Spacewalk (EVA) injury & performance
Also: EVA risk
Hostile/Closed EnvironmentGravity FieldsMusculoskeletalEVA & Surface OpsLEO long-durationLunar surfaceMars transit & surfacePublicClinicianResearcher
- Suit-related training injuries are common, but their causes and risk factors are poorly understood. ◆◆◇◇ Low · F E
- For lunar surface missions, NASA rates the operational risk 5×4, requiring mitigation. ◆◆◆◆ High · E
Proposed certainty (◆ High → ◇ Very low) and evidence-type tags: F flight · A analog · M model/animal · C computational · E expert/operational/standards. AI-proposed, pending reviewer confirmation. How to read the grades.
NASA risk title (verbatim)
Risk of Mission Impacting Injury and Compromised Performance and Long-Term Health Effects due to EVA Operations
NASA short title: EVA · HRP element: Human Health Countermeasures (HHC) · Status: Active [current research ongoing] [1]
What it is
This risk covers injury, poor performance and long-term health effects from extravehicular activity (EVA), that is, working in a spacesuit [1].
Current evidence
- Standards cover suit life support and basic function, with metabolic and human-factors data. There is no guidance on preventing suit-induced injury [1].
- Training injury data exist, but the mechanisms and individual risk factors, such as sex, body size and fitness, aren’t understood [1].
- Spacewalk performance in weightlessness is characterized. The physical demands of planetary spacewalks are not [1].
NASA’s risk posture
NASA scores each risk for each design reference mission (DRM) as likelihood × consequence (LxC). Both run from 1 (lowest) to 5 (highest) on the HSRB’s 5×5 matrix [1][3]. Each score comes with a disposition, such as “Accepted”, “Requires Characterization” or “Requires Mitigation”. These ratings were last approved by NASA’s Human System Risk Board (HSRB) in 12/2023 [1].
| Mission | Duration | In-mission (operations) | Long-term health |
|---|---|---|---|
| LEO | Short (under 30 d) | 4x2 · Accepted | 5x2 · Accepted with Optimization |
| LEO | Long (30 d–1 yr) | 4x2 · Accepted | 5x2 · Accepted with Optimization |
| Lunar orbit | Short | 4x3 · Accepted with Optimization | 5x2 · Accepted with Optimization |
| Lunar orbit | Long | 4x3 · Accepted with Optimization | 5x2 · Accepted with Optimization |
| Lunar orbit + surface | Short | 5x4 · Requires Mitigation | 5x2 · Accepted with Optimization |
| Lunar orbit + surface | Long | 5x4 · Requires Mitigation | 5x2 · Accepted with Optimization |
| Mars preparatory | Under 1 yr | 4x3 · Accepted with Optimization | 5x2 · Accepted with Optimization |
| Mars planetary | 730–1,224 d | 5x4 · Requires Mitigation | 5x2 · Accepted with Optimization |
NASA rates the long-term health likelihood high (5×2) for every mission type [1].
Copied from the Human Research Roadmap on 2026-10-14. Ratings change. Check the live record before citing.
Open knowledge gaps
NASA lists 7 knowledge gaps for this risk, 7 of them open as of 2026-10-14 [1]. Each gap ID links to its page on the Human Research Roadmap (HRR).
Show NASA’s gap list (verbatim)
| Gap | NASA gap statement | Status |
|---|---|---|
| EVA-101 | Characterize EVA preparedness shortly post-landing on a planetary surface. | Open |
| EVA-102 | Characterize surface EVA performance during exploration missions in partial gravity environments | Open |
| EVA-201 | Characterize impacts of variable atmospheric conditions on human health and performance, including exploration atmospheres, variable pressure suits, and alternate prebreathe strategies. | Open |
| EVA-301 | Identify and test countermeasures related to spatial disorientation and motion sickness to enable early EVA’s post g-transition. | Open |
| EVA-302 | Identify and test countermeasures to any physiological decrements associated with increased planetary EVA cadence (ie, exercise and nutrition) | Open |
| EVA-303 | Identify and test countermeasures related to exposure to variable atmospheric conditions | Open |
| EVA-401 | Validate integrated EVA performance countermeasures related to optimizing physiological performance and minimizing DCS risk | Open |
See also Open questions.
Active countermeasure research
- Characterization. NASA is studying spacewalk readiness and performance across gravity transitions, physical and cognitive fitness for high-tempo surface spacewalks, and DCS and hypoxia in low-pressure habitats [1].
- Pre-breathe protocols. Work covers validating and operationalizing pre-breathe protocols for lower-pressure habitats and higher-pressure suits (gaps EVA-101 to EVA-401) [1].
Project-level detail, including status, investigators and results, is in the NASA Task Book and on each HRR gap page.
Clinical articles
For practical, clinic-facing guidance, see:
Evidence profile
- Overall certainty
- ◆◆◇◇ Low (proposed)
- Evidence types
- F · Flight dataE · Expert / operational / standards
- Literature through
- 2026-10-14
- NASA source
- Human Research Roadmap risk page (last published 05/13/25; read 2026-10-14)
Requirements referenced 2
| Requirement | Title | Plain-language meaning |
|---|---|---|
| [V1 4001]–[V1 4002] | EVA Aerobic Capacity | Minimum VO2max for microgravity and surface EVAs. |
| [V1 6006] | EVA Medical Clearance | Every crewmember medically cleared by ground medical support before each EVA. |
IDs as published in NASA-STD-3001 Vol. 1 Rev C (2023-09-15) and NASA-STD-3001 Vol. 2 Rev F (2026-07-14). NASA-STD-3001 binds NASA programs; it is not a regulation for commercial flights. Paraphrased. Standards quick reference.
References 3
- NASA Human Research Roadmap. Risk record: “Risk of Mission Impacting Injury and Compromised Performance and Long-Term Health Effects due to EVA Operations”. Accessed 2026-10-14. humanresearchroadmap.nasa.gov/Risks/?i=84 NASA E
- NASA Human Research Program. Evidence report for the EVA risk (2023). humanresearchroadmap.nasa.gov/evidence/other/EVA%20Injury%20… NASA E
- Antonsen EL, et al. Updates to the NASA human system risk management process for space exploration. NPJ Microgravity. 2023;9:72. doi:10.1038/s41526-023-00305-z PMID:37679359 Peer-reviewed E
Machine-checked on 2026-10-14: each URL resolved, each DOI's title/journal/year matched via Crossref, and claims were checked against the source text (abstract or full NASA page). Human verification against full text is still required before review. NASA documents are U.S. Government works (public domain) and are summarized with attribution; journal articles are summarized, not reproduced.
Article info
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- Pending (AI-assisted draft)
- Reviewer
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- Last reviewed
- Pending review
- Literature through
- 2026-10-14
- AI-assisted
- Yes (disclosed)
- COI
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- License
- CC BY-SA 4.0
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- Cite this version
- Pending first edition