Blue, Rebecca S.

AbstractHuman spaceflight is entering a time of markedly increased activity fueled by collaboration between governmental and private industry entities. This has resulted in successful mission planning for destinations in low Earth orbit, lunar destinations (Artemis program, Gateway station) as well as exploration to Mars. The planned construction of additional commercial space stations will ensure continued low Earth orbit presence and destinations for science but also commercial spaceflight participants. The human in the journey to space is exposed to numerous environmental challenges including increased gravitational forces, microgravity, altered human physiology during adaptation to weightlessness in space, altered ambient pressure, as well as other important stressors contingent on the type of mission and destination. This chapter will cover clinically important aspects relevant to lung function in a normally proceeding mission; emergency scenarios such as decompression, fire, etc., will not be covered as these are beyond the scope of this review. To date, participation in commercial spaceflight by those with pre-existing chronic medical conditions is very limited, and hence, close collaboration between practicing pulmonary specialists and aerospace medicine specialists is of critical importance to guarantee safety, proper clinical management, and hence success in these important endeavors.

Abstract Space radiation remains one of the primary hazards to spaceflight crews. The unique nature of the intravehicular radiation spectrum makes prediction of biological outcomes difficult, with computational simulation-based efforts stymied by lack of computational resources or accurate modeling capabilities. Recent advancements in both Monte Carlo simulations and computational human phantom developments have allowed for complex radiation simulations and dosimetric calculations to be performed for numerous applications. In this work, advanced tetrahedral-type human phantoms were exposed to a simulated spectrum of particles equivalent to a single days exposure in the International Space Station in Low Earth Orbit. 3D Monte Carlo techniques were used to produce and simulate the radiation spectra. Organ absorbed dose, average energy deposition, and the whole-body integral dose was determined for a male and female phantom. Results were then extrapolated for two long-term scenarios: a 6-9 month mission on the International Space Station and a 3-year mission to Mars. The whole-body integral dose for the male and female models were found to be 0.2985 ± 0.0002 mGy/day 0.3050 ± 0.0002 mGy/day, respectively, which is within 10% of recorded dose values from the International Space Station. This work presents a novel approach to assess absorbed dose from space-like radiation fields using high-fidelity computational phantoms, highlighting the utility of complex models for space radiation research.

Abstract Introduction Flight surgeons play a vital role in U.S. Air Force aviation operations by ensuring that pilots are medically prepared to meet the demands of military aviation. However, there is natural tension between pilots and flight surgeons. A pilot may be reluctant to share medical information with a flight surgeon who could negatively impact the pilot’s career or flight status. In this preliminary study, we sought to identify pilot-perceived strengths and weaknesses in the relationship between U.S. Air Force aviators and their flight surgeons. Materials and Methods An online survey regarding pilot–flight surgeon confidence and perceived values was distributed electronically to a convenience sample of U.S. Air Force aviators. Participants included U.S. Air Force active duty and Air Reserve Component (Air Force Reserve and Air National Guard) military aviators in addition to U.S. Air Force Academy aviation cadets. Results One hundred and seventy-three aviators participated in the survey. Respondents reported variable comfort in approaching flight surgeons with medical concerns and suggested that they believed other pilots might be withholding medical information from flight surgeons or seeking care from civilian physicians for career protection. Conclusions We sought to examine the pilot–flight surgeon relationship and its impact on daily flying operations. While limited, results suggest that there may be gaps in trust between pilots and their flight surgeons. These findings could present an opportunity to improve the pilot–flight surgeon relationship by identifying factors that contribute to closer pilot–flight surgeon relationships.

Abstract There are currently no direct regulations and few guidelines regarding restraint design for commercial spaceflight vehicles. Operators designing vehicles intended solely for private commercial use, particularly short-duration suborbital flights, have questioned the need for 5-point restraints, instead considering the options of fewer restraints and less stringent application requirements. We sought to identify risks and benefits of alternative restraint designs for the commercial spaceflight industry, particularly for the diverse population of commercial spaceflight participants (SFPs). A systematic review was conducted on currently available information and published literature of human and animal studies as well as industry standards regarding restraint design, common injuries, and patterns of injuries in vehicular trauma, including automobile, aircraft, and spacecraft. Although data are lacking regarding commercial spacecraft or potential mishap forces, extensive studies are available in analogue environments, including motor vehicle crashes and aviation mishaps, which demonstrate variations of restraint design and relative risks and benefits of these systems. These studies demonstrate superiority of harnesses that include shoulder restraint and a negative-G (crotch) belt to limit torso movement. Injury patterns in anthropometrically varied populations, with factors including gender, obesity, and advanced age, demonstrate increased vulnerability to morbidity and mortality in obese and elderly populations and improved outcomes with more rigorous restraint designs. Given the varied population anticipated for commercial SFPs and significant reduction in morbidity and mortality associated with 5-point restraint designs, evidence suggests that the use of a 5-point restraint is most appropriate for commercial spacecraft.