4

Disciplinary Science Priorities

Results from the Panels on Astrobiology, Atmospheric Science and Space Physics, Biological and Physical Sciences and Human Factors, and Geosciences are distilled to show how these priorities shaped the campaign selections.

Although this chapter is organized by disciplinary areas, campaigns, of course, are inter- and multidisciplinary. The disciplinary perspectives herein provide deep insights that have been incorporated into the cross-disciplinary science for campaigns described in Chapter 2, where the steering committee has explicitly integrated the best science across disciplinary boundaries and identified cross-cutting opportunities that are served by such collaborations.

4.1 RANKED SCIENCE OBJECTIVES

All of the top science objectives are directly traceable to both NASA’s Moon to Mars (M2M) Objectives and to the individual discipline’s decadal surveys and community roadmaps (Table 4-1).

The objective to search for life is particularly strongly supported in the 2023–2032 decadal survey for planetary science and astrobiology, Origins, Worlds, and Life (NASEM 2023a), and NASA’s Mars Exploration Program goals, along with the additional objectives highlighted in this report of understanding the processes that control martian weather and its changing climate over the past 4 billion years, deciphering the evolution of Mars’s surface and interior and the processes that control them, and gathering the essential scientific knowledge necessary to permit humans to land on and explore Mars.

Origins, Worlds, and Life recommends a series of missions tied to the search for life, including a Mars Life Explorer mission to search for life on Mars and a Mars Sample Return mission to bring samples back for analysis on Earth. The Mars Life Explorer would drill into ice deposits to search for biosignatures. The report also recommends the international Mars Ice Mapper mission by arguing that the prime exploitable martian resource is ice, which would be of great use to future explorers as in situ resource utilization (ISRU).

Moreover, Origins, Worlds, and Life recommends that the most important resources are the astronaut explorers who propel exploration missions and research into planetary science, astrobiology, and planetary defense, and that providing opportunities for them to thrive is also a priority.

The high ranking of search for life and identification of habitability in this report is supported by the NASA Astrobiology Strategy (NASA 2015). This strategy recommends to better constrain the environmental conditions that can produce life, to understand linkages among geology, climate, and life, to sustain the human imperative to explore the unknown, and to address key questions, for example, “Are any other bodies in our solar system habitable?”

TABLE 4-1 Science Objectives in Common Among This Report, Moon to Mars Objectives, Relevant Decadal Surveys, and the Human Research Roadmap

NOTES: LPS, lunar and planetary science; HBS, AL, and HS, respectively, refer to the lunar and planetary science, human and biological science, applied science, and heliophysics science identification numbers in the “Lunar Goals, Objectives, and Characteristics and Needs” and “Mars Goals, Objectives, and Characteristics and Needs” in NASA’s Moon to Mars Architecture documentation; Q refers to the priority science questions in Origins, Worlds, and Life, BLiSS refers to Bioregenerative Life Support Systems, and MEPAG refers to the Mars Exploration Program Analysis Group. The following are document naming conventions used by the “Human Research Roadmap” (HRR) and are not acronyms: BMed, EIHSO, Sleep, Team, B, Bone, Cancer, CV, DCS, DL, Dust, EVA, ExMC, FN, Fracture, IM, Medical, Micro, SANS, SM, AEH, Acute.

SOURCES: NASA, 2023c, NASA’s Moon to Mars Strategy and Objectives Development; NASEM, 2023a, Origins, Worlds, and Life, National Academies Press; NASEM, 2023b, Thriving in Space: Ensuring the Future of Biological and Physical Sciences Research: A Decadal Survey for 2023–2032; National Academies Press; Human Research Program, 2025, “Human Research Roadmap,” NASA; National Academies Press; NASEM, 2025, The Next Decade of Discovery in Solar and Space Physics: Exploring and Safeguarding Humanity’s Home in Space.

Further support of the objective to search for life comes from NASA’s M2M Objectives, which recommend answering questions about the origin of life; the geology and chemistry of planetary bodies; understanding how the deep-space, lunar, and martian environments affect living things; developing resource utilization capabilities to support human Mars exploration; and developing technologies and capabilities to live and work on planetary surfaces.

