Major Tim Peake is preparing to install a new electrical unit named 'Dusty' which will see the International Space Station restored to full power. He and Nasa's Tim Kopra have just a 31 minute window to replace the broken voltage regulator, and they have to do it in the dark so that they do not get zapped by any electrical shorts from the solar-powered equipment. NASA does not know why why the power unit failed, so they want the astronauts to avoid any danger from potential sparks by doing the work when the space station is doing a night pass. The space station orbits the Earth every 90 minutes, and spends 31 of those minutes out of the light of the Sun. The task should only take about 15 minutes, but the astronauts have to squeeze into a small area to do their work while wearing bulky space suits and gloves. Major Peake will then venture out on a three hour mission of his own to lay new caballing between two of the space station laboratories. British astronaut Tim Peake on board the International Space Station, in pictures Recent memorable spacewalks captured on film