Humans’ health in the outer space

Obscure, unfriendly, dangerous or unknown – these are no longer the main attributes that define space.  Interplanetary travel is now often seen as an exciting, open and limitless opportunity that humanity should focus on moving forward.  Nonetheless, while we find ourselves in the middle of a transition period moving from the Space known as cold, isolated and undiscovered towards a desirable and insightful place, substantial challenges are still to be addressed.

One of the arising challenges concerns the healthcare of space-travellers.  While technology is continuously developing following an exponentially ascendant trend, human evolution cannot naturally keep up the pace.  Thus, special focus needs to be pivoted around the human mind and body adaptation to space.  It is essential to understand all the factors that contribute to human body changes and especially how these might change with time in order to find optimum human-centred solutions that would make space travel safer and more accessible to a wider range of people.

What are the main spacefaring risks for human health?

As Red Planet missions became a certainty, human adaptation to longer residency in space was addressed and, according to NASA’s Human Research Program, the main hazards astronauts will encounter fall under 5 main categories: cosmic radiation, microgravity, hostile environments, isolation and confinement and distance to Earth.

The highest risk of long space travel is unanimously recognised to be space radiation. While on the space station, astronauts are subjected to over ten times the radiation occurring on Earth and this was found to have a negative impact on astronaut’s health leading to altered cognitive function, reduced motor function, and behavioural changes.  Space radiation can also cause radiation sickness that results in nausea, vomiting, anorexia, and fatigue. Moreover, one can develop degenerative tissue diseases such as cataracts, cardiac, and circulatory diseases. 

Transitioning between the three different gravity fields people would experience on a Mars mission can lead to serious motion sickness while affecting one’s spatial orientation, body parts coordination, balance and locomotion. Furthermore, lack of gravitational force causes bones minerals loss characterized by density dropping at a rate of 1% per month, endurance or cardiovascular deconditioning, vision impairment or even kidney stones.

In space, microbes can evolve and change characteristics making humans easy targets due to limited or hostile environments introduced by living inside a spacecraft over a long period of time. Consequently, there is a significant increase in the risk of allergies, illness and diseases.

Do people feel lonely in space?

However, it is crucial to understand how space affects the human mind and not just the body. A decline in mood, cognition, moral and interpersonal interaction are mild occurrences that have isolation and confinement as root causes. Despite the carefully crafted selection process and training of astronauts, behavioural issues are inevitable in such conditions leading to sleep disorders caused by anomalies introduced in one’s circadian rhythm, or even depression which might impact performance and mission success.

Image credit: Stock

Distance to Earth will surely contribute to delay in communication and limited supplies that can potentially cause frustration or self-doubt and impact one’s mental health while testing both their physical and mental strength and confidence.

Are we there yet?

For observation of physiological, molecular and cognitive changes that could happen to a human from exposure to these spaceflight hazards, NASA conducted the ‘Twins Study’ by comparing Scott Kelly to his brother on Earth. This one-year-long in space study (twice the normal time) is a stepping-stone towards the three-year expedition to Mars as it led to significant discoveries such as lingering changes in Scott’s cognition and DNA.

Image credit: NASA

Despite the identification of cardiovascular, immunological, sensorimotor, musculoskeletal, reproductive and behavioural implications on spaceflight adaptation, supporting data available for men and women is imbalanced due to sex and gender disparity of people who have flown in space – 477 men vs. 57 women as of June 2013. Further innovative research investigated sex and gender-related differences in space, which introduced the concept of Personalised Medicine. Jeffrey P. Sutton, M.D., Ph.D., NSBRI’s President, CEO, and Institute Director believes that “Harnessing the power of 21^st century personalized medicine, as practiced at leading medical schools and hospitals, will further mitigate the human health risks inherent to long-duration deep space missions.”

In the past 50 years, medicine has continuously evolved introducing disruptive innovation by taking a human-centred and inclusive approach. Although there are still many unknowns in the space equation and worldwide excitement for Space-travel pushes for timeliness exploration, ‘Framing questions with precision takes a lot of time and effort’ argues Elon Musk. Having available all current tools (human and technological), we are living in exciting times while talking about private lunar passenger flights (SpaceX), Passengers Space Flights (Virgin Galactic), further Mars exploration (NASA, SpaceX) and colonization (SpaceX). What a time to be alive!