The 2023–2032 decadal survey for biological and physical sciences research in space, Thriving in Space (NASEM 2023b), recommends addressing a set of key scientific questions that enable safe space exploration and are enabled by access to space. These key scientific questions are grouped into three themes: (1) Adapting to Space, which concerns how the fundamental physics of space environments impacts the ability of living systems to survive transition to and extended stays in space; (2) Living and Traveling in Space, which explores living systems and supportive environments over long durations in space, while deriving resources in space under the logistical and physical constraints of space; and (3) Probing Phenomena Hidden by Gravity or Terrestrial Limitations, which seeks scientific insights that can be found only in space.

4.2 SUMMARIES OF SCIENCE INPUT FROM THE PANELS

Each disciplinary panel identified key scientific objectives, listed below (see Appendixes B–E for panel statements and Appendix J for the panels’ science traceability matrices [STMs]). In addition, several areas overlap among panel priorities. Each panel’s priorities are discussed in the following sections.

• Panel on Astrobiology
  • Determine if evidence can be found for extant or extinct life.
  • Determine if niche habitats exist on Mars where life could have survived.
  • Determine the potential for processes leading to prebiotic chemistry or the origin of life.
• Panel on Atmospheric Science and Space Physics
  • Determine what controls the present-day water and CO₂ cycles and the surface/subsurface volatiles.
  • Determine how the climate, water, and CO₂ cycles differed in the ancient past, as indicated by geologic evidence.
  • Determine how the climate, water, CO₂, and dust cycles varied in the recent past (up to tens of millions of years ago), as captured by the layered terrain (e.g., recent past).
  • Determine how the atmosphere is being lost today and how it was lost in the past.
  • Determine the present-day atmospheric isotopic and elemental composition and its sources and sinks.
• Panel on Biological and Physical Sciences and Human Factors
  • Determine whether microbial population dynamics and species distribution in biological systems and habitable volumes are stable and promoting health and performance throughout the mission.
  • Determine the impact of the integrated longitudinal martian environment (ILME) on physiological, cognitive, emotional, and physical aspects of crew members’ global allostatic load¹ and crew cohesion and confirm effectiveness of countermeasures in maintaining allostasis.
  • Determine the impact of an integrated Mars environment on plant physiology and development by measuring quantitative traits, biochemical markers, transcriptome, epigenome, and proteome, at selected time points and more than two generations where possible.
  • Ensure the crew has sufficient resources, capabilities, knowledge, skills, and abilities to perform all required science and engineering tasks to criterion throughout mission duration.
• Panel on Geosciences
  • Characterize past and present water and ice reservoirs within the exploration zone to understand geologic and climate evolution over Mars’s history.
  • Characterize the rock record within the exploration zone to understand environmental changes over Mars’s history.

• • Constrain absolute ages of martian events and tie them to the impact record to calibrate crater counts.
  • Characterize igneous systems within the exploration zone to determine planet formation, differentiation, and volcanic history.
• Overlapping objectives among disciplines
  • Water and ice reservoirs.
  • Characterization of habitability and niche habitats.
  • Atmospheric dynamics and dust storm processes.
  • Integrated human health and martian environment.
  • Prebiotic chemistry and organic molecule detection.
  • Radiation environment.

4.2.1 Astrobiology

Astrobiology, which is the study of life and its interaction with the planetary environment over evolutionary timescales, encompasses life detection and characterization, paleontology, habitability, and more. It overlaps strongly with geosciences and atmospheric science, but adds a connection to biology and evolution, prebiotic chemistry and thermodynamics, and the origin of life. Previous uncrewed Mars landers and rovers had astrobiology as a primary focus, and astrobiology is the number one science objective for the crewed missions discussed in this report, which is to determine if, in the exploration zone, evidence can be found for any of the following: habitability, indigenous extant or extinct life, and/or indigenous prebiotic chemistry. Furthermore, the objectives for astrobiology include the search for (1) life’s origin, (2) evolution, (3) distribution, and (4) future in the universe.²

Astrobiology is more than science alone because of its unique connection to society. Of particular interest is the societal and scientific impact of the search for life beyond Earth in terms of understanding our place in the universe and how those processes began, became organized, and evolved into the myriad lifeforms on Earth. The astrobiology community has been conducting workshops and other means of intellectual exchange for many years in order to gain ideas about communicating the detection of life to the general public. This ongoing effort will continue as we prepare for future potential detection.

