Surface Missions Research Articles

Martian Top of the Atmosphere 10–420 nm spectral irradiance database and forecast for solar cycle 24

Ultraviolet radiation from 10 to 420nm reaching Mars Top of the Atmosphere (TOA) and surface is important in a wide variety of fields such as space exploration, climate modeling, and spacecraft design, as it has impact in the physics and chemistry of the atmosphere and soil. Despite the existence of databases for UV radiation reaching Earth TOA, based in space-borne instrumentation orbiting our planet, there is no similar information for Mars. Here we present a Mars TOA UV spectral irradiance database for solar cycle 24 (years 2008–2019), containing daily values from 10 to 420nm. The values in this database have been computed using a model that is fed by the Earth-orbiting Solar Radiation and Climate Experiment (SORCE) data. As the radiation coming from the Sun is not completely isotropic, in order to eliminate the geometrically related features but being able to capture the general characteristics of the solar cycle stage, we provide 3-, 7- and 15-days averaged values at each wavelength. Our database is of interest for atmospheric modeling and spectrally dependent experiments on Mars, the analysis of current and upcoming surface missions (rovers and landers) and orbiters in Mars. Daily values for the TOA UV conditions at the rover Curiosity location, as well as for the NASA Insight mission in 2016, and ESA/Russia ExoMars mission in 2018 are provided.

Fundamental Understanding of Li-S Battery Electrochemistry

In recent years, commercial realization of rechargeable batteries has revolutionized portable electronic industry affecting mostly microelectronics. However, issues such as safety, high/low temperature performance, cost, and environmental concerns are still being addressed, particularly for high power and high energy applications. Li-ion batteries have been successfully employed in several Mars surface missions, e.g., Mars Exploration Rovers (Spirit and Opportunity), Mars Phoenix Lander, and more recently in the Mars Science Laboratory rover (Curiosity) [1]. The diverse benefits in gravimetric and volumetric densities combined with good low temperature performance of Li-ion batteries, contribute to reduced launch costs, increased payload and science capabilities in the space missions. However, NASA’s upcoming missions need energy storage systems with enhanced performance capability, especially higher specific energies and energy densities. A direct application of the technology involves the astronaut Extra Vehicular Activity (EVA), wherein the astronaut’s Portable Life Support System (PLSS) is expected to support 8 hours of EVA. The state of art batteries, with ~200 Wh/kg at the cell level, can support only four hours of EVA. Among the battery systems, the Li-S is the most attractive due to the high theoretical capacity of sulfur, i.e., 1672mAh/g (~10 times higher than LiCoO2), abundance and low toxicity [2-5]. However, some issues such as (i) mechanical stress on the cathode, (ii) dissolution of sulfur products with the electrolyte, forming redox shuttles have to be understood and mitigated. In recent years, extensive efforts have been made to extend the cycle life of Li-S cells using a variety of approaches. These include new cathode designs with porous carbon structures to contain sulfur and its reduced products, anode coatings to protect against dissolved polysulfides and suitable electrolyte solutions, all of which contributed to improved cycle life in laboratory cells. In the present study, we focused on developing a high energy rechargeable Li-S battery with moderate cycle life that can offer considerable performance enhancements beyond the conventional and advanced Li-ion batteries. To achieve our goal, various advanced cell components for Li-S cell are being developed: (i) a protected Li anode with an intimate thin polymer electrolyte coating stable towards Li organic solvents, (ii) new electrolytes with reduced solubility for polysulfides, (iii) new electrolyte additives to reduce polysulfides shuttle effects and/or to function as redox catalysts for enhancing the sulfide reversibility, and (iv) durable sulfur cathode configurations with a nanoporous and nanostructured substrate (typically carbon or metal) and/ or cathodes blended with electro-active mediators to contain/constrain sulfur and its reduced products. These approaches were studied and analyzed to understand how the enhanced components affects the structure of the cathode, the dissolution of polysulfides in the electrolyte, the kinetics and the electrochemical performance. The results will be presented in detail. 1. B. V. Ratnakumar, W. C. West, P. DeGrosse Jr., M. C. Smart, L. Jones and R.C. Ewell, NASA Battery Workshop, Huntsville, AL, November 6, (2012) 2. Brian L. Ellis, Kyu Tae Lee, and Linda F. Nazar, Positive Electrode Materials for Li-Ion and Li-Batteries, Chem. Mater. 22 (2010) 691–714. 3. Ho Suk Ryu, Zaiping Guo, Hyo Jun Ahn, Gyu Bong Cho, Huakun Liu, Investigation of discharge reaction mechanism of lithium/liquid electrolyte/sulfur battery, J. Power Sources 189 (2009) 1179–1183. 4. A. Manthiram, Y. Z. Fu and Y. S. Su, Challenges and Prospects of Lithium-Sulfur Batteries, Acc. Chem. Res 46 (2013) 1125–1134. 5. Y. X. Yin, S. Xin, Y. G. Guo and L. J. Wan, Angew, Lithium–Sulfur Batteries: Electrochemistry, Materials and Prospects, Chem., Int. Ed., 52 (2013) 13186–13200.

