How Could the APEX Suite Improve Research on Astronaut Teams?

Key Takeaways

• APEX combines psychological surveys, performance tests, and physiological measurements.
• Consistent measurement can make small astronaut and analog studies more useful together.
• Research findings require further validation before becoming operational decision rules.

The APEX Suite Addresses a Small-Sample Problem

A study describing the Assessment of Psychology in Extreme Environments (APEX) suite drew on 119 participants across 38 teams in spaceflight and terrestrial mission simulations. Data collection extended from April 2017 through September 2025, giving the researchers experience with both actual orbital missions and controlled periods of isolation on Earth.

The APEX research paper, led by Suzanne T. Bell and colleagues, appeared online on July 25, 2026. Its assignment to a 2027 volume of Acta Astronautica does not change that earlier availability. The distinction matters because the work describes a measurement framework already available for research use, rather than a study awaiting publication in a future year.

APEX responds to an enduring limitation in human spaceflight research: few people experience the conditions being studied. A terrestrial experiment might recruit hundreds of participants within months. A spaceflight investigation can require years to obtain a much smaller sample, with each participant experiencing a different combination of duties and environmental conditions.

Ground-based simulations expand the available evidence, but they introduce another difficulty. Findings become hard to compare when research teams use different questionnaires, scoring systems, or measurement schedules. Two studies can investigate fatigue without measuring precisely the same thing. A third might record a related concept, such as perceived workload, and describe it as fatigue.

Standardization can reduce this fragmentation. If multiple investigations use compatible measures and document how they administer them, their results can support broader comparisons. That does not make dissimilar environments interchangeable. It creates a more consistent basis for examining their similarities and differences.

The paper describes 18 measures grouped into six domains. These cover individual characteristics, behavioral health, interpersonal relationships, team functioning, objective performance, and physiological measurements. APEX is intended as a framework researchers can adapt, rather than a requirement to administer every measure during every mission.

Its central contribution is methodological. The suite does not establish that astronaut teams will experience a particular psychological outcome, and it does not offer a universal test of mission readiness. It gives researchers a shared set of instruments for studying how people respond to demanding conditions over time.

This approach connects with the broader field of spaceflight human factors, which examines how human capabilities interact with equipment and operating procedures. In that field, reliable measurement determines whether an apparent improvement reflects a useful intervention, an easier task, or a difference between the people being studied.

Different Measurements Answer Different Questions

A questionnaire, a cognitive test, and a wearable monitor can describe different parts of the same experience. APEX combines these approaches because no single instrument provides a complete account of how an individual or team is functioning.

Self-report measures record experiences that external observation may miss. Participants can describe their perceived stress or the support they receive from teammates. These accounts provide information about daily life inside a confined setting, including difficulties that may not immediately affect task completion.

Performance tests address another question. They measure what a participant can accomplish under specified conditions, rather than relying entirely on the participant’s assessment of that ability. Someone may report feeling tired yet perform consistently on a test. Another person may feel capable despite a measurable decline in attention.

Physiological instruments add observations about the body. APEX includes actigraphy, which uses movement measurements to estimate sleep and activity patterns, together with electrocardiographic monitoring of heart activity. These measurements can help researchers examine relationships between physical state and reported experience.

Interpretation requires care. Movement-based sleep estimates do not provide the same information as a full laboratory sleep assessment. Heart-rate patterns also reflect more than psychological stress. Physical activity and other conditions can affect the measurements, so physiological data need to be interpreted alongside mission records and other evidence.

The suite’s individual-difference measures help characterize the participants themselves. Background information can reveal differences in prior experience, and personality measures can support investigations of how people contribute to team composition. Such information is useful for explaining results without treating every difference between teams as an effect of the mission environment.

Behavioral-health measures include established instruments for depressive symptoms and mood. Their inclusion does not turn the entire suite into a clinical diagnostic system. Research measures can identify patterns that deserve further investigation, but diagnosis and care require appropriate professional assessment.

APEX also distinguishes relationships between individuals from processes involving the whole team. Social support concerns the assistance a person perceives as available. Team coordination concerns how members organize their work together. These concepts can influence one another without being equivalent.

The practical value of this separation is analytical precision. A study can investigate whether workload changes accompany poorer sleep without assuming that every change represents a general decline in wellbeing. It can also examine whether a team maintains task performance despite changes in its social relationships.

Living Together Adds Demands Beyond Working Together

APEX includes group living skills because a spacecraft crew shares a home as well as a workplace. Members cannot routinely leave at the end of a shift, select different colleagues, or separate an unresolved disagreement from the place where they eat and rest.