In planning for life detection missions, it is important to rely on multiple lines of evidence and not view it as a binary answer (i.e., alive or not alive) (Green et al. 2021) but as a progressive scale where claims of life detection are reported in terms of the level of confidence and using metrics that are discussed and refined within the astrobiology community. This includes concepts like biosignature assemblages (Mustard et al. 2013), potential agnostic biosignatures (Johnson et al. 2018), the Ladder of Life Detection (Neveu et al. 2018), and suites of nested astrobiological approaches to deciphering the preservation of biosignatures and presence of life (Chan et al. 2019). Community efforts also emphasize the importance of communicating issues of life detection and the uncertainty of interpretations to different audiences (Green et al. 2021).

The Panel on Astrobiology’s STM includes numerous science objectives divided into four different categories. From these, the panel picked three as their highest priorities, all of which are related to the top science objective for these crewed missions.

1. Determine if evidence can be found for extant or extinct life. This is the science driver that distinguishes Mars from the other planets in the solar system, because it is the planet most likely to have harbored Earth-like (liquid-water-requiring) life on or near its surface. Other bodies in the solar system, mostly outer planet moons, are also of interest to astrobiology, but any life found there will be cryptic and exceedingly challenging to reach under kilometers of ice; thus, Mars is still the best candidate for supporting findable life or its past traces. Additionally, Mars is also more accessible from Earth than these other bodies.
2. Determine if niche habitats exist on Mars where life could have persisted. Many different niche habitats at a variety of spatial scales have been identified as possible abodes for extant life on Mars. The panel’s STM lists several of the key types: brines, caves, icy terrains, salt deposits, salt/ice interfaces, ice/rock interfaces,

2. and mud volcanoes. Caves represent potential niche habitats, including possibly for extant life, that would be key to explore, first via robotic scouts, then eventually by humans (see Box 4-1). The deep subsurface is also a tantalizing but challenging potential habitat where (non- or minimally saline) liquid water is expected to be stable at depths of a few kilometers near the equator, or deeper at mid- to high latitudes.
3. Determine whether Mars had processes leading to prebiotic chemistry or the origin of life. At first glance, this seems straightforward: Life on Earth is based on the chemistry of organic carbon, and most astrobiologists (and biologists) agree that life elsewhere is likely to be similar, because carbon bonds in complex ways that no other element can duplicate. But when one examines this objective more closely, problems immediately arise, the biggest one being contamination from organic compounds delivered by meteorites. Carbonaceous chondrites are chock-full of complex organics thought to have been formed in interstellar space, the primitive solar nebula, or within the meteorites themselves during the time that they remained warm from radioactive decay. So, the search for prebiotic chemistry would need to focus on distinguishing actual evidence for such chemistry from these abiotically produced compounds. Similarly, even agreeing on what constitutes evidence for the origin of life is difficult, because biologists and astrobiologists do not agree on how this happened.

BOX 4-1
Caves on Mars

More than 1,000 pits, caves, and volcano-tectonic depressions have been identified and cataloged on Mars (Cushing et al. 2015, Cushing 2017; Wynne et al. 2022) (Figure 4-1-1). Caves and pits on Mars cluster predominantly in two volcanic provinces: Tharsis and Elysium. The majority of Mars’s pits and caves are partially collapsed lava tubes and pit craters and are located in Tharsis. The lava tubes and skylights found to date are predominantly located on the flanks of the giant volcanoes, at high elevation.

