Preparing for the next giant leap for humankind

A twin study in space

By Halima Hassan

After several successful space conquests, the next big venture for space agencies around the world is to figure out how humans can conquer Mars. This mission, called Mars One, has a launch date set for the year 2024 and preparations are already well under way. The possibility of human settlements on Mars is all the more exciting and very plausible now after the discovery of water on the surface of the red planet. A major question is what biological changes occur as a result of extended human space flight. It is estimated that a Mars mission will take around two and a half years in total, with approximately one year spent flying in zero gravity for the trip to and from Earth. After all, there is little point in making such a trip if we couldn’t survive it, or if we were affected so detrimentally on a physical level by the journey alone. This is where the astronaut Scott Kelly and his twin, retired astronaut Mark Kelly, come into play. They suggested organizing and taking part in a study to help answer this particular question, and their genetic similarity provides an excellent opportunity for science. NASA and the Russian space agency, Roscosmos, have some understanding of how human bodies adapt to spaceflight: this comes from the many tests and analysis performed on all returning astronauts. One of the most interesting observations from earlier space excursions relates to vision. A survey of the returning astronauts revealed that 29 percent of shuttle astronauts and 60 percent of station astronauts reported worse vision while in flight. “Many became farsighted or experienced blurriness, possibly because the shape of the eye flattens with pressure changes in the skull,” NASA reports.The proposal from the Kelly twins offers a particularly exciting advantage as they are identical twins. As well as being genetically the same, they have both had very similar trajectories in life. Having one of the twins spend time in space while the other remained on earth gives scientists an ideal experimental set up: Mark Kelly, the retired astronaut acts as a biological control, to which data acquired from Scott Kelly will be compared to upon his return from space. As well as all the physical and physiological changes, the advantage of any twin study is that changes at the genomic level can also be tracked and analyzed. On March 1st 2016 Scott Kelly, along with astronaut Mikhail Kornienko, returned after 340 days on the International Space Station (ISS). This is the longest period of time that a US scientist has spent in space. This mission is not over just because the flight landed. There will be weeks, even months, of data collection continuing post-flight, and samples that are still on the ISS will need to be returned to Earth. So far, the main findings are that Scott Kelly looks great; year-long missions are not the limit; and this mission was successful largely because of the close coordination between the Russians, the US and all the partners. However, some of the results from this twin study may never see the light of day. The Kelly twins are having their entire genomes sequenced, and if they discover sensitive medical information they do not want shared, such as susceptibility to certain diseases, those results may not be published. It is safe to say that though the results of this mission will contribute significantly to the preparations for the Mars One mission in 2024, there will have to be more long duration missions before the final takeoff. This twin study will provide invaluable information about the differences between the human body in space compared to Earth and many of the results may even aid scientists in understanding more about disease susceptibility and treatment on this planet. In this regard, the outcome of this mission will not only help humankind take that step towards exploring another planet but the results may help us achieve a better life here on Earth, our first home.

For more information and updates on this study check:
www.nasa.gov/twins-study/research

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