Astronaut Scott Parazynski has undertaken one of the most dangerous spacewalks ever attempted as he performed emergency surgery on a ripped solar panel on the International Space Station.
The vital repair involved installing a home-made brace on the torn wing and then clipping the snarled wires that had ripped the solar panel as it was being unfurled last week. Until the damage was repaired, construction of the space station could not continue. The next shuttle mission, in December, is scheduled to deliver Europe's main contribution to the ISS project, the Columbus laboratory. But without the repair, Nasa would have had to delay that flight.
To begin his task, Parazynski perched at the end of a 90ft robotic arm then clipped on home-made 'cuff-links' that will hold the two sides of the rip together. Fellow astronaut Douglas Wheelock positioned himself at the base of the wing and guided Parazynski.
The mission was particularly risky because the panel - which converts sunlight into electricity - could have given a powerful shock if touched. To reduce this risk, all the metal parts on Parazynski's space suit and his tools were covered with insulating tape.
During his mission, colleague Paolo Nespoli - inside the station - read him a long list of warnings about sharp edges and other hazards. 'I'm not sure there's much left to touch,' Parazynski replied.