Mars surface context cameras past, present, and future

AbstractMars has been the focus of robotic space exploration since the 1960s, in which time there have been over 40 missions, some successful, some not. Camera systems have been a core component of all instrument payloads sent to the Martian surface, harnessing some combination of monochrome, color, multispectral, and stereo imagery. Together, these data sets provide the geological context to a mission, which over the decades has included the characterization and spatial mapping of geological units and associated stratigraphy, charting active surface processes such as dust devils and water ice sublimation, and imaging the robotic manipulation of samples via scoops (Viking), drills (Mars Science Laboratory (MSL) Curiosity), and grinders (Mars Exploration Rovers). Through the decades, science context imaging has remained an integral part of increasingly advanced analytical payloads, with continual advances in spatial and spectral resolution, radiometric and geometric calibration, and image analysis techniques. Mars context camera design has encompassed major technological shifts, from single photomultiplier tube detectors to megapixel charged‐couple devices, and from multichannel to Bayer filter color imaging. Here we review the technological capability and evolution of science context imaging instrumentation resulting from successful surface missions to Mars, and those currently in development for planned future missions.

The Use of Low Temperature Electrolytes in High Specific Energy Li-Ion Cells for Future NASA Missions to Icy Moons

NASA has a strong interest to explore some of the distant icy moons of Jupiter and Saturn, since these bodies are believed to have liquid oceans beneath the icy surface that may harbor life. More specifically, NASA is considering missions to Europa, one of Jupiter’s moons, as well as other icy moons of Jupiter and Saturn, such as Enceladus, Ganymede, Titan and Callisto. To enable surface exploration of these icy moons using landers and rovers, the power systems will need to be mass and volume efficient and potentially operate at ultra-low temperatures (down to -180oC) and in high radiation environments (> 5 Mrad). To meet these power requirements, a number of power system technology options are available, including: (i) primary batteries, (ii) solar photovoltaic (PV) power sources coupled with rechargeable batteries, (iii) radioisotope thermoelectric generators (RTG) coupled with rechargeable batteries, and (v) fuel cells. Of these options, the use of PV solar arrays combined with rechargeable batteries is potentially attractive, since it will enable long duration missions and have low mass. To address these mission needs, improved rechargeable batteries that can operate at very low temperatures are desired. In response, the Electrochemical Technologies Group (ETG) at the Jet Propulsion Laboratory (JPL) is involved in developing ultra-low temperature rechargeable batteries with high specific energy and long life capability for icy moon surface missions. The performance goal is that these batteries should operate over the temperature range of +40oC to -60oC (delivering up to 100 Wh/kg at -40oC and 75 Wh/kg at -60oC). In addition, it is desirable that continuous operation is possible at these very low temperatures, so the cells should possess good charge characteristics over a wide temperature range. To meet these goals, we are currently evaluating both all carbonate and ester containing low temperature electrolytes that have been incorporated into prototype cells of various chemistries, obtained from a number of vendors, including (i) Eagle Pitcher Technologies-Yardney Division, (ii) Enersys/Quallion, LLC, (iii) E-One Moli Energy Ltd., and (iv) Navitas/A123. These electrolytes have been developed under previous programs, targeting improved low temperature operation of Li-ion cells, for both aerospace and automotive applications. In the case of the Eagle Picher Technologies-Yardney Division Li-ion cells, we are evaluating large capacity prototype cells developed for Mars Science Laboratory (MSL) Curiosity rover and the Mars InSight lander that contain an all-carbonate low temperature electrolyte 1 and a methyl propionate (MP) containing electrolyte 2 , respectively. 3 In collaboration with Quallion, we have obtained MCMB-LiNiCoAlO2-based prototype cells containing both carbonate- and ester-based electrolytes. Previous collaborative efforts with Quallion have demonstrated high power capability over a wide range of temperatures in these cells, in support of a DoE program focused on automotive applications. 4 We are also evaluating LiFePO4-based prototype cells that were obtained from Navitas/A123 with both methyl butyrate (MB) and methyl propionate (MP)-based electrolytes that have been demonstrated to operate well over a wide temperature range (i.e., -60o to +60oC). 5 In collaboration with E-One Moli, we are also engaged in evaluating 18650 Li-ion cells that possess methyl propionate-based electrolytes, which have been observed to provide excellent specific energy down to very low temperatures. 6 During the course of this study, we have investigated the impact of the electrolyte type upon the low temperature capability of the different chemistries, with an emphasis upon obtaining high specific energy under relevant conditions. This involves performing charge and discharge rate characterization over a wide temperature range, as well as cycling continuously at very low temperatures. Furthermore, there is a desire to characterize the likelihood of lithium plating when charging at low temperatures, and the influence that the electrolyte type and additives have upon this behavior. To augment the prototype cell testing, studies were also performed in experimental three-electrode lithium-ion cells to determine the influence that the electrolyte type has upon the electrode kinetics, consisting of MCMB carbon anode and LiNiCoAlO2 cathodes (electrodes fabricated by Quallion, LLC). A number of electrochemical techniques were employed to study these cells, including Electrochemical Impedance Spectroscopy, Tafel polarization, and linear micro-polarization. In summary, good reversibility and high specific energy has been obtained at -40oC with many of the systems, and operating capability has been demonstrated to temperatures as low as -70oC. ACKNOWLEDGEMENT The work described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration (NASA) and supported by the Ocean Worlds Program Office.

