Future Mars Sample Return Mission Research Articles

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.

Developing Tailored Data Combination Strategies to Optimize the SuperCam Classification of Carbonate Phases on Mars

AbstractThe SuperCam instrument onboard the Mars 2020 Perseverance rover investigates Martian geological targets by a combination of multiple spectroscopic techniques. As Raman, Visible‐Infrared Spectroscopy, and Laser‐Induced Breakdown Spectroscopy (LIBS) spectra deliver complementary information about the interrogated sample, the multivariate analysis of combined spectroscopic data sets is here proposed as a tool to optimize the SuperCam capability to discriminate mineral phases on Mars. For this purpose, the laboratory study of carbonate phases within the Ca‐Mg‐Fe ternary system were selected as representative case of study. After the characterization of model samples, the discrimination capability of mono analytical Raman, VISIR, and LIBS data sets was evaluated by applying a chemometric approach based on the combination of principal component analysis (for sample clustering) and Linear Discriminant Analysis (for mineral classification). Afterward, the low‐level combination (LL) of Raman, VISIR, and LIBS data was achieved by concatenating their spectra into a single data matrix. The mineral classification achieved by LL data sets outperformed the mono analytical ones, thus proving the complementarity between molecular and elemental spectroscopic techniques. Mineral classification was further improved by using a mid‐level data combination strategy. After evaluating benefits and limitations afforded by the proposed combination strategies, future developments are finally outlined. As such, the final objective of this research line is to develop a classification model based on data combination to optimize the capability of SuperCam in discriminating relevant minerals on Mars, this being a key requirement for the selection of the optimal targets to be cached for the future Mars Sample Return Mission.

Optimal rendezvous trajectory between Sample Return Orbiter and Orbiting Sample Container in a Mars Sample Return mission

A trajectory optimization problem is examined to determine the most fuel-efficient rendezvous trajectory between spacecrafts in different orbits. To explore the whole range of feasible solutions, the wait time and the total time of flight are treated as free parameters while the initial and transfer orbits are not restricted to a particular one. To improve the accuracy of the numerical computation, the Kepler's time of flight equation is posed in terms of universal variables while the Lagrange coefficients are employed to obtain three-dimensional orbit information. The optimal rendezvous trajectory is then obtained enforcing the determined necessary conditions to be satisfied given only the initial state vectors of the involved spacecrafts. Two optimal rendezvous trajectories between a Sample Return Orbiter (SRO) and an Orbiting Sample Container (OS) are computed in the context of a future Mars Sample Return mission to demonstrate the reliability of the proposed solution. Finally, orbital perturbations due to the real shape of planet Mars and the solar radiation pressure are taken into account to determine the additional energy required to compensate these perturbations while performing the rendezvous manoeuvre.

Preliminary orbit design for a Mars sample return mission

Mars sample return missions are the focus of international deep space exploration planning in recent years. In this paper, the orbit design of the different flight phases of a Mars sample return mission is studied with consideration of practical engineering constraints, using 2028 launch opportunity as an example; based on comparative analysis of different schemes, feasible orbit designs are recommended for future Mars sample return missions. Preliminary analysis and design of the mission orbit are carried out and the analysis results of the main flight phases are provided in the paper, and the discussion focuses on launch opportunity, Earth to Mars transfer, Mars orbit insertion, rendezvous and docking in Mars orbit, and Mars to Earth transfer. It is shown in the paper that the launch opportunities for Mars sample return missions emerge every two years, and the launch windows in 2028 opportunity concentrate in the November; considering the high risk of the research and development of heavy lift rockets, the scheme that the descent and ascent module, the orbiter and reentry module are launched separately using two available rockets is recommended; the Mars to Earth return opportunities emerge about every two years, and the return windows open about two years after the Earth departure.

A Method for Choosing the Best Samples for Mars Sample Return.

