Medical Issues Associated with Winter Survival Training.

During active phases of manned spaceflight there is a possibility of a spacecraft landing at any point traversed by its orbital path on the Earth. Survival training after emergency landing is an important and vital part of pre-mission preparations. In this paper we analyze medical issues associated with winter survival training in marshy and forested terrain. From 2011 to 2019, 50 International Space Station crews participated in winter survival training. Crewmembers included Roscosmos, NASA, CSA, ESA, and JAXA astronauts, spaceflight participants, and instructors. Medical protocols and training final reports were analyzed for conditions and medical events. The health status of crewmembers during training was nominal. Temperature sensation was reported as comfortable or moderately cold during daytime and moderately cold or cold during nighttime. SO₂ (blood oxygen saturation) and heart rate recorded during training did not exceed normal values. SCO (blood carbon monoxide saturation) generally was within normal limits. All participating crewmembers lost some bodyweight, from 0.15.5 kg (average 2.1 kg). Over the course of winter survival training there were 32 medical and environmental events requiring medical intervention. For two of the crewmembers requiring medical intervention, training was subsequently canceled. Winter survival training has successfully prepared spaceflight crews for the possibility of off-nominal landings in challenging terrain under adverse conditions. As this training involves high fidelity flight-like survival equipment and assigned flight crewmembers, the medical problems described here should closely reflect type and prevalence of events during an actual contingency scenario.