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Analytical techniques commonly implemented for in situ organic analysis on space missions lack the sensitivity or specificity necessary to definitively characterize key markers of current or past life, such as amino acids. To this end, our group has developed an analytical method for amino acid analysis at low parts-per-billion levels, utilizing capillary electrophoresis coupled to laser-induced fluorescence detection. Europa has been identified as a particularly appealing target for life detection, but its intense radiation environment presents additional challenges for instrument development and qualification. Here, we present work toward the development of a flight qualifiable laser-induced fluorescence detection system that could be implemented on potential future missions to the Jovian system which could experience total ionizing dose exposures of up to 300 krad. Our results show that a gallium nitride based laser diode and micro-photomultiplier based system can meet our system performance requirements under radiation conditions expected for a potential Europa Lander mission.

It has been experimentally demonstrated that, under alkaline conditions, silica is able to induce the formation of mineral self-assembled inorganic-inorganic composite materials similar in morphology, texture and nanostructure to the hybrid biomineral structures that, millions of years later, life was able to self-organize. These mineral self-organized structures (MISOS) have been also shown to work as effective catalysts for prebiotic chemical reactions and to easily create compartmentalization within the solutions where they form. We reason that, during the very earliest history of this planet, there was a geochemical scenario that inevitably led to the existence of a large-scale factory of simple and complex organic compounds, many of which were relevant to prebiotic chemistry. The factory was built on a silica-rich high-pH ocean and powered by two main factors: a) a quasi-infinite source of simple carbon molecules synthesized abiotically from reactions associated with serpentinization, or transported from meteorites and produced from their impact on that alkaline ocean, and b) the formation of self-organized silica-metal mineral composites that catalyze the condensation of simple molecules in a methane-rich reduced atmosphere. We discuss the plausibility of this geochemical scenario, review the details of the formation of MISOS and its catalytic properties and the transition towards a slightly alkaline to neutral ocean, The research leading to these results has received funding from the European Research Council (ERC) under the European Union's Seven Framework Programe grant agreement n° 340863 , and under the Horizon 2020 research and innovation program grant agreement n° 646894 . JMG-R also acknowledges the Ministerio de Economía y Competitividad of Spain for funding the project CGL2016-78971-P . We acknowledge Lucas Chacón for the artist view of Fig. 6 . This is IPGP contribution n° 4108.

This paper develops an improved algorithm for life detection based on ultra-wide band (UWB) impulse radars in through-wall condition. Usually, the cardiac–respiratory movement is the most significant sign of a living person, which can be extracted from the collected pulses. The proposed algorithm analyzes the variances of the collected pulses, which are mixed with various clutters. The time of arrival (TOA) between UWB radar and human target can be calculated by performing the wavelet packet decomposition on the calculated variances. The rates of human cardiac–respiratory movement are acquired based on the variable time-window (VTW) method. Compared with several well-known algorithms, the developed method can provide competitive performance in life detection. Results acquired from different sites prove the efficiency and reliability of the method.

Remanufacturing cleaning plays an important role in the remanufacturing process. It has a significant influence on the residual life detection and remanufactured products quality. But it is the most polluted and time-consuming phase in the remanufacturing process. In this paper a simple, efficiency and low pollution cleaning method is introduced. This method is based on Hertz and Coulomb theory with flexible cable impact contact and friction, without introducing new pollution medium in the process. In order to study the method in detail, the working mechanism, the kinematic and dynamic characteristics are analyzed. Simulation and application test are carried out on the steel plate and get a good cleaning effect.