On Earth, caves are a subject of popular interest and appeal; however, many planetary scientists and engineers are unaware of the globally rich speleological scientific literature that has been produced over the past ~150 years (UIS 2025). On Mars, surface environmental conditions are so harsh for life that the martian subsurface has been suggested as a more plausible environment for a still extant martian microbiota (Boston et al. 1992). As windows into the planetary crust, caves represent potential unique

The fourth category of science objectives considered by the Panel on Astrobiology was “characterization of martian life if found.” The committee’s guidance for characterizing extant life if it is found is discussed in Appendix G.

In summary, astrobiology is an acknowledged key driver for Mars human missions and also underpins NASA’s entire program of Mars exploration. Finding evidence for life beyond Earth would be a discovery equivalent in magnitude to some of the greatest scientific discoveries of all time. Sara Seager at the Massachusetts Institute of Technology, who studies exoplanets, has described it as “the second Copernican Revolution.” Sending humans to Mars is one way of increasing the odds that this could happen within our lifetimes or those of our children or grandchildren.

4.2.2 Atmospheric Science and Space Physics

The Panel on Atmospheric Science and Space Physics covers atmospheric science, space physics, weather, climate, interactions between the space plasma and the upper atmosphere, and interactions between the atmosphere and the ground, including exchanges of dust, water, and carbon dioxide. Some of the panel’s top objectives overlap with the astrobiology and geosciences panels’ objectives.

The panel’s highest ranked objective is to determine what controls the onset and evolution of dust storms (see Appendixes D and J). Global dust storms can last for months, produce huge planetwide reduction in visibility, and can diminish solar radiation at the surface by more than two orders of magnitude (e.g., Guzewich et al. 2019). In these conditions the martian surface becomes dark during the day, visibility is reduced significantly, and solar power is reduced by orders of magnitude, making surface operations challenging (Figure 4-1).

Dramatic increases in atmospheric dust content owing to regional and global dust storms are the major cause of the present-day variability in Mars weather, climate, and atmospheric loss rates (e.g., Kahre et al. 2017; Guzewich et al. 2020; Vicente-Retortillo et al. 2025). Although robotic missions could contribute to the understanding of dust storms, human missions would enable comprehensive measurements in sites where dust lifting occurs. Sample collection and atmospheric measurements by humans would allow measurements in the subsurface, at the surface, and above the surface to address key science questions not addressed by robotic missions. Human presence uniquely enables rapid, adaptive decision making and complex troubleshooting during atmospheric sampling and instrument deployment, which cannot be replicated by robotic missions. Additionally, humans can deploy instruments in strategic locations and quickly respond to dynamic and unpredictable phenomena such as sudden dust storms, ensuring optimal sample collection and immediate on-site analysis. Above the surface, measurements could be conducted using instruments mounted on towers, drones, and balloons. Atmospheric soundings to high altitudes on Mars could be accomplished by balloons and drones (e.g., Noga et al. 2023).

The panel’s next objective is to determine what controls the present-day water and carbon dioxide cycles and the distribution of volatiles in the subsurface and surface. After the dust cycle, the water and carbon dioxide cycles are the most important processes driving the present-day martian climate (e.g., Buhler and Piqueux 2021; de la Torre Juárez et al. 2024). Although atmospheric measurements made at any location would be useful, measurements near the polar layered deposits, where the bulk of the water and carbon dioxide sublimates seasonally, are of particular interest. Profiling of near-surface atmospheric water vapor and its exchange with the surface are key for understanding what controls the water cycle. Better knowledge of atmospheric aerosol sizes and compositions is needed to characterize the radiative effects of Mars clouds.

The panel’s next objective is to determine how the climate, water, and carbon dioxide cycles differed in the ancient past, as indicated by geologic evidence. This is critical for understanding how the Mars climate transitioned from its more Earth-like past to its current state (e.g., Wordsworth 2016; Palumbo and Head 2018). Humans on Mars would be better to assess, select, collect samples, and analyze rocks in situ as needed for these investigations than robots (e.g., Yingst et al. 2009; Antonenko et al. 2013; Glass and Briggs 2013; and subsequent studies).