ESA ExoMars program: The next step in exploring Mars

The ExoMars program is an ESA–Roscosmos cooperation with some NASA contributions. ExoMars consists of two missions, one in 2016 and one in 2018. The 2016 mission includes an orbiting satellite dedicated to the study of atmospheric trace gases to acquire information on possible on-going geological or biological processes, and a European entry, descent, and landing demonstrator module (EDM) to achieve a successful soft landing on Mars. The orbiter can also provide data communication services for all surface missions landing on Mars until the end of 2022. The 2018 mission is planned to deliver a 300-kg-class rover and an instrumented landing platform to the Martian surface using a landing system developed by Roscosmos. The 2018 mission is to pursue one of the most outstanding questions of our time by attempting to establish whether life ever existed, or is still present, on Mars today. The article gives an overview of the ExoMars program.

High Energy Density, Long-Life Li-S Batteries for Aerospace Applications

Lithium-ion batteries have been successfully employed in several Mars surface missions, e.g., Mars Exploration Rovers (Spirit and Opportunity), Mars Phoenix Lander, and more recently in the Mars Science Laboratory rover (Curiosity).1 With distinct benefits in gravimetric and volumetric densities combined with good low temperature performance relative to the aqueous battery systems, Li-ion batteries contribute to reduced launch costs, increased payload and science capabilities in the space missions. NASA’s upcoming missions however need energy storage systems with enhanced performance capability, especially higher specific energies and energy densities. One such application involves astronaut Extra Vehicular Activity (EVA), wherein the astronaut’s Portable Life Support System (PLSS) is expected to support 8 hours of EVA. The state of art batteries with ~200 Wh/kg at the cell level can support only four hours of EVA. To address these needs, we are developing high-energy and long-life lithium-sulfur cells, with the following performance targets: cell specific energy of 400 Wh/kg ii) cycle life exceeding 200 cycles and iii) ability to operate safely over a wide temperature of -10 to +30 °C. We have been developing improved cell components for Li-S cells, e.g., protected Li anode, dense sulfur cathode and compatible electrolytes, mainly addressing the key technological hurdlesof poor utilization at high cathode loading (necessary for a practical high energy cell) and limited cycle life.2-5 We have developed new sulfur cathodes that show high specific capacities of ≥800 mAh/g at C/5 rate with practical material loadings, ii) Li anode protected with a polymer electrolyte that displays efficient Li cycling and durability in laboratory Li-S cells, and iii) Electrolytes and new proprietary coatings of polysulfide blocking layers which inhibit the deleterious effects of sulfur redistribution and contribute to a good cycle life. We have also developed suitable cell designs and fabricated pouch cells that displayed specific energies of ~300 Wh/kg, moderate cycle and safety towards thermal and electrical abuse. In this paper, we will describe some of these material developments and their performance in laboratory cells and later in prototype cells. B. V. Ratnakumar, W. C. West, P. DeGrosse Jr., M. C. Smart, L. Jones and R.C. Ewell, NASA Battery Workshop, Huntsville, AL, November 6, (2012)Y. Yin, S. Xin, Y. Guo and L. Wan, Angew. Chem. Int. Ed. 2013, 52, 13186 (2013).S. Evers, L. F. Nazar, Acc. Chem. Res., 46, 1135 (2013);X. Ji, K. T. Lee, L. F. Nazar, Nat. Mater. 8, 500 (2009).A. Manthiram, S.-H. Chung, C. Zu, Adv. Mater. 27, 1980 (2015).S. S. Zhang, Front. Energy Res. 1, 1 (2013).

