Astronaut shares selfie taken 400 kms above Earth
NASA astronaut Ricky Arnold has shared a selfie taken during a spacewalk outside the International Space Station, which orbits the Earth at a 400-km altitude. Arnold and fellow spacewalker Drew Feustel worked for over six hours to swap a malfunctioning cooling box nicknamed 'Leaky', the source of an ammonia leak five years ago, with another relatively colder box called 'Frosty'.