Mars Sample Return Research Articles

Diagenetic History and Biosignature Preservation Potential of Fine‐Grained Rocks at Hogwallow Flats, Jezero Crater, Mars

AbstractThe Mars 2020 Perseverance rover discovered fine‐grained clastic sedimentary rocks in the “Hogwallow Flats” member of the “Shenandoah” formation at Jezero crater, Mars. The Hogwallow Flats member shows evidence of multiple phases of diagenesis including Fe/Mg‐sulfate‐rich (20–30 wt. %) outcrop transitioning downward into red‐purple‐gray mottled outcrop, Fe/Mg clay minerals and oxides, putative concretions, occasional Ca sulfate‐filled fractures, and variable redox state over small (cm) spatial scales. This work uses Mastcam‐Z and SuperCam instrument data to characterize and interpret the sedimentary facies, mineralogy and diagenetic features of the Hogwallow Flats member. The lateral continuity of bedrock similar in tone and morphology to Hogwallow Flats that occurs over several km within the western Jezero sedimentary fan suggests widespread deposition in a lacustrine or alluvial floodplain setting. Following deposition, sediments interacted with multiple fluids of variable redox state and salinity under habitable conditions. Three drilled sample cores were collected from this interval of the Shenandoah formation as part of the Mars Sample Return campaign. These samples have very high potential to preserve organic compounds and biosignatures. Drill cores may partially include dark‐toned mottled outcrop that lies directly below light‐toned, sulfate‐cemented outcrop. This facies may represent some of the least oxidized material observed at this interval of the Shenandoah formation. This work reconstructs the diagenetic history of the Hogwallow Flats member and discusses implications for biosignature preservation in rock samples for possible return to Earth.

The search for life signatures on Mars by the Tianwen-3 Mars sample return mission.

We present the proposed strategic study, 'Integrated elements for Martian life signature exploration', to support the sampling and identification of any potential biosignatures in compliance with the engineering constraints of the Tianwen-3 mission.

Magnetite Survivability and Non‐Stoichiometric Magnetite Formation in Presence of Oxyhalogen Brines on Mars

AbstractThe mixed Fe(II)/Fe(III) mineral magnetite [Fe3O4] of various stoichiometric and non‐stoichiometric compositions have been reported in Martian soils and rocks by several rover missions. Magnetite is an important paleomagnetic indicator mineral and can serve as a ‘biogeobattery’ as a consequence of its magnetic properties and the mixed valence state of iron in its structure. Here, we assess the extent of oxidative weathering of magnetite in presence of chlorate and bromate containing solutions that are likely important oxidants on Mars. Oxyhalogen species, chlorate and bromate, produced non‐stoichiometric magnetite [Fe(II)/Fe(III) < 0.5] in Mars‐relevant, near‐neutral pH fluids; no other ferric minerals were produced. The same results were observed in highly acidic fluids with or without oxyhalogens. Owing to its resistance to extensive oxidation, magnetite can serve as an important archive of geochemical, paleomagnetic, and astrobiological information in samples that will be returned by the Mars Sample Return mission.

Organic Carbon and Ca‐Rich Carbonate Detections in Soils of the Northern Plains, Mars: Evaluation of Unreported Data From the Mars Phoenix Scout's Thermal Evolved Gas Analyzer (TEGA)

