Update: The space walk has been aborted after a dangerous water leak in Luca Parmitano's helmet. Parmitano reported feeling a lot of water round the back of his head an hour into the mission.
He suspected it was sweat brought about by the exertion of the work but his partner, Chris Cassidy, assured him it was not and escorted him back into the ISS. Cassidy said he thought it might be water leaking from his drink bag.
NASA are inviting viewers to experience a space walk live, broadcasting routine maintenance being carried out on the International Space Station (ISS) by a pair of astronauts.
Chris Cassidy of NASA and Luca Parmitano of the European Space Agency began their trip - known technically as extravehicular activity or EVA - at 13.00 GMT. It will be Cassidy's sixth spacewalk and Parmitano's second - he became the first Italian astronaut to walk in space after a similarly streamed trip on July 9.
The space walk will last approximately 6 1/2 hours and marks the latest event in a recent string of internet-friendly space fare. Canadian astronaut Chris Hadfield became famous due to his prolific tweeting from onboard the ISS. He eventually left the station in style after making the first ever music video shot in space - a cover of David Bowie's 'Space Oddity.
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