Most applications for an astronaut selection process

Since the original "Mercury Seven", NASA has always selected its astronauts in groups (often called "classes"). These classes, which go on to train and later fly together, vary in size from just six individuals to as many as 44. The recruitment process for Astronaut Group 22, which started in December 2015, saw NASA receive 18,300 applications from the public. This breaks the record of 8,000 set by 1978's Astronaut Group 8 (known as the "Thirty-Five New Guys"). These 18,300 applicants were whittled down by a rigorous selection process to just 12 people, whose names were announced on 8 June 2017. Once they've finished their training – which involves learning to fly supersonic jets, operate robots and speak fluent Russian – they will fly missions to the ISS and possibly beyond as part of NASA's Orion program.

Applicants include Lt Jonny Kim (33), a decorated Navy SEAL who left the military to complete a doctorate in medicine at Harvard; Dr Jessica Watkins (29), a geologist who joins the astronaut corps from the Curiosity Mars Rover programme; and Dr Robb Kulin (33), who joins from SpaceX, where he was Chief Launch Engineer for the Falcon 9 rocket.