Determining the ideal landing sites for achieving the panel’s top objectives would require precursor information to assess the presence of local dust lifting and ice-dust layering. The vision is that instrumentation assembled on Mars by humans would remain in operation long after the astronauts’ departure to continue monitoring weather phenomena on diurnal, seasonal, and interannual scales.

4.2.3 Biological and Physical Sciences and Human Factors

The Panel on Biological and Physical Sciences and Human Factors (BPS/HF) is not a single discipline, but several science disciplines represented by multiple offices distributed across two NASA directorates. Their objectives are intrinsic to the science agenda for crewed missions to Mars, both for understanding current missions and for driving insights to improve the health and performance of future missions. Because they are largely site agnostic, BPS/HF objectives are embedded in every science campaign to the greatest extent possible.

The methods to develop science objectives vary considerably across the panel. The Biological and Physical Sciences Division in NASA’s Science Mission Directorate utilizes the decadal survey process developed in concert with the National Academies. The most recent decadal survey, Thriving in Space, completed in 2023, reviews the current state of biological and physical sciences (NASEM 2023b). The Human Research Program in the Exploration Sciences Mission Directorate utilizes a very different approach: a formal continuous risk management process to ensure that evidence gleaned from flight operations and research can help NASA make risk-informed decisions that protect the astronauts and the mission. These risks consider the immediate, long-term, and lifetime health effects of exposure to the spaceflight environment (Antonsen et al. 2022).

NASA’s Human System Risk Board (HSRB; NASA 2025a) manages the risk reduction process. The initial set of human risks and the mitigation process was developed in the early 2000s by NASA. Both the risks and the process have been vetted extensively by the National Academies (IOM and NRC 2006; IOM 2008, 2014, 2015; NASEM 2016, 2017, 2018b). Using an evidence-based decision-making process, HSRB accepts a risk posture when countermeasures are deemed efficacious or no further risk reduction is considered appropriate at that time.

HSRB operates as part of the Health and Medical Technical Authority of the Office of the Chief Health and Medical Officer of NASA via the Johnson Space Center Chief Medical Officer. It currently tracks and manages the risk posture for the 29 human system risks and concerns (NASA 2025a).

In considering its statement of task, the committee assumed that these robust crew health and safety programs will be in place for any human mission. The core needs and capabilities of these programs will therefore include baseline requirements defined by the medical community and were considered to be outside the committee’s research campaign scope. Consequently, the Panel on BPS/HF was charged with identifying discovery science objectives associated with ecosystems of microbes, plants, animals, humans, and teams which may or may not translate to improved crew health and performance, and translational science objectives that would lead to new practices, procedures, and technologies that could improve crew health, safety, and performance (Box 4-2).

When synthesizing this information into martian campaigns, the steering committee reviewed past decadal surveys, important trends in science, and unique science opportunities associated with the martian environment that would affect the overall scope of campaign objectives. Here the committee highlights several evolving trends that inform the scope and conduct of BPS/HF research during early martian campaigns.

BPS/HF Research Priorities for Exploration

The martian environment poses risks to humans that are different from risks in low Earth orbit: a gravitational acceleration 38 percent of Earth’s; a highly energetic radiation environment; hostile environmental conditions, including temperature, wind, and fine dust that may be abrasive and chemically reactive; isolation and confinement; and a distance from Earth averaging 250 × 10⁶ miles, nearly 600 times greater than the distance to the Moon. Indeed, social isolation for periods exceeding 2 years (surface operations plus transit time) may be among the greatest stress that humans will experience during a Mars mission (Le Roy et al. 2023).

The Panel on BPS/HF referred to these abiotic and biotic features collectively as the “integrated, longitudinal martian environment” (ILME), recognizing that these stresses are both interactive and cumulative. The resultant strain—an allostatic load—affects crew health and performance on Mars, and potentially long after return. For example, isolated teams can experience severe stress and lack of productivity and cohesion when they feel they are ill equipped, under-resourced, or insufficiently supported to carry out their assigned mission (Le Roy et al. 2023).