Adsorption and thermoanalytical studies on the CI chondrite Orgueil as case of early preplanetary matter

The thermal, adsorption, and, in particular, the water-bearing properties of the CI-type meteorite Orgueil as an example of early preplanetary matter have been studied by quantitative sorption experiments with H2O, CO2, N2, and n-heptane, thermogravimetry/differential scanning calorimetry as well as by coupled thermogravimetry/mass spectroscopy. The study contributes to a detailed examination of the behavior of volatile species in carbonaceous chondrites and could support future surface missions on asteroids. The results confirm the presence of phyllosilicates, sulfates, carbonates, and presumably carbon in Orgueil. The decomposition fragments observed during the thermoanalytical experiment indicate somewhat lower temperatures of decomposition for the sulfates. The nature of the distinct partial step around 970K interpreted in terms of a carbon release remains uncertain. The adsorption measurements and thermogravimetric investigations suggest the presence of water-bearing Earth-like minerals such as phyllosilicates. The specific N2 BET surface area is 30m2/g. The total water quantity present in Orgueil may exceed 10wt%. At least half of this amount (as a minimum) is very strongly bonded in the water/OH bearing phases of Orgueil.

Advanced Laser Retroreflectors for Astrophysics and Space Science

We developed advances laser retroreflectors for solar system exploration, geodesy and for precision test of General Relativity (GR) and new gravitational physics: a micro-reflector array (INRRI, Instrument for landing-Roving laser Retroreflectors Investigations), a midsize reflector array for the European Earth Observation (EO) program, Copernicus (CORA, COpernicus laser Retroreflector Array), a large, single-retroreflector (MoonLIGHT, Moon Laser Instrumentation for General relativity High accuracy Tests). These laser retroreflectors will be fully characterized at the SCF_Lab (Satellite/lunar/GNSS laser ranging/altimetry Cube/microsat Characterization Facilities Laboratory), a unique and dedicated infrastructure of INFN-LNF (www.lnf.infn.it/esperimenti/etrusco/). Our research program foresees several activities: 1) Developing and characterizing the mentioned laser retroreflector devices to determine landing accuracy, rover positioning during exploration and planetary/Moon’s surface georeferencing. These devices will be passive, laser wavelength- independent, long-lived reference point. INRRI will enable the performance of full-column measurement of trace species in the Mars atmosphere by future space-borne lidars. These measurements will be complementary to highly localized measurements made by gas sampling techniques on the Rover or by laser back-scattering lidar techniques on future orbiters and/or from the surface. INRRI will also support laser and quantum communications, carried out among future Mars Orbiters and Mars Rovers. This will be possible also because the INRRI laser retroreflectors will be metal back-coated and, therefore, will not change the photon polarization. The added value of INRRI is its low mass, compact size, zero maintenance and its usefulness for any future laser altimetry, ranging, communications, atmospheric lidar capable Mars orbiter, for virtually decades after the end of the Mars surface mission, like the Apollo and Lunokhod lunar laser retroreflectors. MoonLIGHT and INRRI are proposed for landings on the Moon (two Google Lunar X Prize Missions, namely Moon Express; Russia’s Luna-27 mission, as well as others under consideration/negotia- tion, also with the help of ASI, ESA and other partnerships); 2) Precision tests of GR with LLR to MoonLIGHT reflectors. Development of new fundamental gravity physics models and study of experimental constraints to these models use also laser ranging and laser reflectors throughout the solar system: extension of general relativity to include Spacetime Torsion, Non-Minimal Coupling between matter and curvature (so-called “ ” theories, or NMC gravity); 3) Extension of program to: Mars, Phobos and Deimos, Jupiter and Saturn icy/rocky moons, Near Earth Asteroids.

