3

Campaigns

This chapter uses a consistent template of science objectives, notional architecture, measurements and samples, required assets, and strengths and weaknesses to describe the four prioritized crewed Mars campaign options:

• Mars Science Across an Expanded Exploration Zone (30-Cargo-300) in Section 3.3,
• Synergy of Mars Science Measurements (30-Cargo-300) in Section 3.4,
• Seeking Life Beneath the Martian Icy Crust (30-Cargo-300) in Section 3.5, and
• Investigating Mars at Three Sites (30-30-30) in Section 3.6.

These campaigns are general outlines with science priorities that NASA can use to make specific, implementable plans at the correct time; the later development of implementation-level detail is required because of the inevitable changes in the available technology, scientific knowledge, and other aspects of mission planning.

For each campaign considered in this study, this report

1. Describes a science roadmap that includes the highest priority science objectives addressed, secondary science objectives that are also achievable, measurements needed to address the objectives, and key assets and major equipment emplaced at each phase of the campaign (before, during, between, or after crewed missions).
2. Includes a discussion of the crew’s role in achieving the science objectives.
3. Identifies preliminary criteria for appropriate landing sites that will enable science objectives to be met. Examples provided by NASA of landing site criteria that could be considered include (1) ice within a certain surface depth, (2) salt-bearing materials accessible to crew, and (3) caves with accessible entrance points for human explorers. While discussions of specific landing sites are beyond the scope of the present study, criteria to be met by optimal landing sites are identified.
4. Identifies key equipment to address science objectives.
5. Lists some of the strengths and weaknesses of the specific campaign design.

3.1 PRIORITIZING CAMPAIGNS

The campaigns are presented in the order of their priority, as determined by the steering committee. In constructing and evaluating campaigns, each committee member considered several objective and subjective criteria, including

• The criticality of public appeal, that is, the communication of this astonishing step by humans to another planet;
• The science objectives included in each campaign, high-level descriptions of the measurements needed for each, and how completely each might be achieved by a given campaign;
• The need for high-value return on the first mission of any campaign;
• The balance of themes within each campaign, and whether balance (attendance to a wide range of objectives, perhaps less in depth with any single objective) or focus (completion of a group of related objectives) was more desirable; and
• The risk of cancellation of a campaign after the first mission, and the balance of what has been completed versus what lay ahead in the rest of the campaign.

Different campaigns have the potential to answer any given science objectives more or less rigorously, because each campaign would attain different numbers and qualities of the measurements needed for addressing the objective. Although the level of rigor for each science objective will be defined and closely managed by the planning groups closer to campaign launch, as an example of how rigor might be assessed, the committee constructed Tables 3-1 and 3-2 as an example rubric to help assess the depth to which a campaign might answer a science objective.

In this example, the depth to which a campaign answers a science objective is described with three categories:

1. Adequate measurement. The set of measurement characteristics that provide a significant advancement in the state of knowledge in the relevant area. For a high-priority objective, it is envisioned that other work would be deprioritized to achieve this level, but also, if this level is achieved and further advancement becomes unreasonably difficult, other lower- but still high-priority work would be executed.
2. Target measurement. The set of measurements that advance the state of knowledge far enough that further steps in this area would require evaluation of the measurements collected in the context of the knowledge gained. It is envisioned that other work would be prioritized once this level has been achieved.
3. Stretch measurement. A long-term goal that serves as a guiding star for advanced development and/or future action if breakthroughs in capability emerge.

The text for each objective within these three categories will need to be reconstructed freshly by future researchers for the needs of the time. For example, here an adequate measurement objective for Science Objective 1 (search for life) is defined, in part, as “(1) Obtain, examine, and preserve spatially correlated samples from at least 1 water-bearing site, from a depth ranging to at least 2 m with minimal surface contamination. Consider habitability, prebiotic chemistry, and indigenous extant or extinct life.” Future planning teams, knowing the technology and science advances that have occurred, might rewrite it as “(1) Obtain, examine, and preserve spatially correlated samples from at least 5 water-bearing sites, from surface to 20 m depth, with minimal surface contamination. Consider indigenous extant or extinct life.” Much more extensive edits are also possible, of course.

Table 3-1 includes the prioritized science objectives and key measurements of this report, and Table 3-2 shows one possible example of how this information can be formed into a rubric to measure how thoroughly (adequate, target, or stretch) a given science objective is being addressed by measurements and the number and type of samples. Future groups will need to redefine “adequate,” “target,” and “stretch” for their own contexts. Table 3-3 shows the performance of each campaign from this report against the notional rubric.

For Table 3-3, purple indicates that the campaign measurements entirely fulfill the category, blue indicates that fulfillment is possible, and cyan indicates that the campaign as planned does not fulfill the measurement rubric

TABLE 3-1 Prioritized Science Objectives and Key Measurements

NOTE: BliSS, bioregenerative life support system; CHONPS, carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur; ISRU, in situ resource utilization.

TABLE 3-2 Prioritized Science Objectives with One Possible Example Rubric for Adequate, Target, and Stretch Implementation of Measurements in Campaigns

NOTE: ECLSS, Environmental Control and Life Support System; ISRU, in situ resource utilization.

TABLE 3-3 Performance of Each Campaign’s Measurements Against the Notional Rubric of Adequate, Target, or Stretch

NOTES: Colors indicate the degree to which a campaign fulfills a science objective. Light blue for adequate, medium blue for target, and purple for stretch.

in this category. In crafting campaigns, committee members were free to choose not only the 11 top prioritized science objectives but also any objectives presented by the panels. This freedom allowed individual campaigns to highlight additional crucial science within the context of that campaign. One campaign, Investigating Mars at Three Sites, selected 2 science objectives beyond the steering committee’s prioritized list of 11, and the 2 additional objectives are listed in Table 3-3 and Section 3.6.

In the rubric presented below, the “adequate” example is a measurement that would significantly expand the current state of knowledge but would still need confirmation from more measurements (perhaps with refined the objectives) in subsequent missions. The “target” examples are a set that would not only expand the current state of knowledge but also could be reasonably expected to reduce uncertainties from site variability and measurement to measurement uncertainties and redefining the investigation space for future campaigns. The “stretch” examples are a set that are likely achievable only if they are deemed an overriding priority and/or if a technological breakthrough enables investigations deemed not feasible with today’s technologies and an ecumenical investment strategy. In Table 3-3, the assessment against the measurement rubric is a statement that the committee believes that it could be possible to meet a given level. However, doing so will be affected by intervening events and the constraints imposed on a given mission once finally formulated for flight.

3.2 COMMON BIOLOGICAL AND PHYSICAL SCIENCES IN SPACE AND HUMAN FACTORS REQUIREMENTS FOR ALL CAMPAIGNS

Biological and physical sciences in space and human factors (BPS/HF) research objectives will be achieved through a combination of surveillance and experimental research that can and needs to be conducted anywhere on Mars. Therefore, they were included in all campaigns to the greatest extent practicable. Although astronaut health and well-being will be monitored and tended to as a top operational priority on any human mission to Mars, research in BPS/HF might be considered a “secondary objective” in some campaign scenarios depending on their specific scientific drivers. Secondary science objectives are those that can be conducted at any landing site and/or are decoupled from the primary science objectives of the campaign.