A mediated glassy carbon electrode covered by a thin-film polyviologen was used in the present study to rapidly detect bioactivity in a mixed-culture chemostat (dominated by Clostridium sp.). With the addition of 1mM hexacyanoferrate and 9mM glucose, the current increasing rate (dI/dt) measured under a poised potential of 500mV (vs. Ag/AgCl) can be defined as the quantity of metabolic activity. In the experiment of restoring the chemostat from stop-feeding, it is suggested that when the dI/dt was >2μAmin-1, the influent pump could be directly turned on to maintain the high dilution rate of 0.5h-1; when the dI/dt was lower than 2μAmin-1, reducing the dilution rate would be needed to avoid cell wash out. Since the soluble mediators and polyviologen film will enhance performances by favorable electron transfer and positively charged surfaces, respectively, we suggest that the method can also be employed to detect the bioactivities in environmental samples.

International audience; Te-based glasses are ideal material for life detection and infrared-sensing applications because of their excellent far-infrared properties. In this study, the influence of Ag- and AgI- doped Te-based glasses were discussed. Thermal and optical properties of the prepared glasses were evaluated using X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared spectroscopy. Results show that these glass samples have good amorphous state and thermal stability. However, Ge-Ga-Te-Ag and Ge-Ga-Te-AgI glass systems exhibit completely different in optical properties. With an increase of Ag content, the absorption cut-off edge of Ge-Ga-Te-Ag glass system has a red shift. On the contrary, a blue shift appears in Ge-Ga-Te-AgI glass system with an increase of AgI content. Moreover, the transmittance of Ge-Ga-Te-Ag glass system deteriorates while that of Ge-Ga-Te-AgI glass system ameliorates. All glass samples have wide infrared transmission windows and the far-infrared cut-off wavelengths of these glasses are beyond 25 μm. The main absorption peaks of these glasses are eliminated through a purifying method.

The first step in many life detection protocols on Mars involves attempts to extract or isolate organic matter from its mineral matrix. A number of extraction options are available and include heat and solvent assisted methods. Recent operations on Mars indicate that heating samples can cause the loss or obfuscation of organic signals from target materials, raising the importance of solvent-based systems for future missions. Several solvent types are available (e.g. organic solvents, surfactant based solvents and subcritical water extraction) but a comparison of their efficiencies in Mars relevant materials is missing. We have spiked the well characterised Mars analogue material JSC Mars-1 with a number of representative organic standards. Extraction of the spiked JSC Mars-1 with the three solvent methods provides insights into the relative efficiency of these methods and indicates how they may be used on future Mars missions.

Extraction experiments were performed to evaluate suitable sample-extraction and processing protocols that will be used by bioanalytical instruments like Life Marker Chip ( LMC ). These instruments will focus on the detection of molecules associated with life that will be extracted from the Martian soil. LMC is an antibody microarray biosensor instrument with optical readout, which uses fluorescently labeled antibodies, to detect and quantify the presence of polar and non-polar biomolecules, extracted from the Martian soil. The success of the LMC biomarkers detection experiment is dependent on the sample extraction protocol. The currently recommended extraction procedure, optimized for aliphatic biomarkers, consists in sonicating the samples using as solvent system 20:80 methanol:water with 1.5 mg mL −1 tween 80, which respects all the tight requirements associated with LMC biosensor. Examining this procedure for a particular class of biomarkers, the nucleobases adenine, cytosine, uracil and hypoxanthine adsorbed onto magnesium oxide (MgO), we observed low extraction efficiency, confirming that the selected solvent system is not able to extract with high efficiency aromatic biomarkers.