Accordingly, the Panel on BPS/HF adopted an occupational health framework for humans on Mars that would include both real-time monitoring and long-term health surveillance to develop a deep understanding of the cumulative stress that astronauts will experience on this remote world for an unprecedented amount of time. Such a program—the Longitudinal Study of Astronaut Health—was established by NASA in the 1990s and has been reviewed by the National Academies previously (IOM 2004). The panel’s science objectives expand this work further.

Overall, the panel suggested a balanced approach that reflects research priorities in crew health and performance, and space biology. Seven of the 11 Key Scientific Questions from the recent biological and physical sciences in space decadal survey, Thriving in Space (NASEM 2023b), are represented in the panel’s prioritized science objectives. Research themes of special consideration are described below:

• How does the space environment influence biological mechanisms required for organisms to survive the transitions to and from space, and thrive while off Earth?
• How do genetic diversity and life history influence physiological adaptation to the space environment?
• How does the space environment alter interactions between organisms?
• What are the important multigenerational effects of the space environment on growth, development, and reproduction?
• What principles guide the integration of biological and abiotic systems to create sustainable and functional extraterrestrial habitats?
• What principles enable identification, extraction, processing, and use of materials found in extraterrestrial environments to enable long-term, sustained human and robotic space exploration?

The Data Revolution in Life Sciences

Biology and medicine in the 21st century are dominated by “omics,” a broad term referring to the collective characterization of chemical and functional classes of biological molecules and effects to obtain a comprehensive understanding of the biological system under study (Figure 4-2). Omics encompasses technologies to characterize the structure, function, and dynamics of cells, genes, molecules, and organisms. Dozens of “omes” that describe location, structure, and/or function have been identified. For example, genomics includes all genes; transcriptomics, all of the gene products; proteomics, all of the protein; epigenomics, reversible chemical modification of DNA; metabolomics, small-molecule metabolites and metabolic intermediates in a biological sample. The total number of variables being considered (often 10⁴–10⁶) is orders of magnitude greater than traditional biological research. Consequently, omics analyses share common features: high-throughput analytical techniques, statistical methods

to aggregate data and infer cause and effect, and tools to elucidate associations between disparate forms of data such as genomes and medical measurements. These approaches are well suited to describing characteristics of an ecosystem of humans, plants, and microbes that will coexist on Mars, described by the Panel on BPS/HF as the “Human Exploration System.”

The dynamic nature of many omes is associated with changes in health status. Current terrestrial research aims to characterize these temporal shifts to capture dynamic changes in health. However, molecules such as RNA are affected by ionizing radiation and have specific storage requirements such as lyophilization and cryopreservation that make sample return problematic (Kornienko et al. 2024). Consequently, the committee recognized that in situ analysis during campaigns would be necessary to reduce, but not eliminate, sample return requirements. Developing the intelligent, robust, compact, lightweight, and low-power analytical tools for omics research and medical monitoring on Mars will likely precipitate bidirectional technology transfer between the space biomedical and terrestrial biomedical communities.

Multigenerational Studies

A human presence on Mars enables several research objectives probing the same existential question: Can life continue on a planetary body other than Earth? Because growth, development, and reproduction sustain all life, it is not surprising that panels included multigenerational studies of microbial, plant, and animal life in their STM objectives.

The selection of species for these studies will be important. For example, the phenotypic, biochemical, cellular, and molecular responses of Arabidopsis thaliana, a small, adaptable plant with a short life cycle from the Brassicaceae (mustard) family, have been well characterized in the space environment (Olanrewaju et al. 2023). Successful seed-to-seed experiments have been flown on the International Space Station (ISS) (Link et al. 2014). It is expected that any candidate plant species for a martian mission will have been studied with a similar or greater level of fidelity to be part of a Mars mission.

