Abstract
Background: Successful long-duration missions outside low-Earth orbit will depend on technical and physiological challenges under abnormal environmental conditions. Caves, characterized by absence of light, confinement, three-dimensional human movement and long-duration isolation, are identifiably one of the earliest examples of scientific enquiry into space analogs. However, little is known about the holistic human physiological response during cave exploration or prolonged habitation.Objectives: The aim of our review was to conduct a systematic bibliographic research review of the effects of short and prolonged exposure to a cave environment on human physiology, with a view to extend the results to implications for human planetary exploration missions.Methods: A systematic search was conducted following the structured PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for electronic databases.Results: The search retrieved 1,519 studies. There were 50 articles selected for further consideration, of which 31 met our inclusion criteria. Short-term cave exposure studies have investigated visual dysfunction, cardiovascular, endocrine-metabolic, immunologic-hematological and muscular responses in humans. Augmentations of heart rate, muscular damage, initial anticipatory stress reaction and inflammatory responses were reported during caving activity. Prolonged exposure studies mainly investigated whether biological rhythms persist or desist in the absence of standard environmental conditions. Changes were evident in estimated vs. actual rest-activity cycle periods and external desynchronization, body temperature, performance reaction time and heart rate cycles. All studies have shown a marked methodological heterogeneity and lack reproduction under controlled conditions.Conclusions: This review facilitates a further comparison of the proposed physiological impact of a subterranean space analog environment, with existing knowledge in related disciplines pertaining to human operative preparation under challenging environmental conditions. This comprehensive overview should stimulate more reproducible research on this topic and offer the opportunity to advance study design and focus future human research in the cave environment on noteworthy, reproducible projects.
Highlights
RationaleLong duration exploration and future human and robotic planetary surface missions are one of the long-term goals of space agencies (Robinson et al, 2007; Foing, 2016)
Thirteen papers were categorized on the short exposure effects and 18 on prolonged exposure
Changes were evident in estimated vs. actual rest-activity cycle periods and external desynchronization, body temperature, performance reaction time, and heart rate cycles
Summary
RationaleLong duration exploration and future human and robotic planetary surface missions are one of the long-term goals of space agencies (Robinson et al, 2007; Foing, 2016). Preparing for exploration-class missions to other planets requires a close replication of potential environmental and situational characteristics of extreme space conditions. Real world scenarios based in extreme environmental conditions have been adapted to closely replicate the challenges of space exploration. Simulated expeditions have been established in space analog locations around the globe, such as NASA Extreme Environment Mission Operations (NEEMO), Cooperative Adventure for Valuing and Exercising human behavior and performance Skills (ESA CAVES) and Antarctic programs in existing research stations (i.e., Concordia) (Lugg, 2005; Bessone et al, 2013; Anglin and Kring, 2016). Caves, characterized by absence of light, confinement, three-dimensional human movement and long-duration isolation, are identifiably one of the earliest examples of scientific enquiry into space analogs. Little is known about the holistic human physiological response during cave exploration or prolonged habitation
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