Some life detection instruments under development for operation on Mars use solvents to extract organic compounds from samples of Martian regolith and rock and to transfer the extracts to dedicated detectors. However, it is possible that organic compounds extracted from Martian samples and dissolved in the solvent could adsorb to instrument surfaces, potentially resulting in a failure to detect organic matter that could have been avoided by using more appropriate instrument materials. If successful detection and characterisation is to take place it is therefore essential to understand the interactions between dissolved organic targets and the surfaces of space instrument components. One such life detection instrument is the Life Marker Chip (LMC) being developed for the ExoMars mission, which relies on a novel surfactant-based solvent system and antibody-based detectors. We have tested the ability of a range of materials, including titanium, stainless steel, aluminium, the fluoropolymer Viton™, polytetrafluoroethylene (PTFE), nylon, polypropylene, polyethersulfone and cellulose acetate to adsorb a range of organic standards from the surfactant solution intended to be used by the LMC. Results indicate that aromatic hydrocarbons, specifically anthracene, are more prone to adsorption than straight chain, branched and cyclic aliphatic species. Titanium, aluminium and stainless steel show little adsorption ability and are suitable for larger-area applications. PTFE and Viton™ are suitable for use in small-area applications such as seals and filters. Nylon, polypropylene, polyethersulfone and cellulose acetate show stronger adsorption characteristics and should be avoided in the forms employed here. The ability of some materials to selectively adsorb organic compounds from solvent extracts can lower the sensitivity of life detection instruments. In future, it would be prudent to test all space instrument materials for their ability to adsorb target organic compounds from the solvent systems with which they will be used. This work has application beyond LMC and is relevant to future life detection instruments and their associated cleaning procedures that use solvents. The findings will also be pertinent to planned sample return missions involving caching and can inform the selection of materials used in sample return containers and during the subsequent processing of any returned samples.

This paper gives a simple introduction for the UWB radar and its definition. The principle of the radar will be a represent in details. Excellent materials penetration is a fundamental advantage to UWB radar. This point can be used to detect the signals of life without touching anyone. Since the human body's chest wall movement can be assumed a simple harmonic motion, the chaos theory can be applied to detect the low-frequency signal. There are several advantages including high resolution and accuracy. This method is simpler compared with the traditional means.

Fluorescent labeling of bacterial cell walls, DNA, and metabolic processes demonstrates high (potentially single molecule) sensitivity, is non-invasive, and in some cases can differentiate strains and species. Robust microscopes such as the custom instruments presented here can provide good image quality in the field and are potentially suitable for flight. However, ambiguous or false-positive results with bacterial stains can occur and can create difficulties in interpretation even on Earth. We present a “real” life detection problem in a sample of biofilms taken from the Canadian High Arctic. The samples consisted of numerous small sulfur-oxidizing bacteria and larger structures resembling fungi or diatoms. The identity of these latter structures remained ambiguous until electron microscopy and X-ray spectroscopy were performed, indicating that they were unusual sulfur minerals probably precipitated by the bacterial communities. While such mineral structures may possibly serve as biosignatures after the cells have disappeared, it is important that they not be mistaken for cells themselves. It is also possible that unusual mineral structures will be performed under extraterrestrial conditions, so great care is needed to differentiate cell structures from minerals.

Terrestrial analogue environments are places on Earth that present geological or environmental conditions that are similar to those found on an extraterrestrial body. Analogue environments serve four functions: (1) learn about planetary processes on Earth and elsewhere; (2) test technologies, methodologies, and protocols; (3) train highly-qualified personnel, as well as science and operations teams; (4) engage the public, space agencies, media, and educators. Analogue studies also enable the development and validation of biosignatures and detection techniques. Analogue programs include the Canadian Space Agency's Canadian Analogue Research Network, NASA's Astrobiology Science and Technology for Exploring Planets, and NASA's Analog Missions. Examples of technology and instrument testing and validation in analogue environments include the Haughton-Mars Project Research Station, the Arctic Mars Analog Svalbard Expedition (AMASE), the Rio Tinto basin, and NASA's Field Integrated Design and Operations (FIDO).

Since the dawn of the space age, humans have wrestled with concerns about planetary cross-contamination. Spacecraft launched from Earth can transport hitchhiker microbes to new worlds on both robotic and crewed vehicles. As plans proceed for future life detection and human exploration missions, planetary protection considerations are again uppermost on the agendas of mission planners, and microbiologists have an important role to play.