Near infrared cavity ring-down spectroscopy for isotopic analyses of CH4 on future Martian surface missions

A compact Near Infrared Continuous Wave Cavity Ring-down Spectrometer (near-IR-cw-CRDS) was developed as a candidate for future planetary surface missions. The optical cavity was made of titanium with rugged quartz windows to protect the delicate super cavity from the harsh environmental changes that it would experience during space flight and a Martian surface mission. This design assured the long-term stability of the system. The system applied three distributed feedback laser diodes (DFB-LD), two of which were tuned to the absorption line peaks of 12CH4 and 13CH4 at 6046.954cm−1 and 6049.121cm−1, respectively. The third laser was tuned to a spectral-lines-free region for measuring the baseline cavity loss. The multiple laser design compensated for typical baseline drift of a CRDS system and, thus, improved the overall precision. A semiconductor optical amplifier (SOA) was used instead of an Acousto-Optic Module (AOM) to initiate the cavity ring-down events. It maintained high acquisition rates such as AOM, but consumed less power. High data acquisition rates combined with improved long-term stability yielded precise isotopic measurements in this near-IR region even though the strongest CH4 absorption line in this region is 140 times weaker than that of the strongest mid-IR absorption band., The current system has a detection limit of 1.4×10–12cm−1 for 13CH4. This limit corresponds to ~7pptv of CH4 at 100Torr. With no further improvements the detection limit of our current near IR-cw-CRDS at an ambient Martian pressure of ~6Torr (8mbar) would be 0.25ppbv for one 3.3 minute long analysis.

Lithium-Rich NMC Cathodes and Si-C Anodes in Low Flammability Li-Ion Battery Electrolytes

Li-ion batteries were successfully employed in our Mars planetary surface missions, e.g., robotic Mars Rovers, Spirit, Opportunity and Curiosity. However, the future space missions involve human exploration and demand further advances both in energy densities and safety. For example, astronaut Extra Vehicular Activity requires safer batteries with a specific energy in excess of 300 Wh/kg, albeit with moderate cycle life. We have therefore been developing advanced cell components, i.e., high specific capacity cathodes and anodes for improving the specific energy and also low-flammability electrolytes for enhancing safety. Our cathode materials belong to the class of Li-rich, layered-layered composites (of Li2MnO3 and LiMO2)1. Over the last few years, we have: i) optimized their compositions and modified synthesis to maximize specific capacities and tap densities, ii) identified new simpler synthetic methods, based on high energy ball–milling2 and molten salt fluxes iii) and developed new surface coatings, e.g., AlPO4to improve interfacial and cyclic stability. To augment the in-house development, we have also evaluated materials from commercial materials suppliers. A critical component to the performance of the high-energy cathode and anode materials is electrolyte, especially due to the high cathode potentials resulting in electrolyte oxidation and the need to passivate anode for kinetic stability. Further, to improve safety, we adopted low-flammability electrolytes with suitable non-flammable co-solvents, and/or flame retardant additives, e.g., triphenyl phosphate.3 Also, to improve the interfacial stability, especially both cathode and anode, various electrolyte additives, such as vinylene carbonate and lithium bis(oxalate) borate were studied in addition to the surface coatings on cathode particles. We will present the performance of the AlPO4-coated Li-rich NMC cathode against MPG111 anode in different low-flammability electrolytes . Some of these electrolytes have also shown excellent performance in 4V systems, giving comparable cycle life in prototype cells . In this paper, we will present the performance of some of our recent Li-rich NMC cathode materials and Si-C anode composite anodes in conjunction with various low flammability electrolytes. The effect of electrolyte, as well surface coating, on the cathode activation process as well as the (transition) metal leaching from the cathode will be examined. Finally, the performance of the low flammability electrolyte in large-format prototype cells will be presented. Acknowledgments The work described here was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration (NASA) and was supported by the Office of Chief Technologist’s Advanced Space Power Systems project. References J. R. Dahn et al, J. Electrochem. Soc., 149, A778, 2002; K. Amine et al, Electrochem. Solid-State Lett., 6, A183, 2003; M. M. Thackeray et al, Electrochem. Comm., 9, 787 (2007); A. Manthiram et al, J. Electrochem. Soc., 155, A635 (2008).W. C. West, J. Soler, and B. V. Ratnakumar, J. Power Sources (in press).M.C. Smart, F. C. Krause, C. Hwang, W. C. West, J. Soler, G. K. S. Prakash, and B. V. Ratnakumar, 220th ECS Fall Meeting, Boston, MA, Oct. 2012; 222nd ECS Fall Meeting, San Francisco, CA , Oct 24-30 (2013).