AbstractThe Thermal Evolved Gas Analyzer (TEGA) analysis of surface and icy subsurface Phoenix landing site soils consisted of low (300–700°C) and high (>700°C) temperature CO2 evolutions that were attributed to organic carbon (83–1,484 μgC/g) and Ca‐rich carbonate (1.1–2.6 wt.%). Total carbon abundances ranged from 1,143 to 4,905 µgC/g, which is the highest soil carbon concentration so far detected on Mars. Low temperature CO2 was attributed to oxidized organic C (e.g., oxalates, acetates), while hydrocarbon combustion was indicated in two soils by the detection of coevolved CO2 and O2 (perchlorate). Combustion reactions may have prevented the detection of hydrocarbon masses in the Phoenix landing site soils. Organic C was likely derived from meteoritic and igneous/hydrothermal sources, but microbiological sources cannot be excluded. CO2 evolved at high temperatures was consistent with Ca‐rich carbonate along with possible minor contributions from macromolecular organic carbon and mineral/glass vesicle CO2. Carbon detected in the Phoenix landing site soil and other landing site soils and sands (e.g., Gale/Jezero craters) would be consistent with global organic C and carbonate in soils and sand across Mars. However, oxidizing water thin films derived from the near‐surface ice in the Phoenix soils favor Ca‐carbonate over Fe‐carbonate, which is likely more stable in the ice‐free regions of Mars (e.g., Gale/Jezero craters). The global carbon budget on Mars inferred from these results emphasizes that Mars Sample Return should yield carbon bearing soil/rock that would allow the identification of the origin of carbon and any possible connections to ancient martian microbiology.

A High-Reliability Photoelectric Detection System for Mars Sample Return’s Orbiting Sample

The Mars Sample Return campaign is an endeavor of unprecedented technological complexity and coordination that attempts to answer fundamental questions about the habitability of Mars by returning the first samples of Martian material to Earth for analysis. The third mission in the campaign consists of the NASA-provided Capture, Containment, and Return System (CCRS) onboard the European Space Agency’s Earth Return Orbiter, which will retrieve the Orbiting Sample (OS) container from its orbit around Mars. Retrieving a passive sample container from a planetary orbit has never been attempted by any spacecraft and requires the development of new technology to succeed in this ambitious task. This paper introduces the high-reliability Capture Sensor Suite (CSS), a novel optical detection system that provides CCRS with the capability to autonomously detect the OS as it is captured. This article will discuss the challenges and requirements for the fault-tolerant design of the CSS.

Exploring the dielectric loss of Martian regolith in the frequency domain using Zhurong radar data

Martian regolith is one of the primary science objectives of Mars exploration missions. The Rover Penetrating Radar carried by Zhurong rover allows for high-resolution subsurface imaging and in-situ measurements of Martian regolith dielectric properties, which are crucial to advance our understanding of Martian geology and hydrological evolution. While earlier studies have derived dielectric constants for the shallow subsurface, further characterization of subsurface materials requires the determination of attenuation properties. In this study, we applied the centroid-frequency shift method to explore the attenuation property of the Martian regolith in the frequency domain. Lateral attenuation variation was analyzed in detail by integrating subsurface radargram and navigation terrain images. The results show that, within a depth of ∼4 m, the attenuation of radar signal for Zhurong subsurface material is equal to a loss tangent of 0.0079, with a standard deviation of 0.001. Based on the loss tangent value, dielectric permittivity and ground characterization, we preclude the possibility that the regolith is predominantly igneous materials. The lateral variation of the attenuation property could likely be attributed to changes in the proportion of duricrusts, which are heterogeneously distributed along the rover traverse. Our findings offer valuable information for understanding the Martian regolith and its evolution, serving as a important reference for future Mars sample return missions.

Automated Identification of Outgassed Chemical Species Using Mass Spectrometry for Scientific Space Missions

Current and planned space exploration and life detection missions such as NASA Jet Propulsion Laboratory’s Mars 2020, Mars Sample Return, and Europa Clipper require record-low contamination levels. In this work, we develop a novel automated outgassing contamination species identification method using mass spectrometry data. Thanks to the existing knowledge of ASTM-E1559 and direct analysis in real-time mass spectrometry material testing methods, we improved species outgassing deconvolution and physical characterization techniques. We developed a brand-new combined approach that leverages both tests’ complementary insights into contaminants’ chemical identities. Namely, we rely on the Dromey–Foyster algorithm and the Seven Golden Rules of mass spectrometry analysis to narrow down the probable identified molecules by a factor of 10 compared to the sole use of ASTM-E1559. Furthermore, thanks to recent advances in machine learning spectral analysis, we developed a composite spectral score that ranks all candidate contaminants based on their similarity to the measurements. Ultimately, we validated an automated species identification algorithm on samples of NuSil CV4-2946, Dacron, and a spacecraft cable component. The techniques established in this work enable accurate estimations of outgassed contaminant species’ chemical structure, leading to a comprehensive understanding of the effects of outgassing on scientific objectives.