The paper treats these conditions as distinct from conventional teamwork. Operational competence remains necessary, but daily conduct can also affect whether a confined group functions well. Shared spaces and overlapping schedules create repeated contact between people whose preferences may differ.

The Group Living Skills Survey addresses this aspect of prolonged cohabitation. Its purpose is to examine behavior associated with living effectively alongside others, rather than to replace measures of professional performance. A person’s technical expertise and their contribution to shared living conditions are separate dimensions.

APEX also includes measures of conflict and perceived social support. These can help researchers investigate whether relationships change during a mission and whether support from outside the habitat differs from support provided by fellow crew members. The distinction becomes relevant when communication with family or mission support is restricted.

Team cohesion measures examine the group’s sense of connection. Psychological safety concerns whether members believe they can raise concerns or acknowledge mistakes without inappropriate interpersonal consequences. High cohesion does not automatically establish psychological safety, because a closely connected group can still discourage disagreement.

That distinction has operational implications. A crew may appear harmonious because problems are resolved constructively, or because members avoid discussing them. Survey responses need to be interpreted alongside the tasks being performed and the opportunities participants have to communicate.

Team viability provides another perspective by examining whether members see the group as capable of continuing together. A team can complete a demanding assignment yet become less willing to work together afterward. Performance during a single task may conceal a cost that becomes more visible during a longer mission.

Research on astronaut mental health often focuses on individual adaptation. APEX adds a structured way to study the relationships that shape adaptation. It permits analysis at the level of the individual and, where the design supports it, at the level of the team.

The paper does not establish a personality formula for an ideal crew. Team outcomes depend on the assignment and the operating conditions as well as the people involved. A measurement framework can help identify relevant relationships, but it cannot remove the need to study those relationships within specific mission designs.

Analog Missions Expand Evidence Without Reproducing Spaceflight

The APEX development work included the National Aeronautics and Space Administration’s Human Exploration Research Analog (HERA), a habitat used to study isolation and confinement. It also included the Scientific International Research In a Unique terrestrial Station (SIRIUS) program and the International Space Station (ISS).

These settings supplied different kinds of evidence. HERA campaigns in the paper involved 45-day missions with four-person crews. The SIRIUS campaigns included longer periods of confinement, and the ISS data introduced experience from actual spaceflight. The resulting dataset was broader than a single laboratory experiment.

Their differences remain important. An Earth-based habitat can restrict contact with the outside world, but participants remain within an environment where emergency assistance is physically accessible. It also retains Earth’s gravity. Orbital crews experience conditions that a terrestrial facility cannot reproduce in full.

Even studies within one facility can differ. Participants may face different schedules or research requirements, and the conditions imposed during a campaign can change the interpretation of the results. Combining data without preserving those distinctions would weaken the benefit of standardized instruments.

The paper reports that 61% of its participants were male and that 95% held advanced degrees. Their average age was about 41. These characteristics describe a selected population with substantial education, rather than a representative sample of the general public.

Selection is appropriate for many astronaut-related research questions, but it limits broader claims. A measure that performs well among highly trained volunteers may behave differently in another population. Differences in language and cultural expectations can also affect how participants interpret survey items.

NASA’s standard-measures work similarly emphasizes collecting compatible observations before, during, and after missions. That wider effort provides an institutional setting for research that can accumulate across campaigns rather than remaining confined to individual experiments. (ntrs.nasa.gov)

The history of analog missions demonstrates why multiple environments are useful. Each can isolate some conditions more effectively than others. APEX supplies measurement consistency, but the research design must still identify which aspects of a mission an analog represents.

Comparability does not require pretending that HERA and the ISS are equivalent. It requires documenting their differences clearly enough to examine whether a relationship persists across settings. A finding repeated under distinct conditions can provide stronger support than an isolated result, provided the analysis respects how the observations were obtained.

Participant Burden Affects the Quality of Research

Every measurement occupies time or attention. In a mission simulation, research tasks compete with operational assignments and personal activities. In spaceflight, that competition can be more restrictive because crew schedules already include extensive mission work.

APEX addresses this problem by combining relatively brief measures with longer performance assessments. The paper lists some surveys that take less than a minute, but the Cognition battery requires about 30 minutes and the Robotic On-Board Trainer for Research about 45 minutes. Describing the suite as brief does not mean that administering all its components is a trivial commitment.

The timing of measurements matters as much as their duration. A personality assessment may not need frequent repetition. A measure of sleep or current workload may require repeated observations to capture meaningful changes. Applying one schedule to every instrument can produce unnecessary burden or miss short-lived effects.