Table 3-4 summarizes the housing, sampling, analytical, and sample return requirements to execute a nominal BPS/HF research program. They include plant and animal habitats capable of sustaining model species for a duration of up to 300 days with the ability for crew access and remote monitoring, and designed biological

TABLE 3-4 Notional Requirements to Complete BPS/HF Research Objectives (Science Objectives 4, 7, 8, 9 [partial], 10, and 11 [partial])

NOTE: EVA, extravehicular activity; IVA, intravehicular activity.

ecosystems (e.g., a BLiSS), that may be activated at any phase of a mission. Seeds hold advantage over clonal propagants because the former can be held in dry form and germinated at any time. Embryos from model animals such as Caenorhabditis elegans and Drosophila melanogaster may require different treatment, such as cryostabilization at ultralow temperatures (less than −80°C).

Although the majority of research activity will be intravehicular, limited extravehicular activity (EVA) will also be needed to execute this science portfolio, primarily for forward planetary protection monitoring (sampling from caches and dumps). EVA needs to be considered a special human factors research case which includes, in addition to health monitoring, a limited set of biobehavioral measurements from wearable devices that are minimally intrusive to crew. EVA in novel martian environments may also require more rigorous evaluation of human–agent team performance (NASEM 2022).

In the particular case of human research, NASA collects Spaceflight Standard Measures from astronauts on the International Space Station and research volunteers in analog environments. This suite of measurements is designed to capture changes in structure, function, and behavior at selected time points before, during, and

conducted back at the laboratory in the habitat. Significant equipment required would include a drilling system capable of characterizing subsurface materials in place, and of retrieving core samples from depths of 2–10 m. A meteorological tower 10 m in height would also be needed for atmospheric measurements to characterize Mars’s atmospheric boundary layer at the surface, including diurnal temperature variations, wind speeds, and turbulent eddies (Petrosyan et al. 2011). Using a 10-m meteorology tower on Mars, similar in height to standard meteorology towers on Earth, is justified not only by the similarity in boundary layer processes, but also because meteorological measurements on Mars may then be directly compared to those made on Earth. Effective mobility systems—including both unpressurized and pressurized rovers—allowing multiple traverses to explore the EZ and transport field gear (e.g., GPR, drill) on spatial scales of a few to a few hundred kilometers and on timescales of 1 to tens of sols, would also be needed. All LS/EZ-agnostic prioritized science objectives in this report would also be addressed during the campaign.

3.3.1 Campaign’s Science Objectives

The selection of a landing site that meets the requirements of the science objectives (see Section 2.3.3) allows this campaign to address to some depth each one of the report’s 11 prioritized science objectives (Table 3-5). Science Objective 1—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—remains the top priority and its measurement will begin first, and will be conducted based on real-time responsive decision making as early results come in.

Science Objectives 4, 7, 8, 9, 10, and 11 can be conducted at any landing site and will be addressed as possible in the first mission, and more intensely during the 300-sol mission 3. Primary science objectives are the most important to complete and are tied to the landing site choice. Secondary science objectives are those that can be conducted at any landing site and/or are decoupled from the primary science objectives of the campaign.

3.3.2 Notional Architecture

The key aspect of this campaign is its 30-Cargo-300 architecture (Figure 3-2); this architecture allows this campaign (and others with the same architecture) to address to some extent all the prioritized science objectives of the report, given the right LS and ability to reach a wide EZ. See Section 2.1 for campaign architecture definitions.

Landing Site Requirements

To develop a list of LS/EZ criteria, the type of geologic feature or setting was identified for each of the 11 science objectives so that the majority of that science objective’s scope could be met (see Section 2.3.3). For each of the lower-priority objectives on the list, account was taken of the LS/EZ criteria retained in higher-priority objectives, to take advantage of commonalities in LS/EZ criteria to the maximum extent possible.

Science Objective 1 calls for the search for evidence of habitability, the search for evidence of extant life, the search for evidence of extinct life, and the search for evidence of indigenous prebiotic chemistry. The LS criteria for “low- to mid-latitude near-surface water ice” is the key LS/EZ criterion across Science Objective 1, as it maximizes the science that can be achieved at the site.

Then, for Science Objective 2 (characterize past and present water and CO₂ cycles and reservoirs within the exploration zone to understand their evolution), the LS/EZ criterion for Science Objective 1 could optimally apply as well, provided the qualifier “layered” was added. Science Objective 3 required significantly different LS/EZ criteria from those previously used and so were defined separately.

The LS/EZ would be chosen to allow access to low- to mid-latitude near-surface H₂O glacier ice, and present diverse geology to include multiple pristine and altered/degraded impact, volcanic/igneous and sedimentary units, and H₂O activity features (e.g., channels, gullies, recurrent slope lineae, light-toned deposits) spanning Noachian (>3.7 Ga) through Late Amazonian (<0.5 Ga) (Table 3-6).

In addition, the LS/EZ would be close enough to sites of active dust lifting, textured dust clouds, dust devils, and dust storm passage to deploy, with crew or via robots, a network of autonomous dust storm monitoring stations. Access to aeolian deposits and features, ancient and modern, would be a good addition.

TABLE 3-5 Science Objectives for the Mars Science Across an Expanded Exploration Zone (30-Cargo-300) Campaign

NOTE: cDNA, copy deoxyribonucleic acid; DNA, deoxyribonucleic acid; HPLC, high-performance liquid chromatography; ISRU, in situ resource utilization; RNA, ribonucleic acid.

To search for indigenous extant life, the landing site would be chosen to give access to plausible habitable niche(s), in particular near-subsurface ice likely containing brines in the interface with the regolith (e.g., Fischer et al. 2014; Chevrier et al. 2020) and/or a cave. Settings in which extant life might be found on Mars were considered during the “Mars Extant Life: What’s Next?” conference held in Carlsbad, New Mexico, on November 5–8, 2018. Although the conference report does not provide a prioritization among potential habitable niches (Carrier et al. 2020), arguments have been made for caves as a top- or high-priority setting to explore (e.g., Gunn 2004; Léveillé and Datta 2010; Lee 2023).

TABLE 3-6 Landing Site Criteria for the Mars Science Across an Expanded Exploration Zone Campaign

NOTE: See Figure 3-1 for an example notional landing site and exploration zone that would fulfill the landing site criteria.

To search for biosignatures associated with indigenous extinct life, the landing site needs to give access to a well-preserved aqueous sedimentary record covering a long span of time, to include specifically the Noachian when liquid water was more prevalent in the martian near-surface environment than at present.

Crew Role

The Mars Science Across an Expanded Exploration Zone Campaign (30-Cargo-300) is characterized by the opportunity to address a wide range of science objectives across a science target-rich extended exploration zone over a substantial amount of surface time. The likely need to traverse long distances of order tens to hundreds of kilometers in pressurized rovers over multiple days to reach far-ranging targets, or to conduct closer-range excursions with multiple target stops, implies complex surface operations generally requiring vehicle crews of two or more to implement. While it is beyond the scope of the present study to identify specific surface exploration architectures, lessons from terrestrial analogs in which vast tracts of territory were explored and investigated via habitable land vehicles suggests that science operations across large-distance scales on Mars will likely require two or more pressurized rovers working in tandem to implement, that is, crews of at least four assuming a minimum of two per vehicle (Lee and Schutt 2021). Larger crews beyond four members, while desirable for more operational flexibility and redundancy, are not necessarily required for the strict implementation of science objectives in the Expanded Exploration Zone Campaign, assuming all the required science training is sufficiently represented among the crew of four. Compact crews may also be sufficient for the implementation of many science EVAs. While EVAs from either landing site habitats or pressurized rovers are generally assumed to mobilize at least two suited crew members at a time, single-astronaut EVAs may actually be safer and more efficient under some circumstances (Lee 2024b). On the other hand, other aspects of fieldwork may add more to the workload than is obvious at first: an important observation from terrestrial field experience is the frequent need for repeat visits to the same target sites to allow iterating on field observations and/or sampling (e.g., Lee 2024b). Some types of surface science activities, however, are inherently labor intensive, at least in their traditional implementation—for instance, drilling. Field drilling on Earth even to shallow depths of only a few meters often requires crew sizes of two, three, or more, depending on the challenge presented by the substrate and the performance of the drill. On Mars, the exact number of crew members required for shallow drilling would depend on similar factors, and also on the amount of automation built into the drilling system. Geophysical surveys, for example, GPR and seismic surveys, would typically require at least two crew members on EVA as well.

