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Scientists have found new risk to space travel. They have discovered that our DNA can change when going into space. DNA mutations could increase risk of space travellers getting cancer. scientists did research on 14 NASA astronauts who took part in Space Shuttle programme between 1998 and 2001. astronauts provided blood samples ten days before they went into space and three days after returning to Earth. blood has been frozen for past 20 years. Professor David Goukassian said: "Astronauts work in extreme environment where many factors can result in...mutations." He added: "Space radiation...means there is risk that...mutations could develop."

Professor Goukassian said his study could be important for future of space travel. In particular, several nations are working on sending astronauts to Mars. Other countries are preparing to build bases on moon. There is also race by commercial companies to start business of space tourism. Goukassian said there were possible health risks to space travel and to exploring deep space. He said more research was needed to study harmful effects of space travel on body. This could be important for NASA's Artemis project. This aims to send people back to moon for first time in 50 years. last time humans went to moon was during Apollo 17 mission in December 1972.

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