Spaceflight Maximum Allowable Concentrations (SMACs) were previously developed for acetaldehyde in 1994. Acetaldehyde is commonly detected at low levels on the International Space Station, and at higher concentrations it might be expected to cause respiratory and eye irritation. Since 1994, numerous exposure studies in human volunteers and laboratory animals have deepened our understanding of potential effects associated with exposure to acetaldehyde vapor.

Physiological assessment of military pilots and aircrew is performed annually. This includes a simulation of a flight at maximum altitude (25,000 ft/7620 m) with acute hypoxia, where they can recognize their symptoms. By detecting the symptoms of hypoxia, they will take corrective actions to avoid hypoxia-induced impairment. However, there is little evidence of what happens in the heart under these conditions. Cardiac function can be evaluated noninvasively with transthoracic echocardiography. The objective was to evaluate the effect of hypoxia and altitude during this simulation on systolic and diastolic cardiac function, pulmonary artery systolic pressure, and cardiac output with transthoracic echocardiography.

Effective execution of the anti-G straining maneuver (AGSM) is essential for pilots to maintain consciousness under high gravitational forces (+Gz). This study evaluated whether electromyographic (EMG) biofeedback enhances muscle activation patterns during AGSM training in novice cadets.

Spatial disorientation is a leading nontechnical cause of fatal military aviation accidents, triggered by insufficient or misleading cues mainly from the visual and vestibular systems. Spatial disorientation accounts for 20-38% of fatal military aviation accidents, but case reports describing specific illusions during actual flight are rare.

Prolonged exposure to microgravity alters spinal biomechanics, increases disc herniation risk, and complicates perioperative care. With commercial and deep-space missions on the horizon, the need for in-orbit surgical capability has gained prominence as a safeguard for astronaut health.

Astronauts commonly experience space motion sickness, which can impair astronaut performance and safety. Pharmaceuticals are frequently used to reduce space motion sickness symptoms but have not been extensively studied in partial gravity. In this research effort, we investigated the impact of oral promethazine on motion sickness during parabolic flight.

Improved video transmission is needed for telemedicine in austere or remote ground, maritime, and aerospace environments. A prototype compression algorithm named "V-CRAMMIT" (patent pending) streamlines medical images, improving bandwidth efficiency. This study evaluated the technology by assessing diagnostic designations made by medical clinicians using uncompressed vs. compressed video.

Acute mountain sickness (AMS) is a common condition in individuals ascending rapidly to high altitudes and often presents with headaches, fatigue, and gastrointestinal symptoms. AMS is prevalent above 13,000 ft (4000 m), but some individuals experience it at lower elevations. This pilot study assessed the prevalence and timing of AMS symptoms in unacclimatized individuals exposed to 16,000 ft (4900 m) in a controlled hypobaric environment.

Historical and modern science has produced many remedies for motion sickness; however, few if any of these remedies have demonstrated successful mitigation without producing negative side effects. The purpose of this study was to determine if a newly created commercial bone conducted vibration (BCV) device could reduce motion sickness symptoms in a simulated visual and provocative motion flight environment.

Elevated partial pressure of carbon dioxide (Pco2) poses a persistent health challenge during spaceflight. Unlike Earth's environment, the International Space Station experiences Pco2 levels that often exceed terrestrial safety thresholds, creating unique physiological risks for astronauts. In microgravity, localized Pco2 "pockets" can form due to lack of convection, exacerbating hypercapnic symptoms such as headaches, visual disturbances, and cognitive impairments. Moreover, microgravity-induced cephalad fluid shifts amplify the impact of CO2-mediated cerebral vasodilation, contributing to elevated intracranial pressure and potentially exacerbating spaceflight-associated neuro-ocular syndrome. Chronic hypercapnia also raises concerns about bone demineralization and renal stone formation, compounding mission risks. As we move toward longer missions to the Moon and Mars, mitigating CO2-related health effects through engineering controls, physiological countermeasures, and enhanced monitoring is essential. This article discusses current evidence and calls for integrated strategies to safeguard astronaut health and mission success under the compounded stressors of CO2 exposure and microgravity. Evans LA. Carbon dioxide as a multisystem threat in long duration spaceflight. Aerosp Med Hum Perform. 2025; 96(11):1024-1026.

Exposure to microgravity has physiological consequences that can impair astronaut safety and performance. Many can be directly linked to fluctuations in plasma serotonin levels on Earth, like bone loss, nausea, and fatigue. Yet the metabolic activity of serotonin in space is not well known. This study measured plasma serotonin levels and bone density in the mouse hindlimb unloading (HU) model, an established Earth analog of microgravity-induced bone loss.

Magnesium is essential for numerous physiological processes. Changes in magnesium homeostasis during spaceflight could impact astronaut health, particularly as mission durations increase. This review examines trends in serum, urine, and intake-based magnesium data from published human spaceflight studies.

Cervical spine degeneration occurs naturally, often has biomechanical effects on spinal function, and can be accelerated by daily loading environments such as whole-body vibration. Military fighter pilots routinely experience high-magnitude Gz loading with added helmet mass and head-neck in nonneutral orientations. This study characterized spinal degeneration in fighter pilots and identified functional consequences.

Pilots are undoubtedly among employees who undergo rigorous medical evaluations to ensure they are fit to fly. However, accidents like the Germanwings Flight 9525 highlight that medically unfit individuals can still end up in the cockpit.

As international efforts in space exploration continue, spaceflight dermatology is a critical field for ensuring the health of astronauts. Microgravity, limited hygiene, and radiation uniquely impair skin integrity, contributing to issues such as dermal atrophy, xerosis, and increased infection risk during spaceflight. This commentary highlights practical strategies and potential research avenues for preventing and addressing the array of dermatologic changes during spaceflight. There are multiple promising interventions, including retinoids, vitamin-A derivatives, calcitriol, L-asparaginase, advanced dressings, telemedicine, and immune-system enhancement strategies which may help mitigate skin-thinning, dermatitis, and slow wound-healing. Continued interdisciplinary collaboration, more human data, and real-time data collection will refine and validate strategies, improving skin health in space. Routine consideration of novel dermatologic therapies may benefit spaceflight and overall mission success as humans venture farther into space. Henke J, Kamboj S, Barrett D, Idris H, Gangal A, Blalock T. Therapeutic and diagnostic perspectives for advancing spaceflight dermatology. Aerosp Med Hum Perform. 2025; 96(10):947-949.

Human factors are responsible for 80% of accidents and 50% of serious incidents. The Human Factor Analysis and Classification System allows the identification of contributing factors, including pilot preconditions, as the imminent layer prior to errors. This study aimed to investigate the association of pilot preconditions and errors to accidents and serious incidents from 2007-2024 in Indonesia.

Optimal visual function is essential in aviation to ensure flight safety and mission effectiveness. Pachychoroid neovasculopathy is a relatively recently recognized clinical entity of choroidal neovascularization, belonging to the pachychoroid spectrum, for which intravitreal therapy (IVT) is the standard of care. The main aeromedical considerations are degradation of visual function from disease progression, which could preclude aircrew from flying duties, and the compatibility of IVT with flying.