Energy and provision management study: A research activity on fuel cell design and breadboarding for lunar surface applications supported by European Space Agency

This paper addresses the findings of the European Space Agency (ESA) study (Energy and Provision Management Study), performed by an Italian consortium, aimed at designing and breadboarding of an Energy Provision and Management system (EPM), based on Polymer Electrolyte Fuel Cell (PEFC) technology. The EPM has been developed for supporting space exploration applications, specifically for lunar surface missions. The fuel cell technology has been selected through a trade-off activity, and the power requirements of a Lunar Base (LB) power plant and a Pressurized Lunar Rover (PLR) have been identified. A synergetic design of EPM has been proposed for both the LB and the PLR. Finally three technological demonstrators have been designed, manufactured and tested: i) a 1 kW PEFC stack, ii) a stand-alone power system based on the developed stack, iii) a regenerative power system based on the stand-alone stack connected with a commercial electrolyser. The tests carried out on breadboards, have demonstrated the ability of fuel cell power systems to meet the requirements of future space missions.

Diurnal variations of energetic particle radiation at the surface of Mars as observed by the Mars Science Laboratory Radiation Assessment Detector

AbstractThe Radiation Assessment Detector onboard the Mars Science Laboratory rover Curiosity is detecting the energetic particle radiation at the surface of Mars. Data collected over the first 350 Martian days of the nominal surface mission show a pronounced diurnal cycle in both the total dose rate and the neutral particle count rate. The diurnal variations detected by the Radiation Assessment Detector were neither anticipated nor previously considered in the literature. These cyclic variations in dose rate and count rate are shown to be the result of changes in atmospheric column mass driven by the atmospheric thermal tide that is characterized through pressure measurements obtained by the Rover Environmental Monitoring Station, also onboard the rover. In addition to bulk changes in the radiation environment, changes in atmospheric shielding forced by the thermal tide are shown to disproportionately affect heavy ions compared to H and He nuclei.

Field Trial of a Dual-Wavelength Fluorescent Emission (L.I.F.E.) Instrument and the Magma White Rover during the MARS2013 Mars Analog Mission

Abstract We have developed a portable dual-wavelength laser fluorescence spectrometer as part of a multi-instrument optical probe to characterize mineral, organic, and microbial species in extreme environments. Operating at 405 and 532 nm, the instrument was originally designed for use by human explorers to produce a laser-induced fluorescence emission (L.I.F.E.) spectral database of the mineral and organic molecules found in the microbial communities of Earth's cryosphere. Recently, our team had the opportunity to explore the strengths and limitations of the instrument when it was deployed on a remote-controlled Mars analog rover. In February 2013, the instrument was deployed on board the Magma White rover platform during the MARS2013 Mars analog field mission in the Kess Kess formation near Erfoud, Morocco. During these tests, we followed tele-science work flows pertinent to Mars surface missions in a simulated spaceflight environment. We report on the L.I.F.E. instrument setup, data processing, and performance during field trials. A pilot postmission laboratory analysis determined that rock samples acquired during the field mission exhibited a fluorescence signal from the Sun-exposed side characteristic of chlorophyll a following excitation at 405 nm. A weak fluorescence response to excitation at 532 nm may have originated from another microbial photosynthetic pigment, phycoerythrin, but final assignment awaits development of a comprehensive database of mineral and organic fluorescence spectra. No chlorophyll fluorescence signal was detected from the shaded underside of the samples.