The estimated minimal crew size needed to implement all campaign science objectives in the Expanded Exploration Zone campaign might ultimately be four to six, in consideration also of simultaneous IVA science laboratory work needs and the need to organize crew shifts to more optimally implement the science. Such estimates, however, remain uncertain, as the required crew size will depend on overall crew composition and training, and other mission constraints and requirements. The minimal rough estimates suggested here assume highly trained and cross-trained crew members, all capable of carrying out crucial aspects of the campaign’s science investigations, with the means to reliably and efficiently access all science target sites and perform all science tasks.

3.3.3 Strengths and Weaknesses of the Campaign Design

Strengths

• A key feature of the Mars Science Across an Expanded Exploration Zone Campaign (and of all campaigns using the 30-Cargo-300 architecture) is its ability to support long-duration and long-range science operations, which imply the opportunity to iterate on science questions, reach diverse but possibly interrelated science targets within a single mission, conduct repeated visits to some targets, have multiple sampling opportunities, and establish regional networks of long-term monitoring instruments. The establishment of a substantial exploration infrastructure does not benefit only safety and logistics, but also in situ science capabilities, including in-habitat laboratory and instrument capabilities.

• This campaign, if implemented at a strategically well-selected LS/EZ, allows all the prioritized science objectives from this report to be addressed.
• Although defining architectures is outside of the study’s remit, this campaign does lend itself well to establishing a single scientific base on Mars, enabling exploration tools and resources to be sent ahead of time, co-located, and built out to further scientific progress.

Weaknesses

• Although there can be meaningful variety in LS environments when reviewing the entirety of a large EZ, this campaign is initially constrained to a specific area on Mars and therefore may offer a limited view of the planet compared to campaigns visiting three different sites. A strategic LS would have to be identified on Mars that would allow a wide diversity of science targets to be reached within the time and range constraints of the campaign.
• In the absence of a sufficiently diverse EZ, or the capacity to reach distant enough destinations, this campaign would not be able to meet all of its science objectives.

3.3.4 Measurements

This campaign would need to drill to a depth of 2–10 m, assuming a surface with high exposure age, to access fresh samples beyond the oxidized layer or reach an antioxidant-rich zone (such as one rich in manganese). This campaign would also need to have the ability to sample ice-rich materials to similar depths and preserve the integrity of volatile-rich samples through their return transfer to Earth.

The selection of a good site for a 30-Cargo-300 campaign scenario is of the utmost importance given the imperative and opportunity in this scenario to access, investigate, and sample a wide variety of areas of interest. In situ robotic reconnaissance would be crucial prior to crew arrival. The robotic asset deployed for this reconnaissance could remain available in support of exploration activities following crew arrival.

Crew and Equipment Transport: Effective mobility systems allowing multiple traverses to explore the EZ and transport field gear (e.g., drill, ground-penetrating radar) on spatial scales of a few kilometers to a few hundred kilometers and on timescales of 1 to 300 sols—that is, unpressurized and pressurized rovers—are required.

Shallow Drilling: Shallow drilling to a depth of 2–10 m is required to meet Science Objectives 1 and 2. Eventual deeper drilling to depths of up to 5 km to access deep subsurface aquifers remains an important but major equipment- and time-demanding task to more fully address Science Objective 1.

Weather Stations: A network of autonomous meteorology or weather stations for monitoring dust storms that would be deployed robotically or by crew is required for Science Objective 5.

Instruments: Field measurements would require a wide suite of science instruments, specifically imaging instruments from microscopic imagers to digital hand lenses and panoramic imagers; elemental, isotopic, and molecular compositional analyzers; eddy covariance instrument systems; and GPR.

Following crew departure, including on timescales of potentially a few years afterward, it could be highly advantageous and desirable to have autonomous or teleoperated robotic exploration assets left behind by crews in the EZ to continue exploration work, including iterating on science questions raised during the crewed missions.

3.3.5 Key Assets and Major Equipment

Before crew arrival, robotic rotorcraft, a surface rover, or other capable equipment is needed to confirm selection of a good LS/EZ. Key to this campaign’s success when crew are on the surface would be the inclusion of a surface mobility system capable of reliably accessing all science areas of interest within the EZ (Figure 3-3). In the present conceptual study, this could be 100 km to a few hundred kilometers in radius. This scenario requires the availability of one or more pressurized rovers, at least for the 300-sol mission segment, in order to allow crew(s)

and equipment to rapidly reach, and return from, areas of interest within the EZ that would be located many tens of kilometers from the LS (Figure 3-4).

The second critical major equipment needed while the crew is on the surface is the drilling rig and support instrumentation and equipment. Dust monitoring stations would stay in place after the crew leaves, and so power, computing, communications, and other support would be needed.

3.4 SYNERGY OF MARS SCIENCE MEASUREMENTS (30-CARGO-300)

The Synergy of Mars Science Measurements Campaign is designed to advance Mars exploration by leveraging the commonality of the top scientific objective’s common measurement needs, correlated through a comprehensive

analysis of the panel science traceability matrices (STMs). This campaign is distinct from the Mars Science Across an Expanded Exploration Zone Campaign in that this campaign is designed to accomplish common measurements that can be done at a range of possible landing sites. This approach offers a campaign that has looser site-specific needs, although the extent to which each objective can be completed will necessarily vary with the site-specific characteristics.

Spanning an initial 30-sol field campaign followed by an extended 300-sol period, the campaign integrates in situ analyses and sample return to achieve comprehensive scientific objectives. This campaign prioritizes specific goals and measurements during the 30-sol stay to deliver significant scientific breakthroughs while establishing the foundation for more in-depth investigations over the long term. By taking advantage of the unique capabilities associated with a human-led mission, the campaign combines aerial coverage, vertical extent (subsurface and atmospheric), and temporal duration, effectively creating a four-dimensional view of Mars (Figure 3-5).

A campaign constructed around common analytical measurements needed to serve a plurality of the top science objectives would be inclusive to a broad range of U.S. and global science communities. By tackling big goals that necessitate multidisciplinary approaches, the campaign encourages science measurement innovation, especially for instruments and technologies that can accomplish multiple cross-disciplinary needs.

3.4.1 Campaign’s Science Objectives

The Synergy of Mars Science Measurements campaign is designed to advance the understanding of Mars through common samples and measurements that significantly advance the top-rated objectives (Table 3-7).

Primary Science Objectives: Objectives 1, 2, 3, and 5 would be the primary focus of this campaign, with a plurality of the planned analytical needs being accomplished in situ or in laboratories on Mars and/or by sample return to Earth.

Secondary Science Objectives: By establishing the capability to address the top objectives, Science Objectives 6, 9, and 11 are readily addressable as well, rounding out an exciting scientific complement. The 30-Cargo-300 architecture also enables a robust framework for including common activities (see “Biological and Physical Sciences in Space and Human Factors,” Section 3.2).