Martian Dust Storms: Reviews and Perspective for the Tianwen-3 Mars Sample Return Mission

Dust storms play a crucial role in the climate system and the space environment of Mars, significantly impacting human exploration activities on the planet. The Martian dust storms exhibit significant regional, seasonal and interannual variations due to various controlling factors such as large-scale atmospheric circulation, varying solar radiation forcing, and Martial orbital and rotational motions and their coupling to the atmospheric dynamics. This paper aims to review current understandings of Martian dust storms. This paper begins by elucidating the basic properties of dust storms, their driving mechanisms, and their impacts on atmospheric dynamics, atmospheric electric property, space environment, topography, and Mars explorations. The paper then introduces the observation methods on different platforms, including orbiters and landers/rovers, along with datasets constructed based on these historical observations of Martian dust storms. Finally, we propose dust storm monitoring and predicting for the upcoming Chinese Tianwen-3 Mars sample return mission. It concludes by depicting the future research topics aimed at systematically understanding Martian dust storms.

The Preservation and Spectral Detection of Historic Museum Specimen Microbial Mat Biosignatures Within Martian Dust: Lessons Learned for Mars Exploration and Sample Return.

The key building blocks for life on Mars could be preserved within potentially habitable paleo-depositional settings with their detection possible by utilizing mid-infrared spectroscopy; however, a definite identification and confirmation of organic or even biological origin will require the samples to be returned to Earth. In the present study, Fourier-transform infrared (FTIR) spectroscopic techniques were used to characterize both mineralogical and organic materials within Mars dust simulant JSC Mars-1 and ancient Antarctic cyanobacterial microbial mats from 1901 to 1904 Discovery Expedition. When FTIR spectroscopy is applied to cyanobacterial microbial mat communities, the resulting spectra will reflect the average biochemical composition of the mats rather than taxa-specific spectral patterns of the individual organisms and can thus be considered as a total chemical analysis of the mat colony. This study also highlights the potential difficulties in the detection of these communities on Mars and which spectral biosignatures will be most detectable within geological substrates. Through the creation and analysis of a suite of dried microbial mat material and Martian dust simulant mixtures, the spectral signatures and wavenumber positions of CHx aliphatic hydrocarbons and the C-O and O-H bands of polysaccharides remained detectable and may be detectable within sample mixtures obtained through Mars Sample Return activities.

Laboratory testing of desiccation crack growth in terrestrial Martian analog environments using digital image correlation

The unique geologic features of raised ridges and polygonal cracks filled with multiple layers of cement observed in Gale and Jezero craters on Mars have origins that remain uncertain due to limited knowledge and measurement techniques. This study hypothesizes that these cracks result from the volumetric shrinkage of clay fabric due to dehydration and salinity fluctuations in ancient Martian lakes. The research aims to quantify the shrinkage of terrestrial simulants with varying mineral compositions analogous to those found at Gale Crater and Jezero Crater under diverse desiccation conditions. By simulating Martian regolith using the Rocknest soil simulant and examining historical aqueous conditions through sedimentary rock analogs, this study provides new insights into Martian geological structures. The extent and rate of shrinkage in simulant samples were quantified using ImageJ, while strain localization and propagation were measured using the Digital Image Correlation (DIC) technique until full desiccation crack patterns developed. Laboratory testing revealed that desiccation cracks tend to form polygonal patterns, which are patently similar to the polygonal patterns observed in some regions of Mars. However, not all simulants produced visible cracks, with some producing linear rather than polygonal patterns. Key findings indicate that higher temperatures result in wider and deeper cracks, while lower temperatures decrease crack density and length. Increased initial water content leads to more extensive cracking, with higher crack density and length per unit area. Sodium chloride and sodium sulfate significantly impact desiccation cracking, with low concentrations stabilizing the soil and high concentrations promoting extensive cracking. Smectite-rich samples exhibit extensive cracking, and tensile strain distribution during evaporation is non-uniform, influencing crack development based on sample properties and drying conditions. These insights enhance our understanding of polygonal crack formation on Mars, improving Mars sample return missions and informing the design of robust exploration equipment.

