Planetary extravehicular activity (EVA) risk mitigation strategies for long-duration space missions

Abstract

Extravehicular activity (EVA) is one of the most dangerous activities of human space exploration. To ensure astronaut safety and mission success, it is imperative to identify and mitigate the inherent risks and challenges associated with EVAs. As we continue to explore beyond low earth orbit and embark on missions back to the Moon and onward to Mars, it becomes critical to reassess EVA risks in the context of a planetary surface, rather than in microgravity. This review addresses the primary risks associated with EVAs and identifies strategies that could be implemented to mitigate those risks during planetary surface exploration. Recent findings within the context of spacesuit design, Concept of Operations (CONOPS), and lessons learned from analog research sites are summarized, and how their application could pave the way for future long-duration space missions is discussed. In this context, we divided EVA risk mitigation strategies into two main categories: (1) spacesuit design and (2) CONOPS. Spacesuit design considerations include hypercapnia prevention, thermal regulation and humidity control, nutrition, hydration, waste management, health and fitness, decompression sickness, radiation shielding, and dust mitigation. Operational strategies discussed include astronaut fatigue and psychological stressors, communication delays, and the use of augmented reality/virtual reality technologies. Although there have been significant advances in EVA performance, further research and development are still warranted to enable safer and more efficient surface exploration activities in the upcoming future.

Retrospective analysis of somatic mutations and clonal hematopoiesis in astronauts

“…Additionally, astronauts within the studied cohort embarked on EVAs during their Shuttle mission which also modifies degree of stressor exposure. While most EVAs are scheduled around solar activity, most galactic cosmic rays (GCRs) are unpredictable, and spacesuit radiation shielding alone may not be enough to mitigate radiation exposure and its associated risks 32 . Considering cancer patients receiving external beam radiation therapy exhibit pronounced CH mutations in DDR genes ( TP53, CHEK2, PPM1D ) along with faster clone growth following cumulative exposure 33 , it can be postulated that exposure to space IR may alter the fitness landscape of observed CH mutations and warrants further investigation.…”

Wide Range Applications of Spirulina: From Earth to Space Missions

“…Space environments expose astronauts to a high level of oxidative stress due to extravehicular and intravehicular activities (EVA/IVA) and depend on reduced gravity, ionizing radiation, and variable atmospheric conditions, such as hyper- and hypoxia and psychophysical stress [ 166 , 167 , 168 , 169 ]. In addition, several studies show how astronauts experience immunodeficiency with impairment of NK cells, redox imbalance, elevated inflammation, elevated granulocytes, inhibited lymphocyte proliferation, and reduced lymphocyte functions, as well as elevated inflammation during low-Earth orbit missions [ 170 , 171 , 172 , 173 , 174 ].…”

Addressing disaster and health risks for sustainable outer space

“…Planetary EVAs expose astronauts to extreme risks to health, including high-doses of solar radiation, limitations on fluid and nutritional intake, and reliance on life-support systems (Chappell et al, 2017). Analogue missions enable the testing of spacesuits and the rehearsal of space mission designs and protocols to mitigate risks to astronaut health during EVAs (Belobrajdic et al, 2021). Such research makes valuable contributions to health risk reduction for astronauts, including those travelling to Mars (Payler et al, 2019).…”