TABLE 3-7 Science Objectives for the Synergy of Mars Science Measurements Campaign

Initial Measurements: This campaign supports rapid field geology and targeted scientific investigations in the first 30 sols, followed by focused data collection in the 300-sol segment to investigate specific phenomena in detail. The first key measurements include

• A field geology campaign aided by handheld instruments providing mineralogy, composition, and subsurface structure to find promising sites for astrobiology sampling, ISRU follow-up, and to select a drill site.
• Targeted laboratory-based measurements of volatiles and organic geochemistry on samples, in part to select those to return to Earth to deliver high-profile initial science results and inform next samples and actions for the search for life.
• Meteorological measurements to give context to site and determine suitability for a dust lofting study in the 300-sol segment.

3.4.2 Notional Architecture

Why 30-Cargo-300?

This campaign is predicated on making crucial analytical measurements on the martian surface, as well as returning carefully selected, meticulously documented samples to Earth. The 30-Cargo-300 architecture was selected for its ability to balance rapid deployment with long-term scientific investigation. In the initial 30 sols, the crew would conduct an initial geologic field campaign and initial environmental assessments to inform subsequent scientific activities. They would collect samples from a potentially habitable site and examine them for signs of extinct or extant life, providing exciting early science return. Initial activities would also support site validation, ensuring the selected landing site meets all criteria and is safe for extended operations.

This foundation supports the extended 300-sol period, during which more complex operations, such as extended EZ exploration, deep drilling, atmospheric measurements, and laboratory-based data collection, can be established in multiple locations. This structure offers the ability to preplace significant infrastructure assets and enable initial reconnaissance to adapt elements of the extended phase based on real-time findings. Longer-duration stays enable more monitoring of volatile and aerosol exchange rates (including interior and exterior) and cycles with seasonal influence, with the ideal situation being a return of a full Mars year of sets of measurements. Longer stays also allow for iteration and to ensure the instrument installation is conducted properly.

Landing Site Criteria

This campaign is open to a wide range of potential landing sites and exploration zones, with the caveats that the specific location of the landing site drives the magnitude of the return associated with science objectives examining volatile access and dust lifting. The initial 30-sol phase conducts site reconnaissance, enabling elements of the extended phase to be selected or customized based on the characteristics of the site, ensuring that the mission remains flexible and responsive to emerging scientific priorities.

The benefits of this campaign are that it can return a broad swath of high-priority science and at least partially fulfill many of the top science objectives at nearly any landing site chosen for exploration. But with the judicious selection of an EZ, some objectives may be more fully satisfied (see Section 2.3.3). This selection would be driven by current data sets as well as additional global mapping efforts to refine landing site selection and identify geologic features of interest and to detect areas rich in water-related minerals, guiding targeted drilling operations.

Crew Role

Geologic mapping is enabled by extended durations on the surface for two or more crew members to conduct the fieldwork. For the extended 300-sol phase, four crew members would be needed to support the breadth of tasks and iterative exploration, as results come in and point to new areas of geography or lines of inquiry.

The ability to choose which samples to collect for further study, informed by field observations and analytical measurements on the martian surface, makes a huge difference to the potential for scientific discovery. The ability to explore more terrain with more crew members facilitates a comprehensive understanding of geologic setting and characterization of the geologic processes of the site that guide the decision trees for sampling and analysis for astrobiology and resource utilization goals.

The goals of field study are to understand planetary processes in the EZ to be able to guide decision trees for sample collection, analysis, siting assets, and prospecting for resources. These activities require observation in the field, the creation of a conceptual model, the formulation and testing of hypotheses, and repeated visits to the same locations. These tasks take advantage of human flexibility, experience, and judgment. Additionally, astronauts uniquely enable a wide spectrum of biological sciences and human factors research that enhances the safety and productivity of future crewed missions.

3.4.3 Strengths and Weaknesses of the Campaign Design

Strengths

• The use of every sample and measurement is optimized for science output because of the analysis of commonality across all panel STMs.
• This campaign, if implemented at a strategically well-selected LS/EZ, allows all prioritized science objectives of this study to be thoroughly addressed.
• By making foundational measurements of dust, radiation, and ISRU potential, the campaign measurements maximize usefulness for architecture decisions for sustained martian exploration.

Weaknesses

• The principal drawback to this campaign is that, by accommodating the common measurements, some of the specialty measurements for each objective may not be accomplished as envisioned, possibly leading to nonclosure of these objectives within the initial campaign.
• By prioritizing the most common analytical measurements, the geology, astrobiology, and atmospheres objectives are emphasized and many of the principal BPS/HF objectives become secondary or opportunistic.

3.4.4 Measurements

The range of specific analytical measurements mapped to science objectives is captured in Table 3-7. Common, crucial measurements include those made in situ across the EZ and those made in laboratories either on Mars or back on Earth. Table 3-8 maps measurements to science objectives for this campaign. The gold boxes denote measurements to be done in the 30- and 300-sol phases. The teal boxes denote additional measurements to be done in the 300-sol phase. There are no measurements that are only to be made in the 30-sol phase.

Measurements to Be Made In Situ on Mars

The following are measurements to be made in situ on Mars:

• Geologic relationships;
• Mineralogy and petrology;
• Subsurface structure;
• Subsurface volatiles;
• Atmospheric abundance and composition (water, CO₂, Ar);
• Pressure, temperature, and wind;
• Dust mixing ratio, particle distribution, and turbulence; and
• Electric field and radiation.

The first 30-sol segment would focus on observations and measurements of martian surface and atmospheric conditions, identifying and returning samples with the highest likelihood of containing extant or extinct life, and characterizing the EZ (dust, radiation, and ISRU potential) to make informed choices for the 300-sol segment. A geologic field campaign, including observations, imaging, and sampling, would be crucial in identifying and characterizing surface features, for example, sedimentary layers, volcanic structures, and impact craters. Along with mapping, handheld instruments to capture geochemical information, subsurface structure, and other discriminators would be crucial to selecting a location for deep drilling. Monitoring atmospheric phenomena and dynamic weather events that influence surface and subsurface conditions would also be accomplished to better understand the site and its potential for in-depth atmospheric science goals.

TABLE 3-8 Measurements Mapped to Science Objectives for the Synergy of Mars Science Measurements Campaign

NOTE: Gold indicates measurements to be made in 30-sol and 300-sol phases; teal indicates additional measurements to be made in the 300-sol phase.

The in situ measurements in the 300-sol segment would provide the opportunity to explore more of the EZ, but also crucially to focus on the vertical and time dimensions. The vertical dimension is pivotal, encompassing both subsurface access and atmospheric profiling. Continuous data acquisition allows for the observation of diurnal cycles, weather events, and seasonal variations.

Subsurface drilling would provide unique measurements to determine if evidence can be found for extant or extinct life at the landing site and to identify and characterize past and present water and other volatile reservoirs (e.g., location, timing, and extent of ancient water reservoirs). The campaign would use a drill station to penetrate deep into the martian crust, reaching depths where organic materials and microbial fossils are more likely to be preserved (greater than 10 m, up to 1 km depth or more), extracting core samples from various depths to analyze the stratigraphy and search for evidence of past or present life, and investigating the layering and composition of subsurface materials to identify ancient water reservoirs and habitable zones. A tall drill station may serve dual duty by providing a large mast upon which height profiling sensors can be attached.