Research on Heat Transfer Characteristics of Nano-Porous Silica Aerogel Material and its Application on Mars Surface Mission

Based on the nanoporous network structure features of silica aerogel, the gas-solid coupled heat transfer model of silica aerogel is analyzed, and the calculation formulas of the gas-solid coupled, the gas thermal conductivity and the heat radiation within the aerogel are derived. The thermal conductivity of pure silica aerogel is calculated according to the derived heat transfer model and is also experimentally measured. Moreover, measurements on the thermal conductivities of silica aerogel composites with different densities at ambient conditions are performed. And finally, a novel design of silica aerogel based integrated structure and thermal insulation used for withstanding the harsh thermal environment on the Martin surface is presented.

Science applications of a multispectral microscopic imager for the astrobiological exploration of Mars.

Future astrobiological missions to Mars are likely to emphasize the use of rovers with in situ petrologic capabilities for selecting the best samples at a site for in situ analysis with onboard lab instruments or for caching for potential return to Earth. Such observations are central to an understanding of the potential for past habitable conditions at a site and for identifying samples most likely to harbor fossil biosignatures. The Multispectral Microscopic Imager (MMI) provides multispectral reflectance images of geological samples at the microscale, where each image pixel is composed of a visible/shortwave infrared spectrum ranging from 0.46 to 1.73 μm. This spectral range enables the discrimination of a wide variety of rock-forming minerals, especially Fe-bearing phases, and the detection of hydrated minerals. The MMI advances beyond the capabilities of current microimagers on Mars by extending the spectral range into the infrared and increasing the number of spectral bands. The design employs multispectral light-emitting diodes and an uncooled indium gallium arsenide focal plane array to achieve a very low mass and high reliability. To better understand and demonstrate the capabilities of the MMI for future surface missions to Mars, we analyzed samples from Mars-relevant analog environments with the MMI. Results indicate that the MMI images faithfully resolve the fine-scale microtextural features of samples and provide important information to help constrain mineral composition. The use of spectral endmember mapping reveals the distribution of Fe-bearing minerals (including silicates and oxides) with high fidelity, along with the presence of hydrated minerals. MMI-based petrogenetic interpretations compare favorably with laboratory-based analyses, revealing the value of the MMI for future in situ rover-mediated astrobiological exploration of Mars.

Robotics and Automation for “Icebreaker”

The proposed “Icebreaker” mission is a return to the Mars polar latitudes first visited by the Phoenix mission in 2007–2008. Exploring and interrogating the shallow subsurface of Mars from the surface will require some form of excavation and penetration, with drilling being the most mature approach. A series of 0.5–5 m automated rotary and rotary‐percussive drills developed over the past decade by NASA Ames and Honeybee Robotics provide the capability to fly on a Mars surface mission within the next decade. Surface robotics have been integrated for sample transfer to deck instruments, and the Icebreaker sample acquisition system has been tested successfully in Mars chambers and analog field sites to depths between 1 and 3 m, most recently in the Antarctic Dry Valleys in January of 2013. This paper provides a hardware and software systems overview of the Icebreaker sample acquisition system, and discusses test results of this robotic system in relevant environments. Test results from recent Arctic and Antarctic field campaigns demonstrate a hands‐off “dust to data” capability.