Participants also evaluated the acceptability of the instruments. In the reported HERA campaigns, actigraphy and the objective performance measures received relatively favorable ratings. Surveys received more moderate ratings, with comments pointing to fatigue or unclear instructions.

Electrocardiographic monitoring received the lowest average acceptability rating among the listed instrument types. Some participants reported skin irritation at electrode sites. The research team used feedback to refine implementation, including practical steps to reduce discomfort.

These observations connect measurement design to data quality. A demanding questionnaire can encourage rushed responses. An uncomfortable sensor may be worn inconsistently. An instrument that works well under laboratory supervision may produce a less complete record during a busy mission.

The paper discusses careless responding and social-desirability bias. Careless responding occurs when answers do not reflect attention to the questions. Social-desirability bias arises when participants present themselves or their team more favorably than their experience warrants.

Highly selected participants may feel pressure to appear capable or cooperative. That possibility does not mean their responses are unreliable by default. It means researchers need procedures for detecting response patterns that could distort the findings.

A consistent measurement schedule also needs a record of deviations. Missed assessments during a demanding mission period may contain information about workload, rather than representing random gaps. Treating every missing observation as equivalent can obscure a relationship between the conditions being studied and the ability to collect data.

Research Instruments Are Not Automatic Mission Decisions

The APEX paper discusses possible operational uses, including feedback to crews and information for mission-support personnel. Those possibilities require a further step beyond demonstrating that an instrument can collect useful research data.

An operational system must establish what a result means for a decision. A changing score might justify another assessment, a conversation with a qualified professional, or a review of scheduling. The appropriate response depends on the measure and the surrounding circumstances.

The paper does not validate a single threshold that determines whether someone should continue a mission. Nor does it establish a universal score that predicts team failure. Such claims would go beyond the evidence presented.

Repeated measurements may help reveal a person’s pattern over time, but repeated testing also introduces complications. Participants can improve through familiarity with a task. Researchers need to distinguish practice effects from changes associated with mission conditions.

Baseline measurements have similar limits. An observation recorded before departure may be influenced by preparation demands or anticipation. It provides a comparison point, but it should not automatically be treated as a perfectly stable measure of ordinary functioning.

Privacy becomes more consequential when research data enter operational use. Information about perceived conflict or depressive symptoms can affect relationships and professional decisions. Clear rules about access and purpose are necessary if participants are to understand how their responses will be used.

Data sharing also needs to account for the small size of astronaut populations. Removing a name may not prevent identification when a record includes a distinctive mission and professional background. The analytical value of combining datasets must be considered alongside those identification risks.

The suite currently lacks an objective team-performance measure, a limitation the authors identify. Individual cognitive tests and ratings of team behavior provide useful evidence, but they do not directly measure every aspect of coordinated group performance. This gap limits claims about how comprehensively the suite captures team effectiveness.

The wider discussion of human research planning shows why such distinctions matter. A promising research instrument becomes operationally useful only after its interpretation, implementation, and consequences have been assessed for the mission where it will be used.

Shared Measures Could Strengthen a Broader Research Network

APEX was developed using spaceflight and spaceflight-analog data, but the authors describe potential relevance to other demanding environments. Polar expeditions and remote operational teams share some conditions with space crews, including restricted living space or limited access to outside support.

Transfer between settings should be tested rather than assumed. A research station and a spacecraft can both involve confinement, yet their personnel structures and mission tasks differ. The same questionnaire may remain useful, but the meaning of a score can depend on the setting.

The potential benefit comes from building compatible evidence across research programs. Shared measures can make it easier to investigate which findings appear repeatedly and which are specific to a particular environment. That distinction can guide the development of countermeasures without requiring every program to begin with unrelated instruments.

A common suite also helps research sponsors. When multiple studies collect compatible observations, funding can produce a dataset that supports questions beyond the original experiment. The value depends on documentation and appropriate permissions, rather than on collecting as many measurements as possible.

For commercial human spaceflight, the implications are indirect but relevant. Companies developing crewed vehicles or habitats need evidence about workload and team functioning. Standardized research may support that evidence base, but APEX should not be presented as an existing commercial certification standard.

There is also a workforce dimension. Researchers need training in administration and interpretation, and mission planners need to understand what the measures can establish. Consistency cannot be achieved through a questionnaire title alone if the implementation differs substantially between programs.

The broader mental-health space economy includes research services and support capabilities. APEX contributes a scientific framework relevant to those activities, rather than a forecast of their commercial size or a claim that a particular business model will succeed.