Lessons Learned in Designing a Proposed Ultraviolet Sterilization System for Space

This paper presents a number of lessons learned while designing a proposed sterilization system for Mars Sample Return. This sterilization system is needed to inactivate any potentially hazardous Mars material on the exterior surface of the vessel containing sealed sample tubes filled with Mars rock cores, regolith and atmosphere. These returned samples would provide information on the geologic history of Mars, the evolution of its climate and the potential for ancient life. Mars Sample Return is categorized at Planetary Protection Category V Restricted Earth Return, so it is required to protect the Earth–Moon system from the biological impact of returning samples from Mars to Earth. This article reviews lessons learned in the development of a particular engineering implementation to support the protection of the Earth–Moon biosphere: the use of in situ ultraviolet LED illumination. The details of the biological efficacy of this approach or the policy-related impacts are outside of the scope of this manuscript. The lessons learned presented here include establishing design requirements for the system, the selection of a light source, optical design options, contamination control and approaches to thermal and power management.

Development of ballistic limit equations in support of the Mars sample return mission

NASA and ESA are currently planning the Mars Sample Return campaign, comprising missions whose combined objective is to bring the first samples of Mars material back to Earth for detailed study. Until recently, the NASA-ESA plan was to return samples to Earth using three missions. The final component, the Earth Entry System (EES), will bring the Mars samples back to the Earth, where it will land following safe entry through the Earth's atmosphere. There is a concern regarding the risk of biological contamination of the Earth's biosphere from returned Mars samples if, for example, the structural integrity of the EES were compromised during its return mission due to a perforation of a critical surface resulting from a high-speed meteoroid impact. To assess the risks associated with such an event, NASA is developing equations that predict the damage that various EES elements will sustain as a result of such an impact, as well as equations that predict whether or not a particular system will sustain a critical failure following such an impact. In this paper, we review recent progress in the development of such equations for the EES forebody and the EES aftbody, the two elements of the EES that are most exposed to the meteoroid environment. Limitations of the BLEs are also discussed, which can also be used to further inform the next steps in the BLE development.

NASA’s Capture, Containment, and Return System: Bringing Mars samples to Earth

The Mars Sample Return (MSR) campaign is one of the most ambitious and complex planetary science exploration missions ever pursued. With the participation of NASA, ESA, and many industry partners, MSR aims to bring Martian rock and atmosphere samples to Earth with the goal of answering key questions about Mars’ geological, climatological and, potentially, biological evolution. To accomplish this ambitious goal, the MSR campaign relies on three distinct flight elements and a ground element. The Earth Return Orbiter mission that would host the Capture, Containment, and Return System (CCRS) is the last flight element of the trio. The mission would capture the orbiting sample in low Mars orbit (launched into orbit by another mission), contain it, and return it to Earth, landing at the Utah Test and Training Range. Since its early architecture, several changes were adopted by CCRS to improve overall payload efficiency and reduce mass. This paper will discuss the CCRS design, how the current CCRS architecture contributes to an improved mission concept, and the next critical steps of the mission toward its launch.