Atmospheric height profiling would provide measurements for determining what controls the onset and evolution of major dust storms, which dominate present-day climate and weather variability:

• Vertical dust fluxes and particle size distributions: Assessing how dust particles are transported and deposited across different atmospheric layers.
• Surface wind stress: Measuring wind speeds and directions at multiple heights to understand surface–atmosphere interactions.
• Electric field: Monitoring atmospheric electric fields to study dust storm dynamics and their effects on atmospheric circulation.
• Pressure and temperature profiles: Capturing rapid pressure changes and temperature variations at various altitudes to model weather patterns and vortex activities.
• Solar and thermal radiative fluxes: Measuring incoming and outgoing radiation to evaluate the energy balance and its impact on climate processes.

Measurements to Be Made in Laboratories on Mars and/or Earth

The following are measurements to be made in laboratories on Mars and/or Earth:

• Mineralogy and petrology,
• Total carbon,
• Organic composition and abundance,
• Volatile composition and abundance, and
• Isotopic measurements (stable and radiometric).

More detailed composition, abundance, isotopic analysis, and imaging of specific samples can be conducted in laboratory facilities inside or attached to the habitat. They enable a suite of analyses to determine the chemical and physical properties of martian materials in order to characterize possible biosignatures and to guide further crew exploration of the EZ. Some of the more important measurements for analysis on Mars include

• Organic molecule detection: Identifying complex organic compounds that may indicate past life.
• Isotopic analysis: Stable isotopic ratios to understand geologic and atmospheric processes.
• Redox state: Abundance of reducers and oxidizers in solids and liquids if present.
• Microscopic examination for microfossils: Searching for fossilized microbial life within drilled samples.
• Mineralogical and geochemical analyses: Assessing mineral compositions to identify potential biominerals.
• Water content analysis: Measuring the presence and distribution of water in surface and subsurface materials.

Many of the in-depth analyses needed to fully address the science objectives would require returning samples to Earth (see Section 2.3.7). Sample return enables more in-depth analysis and comparison of analyses between laboratories:

• Organic molecule detection: The nature and distribution of organic carbon (chirality, structural isomers, repeating subunits, potential for storing information, and nonequilibrium distribution patterns).
• Isotopic analysis: Radiometric isotopic ratios to accurately and precisely date lithologic units.
• Mineralogical and geochemical analyses: Small-scale geochemical gradients, trace elements abundances and ratios, volatile elements, and nitrogen speciation (e.g., nitrates), particularly given nitrogen’s critical role in biological processes and habitat sustainability.

Measurements to Be Made Using Preplaced Assets

No measurements are required to be accomplished by preplaced assets for this campaign, but, as discussed below, preplaced logistics and significant infrastructure elements (drill, mast, and laboratory) would expand exploration capabilities and ensure comprehensive data collection within the limited mission period.

3.4.5 Key Assets and Major Equipment

Key assets and major equipment required for this campaign include a deep drilling apparatus (1 km or greater), a tall tower structure (30 m), and laboratory equipment available in a stable, internal environment. Enabling assets for supporting these capabilities include mobility, communication, power, and sample return capability. In particular, mobility (via drones, rovers, or mobile habitats) enables more of the EZ to be examined in detail, to give context to the in-depth measurements and to provide diversity and trends across the geologic terrain. Power and data relay and communications are clearly important to allow the equipment to be used by the crew but could be expanded after the crew departs to continue investigations remotely, which would be particularly advantageous for preparing for the 300-sol mission (see also Section 2.4.1).

Before Crew Arrival

Before the initial 30-sol segment, it would be beneficial to preplace large assets, enabling the crew to more readily explore the EZ. Drones or rovers that are already deployed would enable crew to conduct preliminary reconnaissance, map the terrain, and identify optimal locations for detailed investigations. Maximizing coverage of the EZ would allow crew to readily decide where best to position the larger infrastructure for the 300-sol segment. Prior to the 300-sol segment, preplacement of major cargo elements would facilitate setup when crew members arrive. The deep drilling apparatus would be positioned at the designated landing site. The drill rig tower could double as a tall mast to support atmospheric sensors and communication equipment, and additionally to enable continuous environmental monitoring and data transmission. Laboratory equipment and sample collection and containment supplies could be preplaced and be ready to install in a controlled habitat module that provides a reliable environment for initial scientific analyses and equipment testing. Solar arrays, data relays, essential supplies, tools, and spare parts to support long-term mission sustainability could also be prepositioned.

Crewed Operations

Crew members would operate the deep drill to extract subsurface samples for biosignature and water detection; install and monitor instruments on the tall mast for continuous atmospheric data collection to study climate dynamics and dust storm activities; conduct on-site laboratory analysis, including time-sensitive analysis of collected samples using onboard laboratory equipment to identify organic molecules and geologic features; and prepare samples by securing and cataloging collected samples for potential return to Earth, ensuring their preservation and integrity. Although it is difficult to place specific mass requirements on the amount of samples to be

Below the cryosphere, Mars is expected to be habitable to life as we know it (e.g., Jones et al. 2011; Michalski et al. 2013a; Stamenković et al. 2020; Tarnas et al. 2021; Cockell et al. 2024) and may have been habitable over billions of years. Evidence of subsurface habitability is supported by inferred surface habitability of ancient Mars, including wildly different parts of the planet at Gale Crater (Grotzinger et al. 2014; Losa-Adams et al. 2021) and Jezero Crater (Kizovski et al. 2025). The depth to where liquid water may exist is closest for near-equatorial low-altitude sites (Clifford et al. 2010; Jones et al. 2011) (Figure 3-7). This campaign seeks a site with a Noachian-to-Hesperian transition zone. Ideally, such a site would include deposits of water ice above possible liquid water. Habitable zones for ancient life may be more accessible in near-equatorial regions owing to a higher frequency of impact events creating temporary habitable zones linked to permanently habitable deep subsurface environments (Schwenzer et al. 2012).

3.5.1 Campaign’s Science Objectives

The search for, and sampling of, indigenous extant life is one of the most complex surface activities on Mars because of the high requirements for in situ identification, sampling, containment, limited in situ analysis, and potential curation and storage for return to Earth.

Science Objective 1 is the primary focus of this campaign, with Science Objectives 2, 3, and 11 providing context for the astrobiology objectives. By establishing the capabilities to monitor crew health and address the primary objectives, Science Objectives 4, 6, 8, 9, and 11 become opportunistic and provide valuable data to support future mission planning (Table 3-9).

TABLE 3-9 Science Objectives for the Seeking Life Beneath the Martian Icy Crust Campaign

NOTE: ECLSS, Environmental Control and Life Support System; IRSU, in situ resource utilization.

The opportunities to include supplemental science at minimal cost or time include primarily measurements that are required for other operational reasons (e.g., medical research enabled by data already collected for astronaut health and medical operations, operational risk reduction) and measurements that leverage tools already needed for the primary campaign (e.g., drilling and coring, radiation dosimetry needed for astrobiology sample curation also being used for habitat monitoring).

3.5.2 Notional Architecture

Mission design splits efforts into an “establishing” 30-sol mission and an “executing” 300-sol one: The first mission would establish geologic context and pick specific sites of interest, install a seismic network or other means to map out deeper structure to optimize deep drilling site selection, and conduct analysis on ancient rocks including at the near surface (2–10 m), low–exposure age samples, investigations of which could target signs of prebiotic chemistry and ancient life and, opportunistically, extant life (Table 3-3, Science Objective 1 both adequate and target scope). An intermediate cargo delivery mission would provide infrastructure in support of a long surface stay and deep drilling. In contrast, the 300-sol mission would set up deep drilling infrastructure and obtain samples from below the cryosphere, analyze samples, and expand drilling to additional sites as time allows.