ExoMars Rover PanCam: Autonomous & Computational Intelligence [Application Notes

As a part of the Aurora programme for Mars exploration, funded by the United Kingdom Space Agency (UKSA) and European Space Agency (ESA), the UK contributes to the Exobiology on Mars (ExoMars) rover science and engineering programme, with a scheduled launch in 2018; Hence, our Panoramic Camera (PanCam) [9][15] research and development (R&D) is timely. PanCam consists of two stereo Wide Angle Cameras (WAC) and one High Resolution Camera (HRC). While the development is still ongoing, we used funding awarded by the University College London (UCL) Graduate School to conduct investigations in the Himalayas and at Mount Everest Base Camp (EBC), according to the ExoMars rover Reference Surface Mission (RSM). The investigations included capturing stereo and high resolution images using stereo WAC emulators and HRC emulator at altitudes 3490 m, 5150 m and above. Images from different WAC filters, and color images from HRC were acquired at various Pan and Tilt Unit (PTU) mast positions. Our investigation results show significant reduction in data volume with minimum loss in image quality. Furthermore, we introduce a novel autonomous and computational intelligent system called Mission-Specific Data Processor (MSDP) for the rover. It includes Pan-Cam, Visual Data Fusion (VDF), Learning-enabled Object Detection (LOD), Self-Learning Agent (SLA) [22], and Environment Model Library (EML) as part of the rover's computational intelligence [7].

Observations of wind direction by automated analysis of images from Mars and the MSL rover

Past missions to Mars have revealed the presence of clouds in the atmosphere, visible both from the surface and from orbit. Where atmospheric sounding instrumentation is not available, the motion of such clouds can be used as a proxy for wind observations. Such observations aid in the study of the Martian climate, as well as of mass and moisture transport in the atmosphere. An understanding of the water cycle on Mars has important implications for models of the transport, distribution, and preservation of any biomarkers which might exist from past or present life on the planet.The present work describes an algorithm for automated image analysis, the function of which is to identify clouds in sequences of images of the Martian sky, and to track their movement across frames in the sequence to allow a calculation of the wind vector. The system is currently under development using imagery from previous surface missions, particularly the Phoenix lander, for reference and test. Past work has used these images for manual tracking of clouds and wind estimation; the current effort aims to automate the process to allow faster and more accurate analysis. The work will be finalized with the availability of data from the NavCam imager aboard the Mars Science Laboratory (MSL) rover, now operating on Mars since August 2012. Once tested with the MSL imagery, the system will be used for regular observations of the wind in the atmosphere near the MSL landing site.The image-analysis strategy used in the algorithm is presented, and its performance to date in recognizing the types of clouds expected on Mars is described. The tracking performance between frames in the reference data is shown, and the future utility of the system is described.The work is undertaken under a NASA Participating Scientist project, with support from the Canadian Space Agency.

Missions to Mars: Characterisation of Mars analogue rocks for the International Space Analogue Rockstore (ISAR)

Instruments for surface missions to extraterrestrial bodies should be cross-calibrated using a common suite of relevant materials. Such work is necessary to improve instrument performance and aids in the interpretation of in-situ measurements. At the CNRS campus in Orléans, the Observatoire des Sciences de l'Univers en région Centre (OSUC) has created a collection of well-characterised rocks and minerals for testing and calibrating instruments to be flown in space missions. The characteristics of the analogue materials are documented in an accompanying online database. In view of the recent and upcoming rover missions to Mars (NASA's 2011 Mars Science Laboratory (MSL) and ESA/Roscosmos' 2018 ExoMars), we are concentrating initially on materials of direct relevance to the red planet. The initial collection consists of 15 well-studied rock and mineral samples, including a variety of basalts (ultramafic, weathered, silicified, primitive), sediments (volcanic sands, chert, and a banded iron formation –BIF-), and the phyllosilicate nontronite (a clay). All the samples were characterised petrographically, petrologically, and geochemically using the types of analyses likely to be performed during in-situ missions, in particular ExoMars: hand specimen description; optical microscopy; mineralogical analysis by XRD, Raman and IR spectrometry; iron phase analysis by Mössbauer spectroscopy (MBS), elemental analysis by Energy-Dispersive X-ray spectroscopy (EDX), microprobe, Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) and Mass Spectrometry (ICP-MS); and reduced carbon analysis by Raman spectrometry.

Performance of a small and low-cost chamber to simulate lunar surface environment

The performance of a small and low-cost metal chamber built to simulate the pressure and temperature conditions of lunar surface was assessed and the results are presented. This chamber is intended for studying the physical properties of lunar surface and subsurface (using soil simulants) and also to validate the technology readiness of certain newly developed payloads planned for future lunar surface missions (Lander/Rover). It is possible to reach down to ∼10−7Pa under specific conditions and maintain the temperature of the sample under investigation to lunar day and night temperatures. The designed system has been subjected to various tests to evaluate its performance and suitability for carrying out experiments in a simulated lunar environment.