With the three-year journey to Mars in mind, NASA is studying the risks of spending long periods of time in space. Scott Kelly will live for one year in the International Space Station (ISS), instead of the usual six months, to assess the body response to the stresses of life in space: gravity, isolation, hostile environments, radiation and distance from Earth.
Gravity, isolation and hostile environments
Mars’ gravity is one third of Earth’s. Changes in gravity affect our coordination, orientation, balance and locomotion. Bones lose density, muscles lose strength and the cardiovascular system deteriorates. Medications act differently. For all these reasons, NASA will analyze all body changes happening in the ISS and when returning to Earth. The researchers are developing fine motor skills tests and functional tasks testings to detect changes in the astronaut´s abilities. Space travelers will exercise often and perform fitness self-evaluations, and their bodily fluid distribution will be monitored.
Isolation and confinement affect the behavior and mood of humans. Cognitive disorders are expected to happen when a small group of people lives for a long time in a limited space. Depression and decline in morale and motivation are characteristic of the third-quarter effect. NASA plans to use actigraphy devices, which records sleep-wake cycles and light exposure, LED technology to align circadian rythms, and fatigue self-tests.
A spacecraft can be a hostile environment. Microbes will be easily passed among the crew, stress hormones and the immune system will be altered. NASA monitors the ISS air quality, and astronauts analyze their urine, saliva and blood with advanced molecular techniques, as well as external parts of their body and surfaces of the space station.
Radiation and distance to Earth
Radiation in space is ten times higher than the one experimented under the protective Earth atmosphere. Astronauts are more exposed to cosmic rays, that can cause cancer and nervous system damage, as well as symptoms like nausea and fatigue. NASA is developing shielding and monitoring devices to avoid radiation damage, and studying how it affects biological systems.
On average, Mars is 140 million miles away from Earth. NASA must carefully plan what procedures and equipment are required for astronauts to survive basically in their own. Some self-sufficiency techniques developed in the ISS are intravenous solutions made from cabin water and salt crystals, self-ultrasound scans, new food formulations and packagings, and space-resilient drugs.
NASA is constantly working to assess the risks of space travel and minimize its negative effects on the human body. The results of the one year mission in the ISS will be very useful to carefully plan longer space trips like the one to Mars.