The architecture of this campaign is driven by the assumption that deep drilling to 2–5 km requires more than 30 sols. A 30-sol mission would allow for initial science and more precise location of the desired deep drilling site(s). Shallow (initially 1–2 m, and up to 10 m) cores could be taken to characterize geotechnic properties and to enable preliminary science (e.g., ancient life preserved within previously habitable zones or extant life within transiently habitable refugia in the near surface). A following 300-sol mission would focus on the hard work of deep drilling, core collection, and initial analyses, with the bulk of the selected samples returned to Earth for access by multiple laboratories and curation for investigations using future technologies.

Based on current understanding of Mars, accessing below the cryosphere may require drilling to 2–5 km or more below the surface. While drilling 800 m through glacial ice to reach subglacial Lake Whillans took only a few days (Rack 2016) and required ~450 metric tons of gear, hard rock drilling is expected to take orders of magnitude longer. The Lake Whillans effort, however, was not optimized for minimum mass. If precursor development accelerates deep drilling capabilities, obtaining deep cores from multiple sites would enhance science return during a future extended-stay mission. Specific science needs will drive the specific drilling capabilities required. (For an example see the Section 5.3.3 case study, “Drilling on Mars for In Situ Resource Utilization.”)

Landing Site Criteria

Mars and Earth have significant overlap in the temperature and pressure regime known to support life on Earth (Jones et al. 2011). The most extensive overlap is in the deep subsurface (Carrier et al. 2020). Radiolytic decay alone could support cell densities of millions of cells per kilogram of rock (Tarnas et al. 2021). The best locations for extant life as it is now understood are in places with permanent liquid water that are sheltered from surface radiation and chemical reactions. Liquid water/ice water table depth is most shallow near the equator and could be up to 5 km or more (Clifford et al. 2010). The estimated thermal skin depth, based on InSight Lander measurements, is a few centimeters (Spohn et al. 2024); thus, surface-driven thermal fluctuations are limited to less than 1 m depth. Gases may permeate significantly deeper depending upon porosity. Below 10 m, radiation is dominated by naturally occurring radioactivity (Horne et al. 2022). Interactions of impact events can result in transient habitable environments (Schwenzer et al. 2012; Osinski et al. 2013), resulting in preserved ancient life above the current cryosphere/hydrosphere boundary. These transient zones for ancient life may be more accessible in near-equatorial regions, owing to a higher frequency of impact events creating temporary habitable zones linked to permanently habitable deep subsurface environments (Schwenzer et al. 2012).

Few low-latitude sites have been observed to have abundant near-surface ice, and modeling shows conditions for transient near-surface habitability are more likely at latitudes greater than 33°N (Mellon et al. 2024). However, prioritizing extant life means seeking persistent, deep water. The easiest access to below the cryosphere (Figure 3-7) would likely be provided by targeting a low-latitude and low-altitude site (Clifford et al. 2010; Jones et al. 2011). Such sites exist and have been identified in the literature (Gourronc et al. 2014; Horvath et al. 2021; Mitrofanov et al. 2022; Fastook and Head 2024; Gou et al. 2024).

Crew Role

For both the 30-sol and 300-sol missions, a bifurcated crew is anticipated, with one subteam focused on drill setup, operations, and maintenance, and a second subteam focused on in situ sample collection, curation, and analysis. During drilling, the science team might be able to conduct additional surface science while they await core samples. Where more hands are needed for a given operation, cross-training would apply. With NASA’s standard assumption of a buddy system, this drives a minimum of a four-person crew focused on this campaign, with the need for larger crew complements evaluated as drilling operations and automation are refined and prototyped.

3.5.3 Strengths and Weaknesses of the Campaign Design

Strengths

• Interrogates a cross section of martian history by deep drilling.
• Maximizes time on target for the top scientific objective and increases hyperlocal context and depth of understanding of samples.
• Minimizes secondary science hardware, training, and overhead by focusing first and foremost on one field of study.
• Simplifies messaging by focusing on fewer primary objectives.

Weaknesses

• Overhead of deep bore drilling to 2–5 km depth limits the number of sites, requiring correct site selection before drilling begins.

• Science returns and community engagement for biological and physical sciences and human factors and for atmospheric and space science are more limited than for other disciplines.
• The risk of mission failure is high when the mission is so heavily focused on a single objective.

3.5.4 Measurements and Samples

The measurements to be done with preplaced assets include

• Measuring the distribution and extent of near-equatorial subsurface ice and the lower limit of the cryosphere.
• Mapping of spatial boundaries of potentially habitable areas within the upper 20 m to identify potential niche habitats based on, for example, ice, water vapor transport, thermal inertia, salt content, or mineralogy.

The measurements to be done in situ include the following:

1. Search for life, including both Earth-life agnostic and Earth-life targeted approaches, especially in deep core measurements to 5 km or more, and surface and shallow (1–2 m depth) samples:
   • Determine organic composition and abundance, for example, untargeted and targeted analysis including diverse approaches, not limited to nucleic acids, sugars, cofactors, amino acids, and lipids. Characterize the abundance, nature, and spatial distribution of organic molecules, including information on chirality, structural isomers, and repeating subunits.
   • Seek to identify near-surface regions on Mars that are or could have been habitable (e.g., brines, caves, ice, salt deposits, salt/ice interfaces, ice/rock interfaces, or mud volcanoes).
   • Assess characteristics that influence habitability: the presence and abundance of water, ice, organics, and salts; protection from radiation; and hydrologic activity.
2. Study attendant biology and human factors of the mission itself:
   • Collect spaceflight standard measures to characterize crew physiological, cognitive, and emotional health, including team dynamics.
   • Characterize the evolution of microbial population dynamics and species distribution in biological systems and habitable volumes.
3. Mapping and mineralogy:
   • Map surface and subsurface features, including spatial boundaries of potentially habitable areas, and subsurface geomorphology.
   • Map mineralogy of bulk and microscale rock along the depth profile, especially searching for alteration minerals that inform sediment diagenesis, including cementation processes, dissolution, authigenesis, recrystallization, oxidation/reduction, fluid–mineral interactions, and hydrated minerals.
   • Hand-sample/scale optical and multispectral imaging to reveal the structure of the macro- and microenvironment.
   • Perform high-resolution multispectral imaging of the environment, which could elucidate local-scale geochemical processes.
4. Chemical composition:
   • Determine the abundance of inorganic elements in rock, ice, and liquid, including CHONPS and electron donors (H₂, Fe²⁺, H₂S, CH₄, NH₄⁺) and acceptors (CO₂, Fe³⁺, SO₄, ClO₄⁻). Include redox state.
   • Determine chemical composition with regard to oxidants (peroxide, perchlorate, chlorate, NO₃, O₂), and oxidation state of Fe and Mn.
   • Determine the composition and abundance of reduced, greenhouse, and noble gases in rocks, ice, and the atmosphere (e.g., CH₄ and H₂). Include related isotopic fractionation.
   • Determine salinity, redox potential, pH, water activity, and temperature of brines, solutions, and water.
5. Environmental characterization via:
   • Light flux;
   • Temperature, pressure, and relative humidity; and
   • Radiation dosimetry at relevant sites and sampling depths.

The measurements to be done via sample return include additional characterization on Earth (accelerator mass spectrometry, life detection testing [e.g., stable isotope priming]), noting that careful curation of cores is required to avoid loss of volatiles, breakdown owing to sunlight and/or atmospheric exposure, or other external influences.