Success of a future Mars Sample Return mission will depend on the correct choice of samples. Pyrolysis-FTIR can be employed as a triage instrument for Mars Sample Return. The technique can thermally dissociate minerals and organic matter for detection. Identification of certain mineral types can determine the habitability of the depositional environment, past or present, while detection of organic matter may suggest past or present habitation. In Mars' history, the Theiikian era represents an attractive target for life search missions and the acquisition of samples. The acidic and increasingly dry Theiikian may have been habitable and followed a lengthy neutral and wet period in Mars' history during which life could have originated and proliferated to achieve relatively abundant levels of biomass with a wide distribution. Moreover, the sulfate minerals produced in the Theiikian are also known to be good preservers of organic matter. We have used pyrolysis-FTIR and samples from a Mars analog ferrous acid stream with a thriving ecosystem to test the triage concept. Pyrolysis-FTIR identified those samples with the greatest probability of habitability and habitation. A three-tier scoring system was developed based on the detection of (i) organic signals, (ii) carbon dioxide and water, and (iii) sulfur dioxide. The presence of each component was given a score of A, B, or C depending on whether the substance had been detected, tentatively detected, or not detected, respectively. Single-step (for greatest possible sensitivity) or multistep (for more diagnostic data) pyrolysis-FTIR methods informed the assignments. The system allowed the highest-priority samples to be categorized as AAA (or A*AA if the organic signal was complex), while the lowest-priority samples could be categorized as CCC. Our methods provide a mechanism with which to rank samples and identify those that should take the highest priority for return to Earth during a Mars Sample Return mission. Key Words: Mars—Astrobiology—Search for Mars' organics—Infrared spectroscopy—Planetary habitability and biosignatures. Astrobiology 18, 556–570.

Spatial Spectroscopic Models for Remote Exploration.

Ancient hydrothermal systems are a high-priority target for a future Mars sample return mission because they contain energy sources for microbes and can preserve organic materials (Farmer, 2000 ; MEPAG Next Decade Science Analysis Group, 2008 ; McLennan et al., 2012 ; Michalski et al., 2017 ). Characterizing these large, heterogeneous systems with a remote explorer is difficult due to communications bandwidth and latency; such a mission will require significant advances in spacecraft autonomy. Science autonomy uses intelligent sensor platforms that analyze data in real-time, setting measurement and downlink priorities to provide the best information toward investigation goals. Such automation must relate abstract science hypotheses to the measurable quantities available to the robot. This study captures these relationships by formalizing traditional "science traceability matrices" into probabilistic models. This permits experimental design techniques to optimize future measurements and maximize information value toward the investigation objectives, directing remote explorers that respond appropriately to new data. Such models are a rich new language for commanding informed robotic decision making in physically grounded terms. We apply these models to quantify the information content of different rover traverses providing profiling spectroscopy of Cuprite Hills, Nevada. We also develop two methods of representing spatial correlations using human-defined maps and remote sensing data. Model unit classifications are broadly consistent with prior maps of the site's alteration mineralogy, indicating that the model has successfully represented critical spatial and mineralogical relationships at Cuprite. Key Words: Autonomous science-Imaging spectroscopy-Alteration mineralogy-Field geology-Cuprite-AVIRIS-NG-Robotic exploration. Astrobiology 18, 934-954.

The western Qaidam Basin as a potential Martian environmental analogue: An overview

AbstractThe early Martian environment is interpreted as warmer and wetter, before a significant change in its global climatic conditions irreversibly led to the current hyperarid environments. This transition is one of the most intriguing processes of Martian history. The extreme climatic change is preserved in the salt deposits, desiccated landscapes, and geomorphological structures that were shaped by the evaporation of water. However, until a manned journey to Mars is feasible, many Martian materials, morphological structures, and much of its evolutionary history will continue to be poorly understood. In this regard, searching and investigating Martian analogues are still meaningful. To find an Earth environment with a whole set of Martian structures distributed at a scale comparable to Mars is even more important to test landing crafts and provide optimized working parameters for rovers. The western Qaidam Basin in North Tibetan Plateau is such a Martian analogue. The area harbors one of the most extreme hyperarid environments on Earth and contains a series of ancient lakes that evaporated at different evolutionary stages during the rise of the Tibetan Plateau. Large quantities of salts and geomorphological features formed during the transition of warmer‐and‐wet to colder‐and‐dry conditions provide unique references to study the modern Martian surface and interpret the orbital data. We present numerous similarities and results of investigations that suggest the Qaidam Basin as a potential analogue to study modern geomorphic processes on Mars, and suggest that this is an essential site to test future Mars sample return missions.

