Polaris Dawn Mission Reveals Critical Insights into Spaceflight’s Effects on Vision, Neurology, and Physiology

During SpaceX’s Polaris Dawn mission, each of the four crew members encountered unique physical sensations, highlighting the diverse effects of space travel on the human body. Scott “Kidd” Poteet, a former U.S. Air Force pilot, reported deteriorating vision shortly after reaching orbit, a symptom linked to conditions like spaceflight-associated neuro-ocular syndrome (SANS).

Anna Menon, a SpaceX engineer, and medical officer for the mission, experienced space adaptation syndrome—a common reaction to space travel causing symptoms from mild nausea to vomiting. These firsthand experiences underscore the range of physiological responses humans have to spaceflight, especially when exposed to higher altitudes than typical space missions.

The Polaris Dawn mission aimed to push space medicine research beyond NASA’s current findings by testing new methods to monitor and counteract space-related health issues. During the mission, the crew conducted health-focused experiments, including wearing specialized contact lenses to measure eye pressure and undergoing brain MRI scans to document anatomical changes due to fluid shifts in microgravity.

The team hoped that gathering this real-time data would reveal new insights into how prolonged space exposure affects vision and neurological health, information crucial for future long-duration missions.

Jared Isaacman, the mission’s commander, emphasized the importance of understanding space adaptation syndrome and related ailments, especially if humanity aims to send thousands of people to space or Mars. Isaacman noted that even highly trained government astronauts, who represent a small, rigorously screened population, commonly experience such symptoms.

The potential for widespread, debilitating effects on vision and other functions presents a significant barrier to extended space missions, reinforcing the need for solutions that could benefit a broader, less specialized group of future space travelers.

During the mission, the crew also conducted the first commercial spacewalk and ventured into Earth’s Van Allen radiation belts. Although no immediate radiation-related health effects were documented, Isaacman reported seeing “sparkles or lights” when he closed his eyes, a phenomenon observed by previous astronauts exposed to high-radiation environments.

Additionally, Poteet’s experience of temporary vision loss, potentially due to SANS, suggested that bodily fluid shifts in space might elevate intraocular pressure—a hypothesis the mission’s contact lens experiment aimed to investigate in greater detail.

Following their return to Earth, the Polaris Dawn team continued their research to understand how space affects drug metabolism and brain structure. Blood samples collected before and after the mission allowed scientists to compare drug processing differences between Earth and orbit.

MRI scans conducted immediately post-mission indicated changes in brain anatomy, such as upward brain shifts and expanded ventricles, phenomena that scientists, including Dr. Donna Roberts, are only beginning to understand. These findings contribute to a growing body of knowledge essential for addressing the physiological challenges of spaceflight.

Reflecting on her experience, mission specialist Sarah Gillis emphasized the discomfort inherent in human spaceflight and the importance of studying these bodily changes. From fluid shifts to the movement of organs, her observations highlighted how microgravity strains human physiology, underscoring the urgency of research efforts to make long-term space habitation feasible.

As human space exploration advances, findings from missions like Polaris Dawn could inform medical protocols and technology essential for keeping future space travelers healthy and functional on journeys beyond Earth’s orbit.