NASA has recently announced that it is actively recruiting new astronauts:

“In anticipation of returning human spaceflight launches to American soil, and in preparation for the agency’s journey to Mars, NASA announced it will soon begin accepting applications for the next class of astronaut candidates,” said NASA on its website. “With more human spacecraft in development in the United States today than at any other time in history, future astronauts will launch once again from the Space Coast of Florida on American-made commercial spacecraft, and carry out deep-space exploration missions that will advance a future human mission to Mars.”

However, the announcement happens to coincide with the release of a new study that demonstrates time in space has severely negative effects on a human’s health.

Researchers from NASA used MRI scans to examine the brains of astronauts before and after they spent time in the International Space Station. They discovered that the space travel caused significant changes in the brain, presumably as the organ tries to adapt to the physiological stress of being in zero gravity.

These changes dramatically reduced the astronauts’ cognitive abilities.

While on board the ISS, NASA asked the astronauts to perform regular mental and physical tasks to track any functional changes. They discovered that over the course of a six-month stint on the ISS, an astronauts coordination and motor skills grew weaker and their ability to think diminished.

A previous study by the European Space Agency and the Russian space agency discovered that the cortex of the brain is capable of reorganizing itself to deal with the challenging environment of space as well as the strain of the long spaceflight.

“Factors that can have an impact consist of, but are not limited to, weightlessness, cosmic radiation, isolation, confinement and disturbed day-night rhythm,” said study co-author Angelique Van Ombergen of the University of Antwerp. “As one can imagine, all these factors can have an impact on the human brain, as they are new, challenging and stressful.”

Further research is needed to understand exactly what happens and why but the initial MRI scans show substantial changes to the brain’s neural networks.

“We found less connectivity strength in several motor- and vestibular-related areas, which we know that they are responsible in movement and balance,” said Van Ombergen. “This could explain why astronauts typically present with temporary movement problems (problems with walking, gait and posture) and vestibular/balance problems (dizziness, vertigo, nausea) when returning to Earth.”

Amazingly, the brain is able to make these adaptions in a matter of days. Converting the brain back to normal is not as easy.

NASA is looking very closely in the physical and mental strains caused by space travel as it prepares for human missions to Mars.

Applications for the open astronaut positions can be submitted on this website.