For animal studies, the selection of species is even more critical. Cross-species ontologies combine data about genes, phenotypes, and diseases from different species to provide important insight about human disease mechanisms and aid disease diagnosis. For example, current terrestrial efforts such as the Monarch Initiative capture phenomic knowledge in all its forms, including human and model organisms’ phenotypic data, with the intent to elucidate the causes and mechanisms of human disease (Putman et al. 2024). Using such tools, information obtained from life-cycle experiments of model organisms could provide early insight relevant to human adaptation on future, permanently inhabited martian outposts. Potential model organisms for early martian campaigns include the nematode Caenorhabditis elegans, the first multicellular organism to have its whole genome sequenced, and Drosophila melanogaster, the common fruit fly. Both are extremely well characterized (e.g., Riddle et al. 1997; Wormbook 2018; Braendle and Paaby 2024; Genetics Society of America 2025), have genotype–phenotype associations analogous to human diseases, and have flown in space previously (Iyer et al. 2022; Scott et al. 2023). Practical cryopreservation techniques for long-term storage and later reactivation have been vetted for both species. With lifespans of approximately 15 days for C. elegans and 70 days for Drosophila, multigenerational and lifespan studies are best completed during longer missions, such as the 300-sol missions included in some campaigns.

The Ubiquitous Nature of Microbiomes

Microbes play essential roles in terrestrial systems as vital components of all macroorganisms and ecologies. Microbiomes underlie and strongly affect the health and performance of humans and other species, including plants, and are intrinsic symbionts of all Earth-derived organisms. Furthermore, symbiosis is an important part of proposed bioregenerative life support systems, which utilize microbial activity to clean and renew air, water, and waste in habitat. For example, bioreactors could be used to process urine, condensate, and gray water. Managing microbial communities to reduce organic carbon and convert and recover nitrogenous compounds offers an alternative to more traditional physiochemical solutions (Loader et al. 1998; Sevanthi et al. 2014). Previous research on the International Space Station (ISS) and Space Shuttle, submarines, Antarctic overwintering facilities, hospitals,

Recent Mars Geosciences Prioritized Objectives

Several key documents have been compiled by the Mars and broader planetary science community to help identify and guide science priorities in Mars exploration in the geosciences, specifically (a) the Mars Exploration Program Analysis Group (MEPAG) goals document; (b) the report of the MEPAG Tiger Team which, in Summer 2023, was tasked to rapidly identify preliminary science objectives for humans on Mars; and (c) the National Academies decadal surveys in planetary sciences from 2011 and 2023. Although some of these documents have historically been created to help prioritize investigations of Mars via robotic exploration, they all identify fundamental

geosciences questions (and questions beyond the geosciences) that would also need to be answered in the context of crewed missions to Mars (e.g., Beaty et al. 2019).

While these documents have provided, and continue to provide, important guidance in prioritizing Mars geosciences investigations, the scientific objectives proposed by the Panel on Geosciences providing input into the present study, as well as the resulting geosciences objectives among the highest priority science objectives identified in this study, are notable for their greater level of detail and specificity. These objectives are formulated so as to be actionable by human crews on Mars going about investigating the exploration zone accessible from their landing site.

Input from the Panel on Geosciences

The Panel on Geosciences examined the breadth of investigations relating to the origin and geologic history of Mars, from the planet’s formation to the present, that crewed missions to Mars could address from the first campaign onward (see Appendix E). These investigations would serve to reveal Mars’s original starting state upon accretion through its subsequent geologic and environmental evolution. They would also provide crucial context for other domains of investigation, in particular astrobiology and atmospheric sciences.

The panel identified a list of 10 prioritized objectives and constructed an accompanying STM. The following objectives top their list, with no prioritization between them:

1. Characterize past and present water and ice reservoirs within the exploration zone to understand geologic and climate evolution over Mars’s history.
2. Characterize the rock record within the exploration zone to understand environmental changes over Mars’s history.
3. Constrain absolute ages of martian events and tie to the impact record to calibrate crater counts.
4. Characterize igneous systems within the exploration zone to determine planet formation, differentiation, and volcanic history.

