One in, one out. Or to be more specific, three in and three out. A trio of astronauts descended from the International Space Station (ISS) on Friday, making way for a new group of space-smitten explorers. Among the group blasting off today is Tim Peake, the first British astronaut to visit the ISS and the first UK astronaut to explore space in over 20 years. He'll be joined by NASA astronaut Tim Kopra and experienced cosmonaut Yuri Malenchenko, who in 2003 became the first person to marry in space.