Contemporary Impact Analysis Methodology for Planetary Sample Return Missions

Development of an Earth entry vehicle and the methodology created to evaluate the vehicle’s impact landing response when returning to Earth is reported. NASA’s future Mars Sample Return Mission requires a robust vehicle to return Martian samples back to Earth for analysis. The Earth entry vehicle is a proposed solution to this Mars mission requirement. During Earth reentry, the vehicle slows within the atmosphere and then impacts the ground at its terminal velocity. To protect the Martian samples, a spherical energy absorber called an impact sphere is under development. The impact sphere is composed of hybrid composite and crushable foam elements that endure large plastic deformations during impact and cause a highly nonlinear vehicle response. The developed analysis methodology captures a range of complex structural interactions and much of the failure physics that occurs during impact. Numerical models were created and benchmarked against experimental tests conducted at NASA Langley Research Center. The postimpact structural damage assessment showed close correlation between simulation predictions and experimental results. Acceleration, velocity, displacement, damage modes, and failure mechanisms were all effectively captured. These investigations demonstrate that the Earth entry vehicle has great potential in facilitating future sample return missions.

Oriented Planetary Exploration Robotic Vision Binocular Camera Calibration

One of the goals of planetary exploration is to cache rock samples for subsequent return to Earth in the future Mars Sample Return (MSR) mission. This paper presents a method of binocular camera calibration. Robotic vision has become a very popular field in recent years due to the numerous promising applications it may enhance. However, errors within the cameras and in their perception of their environment can cause applications in robotics to fail. To help correct these intrinsic and extrinsic imperfections, stereo camera calibrations are performed. There are currently many accurate methods of camera calibration available; however, most or all of them are barely theoretical and difficultly practical. Because the authors' robot need to accurately approach and placement scientific objects, in this paper the authors present an image rectification method that is an extension to two-step method. There is an additional step for correcting the distorted image coordinates. The image rectification is performed and accurately compensates for radial and tangential distortions. Finally, through Matlab tool developed the results of experiment are accurate and available.

Selecting samples for Mars sample return: Triage by pyrolysis–FTIR

A future Mars Sample Return mission will deliver samples of the red planet to Earth laboratories for detailed analysis. A successful mission will require selection of the best samples that can be used to address the highest priority science objectives including assessment of past habitability and evidence of life. Pyrolysis is a commonly used method for extracting organic information from rocks but is most often coupled with complex analytical steps such as gas chromatography and mass spectrometry. Pyrolysis–Fourier transform infrared spectroscopy is a less resource demanding method that still allows sample characterisation. Here we demonstrate how pyrolysis–Fourier transform infrared spectroscopy could be used to triage samples destined to return to Earth, thereby maximising the scientific return from future sample return missions.

The Search for Sustainable Subsurface Habitats on Mars, and the Sampling of Impact Ejecta

