotics from different classes exposed to environmental conditions and compare it to the same unexposed antibiotics. The antibiotics efficacy will be estimated on the basis of the minimum concentration of antibiotics required to inhibit bacterial growth: the lower this concentration, the more effective the antibiotic. Thanks to this experiment, we will know which antibiotics to bring to Mars with us.

© M.A.R.S. UCLouvain 2020