Yurchikin and Fischer will return to Earth on June 2 after a 135-day mission, and filling the third seat of their flight is astronaut Whitson. Soyuz MS-04 is the 50th Soyuz spacecraft launched to the ISS.
Neil Armstrong is probably the most popular astronaut but his lesser known but equally significant counterpart, Yuri Gagarin, deserves the attention, too. Gagarin is the first man to journey to space. And to commemorate that, the United Nations is celebrating the International Day of Human Space Flight this month.