# Fifteen astronauts and mission experts mapped the mental skills needed for lunar spacewalks and the failures most likely to put a surface crew at risk

> Astronauts walking across the Moon will face an invisible challenge inside their helmets. Every step may require them to watch their oxygen supply, judge the ground ahead, remember procedures, communicate with Mission Control and keep working while wearing a stiff and physically...

Canonical URL: https://www.argo.net/fifteen-astronauts-and-mission-experts-mapped-the-mental-skills-needed-for-lunar-spacewalks-and-the-failures-most-likely-to-put-a-surface-crew-at-risk/
Byline: ARGO.net Editorial Team
Published: 2026-08-22T06:30:03+00:00
Categories: Explainer, Space

![Astronaut in spacesuit climbing ladder inside a dark setting](https://www.argo.net/wp-content/uploads/2026/08/astronaut_lunar_spacewalk.jpg)

Astronauts walking across the Moon will face an invisible challenge inside their helmets. Every step may require them to watch their oxygen supply, judge the ground ahead, remember procedures, communicate with Mission Control and keep working while wearing a stiff and physically demanding spacesuit.

A peer-reviewed [study in npj Microgravity](https://www.nature.com/articles/s41526-025-00545-1) has mapped the mental abilities needed for future **surface EVA**, the term NASA uses for work performed outside a lander or habitat. Researchers connected with the **NASA Johnson Space Center** interviewed 15 people with experience in astronaut operations, EVA research and spaceflight.

The results identify navigation, preparation procedures, maintenance work and geological sampling as major sources of mental strain. The study also examines how fatigue, difficult lighting, physical effort, emergencies and delays in voice communication could affect crew safety during future Moon missions.

## Surface spacewalks place heavy demands on the brain

Working on another world asks an astronaut to combine movement with constant judgment. A crew member may need to follow a route across uneven ground while checking life-support supplies and listening to instructions. Scientific work continues at the same time, including describing rocks accurately enough for researchers on Earth to understand what the astronaut sees.

The paper's abstract states, "Surface extravehicular activity (EVA) is one of the most cognitively demanding actions that astronauts can execute." The demands come from the number of tasks competing for attention and from the serious consequences of missed information. A navigation mistake could consume extra oxygen, while a skipped spacesuit step could place the crew in immediate danger.

Researchers used a **cognitive task analysis**, a method that breaks complicated work into its smaller actions and identifies the knowledge and mental abilities behind each one. The approach allowed experts to discuss normal surface operations as well as failures that would force astronauts to make decisions under pressure.

## NASA experts rank the hardest EVA tasks

The study included four astronauts, five experts in EVA operations and six EVA researchers. Together, they brought experience from the International Space Station and from training systems that reproduce parts of a spacewalk. Such systems included NASA's Neutral Buoyancy Laboratory, virtual reality environments and the Active Response Gravity Offload System, which can simulate reduced gravity.

Across the group, the experts averaged 7.5 years of EVA-related experience. The astronauts had accumulated a combined 71 hours and 33 minutes of spacewalk time outside the International Space Station. Their backgrounds gave the researchers several views of the same work, including firsthand spaceflight experience and the planning required on the ground.

Experts ranked preparation and post-EVA operations most often as the task with the highest mental demand. Sample identification followed, while inspection and maintenance also received high rankings. A NASA [technical presentation](https://ntrs.nasa.gov/api/citations/20240012797/downloads/CTA%20Results_pubpressapproved.pdf) records the study's broader findings, including concerns about communication delays and emergency operations.

## Navigation carries the highest overall workload

When researchers combined the ratings across all 15 experts, **lunar traverse** received the highest average cognitive demand score, 72.4 on a scale running from low demand at zero to high demand at 100. EVA preparation and post-operation work averaged 61. Surface mobility, maintenance and lunar soil collection followed closely behind.

Different professional groups emphasized different challenges. Astronauts rated sample identification as their most mentally demanding parent task. EVA operations specialists gave their highest score to payload operations, while EVA researchers placed traverse at the top. The variation suggests that experience and job responsibilities influence which risks each person notices most strongly.

Navigation on the Moon may be especially difficult near the lunar south pole, where the Sun can sit low over the horizon. Bright ground and deep shadows can appear side by side, hiding rocks and changes in slope. Large areas may also look alike, giving astronauts few clear landmarks. Experts interviewed for the study warned, "Getting lost on the Moon is a life-threatening scenario."

## Darkness and suit checks raise the pressure

Several smaller tasks received even higher scores than the broad EVA categories. Solo spacesuit checks and procedures averaged 92.5. Prebreathing, which helps remove nitrogen from the body before a spacewalk, received a score of 90. Depressurizing or repressurizing the airlock also received a rating of 90 from the expert who assessed it.

Traversing in darkness averaged 90, showing how strongly poor visibility can increase mental workload. An astronaut must read the landscape while remaining aware of slopes, craters and rocks. A shadow may hide a hazard until the crew member is close to it, leaving less time to change direction.

