As commercial space travel becomes more of a reality - companies like Blue Orbit hope to have passengers in space as early as 2018 - there are still some serious health risks to consider before opting to go into orbit.

Astronaut Scott Kelly, who recently returned to Earth after a year in space, has opened up about the effects his time in orbit had on his body.

"I lost bone mass, my muscles atrophied, and my blood redistributed itself in my body, which strained my heart," he said in a news release for his upcoming memoir, Endurance: My Year in Space and Our Journey to Mars.

"Every day, I was exposed to ten times the radiation of a person on Earth, which will increase my risk of a fatal cancer for the rest of my life. Not to mention the psychological stress, which is harder to quantify and perhaps as damaging."


While space tourists would spend far less time in space, the effects of gravity could still cause problems.

According to Medical News Today, "gravity affects blood circulation and the musculoskeletal system, among other things", which means "the effects of microgravity could prevent astronauts, and their bodies, from performing necessary functions in space."

Space travel can also increase the risk of high blood pressure and cardiac arrhythmia and atrophy.

Even on a short trip, tourists would still have to deal with exposure to radiation, cosmic rays and extreme cold, as described by Kelly.

Some studies believe that just one particle of the cosmic rays "has the power to charge through human tissue and destroy DNA, raising the risk of mutations and cancer".

The close quarters involved in space travel could also pose a problem, as bacteria is easily shared when people are in close proximity.

As with more conventional forms of travel, passengers could also be affected by motion sickness and disorientation, which can "affect vision, cognition, balance and motor control".