TY - JOUR
T1 - Human Adaptations to Multiday Saturation on NASA NEEMO
AU - Koutnik, Andrew P.
AU - Favre, Michelle E.
AU - Noboa, Karina
AU - Sanchez-Gonzalez, Marcos A.
AU - Moss, Sara E.
AU - Goubran, Bishoy
AU - Ari, Csilla
AU - Poff, Angela M.
AU - Rogers, Chris Q.
AU - DeBlasi, Janine M.
AU - Samy, Bishoy
AU - Moussa, Mark
AU - Serrador, Jorge M.
AU - D’Agostino, Dominic P.
N1 - Funding Information:
This study was supported by Ketone Technologies LLC and NASA Human Research Program Grant (NNX10AO19G).
Funding Information:
scientists (n = 4), and/or professional habitat technicians (n = 3) underwent a multistep verification process including, medical and physical evaluation, confirmation of accredited national or international diving certification and experience, and mission training at NASA Johnson Space Center (JSC) to participate in NASA NEEMO 22 and 23. Upon selections, aquanauts underwent continual internet-based planning, training and familiarization along with a week-long mission training and evaluation program at JSC involving equipment, timeline, research projects, and personnel familiarization. 7 days before entering HBS, participants arrived at FIU On-Shore Mission Control Facility in Islamorada, Florida where they underwent pre-mission preparation involving training, planning, dives, etc. JSC and/or ARB training week provided an analogous physical and mental task load environment to within habitat HBS and was used as a normobaric pre-saturation control timepoint. Following 7 days of ARB training, aquanauts dove into the HBS environment (AURL) where they lived and executed full-day mission objectives for 9–10 days which included extravehicular activities, continual communication with FIU On-Shore Mission Control, research implementation, and other activities, analogizing space-flight operational demands and inherent risks. Throughout HBS, aquanauts were supported by Navy Medical Divers and additional support divers to ensure safe mission completion. Within 24 h of resurfacing, aquanauts underwent a 14–18 h desaturation protocol to lower arterial PN2. Following resurfacing, participants underwent 2-days of mission debriefing. This period was used for the normobaric post-saturation recovery timepoints. Intrapersonal physical burden, mental burden, mood, work satisfaction, cardiac function, autonomic function, sleep quality, subjective sleep, respiration, and body temperature measurements were taken twice pre-saturation (ARB Pre-Saturation Day 4&5), twice in saturation (Mission Day 4&8), and once post-saturation (Debriefing Day 1). Peripheral and cerebrovascular hemodynamics were measured once pre-saturation (JSC Pre-Saturation), three time during saturation (Mission Day 2 or 3, 5 or 6, 8 or 9), and once post-saturation (Debriefing Day 1). Body composition was measured 24 h prior to saturation and within 24 h of resurfacing. All crewmembers gave informed consent, as approved by the Institute for Human and Machine Cognition, Johns Hopkins University, NASA JSC, and/or European Space Agency Institutional Review Boards. Aquanaut baseline anthropometric characteristics are described in Table 1.
Funding Information:
We would like to thank participating aquanauts. We would like to thank Bill Todd, Marc Reagan, Kristen Todd, Dawn Kernagis, Marc O?Griofa, NASA NEEMO Administration, FIU AURL, and remaining support staff for their continual technical and logistical assistance. We would like to thank Jay Dean and Geoff Ciarlone for discussion on HBS. We would like to thank Harpreet, Hannu Kinnunen, and the OURA team for providing OURA rings and/or mission support. We would like to thank Polar for providing V800 watches and H7 chest strap. We would also like to thank Chad Dolan and Eric Trexler for discussion revolving muscle thickness assessment. Funding. This study was supported by Ketone Technologies LLC and NASA Human Research Program Grant (NNX10AO19G).
Publisher Copyright:
© Copyright © 2021 Koutnik, Favre, Noboa, Sanchez-Gonzalez, Moss, Goubran, Ari, Poff, Rogers, DeBlasi, Samy, Moussa, Serrador and D’Agostino.
PY - 2021/1/12
Y1 - 2021/1/12
N2 - Human adaptation to extreme environments has been explored for over a century to understand human psychology, integrated physiology, comparative pathologies, and exploratory potential. It has been demonstrated that these environments can provide multiple external stimuli and stressors, which are sufficient to disrupt internal homeostasis and induce adaptation processes. Multiday hyperbaric and/or saturated (HBS) environments represent the most understudied of environmental extremes due to inherent experimental, analytical, technical, temporal, and safety limitations. National Aeronautic Space Agency (NASA) Extreme Environment Mission Operation (NEEMO) is a space-flight analog mission conducted within Florida International University’s Aquarius Undersea Research Laboratory (AURL), the only existing operational and habitable undersea saturated environment. To investigate human objective and subjective adaptations to multiday HBS, we evaluated aquanauts living at saturation for 9–10 days via NASA NEEMO 22 and 23, across psychologic, cardiac, respiratory, autonomic, thermic, hemodynamic, sleep, and body composition parameters. We found that aquanauts exposed to saturation over 9–10 days experienced intrapersonal physical and mental burden, sustained good mood and work satisfaction, decreased heart and respiratory rates, increased parasympathetic and reduced sympathetic modulation, lower cerebral blood flow velocity, intact cerebral autoregulation and maintenance of baroreflex functionality, as well as losses in systemic bodyweight and adipose tissue. Together, these findings illustrate novel insights into human adaptation across multiple body systems in response to multiday hyperbaric saturation.
AB - Human adaptation to extreme environments has been explored for over a century to understand human psychology, integrated physiology, comparative pathologies, and exploratory potential. It has been demonstrated that these environments can provide multiple external stimuli and stressors, which are sufficient to disrupt internal homeostasis and induce adaptation processes. Multiday hyperbaric and/or saturated (HBS) environments represent the most understudied of environmental extremes due to inherent experimental, analytical, technical, temporal, and safety limitations. National Aeronautic Space Agency (NASA) Extreme Environment Mission Operation (NEEMO) is a space-flight analog mission conducted within Florida International University’s Aquarius Undersea Research Laboratory (AURL), the only existing operational and habitable undersea saturated environment. To investigate human objective and subjective adaptations to multiday HBS, we evaluated aquanauts living at saturation for 9–10 days via NASA NEEMO 22 and 23, across psychologic, cardiac, respiratory, autonomic, thermic, hemodynamic, sleep, and body composition parameters. We found that aquanauts exposed to saturation over 9–10 days experienced intrapersonal physical and mental burden, sustained good mood and work satisfaction, decreased heart and respiratory rates, increased parasympathetic and reduced sympathetic modulation, lower cerebral blood flow velocity, intact cerebral autoregulation and maintenance of baroreflex functionality, as well as losses in systemic bodyweight and adipose tissue. Together, these findings illustrate novel insights into human adaptation across multiple body systems in response to multiday hyperbaric saturation.
KW - NASA
KW - adaptation
KW - extreme environment
KW - hyperbaric (underwater)
KW - saturation
UR - http://www.scopus.com/inward/record.url?scp=85100054868&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85100054868&partnerID=8YFLogxK
U2 - 10.3389/fphys.2020.610000
DO - 10.3389/fphys.2020.610000
M3 - Article
AN - SCOPUS:85100054868
SN - 1664-042X
VL - 11
JO - Frontiers in Physiology
JF - Frontiers in Physiology
M1 - 610000
ER -