Vision System for the Mars Sample Return Capture Containment and Return System (CCRS)

The successful 2020 launch and 2021 landing of the National Aeronautics and Space Administration’s (NASA) Perseverance Mars rover initiated the first phase of the NASA and European Space Agency (ESA) Mars Sample Return (MSR) campaign. The goal of the MSR campaign is to collect scientifically interesting samples from the Martian surface and return them to Earth for further study in terrestrial laboratories. The MSR campaign consists of three major spacecraft components to accomplish this objective: the Perseverance Mars rover, the Sample Retrieval Lander (SRL) and the Earth Return Orbiter (ERO). Onboard the ERO spacecraft is the Capture, Containment and Return System (CCRS). CCRS will capture, process and return to Earth the samples that have been collected after they are launched into Mars orbit by the Mars Ascent Vehicle (MAV), which is delivered to Mars onboard the SRL. To facilitate the processing of the orbiting sample (OS) via the CCRS, we have designed and developed a vision system to determine the OS capture orientation. The vision system is composed of two cameras sensitive to the visible portion of the electromagnetic spectrum and two illumination modules constructed from broadband light emitting diodes (LED). Vision system laboratory tests and physics-based optical simulations predict CCRS ground processing will be able to correctly identify the OS post-capture orientation using only a single vision system image that is transmitted to Earth from Mars orbit.

Phosphates on Mars and Their Importance as Igneous, Aqueous, and Astrobiological Indicators

This paper reviews the phosphate phases in meteorites and those measured by landed spacecraft, what they reveal about past igneous and aqueous conditions on Mars, and important implications for potential prebiotic chemistry, past habitability, and potential biosignatures that could be detected in samples returned from Mars. A review of the 378 martian meteorites as of 2023 indicate that of the two most common phosphate minerals in Mars meteorites, merrillite and apatites, the apatite composition is largely F- and Cl-rich, with shergottites containing more OH. The phosphate concentrations examined across multiple missions show a relatively narrow range of phosphate, with higher concentrations observed in the Mount Sharp Group in Gale crater and Wishstone at Gusev crater and lower concentrations observed at Jezero crater floor and Jezero fan. Possible secondary phosphates detected on Mars, including Fe phosphates at Jezero crater and Gusev crater and Ca- and Al-bearing secondary phosphates, temperatures of formation of secondary phases and their dissolution rates and solubilities are reviewed and summarized. Despite this wealth of information about phosphates on Mars, due to their fine scale and relatively low concentrations, Mars Sample Return is needed to better understand phosphate and its implications for the igneous, aqueous, and astrobiological history of Mars.

The planetary protection strategy of Mars Sample Return’s Earth Return Orbiter mission

The Mars Sample Return campaign aims to use three flight missions and one ground element to safely bring rock cores, regolith and atmospheric samples from the surface of Mars to Earth to answer key questions about the geologic and climate history of Mars, including the potential for ancient life. Since its landing in Jezero Crater in 2021, the first mission, NASA’s Mars 2020, has collected a number of samples on the crater floor and on the delta using the Perseverance rover. Subsequent missions would recover the sealed sample tubes, launch them into Mars orbit, and transport them back to Earth. The ground element would be a high-containment facility that would isolate and protect the samples during initial sample characterization, which would include sample safety assessments and time-sensitive scientific investigations. These elements are currently in the planning and design stages of development, and represent an international effort of NASA, the European Space Agency (ESA), and many industry partners. The work presented here provides an overview of the planetary protection strategy of the third flight mission, the ESA-led Earth Return Orbiter, which hosts the NASA-provided Capture, Containment, and Return System. The orbiter would detect and capture the container with up to 30 sealed tubes previously put in Martian orbit, contain them in redundant containers to ensure that no potentially hazardous Mars particles are released, and return them to Earth through an entry vehicle. Both NASA and ESA policies comply with the United Nations’ Outer Space Treaty by planning to protect Earth’s biosphere from any potential adverse effects from material returned from solar system bodies beyond the Earth-Moon system. In the conduct of Mars Sample Return, the two agencies have mutually agreed to apply approaches consistent with their own planetary protection standards to the campaign elements they each provide.

Mars Mission’s Monetary Roller Coaster Hits New Lows

In February, the NASA research center laid off more than 500 people, citing congressional budget uncertainties over the controversial Mars Sample Return mission. What is its path forward?

