Whitson, 57, became the first American astronaut to set a record for the longest mission on the ISS. "I find it incredible, this is the most rewarding job I have ever done," said Whitson, who is also a biochemist.
She conducted various experiments on the ISS, which flew at an altitude of 400 kilometers above the earth. One is a network of tissue studies of lung and bone cells that have cancer. In addition, he also performed four times outside the ISS. Previously, two Whitson colleagues had returned to Earth three months ago.