Radiation, isolation, microgravity and more: NASA's top 5 hazards for human spaceflight

Space missions, while they may sound fascinating are arguably among the most demanding and high-risk endeavours ever undertaken by humans. This especially true for human spaceflight, as even a small miscalculation can lead to life-threatening consequences. NASA has identified these five hazards that make long-duration missions particularly complex.

The astronauts are exposed to ionising radiation in space from galactic cosmic rays and solar events. While the earth is shielded by a magnetic field and atmosphere, space offers no such protection and hence it poses as a hazard for human spaceflight. This radiation can have serious health impacts, they can increase cancer risk, damage the central nervous system, and impact overall health. NASA is developing technologies to detect and protect against these invisible but harmful rays.

For extended space missions astronauts are required to live and work in very small, enclosed spaces for months or even years. This isolation from Earth, coupled with very limited social interaction and workload stress, can have a bad impact on the overall mental wellbeing of the astronauts. The major challenges include depression, sleep disturbances, anxiety, and reduced performance. NASA has been working on this. It has started testing behavioural health tools, including light therapy and workload management strategies to mitigate these effects.

While moon missions have their own set of challenges, a journey to Mars involves a much greater distance, this distance is approximately 140 million miles, while becomes the cause of communication delays of up to 20 minutes one way. Thus, the ability to send help or supplies in emergency situations is limited. Astronauts must, therefore, be self-sufficient, very cautious, and well equipped to manage medical issues, repair their equipment, and conserve resources with minimal support from Earth.

One of the biggest challenge for human space missions is caused by prolonged exposures. In space, astronauts face prolonged exposure to microgravity, which severely impacts their balance, coordination, and spatial awareness. This, additionally, also leads to muscle atrophy and bone density loss, with up to 1.5 per cent bone loss per month. Body fluids start shifting upward, in turn not only causing potential vision problems but also increasing the risk of kidney stones. Therefore, upon returning to Earth or landing on Mars, it becomes important for crews to adapt and readapt to changing gravity levels.

Its crucial for spacecraft and habitats to regulate temperature, air quality, and lighting according to the human survival needs. However, confined living conditions do pose major biological risks. It might be possible for microorganisms to change their behaviour in space, spreading more easily and in turn affecting astronauts' health. Not just that, stress coupled with altered immune responses further complicate matters. A malfunction in critical systems like life support or temperature control can have severe consequences for life and death situations.

NASA’s research focuses on creating reliable systems that ensure both physical and psychological well-being in space. For example, spacesuits are engineered so excellently that they protect from extreme temperatures and radiation, while life-support systems must maintain a safe internal environment for extended durations for astronauts.