In the near future, an increasing number of in situ life detection and sample return missions to planets and other solar system bodies will be launched. The demand to control spacecraft-carried microbial contamination becomes obvious. COSPAR (Committee of Space Research) has defined guidelines and bioburden limits for different types of missions and target bodies. The first step in the implementation of these planetary protection guidelines encompasses a qualitative and quantitative inventory of the bioburden of spacecraft assembly facilities. With information about the composition of these microbial communities the development and/or optimization of adequate cleaning, disinfection, and sterilization procedures for spacecraft preparation before launch will be possible. In the ESA project MiDiv, we started to investigate the diversity of cultivable microorganisms found on spacecraft and spacecraft assembly halls using the satellites SMART-1 and ROSETTA as test objects. The analyses to date include cultivation of microorganisms by varying pH, temperature, oxygen, and pasteurization. A culture collection of bacterial isolates and a database of 16S RNA gene sequences have been established. The results of our preliminary work, including the numbers of colony forming units, differentiated as aerobes and facultative anaerobes as well as their phylogenetic classification, give a first overview of the breadth of physiological potential of the identified microorganisms and their capability to withstand various cleaning and sterilizing procedures currently used for the planetary protection.

The Nuclear Europa Mobile Ocean (NEMO) mission would land on the surface of Europa, and deploy a small, lightweight melt probe powered by a compact nuclear reactor to melt down through the multi-kilometer ice sheet. After reaching the sub-surface ocean, a small nuclear Autonomous Underwater Vehicle (AUV) would deploy to explore the sub-ice ocean. After exploration and sample collection, the AUV would return to the probe and melt back to the lander. The lander would have replenished its H 2 propellant by electrolysis of H 2 O ice, and then hop to a new site on Europa to repeat the probe/AUV process. After completing the mission, the NEMO spacecraft would return to Earth with its collected samples. The NEMO melt probe and AUV utilize enriched U-235 fuel and conventional water reactor technology. The lander utilizes a compact nuclear thermal propulsion (NTP) engine based on the 710 tungsten / UO 2 cermet fuel and high-temperature H2 propellant. The compact nuclear reactors in both the NEMO melt probe and AUV drive a steam power cycle, generating over 10 kW(e) for use in each. Each nuclear reactor's operating lifetime is several years. With its high-mobility and long-duration mission, NEMO provides an ideal platform for life detection experiments.

A large number of missions are scheduled, particularly on Mars, in order to search for life or traces of past life. Taking into account CNES past experience in planetary protection related to the Mars 96 mission 4,5,6 , its planned participation in exobiological missions with NASA as well as its works and involvement in Cospar activities, the paper will give the main requirements in order to avoid celestial bodies biological contamination, including Earth, and to protect exobiological science. For ethical, safety and scientific reasons, the space agencies have to respect the article IX of the Outer Space Treaty (London / Washington January 27., 1967) and consequently to comply with the related COSPAR planetary protection recommendations. The goal is to protect target planets from Earth microbiological contamination and also to protect Earth environment from an eventual biocontamination coming from extraterrestrial samples or carried by contaminated sample return probes. Planetary protection takes also into account the protection of exobiological science. The validation of its results depends strongly of the biological and organic chemical cleanliness of samples, and more generally of how the samples have been preserved. Take into account such requirements gives to project teams specifications for equipement or probe sterilization, microbiological controls, special integration procedures, recontamination avoidance, …etc, needing specific and unusual implementations. One of CNES present interest is focussed on exobiological missions, including sample return missions 7 , as well as works and involvement in COSPAR activities linked to planetary protection. The search of life, organic molecules or compounds related to life imposes harder biological and organic cleanliness specifications, associated with constraints for sample preservation, in order to avoid any mistake or doubt on scientific results. Biological and organic cleanliness is probably the main constraint, but function of where and how the samples are collected, confined, transported and analyzed could have effects on samples characteristics.