On Earth, the deep subsurface biosphere of both the oceanic and the continental crust is well known for surviving harsh conditions and environments characterized by high temperatures, high pressures, extreme pHs, and the absence of sunlight. The microorganisms of the terrestrial deep biosphere have an excellent capacity for adapting to changing geochemistry, as the alteration of the crust proceeds and the conditions of their habitats slowly change. Despite an almost complete isolation from surface conditions and the surface biosphere, the deep biosphere of the crustal rocks has endured over geologic time. This indicates that the deep biosphere is a self-sufficient system, independent of the global events that occur at the surface, such as impacts, glaciations, sea level fluctuations, and climate changes. With our sustainable terrestrial subsurface biosphere in mind, the subsurface on Mars has often been suggested as the most plausible place to search for fossil Martian life, or even present Martian life. Since the Martian surface is more or less sterile, subsurface settings are the only place on Mars where life could have been sustained over geologic time. To detect a deep biosphere in the Martian basement, drilling is a requirement. However, near future Mars sample return missions are limited by the mission’s payload, which excludes heavy drilling equipment and restrict the missions to only dig the topmost meter of the Martian soil. Therefore, the sampling and analysis of Martian impact ejecta has been suggested as a way of accessing the deeper Martian subsurface without using heavy drilling equipment. Impact cratering is a natural geological process capable of excavating and exposing large amounts of rock material from great depths up to the surface. Several studies of terrestrial impact deposits show the preservation of pre-impact biosignatures, such as fossilized organisms and chemical biological markers. Therefore, if the Martian subsurface contains a record of life, it is reasonable to assume that biosignatures derived from the Martian subsurface could also be preserved in the Martian impact ejecta.

The Price of Exploration

NASA is in the final throes of implementing the most powerful surface reconnaissance mission ever undertaken to Mars. Dubbed the Mars Science Laboratory (MSL), it represents NASA's first life inference mission equipped with instruments capable of detecting the chemical building blocks of life more than an order of magnitude more sensitive than those used by the Viking mission of the 1970s. MSL will also demonstrate multiple technical capabilities needed to enable a future robotic Mars sample return mission. In his 31 October Letter (“Viewing NASA's Mars budget with resignation,” p. [672][1]), former NASA Associate Administrator S. A. Stern suggested that excessive cost growth of MSL is deeply damaging NASA's overall planetary exploration agenda and destroying the opportunity for a future Mars sample return mission. He blames senior NASA leaders for disbanding his MSL independent technical review team, which he claims forced his resignation. ![Figure][2] Let's roll. Wheels have been fitted to NASA's Mars Science Laboratory (MSL) rover, which is being assembled at NASA's Jet Propulsion Laboratory, Pasadena, California. The rover has a ground clearance of about 60 cm, or 2 feet, and is about the size of a small automobile. CREDIT: NASA/JPL Now is the time to set the record straight. NASA consolidated its independent standing review boards to streamline the process for all major flight programs in 2007. The MSL Standing Review Board remains in effect and was never disbanded. Stern also claims that MSL was “assigned” a cost level of $650 million. He fails to mention when and by whom. The $650 million cost was a placeholder assigned to a medium-class Mars rover mission by the National Research Council Solar System Decadal Survey committee in 2002, before NASA had developed a basis of cost estimate for MSL. This served as input to NASA studies from 2000 to 2004 to fully define the MSL mission and culminated in the competitive selection of its science payload in late 2004. At that time, the overall mission was baselined at a cost of $1.4 billion, not including several costs associated with the radioisotope power system. Given the experience with the cost of the Mars Exploration Rovers and the increased scientific and technical scope of the MSL mission, the so-called assigned value of $650 million is not credible. Stern's own New Horizons flyby mission to Pluto cost NASA more than $650 million; it is unrealistic to expect that a 700-kg analytical laboratory that must soft-land on Mars and drive around with 100 kg of scientific instruments could possibly cost less than a planetary flyby mission. Indeed, MSL's 2 years of intensive surface science operations are difficult to compare to any missions in the $650 million price class given typical science-per-dollar metrics. The established NASA cost to implement MSL as of the time of its confirmation review was $1.55 billion (August 2006), which grew due to NASA-wide issues with thermal protection system materials in 2007 to approximately $1.7 billion. The total cost growth of the MSL mission development since NASA confirmed the mission is typical of other Mars exploration missions successfully flown over the past decade. The cost to fly MSL in 2009 will be less than the cost (in today's dollars) of flying a nonmobile Viking Lander laboratory to Mars, and MSL includes a whole new generation of instruments and mobility. NASA has an exemplary record of honoring its commitments to implement flagship-class missions that frequently “rewrite the textbooks” as they discover how the universe operates. To abandon MSL at this time would represent an unprecedented break with this guiding philosophy. As President John F. Kennedy once stated, we choose to do these things not because they are easy, but because they are hard. NASA succeeded with Apollo to the Moon, Hubble to the universe, and Cassini to Saturn. The agency is ready now to assault the martian frontier with MSL. [1]: /lookup/doi/10.1126/science.322.5902.672b [2]: pending:yes

