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On February 6, 2020, American astronaut Christina Koch arrived back on Earth after 328 days in space. Her time in space is just one of the records set by herself. That's the longest spaceflight ever made by a woman, and just one of the many things Ms Koch achieved in space.
Ms Koch took off from Earth for the International Space Station (ISS) on March 12, 2019. While in space, she made 5, 248 trips around the Earth, travelling 2, 237 million kilometres, which is roughly the same as 291 trips to the Moon and back. During her 11 months on the ISS, Ms Koch took part in six spacewalks, spending over 42 hours in all outside the station. In October of 2019, Ms Koch led the first ever all-female spacewalk with Jessica Meir.
But for most astronauts, space travel isn't about setting records. It's about doing science. Ms Koch took part in a wide variety of special experiments including studying how crystals (晶体) grow in space, how atoms (原子) behave in extreme cold and learning more about growing plants in low gravity. Growing plants in space could be an important way to provide food on future trips. She also tested a new way of separating liquids from gases. This experiment could lead to simple methods of cleaning water and air in space, which could be very important for future space travel.
Ms Koch isn't just a scientist and an astronaut. She is also being studied. She's part of a NASA program studying how astronauts are affected by being in space for long periods of time. Her trip was only 12 days shorter than the American record set by Scott Kelly in 2016. As they did with Mr Kelly, NASA scientists are looking carefully at ways Ms Koch's body has been affected by her time in space. That research is important for the longer space trips NASA hopes to make in the future, such as for a base on the moon or a trip to Mars.