When a human body is illuminated by an electromagnetic wave, the backscattered wave is modulated by the periodic body (thoracic) movements due to the heartbeat and breathing of the human target. With proper processing of this backscattered wave, it is possible to extract useful information about the heart and breathing signals that modulate it. The aim of this research work is the design and development of an X-band microwave life detection system for detecting humans trapped behind rubble or obstacles. The mobile microwave sensor that was constructed permits the detection of body movements due to breathing at a distance of 3–5 m (without any obstacle in between) and also at a distance of 2 m behind a concrete obstacle (a door or wall) of medium thickness.

Study on the progress of automatic machining systems has been centred actively onto CNC machine tools recently, to lead applied production technology such as unmanned machining to a practical level. In order to make this application more efficient, in-process methods of tool wear and breakage detection are required. In this study, which is chiefly on turning, the cutting force around the tool surface is determined by use of a cutting-resistant sensor and then changed into an electric signal and compared with standards, to enable the tool-life detection system to assess the tool life. When the cutting resistance detected by the cutting-resistant sensor has increased to the level of the standards, the measuring system can decide whether the tools should be changed on the basis of a comparative circuit. The model is shown to be very reliable for a cutting-tool-life detection system.

Tsapin et al. (2000, Icarus147, 68–78) propose the strong oxidant ferrate(VI) to explain the Viking Labeled Release Mars life detection results. However, their data do not support that theory. Further, sensitive IR searches for oxidants on Mars found none, and Viking produced physical evidence against an oxidizing surface. Finally, Tsapin et al. (2000, Icarus147, 68–78) report no precautions to prevent microbial contamination from confounding their results.

The adsorptive and/or catalytic properties of clays, silicates in general, and other minerals are well known. More recently, their probable role in prebiotic syntheses of bio-organic compounds has become a matter of record. We demonstrate that, in addition to their role in de novo formation of important biomolecules, clays, micas, fibrous silicates and other minerals mimick the activities of contemporary enzymes including oxidases, esterases, phosphatases and glucosidases. The existence of such capabilities in substances likely to be represented on the surfaces of Earth-like planets may offer a challenge to the technology and design of remote life detection systems which must then distinguish between bona fide biological chemistry and mineral-base pseudometabolism. It also raises questions about the importance of mineral surfaces in post-mortem transformations of organic metabolites in our own biosphere.

The Viking Labeled Release (LR) data obtained on Mars satisfy the criteria established for a biological response. The importance of the issue, especially when viewed against the harsh environment on Mars, requires careful consideration of possible nonbiological reactions that may have produced false positive results. A 3 1 2 - year laboratory effort to investigate possible chemical, physical, and physicochemical agents or mechanisms has been concluded. Among nonbiological possibilities, hydrogen peroxide, putatively on Mars, emerged as the principal candidate. When placed on analog Mars soils prepared to match the Viking inorganic analysis of the Mars surface material, hydrogen peroxide did not duplicate the LR Mars data. When other materials were used as substrate, hydrogen peroxide could be made to evoke the type of responses obtained by the LR Mars experiment. However, essential criteria concerning the formation, accuumulation, and preservation of hydrogen peroxide to qualify it as the active agent on Mars have not been met and new data show it to be essentially absent from the Mars atmosphere. The presence of a biological agent on Mars must still be considered. This interpretation of the LR results is strengthened by a recent report that the Viking organic analysis instrument (GCMS) failed to detect organics in an Antarctic soil in which the LR instrument had demonstrated the presence of microorganisms.

The implementation of the United States planetary protection program, intended to prevent the contamination of the celestial bodies in the solar system during their exploration, in recent interplanetary projects is reviewed. The shift in planetary protection policy from that of absolute sterilization to a probabilistic approach is noted. Attention is then given to the use of microbiological assay, organic materials inventory, microbial burden reduction, contamination control, trajectory biasing and the analysis and identification of contaminating processes for purposed of planetary protection for the Pioneer 10 and 11, Viking and Voyager projects. The success of these measures, as demonstrated by the prevention of accidental planetary impact and the failure to detect terrestrial organisms by the Viking life detection experiments, is pointed out.

Extraterrestrial life detection studied from knowledge of major and trace components of atmospheres