Mars’s geologic record of the nature, duration, and extent of water and ice reservoirs provides key information about the evolution of Mars’s climate and surface environmental conditions through time, with implications for the role of orbital forcing (analogous to Milankovitch cycles on Earth), the planet’s habitability, and the evolution of planetary volatiles in the solar system. Reconstruction of local, regional, and global stratigraphic relationships is essential for understanding the timing of Mars’s climatic and geologic events throughout the planet’s history. Dating Mars sample materials to determine the absolute ages of geologic events and their resulting features, including calibration of impact crater surface densities, is fundamental to reconstructing the chronology of Mars’s history, of its habitability, and of planetary evolution. Igneous materials preserve isotopic and chemical fingerprints of Mars’s origin and evolution through time, from early accretion and differentiation to degassing, atmosphere and hydrosphere development, and volcanic evolution.

The Panel on Geosciences identified requirements and assumptions to optimally meet its objectives. These include the establishment of “a basecamp with the buildup of supporting infrastructure,” the inclusion of “a professionally trained planetary field scientist(s) on the crew,” and “substantial planetary science training . . . for all crew members.”

The panel also recognized that the emphasis of geosciences investigation activities on Mars will vary with surface mission duration. For instance, considering the ratio of time spent conducting analyses in situ versus time spent collecting samples, a 300-sol mission would likely be characterized by a higher such ratio than a 30-sol mission.

The panel also emphasized the importance of building sufficient flexibility in campaign and mission planning to allow these to remain discovery responsive. The panel suggested that although having in situ analytical capabilities will enable discovery responsiveness, samples being returned to Earth need to be kept pristine and not analyzed in transit but instead examined via an array of state-of-the-art analytical capabilities once returned to Earth.

The panel identified mapping, in particular, of near-surface water ice at low- to mid-latitudes as a key robotic precursor activity crucial to informing landing site selection and allowing site characterization. Topographic information will be needed to plan campaigns; the higher the resolution, the more useful it would be. Some data can be

4.2.5 Overlapping Science Objectives

A review of the scientific objectives identified by the Panels on Astrobiology, Atmospheric Science and Space Physics, Biological and Physical Sciences and Human Factors, and Geosciences revealed several important areas of overlap. These intersections highlight opportunities for interdisciplinary collaboration, enabling optimized mission planning and enhanced scientific returns. Key overlapping objectives include the following:

• Water and ice reservoirs
  • This objective was prioritized by both the Panel on Astrobiology and the Panel on Geosciences, reflecting its crucial importance for assessing habitability, understanding Mars’s climate evolution, and enabling ISRU.
• Characterization of habitability and niche habitats
  • Highlighted by the Panels on Astrobiology, Geosciences, and BPS/HF, this objective emphasizes the importance of investigating environments such as brines, ice deposits, subsurface habitats, and caves. These habitats hold potential for supporting life or sustaining biological systems, directly influencing landing site selection and exploration strategies.
• Atmospheric dynamics and dust storm processes
  • This priority was explicitly identified by the Panel on Atmospheric Science and Space Physics and was recognized by the Panel on Geosciences owing to dust storms’ impact on surface geologic processes. A thorough understanding of dust storm dynamics is essential not only for crew safety but also for interpreting Mars’s geologic and climatic history.
• Integrated human health and martian environment
  • The Panel on BPS/HF strongly emphasized assessing human physiological and psychological responses, microbial interactions, and habitat sustainability in martian conditions. This objective aligns with planetary protection considerations highlighted by the Panel on Astrobiology, as well as environmental characterization priorities within the Panel on Atmospheric Science and Space Physics.
• Prebiotic chemistry and organic molecule detection
  • Central to the Panel on Astrobiology, this objective closely intersects with the analyses of Mars’s rock records by the Panel on Geosciences. Investigating Mars’s potential for prebiotic chemical processes aligns with geochemical assessments of ancient environmental conditions and their capability to preserve organic materials.
• Radiation environment
  • Understanding the radiation environment on the surface is Mars is critical to assessing risk to astronauts and to planning infrastructure. The radiation environment of each sample taken is a crucial measurement to understand the sample (e.g., was it taken on the surface but protected by overhanging rock formations?).

These overlapping objectives underscore the value of integrated, multidisciplinary approaches. By combining expertise across panels, mission planners can enhance astronaut safety, maximize scientific outcomes, and deepen humanity’s understanding of Mars as a complex and dynamic planetary system.