Why Famous: Kelly was began a year-long mission to the International Space Station in March 2015. He has served previously on three different missions.
His identical twin brother is also an astronaut, and the two are the only siblings to have traveled to outer space.
- 2016-03-02 US astronauts Scott Kelly and Russian cosmonaut Mikhail Kornienko return to earth after nearly a year (340 days), setting an ISS record
- 2018-03-14 NASA twin study finds that Scott Kelly is no longer identical to his twin brother after one year in space, 7% of his genes altered