Canadian astronaut Commander Chris Hadfield spent five months living on the International Space Station and won an online audience of millions with his tweets about daily life and his music recordings.

Nujeen Mustafa was born with cerebral palsy, and for most of the first 16 years of her life had barely left her home in the Syrian city of Aleppo. When the war made life there too dangerous, Nujeen had to make the perilous journey to Europe in her wheelchair. She now lives in Germany and dreams about becoming an astronaut.

Cosmonaut Abdul Ahad Mohmand is the only Afghan to have gone into space. It was 1988, in the last days of Russia's hold on Afghanistan, and Abdul went to visit the Mir space station with a Russian commander. But their attempts to return to earth didn't go according to plan.

Image: untethered astronaut drifting off into deep space above the earth

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