Preliminary Program for Mars Samples Analysis

The main goals of the French Mars exploration program are the development of a netlander for geophysical studies. This project is conducted in the framework of a consortium of European partners (Finland, Germany and Belgium), and an orbiter vehicle of the future Mars sample return mission (MSR) is being developed in cooperation with NASA. Also, we discuss the preparatory program for volatile and rare gas analysis, sample pollution, site selection and Astrobiology.

French involvement in Mars exploration

We hereafter present an update of the status of the French Mars exploration program. This program named PREMIER ( P rogramme de R etour d' E chantillons M artiens et Installation d' E xpériences en R éseau) has two main components: • - the development with European partners, the deployment and the operation of a network of four small Mars landed stations for performing geophysical measurements (NetLander project); • - the development and the operation of the orbiter vehicle of the future Mars sample return (MSR) mission to be implemented in co-operation with NASA. In addition it plans the provision of payload contributions to the orbiters, landers and rovers to be launched to Mars in 2003, 2005, 2007, and beyond. An important milestone of the present program plan is a CNES orbiter launched in 2007; this orbiter, as prototype of the vehicle of the future MSR mission, will test some critical stages of MSR; it will also deliver the NetLanders at Mars and it will perform a complementary scientific mission dedicated to orbital science. In parallel, the definition phase of several instruments for in situ science which could be installed on a Mars lander such as NASA's future “Smart Lander” is ongoing.

Martian meteorites do not eliminate the need for back contamination precautions on sample return missions

The phenomenon of natural transport of material from the surface of Mars to the surface of planet Earth, in the form of martian meteorites, cannot be used as justification to relax or abolish plans and procedures for quarantine and strict sample containment for future Mars sample return missions (MSR). Biosphere upsets, ecological disasters, and species extinctions have been far too numerous and their causes too poorly understood to rule out occasional possible contributions from exogenous biological invaders. In addition, in today's large, highly intertwined global civilizations, even small perturbations to public health, ecological stability, economic balances, or perceived threat of any of these could eclipse the public support that will be needed for space exploration and sample return programs with responsible planetary protection measures.

Nomad Rover Field Experiment, Atacama Desert, Chile: 2. Identification of paleolife evidence using a robotic vehicle: Lessons and recommendations for a Mars sample return mission

During the Nomad Rover Field Experiment in the Atacama Desert (Chile), a potential fossil was identified in a boulder by the science team remotely located at NASA Ames Research Center, California. The science team requested the collecting of the boulder that was returned for laboratory analysis. This analysis confirmed the evidence of paleolife. As the first fossil identified and sampled by a remotely located science team using a rover, we use the case of sample I‐250697 to describe the process, both in the field and later in the laboratory during the rock analysis, which led to the identification, characterization, and confirmation of the evidence of paleolife evidence in I‐250697. We point out the lessons that this case provides for future Mars sample return missions.

Planetary protection, legal ambiguity and the decision making process for Mars sample return

As scientists and mission planners develop planetary protection requirements for future Mars sample return missions, they must recognize the socio-political context in which decisions about the mission will be made and pay careful attention to public concerns about potential back contamination of Earth. To the extent that planetary protection questions are unresolved or unaddressed at the time of an actual mission, they offer convenient footholds for public challenges in both legal and decision making realms, over which NASA will have little direct control. In this paper, two particular non-scientific areas of special concern are discussed in detail: 1) legal issues and 2) the decision making process. Understanding these areas is critical for addressing legitimate public concerns as well as for fulfilling procedural requirements regardless whether sample return evokes public controversy. Legal issues with the potential to complicate future missions include: procedural review under NEPA; uncertainty about institutional control and authority; conflicting regulations and overlapping jurisdictions; questions about international treaty obligations and large scale impacts; uncertainties about the nature of the organism; and constitutional and regulatory concerns about quarantine, public health and safety. In light of these important legal issues, it is critical that NASA consider the role and timing of public involvement in the decision making process as a way of anticipating problem areas and preparing for legitimate public questions and challenges to sample return missions.

