5-Centimeter Height Increase After One Year in Space

After a year living in the International Space Station, NASA astronaut Scott Kelly has grown 2 inches (5.08 centimeters) taller while his twin brother on Earth has remained the same height. According to CNBC, one of the main goals of this mission was to study how humans can physically, mentally, and emotionally endure long-term space travel. Scott Kelly, who has spent more time in space than any other American astronaut, reports that he feels generally very good. A unique aspect of his study is his identical twin brother, Mark, who has also been a NASA astronaut. Comparing these twins will help researchers identify any genetic changes that may have occurred in space. In his latest video conference from the space station, Scott mentioned experiencing vision problems, a common phenomenon among astronauts. Ultimately, medical tests will reveal the impact of his year in space on his body. He noted that many astronauts need to change their glasses a few months into their missions. For about a year, Scott did not use his legs to walk and instead floated in the space station. In the past, astronauts faced issues with brittle bones and weak muscles upon returning to Earth. However, researchers have reduced these harmful effects by prescribing regular strenuous activities for astronauts. Scott stated that he exercised for 2 to 2.5 hours a day using a stationary bike and treadmill. The Washington Post quoted Andrew Feinberg from Johns Hopkins University School of Medicine, who said, 'It is clear that this is a small sample. Therefore, we are not really looking to see exactly how Scott and Mark differed over the course of a year.' Feinberg made these comments before Scott's space journey, stating that statistically, it is not valid to claim that the differences between them must be due to this space travel. However, Feinberg also mentioned that whether environmental differences cause genetic changes is still an interesting topic. There is hope that scientists will find a way to protect astronauts sent to Mars. The journey to Mars, the closest planet to Earth, is expected to take 9 months each way. Last March, Feinberg stated that NASA is working on the largest project of its kind in the history of civilization. 'They are transforming humanity from a terrestrial species to a spacefaring one. One day, humanity will evolve to the point where it can inhabit other planets. It may take a hundred years for humans to live on Mars. This is a multi-generational effort.'