It is a day neither man will ever forget. <br /><br />American Reid Wiseman and German Alexander Gerst have headed out of the International Space Station for their first ever space walk. <br /><br />But sightseeing from the stars was not an option with plenty of repairs and maintenance to be carried out, including dealing with a failed cooling pump.<br /><br />The 15-nation ISS laboratory, which flies at an altitude of about 420 km, is overseen by Russia and the United States.