The Martian stratigraphy ? Short review and perspectives

The main aspects of the Martian stratigraphy have been determined from the detailed study of Mariner 9 and Viking Orbiter images. Three major stratigraphic systems, the Noachian System, the Hesperian System, and the Amazonian System, are inferred from these studies. The global geological evolution of Mars is essentially derived from its stratigraphy. It reveals that tectonism and volcanism were widespread during two major periods (Noachian and Lower Hesperian) and became more localized during the Upper Hesperian and Amazonian periods. The transition between these two major periods occurred about 2 Ga ago, and significant geologic activity could still be present. However, a number of geologic features and processes remain little understood. Future investigations, including complete high resolution imaging and detailed mapping, geochemical mapping, in situ chemical analyses, etc., will be necessary in order to improve our knowledge of the Martian stratigraphy and geologic evolution and are essential to prepare any future Mars Sample Return mission and the Human Exploration of this planet.

Origin and evolution of the layered deposits in the Valles Marineris, Mars

Thick sequences of layered deposits are found in the Martian Valles Marineris. They exhibit fine, nearly horizontal layering, and are present as isolated plateaus of what may have once been more extensive deposits. Individual sequences of layered deposits are as thick as 5 km. The greatest total thicknesses of deposits are found in Candor, Ophir, and Melas chasmata. individual layer thicknesses range from about 70 to 300 m. Some tilting of sequences is observed, but at the best image resolutions, no angular unconformities are detectable in the layers. The sequences of events in the canyons, as deduced from morphologic and stratigraphic evidence, was (1) graben formation in response to the tharsis uplift, (2) canyon wall retreat and canyon enlargement, roughly contemporaneous with formation of the layered deposits, (3) deep erosion of the layered deposits, (4) landsliding of the canyon walls, and (5) eolian erosion of the layered deposits, perhaps continuing up to the present. We consider four hypotheses for the origin of the layered deposits: they are eolian deposits, they are remnants of the material that makes up the canyon walls, they are deposits of explosive volcanic eruptions, or they were deposited in standing bodies of water. The rhythmic nature of the layers and their lateral continuity, horizontality, great thickness, and stratigraphic relationships with other units in the canyons all appear most consistent with deposition in an aqueous environment. If standing bodies of water existed in the Valles Marineris, they were almost certainly ice-covered. there are three ways in which sediment could have entered an ice-covered lake: down through the ice cover, up from the lake bottom, or in from the lake margins. Layers of sediment could have been transported downward through an ice cover by foundering or Rayleigh-Taylor instabilities, but it is not clear whether there was a viable mechanism for repeatedly accumulating thick sediment layers on top of the ice cover. Subaqueous volcanic eruption on the lake bottom does not suffer from many of the morphologic arguments that make origin by subaerial volcanism seem improbable. While this mechanism is attractive, there are no eruptive centers observed and there is no other direct evidence to support it. Because canyon enlargement took place at roughly the same time as layer deposition, debris from the canyon walls is an obvious and likely source for some of the material in the layered deposits; however, the volume of material removed from the canyon walls may be insufficient to account for all of the presently observed material. We conclude that there are several geologically feasible, but as yet unproven, mechanisms that could have led to formation of thick deposits in ice-covered paleolakes in the Valles Marineris. Present data are insufficient to choose conclusively among the various possibilities. Several types of data from the Mars Observer mission will be useful in further characterizing the deposits and clarifying the process of their origin. The deposits should be considered important targets for a future Mars sample return mission.