Present-day thermal and water activity environment of the Mars Sample Return collection

The Mars Sample Return mission intends to retrieve a sealed collection of rocks, regolith, and atmosphere sampled from Jezero Crater, Mars, by the NASA Perseverance rover mission. For all life-related research, it is necessary to evaluate water availability in the samples and on Mars. Within the first Martian year, Perseverance has acquired an estimated total mass of 355 g of rocks and regolith, and 38 μmoles of Martian atmospheric gas. Using in-situ observations acquired by the Perseverance rover, we show that the present-day environmental conditions at Jezero allow for the hydration of sulfates, chlorides, and perchlorates and the occasional formation of frost as well as a diurnal atmospheric-surface water exchange of 0.5–10 g water per m2 (assuming a well-mixed atmosphere). At night, when the temperature drops below 190 K, the surface water activity can exceed 0.5, the lowest limit for cell reproduction. During the day, when the temperature is above the cell replication limit of 245 K, water activity is less than 0.02. The environmental conditions at the surface of Jezero Crater, where these samples were acquired, are incompatible with the cell replication limits currently known on Earth.

Multi-Technique Characterization of 3.45 Ga Microfossils on Earth: A Key Approach to Detect Possible Traces of Life in Returned Samples from Mars.

The NASA Mars 2020 Perseverance rover is actively exploring Jezero crater to conduct analyses on igneous and sedimentary rock targets from outcrops located on the crater floor (Máaz and Séítah formations) and from the delta deposits, respectively. The rock samples collected during this mission will be recovered during the Mars Sample Return mission, which plans to bring samples back to Earth in the 2030s to conduct in-depth studies using sophisticated laboratory instrumentation. Some of these samples may contain traces of ancient martian life that may be particularly difficult to detect and characterize because of their morphological simplicity and subtle biogeochemical expressions. Using the volcanic sediments of the 3.45 Ga Kitty's Gap Chert (Pilbara, Australia), containing putative early life forms (chemolithotrophs) and considered as astrobiological analogues for potential early Mars organisms, we document the steps required to demonstrate the syngenicity and biogenicity of such biosignatures using multiple complementary analytical techniques to provide information at different scales of observation. These include sedimentological, petrological, mineralogical, and geochemical analyses to demonstrate macro- to microscale habitability. New approaches, some unavailable at the time of the original description of these features, are used to verify the syngenicity and biogenicity of the purported fossil chemolithotrophs. The combination of elemental (proton-induced X-ray emission spectrometry) and molecular (deep-ultraviolet and Fourier transform infrared) analyses of rock slabs, thin sections, and focused ion beam sections reveals that the carbonaceous matter present in the samples is enriched in trace metals (e.g., V, Cr, Fe, Co) and is associated with aromatic and aliphatic molecules, which strongly support its biological origin. Transmission electron microscopy observations of the carbonaceous matter documented an amorphous nanostructure interpreted to correspond to the degraded remains of microorganisms and their by-products (extracellular polymeric substances, filaments…). Nevertheless, a small fraction of carbonaceous particles has signatures that are more metamorphosed. They probably represent either reworked detrital biological or abiotic fragments of mantle origin. This study serves as an example of the analytical protocol that would be needed to optimize the detection of fossil traces of life in martian rocks.

Combined Neutron and X‐Ray Tomography—A Versatile and Non‐Destructive Tool in Planetary Geosciences

AbstractWith several upcoming sample return missions, such as the Mars Sample Return Campaign, non‐destructive methods will be key to maximizing their scientific output. In this study, we demonstrate that the combination of neutron and X‐ray tomography provides an important tool for the characterization of such valuable samples. These methods allow quantitative analyses of internal sample features and also provide a guide for further destructive analyses with little to no sample treatment, which maintains sample integrity, including minimizing the risk of potential contamination. Here, we present and review the results from four case studies of terrestrial impactites and meteorites along with their analytical setup. Using combined X‐ray and neutron tomography, a Ni‐Fe silicide spherule, that is, projectile material, was located within a Libyan Desert Glass sample and the distribution of hydrous phases was pinpointed in selected impactite samples from the Chicxulub IODP‐ICDP Expedition 364 drill core and the Luizi impact structure, as well as in the Miller Range 03346 Martian meteorite.