First twin space log

摘要

Twin astronauts are ready to shed blood in the name of space exploration. Next year, scientists from across the US will collect blood samples and run a battery of physical and mental tests on identical twins Mark and Scott Kelly. Mark, a retired astronaut, will remain on Earth while Scott spends a year on the International Space Station. With the twins' help, NASA will explore the health effects of space flight without genetic variations getting in the way.