Geological description averaged 88.3. During this work, an astronaut has to recognize subtle differences between samples, remember scientific terms and explain each observation over the radio. Life-support monitoring and navigation continue in the background, so the astronaut must move attention between science and safety without losing track of either.

## The mental skills behind a lunar traverse

Researchers linked the hardest activities to specific brain functions. Traverse requires **executive function**, which helps people plan, solve problems and choose between possible actions. It also depends on mental flexibility, allowing an astronaut to revise a route when a crater, equipment issue, or other unexpected condition changes the plan.

**Working memory** keeps a small amount of useful information available for immediate use. During a traverse, it could help an astronaut remember the next waypoint while checking a map and listening to Mission Control. Vigilant attention supports the steady monitoring of suit readings and the surrounding terrain over long periods.

Visual and spatial processing helps the crew judge direction, distance and slope. Language skills are needed for scientific descriptions and clear radio reports. The body also depends on motor control to move in a pressurized suit, handle tools and keep balance in reduced gravity. Several brain systems therefore contribute to a single walk across the lunar surface.

## Physical effort drains attention

Surface EVA can place a heavy load on the body. Walking in a spacesuit, climbing a slope, or pushing equipment requires energy and discomfort may pull attention away from the mission. Experts described situations in which astronauts could spend part of their limited mental capacity managing pain, pressure points, or overheating.

High physical workload can weaken **situational awareness**, the crew member's active picture of what is happening around them. Poor sleep can add another layer of strain. Fatigue may reduce attention to details during suit preparation, life-support checks and dust removal after an EVA.

A NASA [preliminary assessment](https://ntrs.nasa.gov/citations/20220015784) has also examined cognition and fatigue during simulated lunar EVAs. The small early study found limited changes in its selected cognitive tests, while the newer task analysis identifies situations where mental demand may become much higher. More simulations can help researchers measure how workload changes as tasks become longer or more complicated.

## A rescue scenario tests critical decisions

The researchers asked experts to consider an **incapacitated crew rescue** two kilometers from a lunar lander. One astronaut had injured their back during field geology and could no longer walk. Their partner had to evaluate the injury, contact Mission Control, prepare a transport device, secure the injured astronaut and select a safe return route.

Each stage created opportunities for error. The rescuing astronaut might underestimate pain or overlook a suit puncture. They could select the wrong checklist, leave important equipment behind, or place the transport device on unstable ground. A poorly secured crew member could suffer further injury during the journey.

The return traverse added a difficult set of moving conditions. Oxygen and other consumables could be used faster because the astronaut was pulling or pushing extra weight. A route that appeared short might cross a hidden slope. Regular stopping points would allow the rescuer to check location, life-support readings and the injured astronaut's condition.

The scenario illustrates how emergencies concentrate many mental demands into a short period. Training may provide less automatic "muscle memory" for rare events, so crews need procedures that remain clear during fatigue and stress.

## Communication delays add to the strain

Experts also considered a five to 12 second **lunar communication delay** during future Artemis operations. Delayed replies could lead people to repeat messages or speak over one another. Frustration may rise as astronauts wait for confirmation during a time-sensitive problem.

Mission Control also needs an accurate picture of conditions at the worksite. An astronaut who gives too little detail may leave ground teams unaware of a hazard. Excessive detail can occupy valuable radio time and increase the amount of information everyone must process. Shift changes on Earth may add further difficulty if incoming controllers lack part of the recent context.

The NASA-hosted [conference paper](https://ntrs.nasa.gov/api/citations/20240012742/downloads/CTA_Manuscript_final.pdf) describes expert concerns about delayed lunar voice links. Participants recommended clear rules for ending transmissions and consistent procedure words such as "over" and "copy." Rehearsing those habits during ground simulations could make radio exchanges easier to follow.

## Training and displays could reduce workload

Extensive **pre-mission training** gives astronauts more practice with normal work and rare emergencies. Well-designed procedures can also help crews find the correct step quickly. Experts suggested digital checklists that clearly mark the current action, reducing the need to search through several pages while wearing gloves.

Team composition has an important role. Partners who understand each other's communication and working styles can share mental tasks. One astronaut might focus on the route while another tracks consumables and mission time. Clear division of responsibility can prevent both crew members from concentrating on the same detail while another warning goes unnoticed.

Researchers have also examined [multimodal displays](https://pubmed.ncbi.nlm.nih.gov/36757234/) that present information through more than one channel, such as visual signals combined with sound. Carefully selected alerts could direct attention toward a suit warning or navigation cue. Poorly timed information could add distraction, so display designs will need testing in realistic surface simulations.

The study offers a foundation for measuring cognitive performance during future EVA training. Its results come from expert interviews and ratings, while future simulation data can test how these judgments relate to measurable errors, response times and physical strain. Such work can guide NASA standards, crew preparation and equipment design before astronauts begin extended exploration on the Moon.