The approximately 7000 people who have a rare performance from Kraftwerk attended in Germany, got a special bonus. An astronaut played live along with the legendary German group from the ruimestation ISS. This he did because the concert ended with the song Spacelab. Alexander Barley is a German astronaut that is 400 km above the ground works for the European Ruimtevaartbureau ESA. He was able to play using a tablet-pc with a synthesizer app that he brought to the place had taken.