Mission timers for professional users also play an important role. These include special forces such as the marine unit of the German federal police GSG 9, the fire service, divers and pilots. German physicist and astronaut Reinhard Furrer wore the 140 S on his wrist during the Spacelab D1 mission in 1985, thus proving that a mechanical SINN watch with automatic movement also works with zero gravity. During the Mir ’92 mission in 1992, astronaut Klaus-Dietrich Flade flew into space with a 142 S from Sinn Spezialuhren on his wrist. In 1993, it was the 142 from Sinn Spezialuhren that was on board the Columbia on Mission D2.