This campaign may not be achievable to the level of the full stretch objective within the 300-sol second mission (e.g., if the cryosphere is deeper than expected, there are issues with drilling, or the available crew time is too low). A plan to achieve this campaign’s objectives will need to include mitigations with precursor activities and extended and/or follow-up missions.

3.5.5 Key Assets and Major Equipment

Before Crew Arrival

The most crucial precursor work is identifying promising subsurface sites for accessing the subsurface beneath the cryosphere. There is a technology gap for the equipment that can characterize the subsurface at the most accessible low-latitude cryosphere depths (5 km and perhaps up to 10 km at low latitudes; Figure 3-7). Evaluation of assets capable of mapping geomorphology deeper than Mars Advanced Radar for Subsurface and Ionosphere Sounding (low-frequency GPR) may include seismic methods, or transient electromagnetic sounding (Carrier et al. 2020; Nunes et al. 2022).

Finding: Targeting a drill site with maximal likelihood of accessing liquid water requires characterization of subsurface structures at relevant depths. There is a technology gap for such characterization at depths greater than a few kilometers.

Crewed Operations

The primary work is site characterization, drill setup, and deep subsurface sampling. This requires surface mobility for carrying heavy equipment and core samples to and from the drilling sites, shallow and deep drilling infrastructure, analytic tools, and sample storage capabilities. Deep drilling will require more capable tooling than ever used on an extraterrestrial body.

For the secondary objectives, no unique major equipment is required. The campaign leverages existing operational measurements as described above, including crew health and performance instrumentation, dosimeters, omics tools, and geologic sampling kits as outlined in Section 3.2.

After Crew Leaves

There are no additional key assets specified, but for all automated exploration-enabling systems left on the martian surface, or set up for recurring human presence, the attendant science opportunities need to be evaluated, for example,

• Life detection instrumentation on any water collection systems;
• Biology of the built environment monitoring over time;
• Environmental characterization, such as dosimetry, and temperature and pressure changes;
• Video and light flux of dust storms; and
• Any automated preparatory activities required for cargo infrastructure delivery and/or setup.

3.6 INVESTIGATING MARS AT THREE SITES (30-30-30)

A 30-30-30 architecture would pose less risk for the astronauts and would satisfy some science objectives from each of the four disciplinary panels. First and foremost, it would enable landings at three widely separated sites, which maximizes the science return from dating of martian rocks, helping to validate estimates of surface ages based on cratering counts (Figure 3-8). Admittedly, this enhanced science return requires the ability to bring

back useful samples from Missions 2 and 3, which are focused on different objectives. Wide separation would also enhance the return from seismometers and meteorological towers, both of which could be deployed during relatively short stays and yet continue to collect data for extended periods after each landing. Many of the astrobiological science objectives could be achieved as well, although not to the extent allowed by longer surface missions. Although the exact choice of sites remains negotiable, three possibilities are listed below:

1. Igneous and impact melt geology. The first landing would be at a site that offers a good selection of igneous rocks and impact melts to perform radiometric dating. It would be located somewhere in the southern highlands, in a region that will provide a good set of measurements to help establish martian cratering chronology, which heretofore has been calibrated by analogy to the lunar record. Other hard-rock geology science objectives will also be emphasized, although sample collection time will be limited because of the relatively short stay.
2. Sedimentary rocks for evidence of ancient life and/or prebiotic processes. The second landing would be at a site that offers a good record of sedimentary rocks, similar in many respects to previous rover explorations of the Gale and Jezero craters. The main objectives will be to look for evidence of extinct life, along with indirect evidence for extant life (e.g., resolving the abundance and source of martian methane). This site would also be located within the southern highlands, preferably at some location that also contains igneous rocks and/or impact melts that could be used to establish a second data point in the martian cratering chronology.
3. Glaciers within a dust storm–forming region. The third landing would be at a low- to mid-latitude site that shows evidence for subsurface ice. The two key goals will be (1) to establish the viability of this site for a future long-term stay that will require ISRU and (2) to look for any signs of life within the ice or within associated brines. The landing site is located within a dust lofting region that can be studied with instruments deployed on weather stations and a meteorological mast. This site has similar characteristics to the Mars Science Across an Expanded Exploration Zone Campaign (Section 3.3), which involves a 30-Cargo-300 stay at a particular location.

3.6.1 Campaign Science Objectives

The science objectives of this campaign could be described as being broad but not deep. They are broad because the campaign involves three 30-sol missions to widely separated parts of the martian surface that will provide information on a variety of different scientific questions of interest to all four of the subpanels. They are not as deep, however, as the questions addressed by some of the other representative campaigns that involve one

NOTE: DNA, deoxyribonucleic acid; ISRU, in situ resource utilization; RNA, ribonucleic acid.

during different missions. Additional science objectives that are specific to this campaign but that are not among the 11 prioritized science objectives shown in Table 3-1 are also noted.

Mission 1: Igneous and Impact Melt Geology

1. Constrain the geochronology of the martian cratering record by dating igneous rocks and impact melts at a variety of different sites.

Because it visits different spots, this campaign is ideally suited for establishing the chronology of the martian cratering record, something that has heretofore been accomplished previously only by analogy with the lunar cratering record. The lunar analogy, while credible, might fail if the numbers of planetesimals at Earth’s and Mars’s orbital distances decreased at different rates. Bringing back samples of igneous rocks and impact melts from close to the landing site on the very first mission will allow researchers to test the lunar analogy at one location on Mars’s surface. The landing site for this first mission will be optimized for this purpose. If the landing sites for the next two missions contain igneous rocks, it may be possible to further constrain the cratering timescale by obtaining samples of different ages.

2. Characterize igneous systems within the exploration zone to determine planet formation, differentiation, and volcanic history.

The same igneous rocks that allow accurate dating will provide a host of other useful information regarding the planet’s early history. Mars is a small planet that stopped growing well before its larger counterparts in the inner solar system. Parts of its surface have also been preserved for much longer than on Earth, so it can provide fresh insight into processes like core formation that occur early in a planet’s history.

Mission 2: Sedimentary Rocks for Evidence of Ancient Life and/or Prebiotic Processes

1. Determine if evidence can be found for extant or extinct life at the landing site.

This mission will visit a region hosting ancient sedimentary rocks, similar to the Gale Crater and Jezero Crater being explored by the Curiosity and Perseverance rovers. These rocks can be analyzed using a variety of different techniques (e.g., optical imaging, chemical and isotopic analysis) to look for evidence of extinct life. The focus here is on extinct life, not extant life, because these rocks have been exposed to a cold, dry, high-radiation environment for millions of years and hence are not likely to host viable organisms, even if life did arise on Mars at one time.

2. Characterize the rock record within the exploration zone to understand environmental changes over Mars’s history.

Sedimentary rocks also contain a record of surface processes and climate change and hence can be used to learn about Mars’s environmental history over millions to billions of years. Where possible, this stratigraphy can be correlated with crater counts using the information gleaned from Mission 1. Sedimentary rocks may contain time-sensitive phases that offer insights into the climate history of Mars, including the timing of the transition from a wetter to a drier environment.

3. Determine the present-day atmospheric isotopic and elemental composition and its sources and sinks.

This has been a goal of several past lander and rover missions, beginning with Viking in 1976 and including the Curiosity rover, which has been active on Mars since 2012. One of the goals of both missions is to measure the abundance and isotopic ratios of noble gases, which can provide information on atmospheric formation and

• Determine throughout the mission whether or not microbial population dynamics and species distribution in biological systems and habitable volumes are stable and are not detrimental to astronaut health and performance.

