Published: March 10, 2016
Astronaut Scott Kelly returned to Earth after spending 340 days aboard the International Space Station on March 2.
On March 25, Kelly launched into space in an effort to explore the effects of long term space travel in hopes of sending an astronaut to Mars. While aboard the ISS, Kelly participated in 28 experiments, including a twins study with his identical twin, Mark Kelly, to see the effects of the high-radiation environment and the weightlessness experienced in space on one’s genes.
The National Aeronautics and Space administration, NASA, released protocols regarding the experiments they intend to perform on the Kelly twins
Many different areas are being researched including changes in physiology, behavior, the microbiome and telomeres. Traveling to Mars will take a long time, at least a two-year mission, so the effects of a long-duration spaceflight will be examined paying particular attention to the effects on the cardiovascular system.
This study is being conducted independent of one’s genotype because of the comparison to Kelly’s twin, who has an almost identical genome. Researchers want to determine if long-term space travel will disrupt the normal genomic sequences and metabolite activity resulting in an increased susceptibility to atherosclerosis, a thickening of the artery walls, resulting in narrowed arteries that block normal blood flow.
Another study focusing on the physiology of humans includes studying how spaceflight affects fluids within the body, specifically in the eyes and the brain. Many astronauts report changes in their vision during their time in space and after returning to Earth.
Changes in vision are the result of many factors, including swelling of the optic nerve and a farsighted shift. The fluid redistribution that occurs in microgravity conditions results in increased intracranial pressure that could be the reason that decreased visual acuity is reported by astronauts. During flight, intracranial and intraocular pressure, blood pressure and heart rate are measured. The ocular structure is also examined to determine changes in-flight.
Cognitive performance will be studied to see if a longer duration in the spaceflight environment could cause changes in an astronaut’s neuropsychological health. The tests are currently being used on astronauts who spend six months aboard the ISS.
These tests examine spatial orientation, abstract reasoning, risk decision making, attention and working memory, sensory-motor ability and emotion recognition.
Shortening of telomeres, protective ends of our DNA, is thought to cause aging. Researchers hope to identify changes in telomere length during spaceflight to see if exposure to microgravity results in a shorter life-span. Elevated radiation levels and physical and physiological stress while in space may lead to an increased rate of shortening of the telomeres.
Telomere length will be measured pre-flight, in-flight and post-flight to establish a baseline length, examine temporary changes in length and study long-term changes in length.
After returning to Earth, Kelly underwent more tests to see how his body was adjusting to life back on Earth. The results of the numerous experiments will aid NASA in sending a manned mission to Mars.
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