The authors leave room to refine the suite and introduce additional measures. This flexibility is useful, but changes require version control. A shorter questionnaire can reduce burden yet alter comparability with earlier data, so revisions need evidence and clear documentation.

Long-term usefulness will depend on that balance between consistency and improvement. A framework that never changes can preserve weaknesses. One that changes without a documented relationship to earlier versions can fragment the evidence it was created to connect.

Summary

APEX’s most consequential contribution may be its treatment of measurement as shared research infrastructure. The suite organizes instruments that can help investigators compare behavior and performance across scarce opportunities to study people living and working in demanding environments.

Its usefulness will depend on decisions made after publication. Research programs must preserve implementation details, assess whether measures remain appropriate, and protect participants when datasets are shared. Operational adoption requires separate evidence about how results should influence action.

The framework also changes how progress can be evaluated. A successful investigation need not produce a dramatic finding about astronaut psychology to contribute useful knowledge. Consistent observations from a small team can become more informative when later studies measure the same concepts under clearly documented conditions.

Appendix: Useful Books Available on Amazon

• Space Psychology and Psychiatry
• Psychology of Space Exploration: Contemporary Research in Historical Perspective
• On Orbit and Beyond: Psychological Perspectives on Human Spaceflight
• Psychology and Human Performance in Space Programs: Extreme Application
• Packing for Mars: The Curious Science of Life in the Void

Appendix: Top Questions Answered in This Article

What is the APEX suite?

APEX is a collection of psychological surveys, performance tests, and physiological measurements for studying people in demanding environments. It covers individual and team functioning. The framework supports comparable research across missions without requiring every study to administer every available instrument.

How many measures does APEX include?

The published suite contains 18 measures organized into six domains. These address individual differences, behavioral health, interpersonal relationships, team dynamics, objective performance, and physiological measurements. Researchers can select appropriate components according to their questions and the practical constraints of a mission.

Who participated in its development studies?

The paper describes 119 participants across 38 teams in spaceflight and terrestrial analog settings. Data collection extended from April 2017 through September 2025. Participants were highly selected and mostly held advanced degrees, which limits direct generalization to broader populations.

Why does standardization matter?

Small studies become more useful together when they measure compatible concepts using documented methods. Standardization supports comparisons across research programs. It does not remove differences between mission environments, so investigators still need to account for participant characteristics and study conditions.

Does APEX diagnose mental illness?

APEX is a research framework, not a universal diagnostic system. Some included instruments measure symptoms relevant to behavioral health. Clinical diagnosis and treatment require appropriate professional evaluation, and the paper does not establish an automatic mission decision based on one score.

Why measure group living skills?

Space crews share living quarters as well as work assignments. Everyday conduct can affect relationships over long periods of confinement. Group living measures examine that dimension separately from technical competence and task performance, helping researchers study conditions that conventional workplace assessments may overlook.

Can terrestrial simulations reproduce spaceflight?

Terrestrial analogs reproduce selected conditions, such as isolation or restricted communication. They do not reproduce every feature of spaceflight. Their scientific value depends on identifying which conditions they represent and interpreting their results alongside evidence from other settings, including orbital missions.

How does participant burden affect results?

Long or repetitive assessments can encourage rushed answers or missed measurements. Sensors can also cause discomfort that affects use. APEX’s development included participant feedback, and its implementation guidance emphasizes matching assessment frequency to the concept being measured and the mission schedule.

Can APEX support operational decisions?

The authors identify possible operational applications, including crew feedback and support monitoring. Those applications require further validation for their intended purpose. A research association alone does not establish which action should follow a result or whether a threshold reliably predicts a mission problem.

Can organizations outside spaceflight use it?

The framework may support research in other isolated or demanding settings. Transfer requires assessment of whether the instruments remain appropriate for the population and work involved. Common conditions can justify comparison, but they do not establish that different operational environments produce equivalent results.

Appendix: Glossary of Key Terms

Analog Mission

An Earth-based activity designed to reproduce selected conditions of a space mission. It allows researchers to study those conditions under controlled circumstances, but its findings require interpretation according to the features it reproduces and those it cannot represent.

Actigraphy

A method that uses a wearable device to record movement over time. Researchers use these measurements to estimate activity and sleep patterns, usually alongside other information because movement alone does not capture every aspect of sleep.

Psychological Safety

A team condition in which members believe they can raise concerns or acknowledge mistakes without inappropriate interpersonal consequences. It concerns the handling of interpersonal risk and should not be treated as equivalent to friendship or agreement.

Social-Desirability Bias

A response tendency in which people present themselves or their group more favorably than their actual experience warrants. It can affect surveys, making careful study design and attention to response patterns important for interpretation.