Most of the monitoring of microbial populations will occur during the two long cruise phases of these missions; however, these activities will continue while the astronauts are on the planet’s surface.

• Determine the longitudinal impact of the integrated martian environment on crew physiological, cognitive, and emotional health, including team dynamics.

As noted, the crew members will spend most of their time in space, not on the planet’s surface. So, any study of the effects of the integrated martian environment on crew health and behavior would focus on early adaptation to the martian environment.

• Characterize the primary and secondary radiation at key locations in the crew habitat and astrobiological sampling sites to contextualize sample collection and improve models of future mission risk.

3.6.2 Notional Architecture

The 30-30-30 campaign is different in nature from the 30-Cargo-300 campaigns in that it does not involve long-duration stays on Mars’s surface. In that sense, it is less risky but also less ambitious than the other campaigns outlined in this document. To think of it another way, it is more like the 1969–1972 Apollo missions to the Moon, except that the in-flight travel times are much longer. The stay times on Mars’s surface are also an order of magnitude longer than on the Apollo missions but comparable to planned Artemis missions to the Moon.

Landing Site Requirements

These are described above in Section 3.6.1, “Campaign Science Objectives.”

Crew Role

Given the high density of science folded into just 30 sols per landing, a crew large enough to support multiple science operations simultaneously would be optimal. With NASA’s standard assumption of a buddy system, this drives a minimum of a six-person crew focused on this campaign, with the need for larger crew complements evaluated as operations and automation are refined and prototyped.

3.6.3 Strengths and Weaknesses of the Campaign Design

Strengths

• This strategy maximizes the number of different locales that can be investigated in a three-mission campaign. It thus addresses science objectives from all four of the disciplinary subpanels.
• The cadence of this campaign would create a high level of excitement and possible unexpected findings that propel the future engagement of the interested community and the resources needed for the next segments.
• This campaign will arguably do the best job at establishing the chronology of cratering on Mars. The first landing site is picked specifically for this purpose, and the second and third landing sites may provide additional data points if they are located in regions that have different crater counts than the first mission and if they contain datable rocks.
• Placing seismometers at three widely separated locations on Mars’s surface will maximize the return from seismology, assuming these stations can remain operative after the astronauts have left.
• Likewise, leaving meteorology stations at all three landing sites will allow measurements of atmospheric properties that may be useful in constraining Mars atmospheric circulation models.

Weaknesses

• Some objectives will be addressed, but it may be difficult to do so in an optimal manner. For example, drilling into subsurface ice in Mission 3 will have to be done quickly, limiting both the depth of drilling and the number of different sites that can be studied. Most sample analyses will likely need to be done on Earth because of the limited time available on Mars’s surface.
• The astronauts will have limited ability to react to discoveries made within the first few sols after landing. It is possible to find life on Mars’s surface but not know it until samples are brought back to Earth.
• Given the limited amount of time at each landing site, some science objectives, such as acquiring samples of igneous materials for geochronology, as would be done during Mission 1, might be difficult to achieve during Missions 2 and 3 that focus on other primary objectives. It takes time to identify and acquire adequate samples and characterize their context.

The limited amount of time spent on the surface in each mission will mean that some of the longer-term, BPS/HF objectives will not be able to be achieved. For example, the goal of “studying the longitudinal impact of the integrated martian environment on plant and animal physiology and development across multiple generations where possible as part of an integrated ecosystem of plants, microbes and animals” cannot be accomplished with this architecture. As another example, “A typical, healthy and well-maintained outbred Drosophila population will have a median lifespan of approximately 70 days and maximum of approximately 90 days at 25°C” (Piper and Partridge 2018), which exceeds the proposed surface stay time.

3.6.4 Measurements and Samples

The measurements to be made are quite different for each of the three missions, and so are broken down in that way.

Mission 1

The key measurements for Mission 1 involve sampling of igneous rocks and impact melts for later radiometric dating and elemental and isotopic analysis to study planetary formation and differentiation. Low-precision (K-Ar, Ar-Ar) dating can likely be done in situ with samples larger than 30 mg for the K-Ar system and larger than 2 mg for the Ar-Ar system. High-precision dating using ⁸⁷Rb/⁸⁷Sr ratios will require several kilograms of rocks. The mass spectrometers required to perform these analyses are typically bulky and require carefully maintained climate and dust controls, so these measurements likely will require bringing rock samples back to Earth. In situ analyses of rocks to determine their promise as returned samples may include, at a minimum, abrasion, imaging, and compositional analysis. Planetary formation and differentiation can be studied by measuring other properties of igneous rocks, including their chemistry, petrology, mineralogy, and isotopic composition of many elements, but Nd, W, and Xe, in particular. Several kilograms of rocks need to be returned to Earth to accomplish this task.

Mission 2

The measurements enabled by Mission 2 span a wider variety of techniques. Sedimentary strata can be studied by eye to look for textures such as stromatolites. Multiscale, stereo, and multispectral imaging may also prove to be useful tools. A combination of a Mars compass and a portable 3D camera with mapping capabilities and a zoom, coupled to a data recorder (for continuous recording), would meet this requirement.

Several kilograms of rocks from interesting-looking formations would be returned for detailed chemical and isotopic analyses in laboratories back on Earth, just as in Mission 1. But analysis of air samples—for example, to look for methane—would ideally be done first on Mars to avoid the possibility of contamination or leakage during the trip back to Earth. This would require a sophisticated gas chromatograph/mass spectrometer (GCMS) like the one that is part of the Sample Analysis at Mars instrument package on Curiosity.

As with Mission 1, the astronauts will also look for igneous rock samples to bring back to Earth for radiometric dating to help calibrate the cratering record. This can be facilitated by having more astronauts (at least four) so that they can share these duties. The same initial characterization of samples will need to be performed to ensure that the samples are datable.

Mission 3

This mission has perhaps the most diverse set of measurement requirements of the three missions studied here. A prime objective is to drill as deeply as possible, but at least 2 m, to sample subsurface ice. This will ideally be done at multiple locations near the LS. Measurements would include looking for organic material within the ice or within associated brines. Ideally, some of these measurements would be conducted at the LS to avoid contamination (or melting) during the long return trip to Earth.

A completely different set of measurements will be required to study dust lofting near the LS. Sampling the regolith and making measurements (e.g., of particle size, shape, and composition) is one step. These measurements can be safely done at laboratories back on Earth. A related set of measurements will be conducted with saltation sensors, meteorology stations, and instruments set up on an approximately 10-m-high meteorological tower for eddy covariance measurements to study turbulence, fluxes, and their relationship to dust lofting. This tower and weather stations would remain in place following the mission, and the instruments would be designed to return data for a full martian year.

Any igneous rocks that can be identified will be brought back to Earth for dating to further calibrate the cratering record.

3.6.5 Key Assets and Major Equipment

Mission 1

Pre-mission mapping will be used to identify the optimal landing site for this mission. This requirement applies to all three missions. No major equipment is needed for this task. Uncrewed rover exploration of possible landing sites could allow for low-resolution K-Ar or Ar-Ar dating, thereby testing whether one or more of them is suitable for a more capable human mission.

Mission 2

A sensitive GCMS instrument will be included to enable analysis of the composition of air samples in real time during the mission.

Mission 3

The key pieces of equipment for this mission are a drill capable of penetrating rock and/or ice to a depth of 2 m or more and a deployable meteorological tower that extends to a height of ~10 m. This tower would be equipped with instruments designed to provide general meteorological data in addition to measurements targeted at understanding the initiation of dust storms.