In 1927 the German car manufacturer Opel began to research rocket vehicles together with Mark Valier and the solid-fuel rocket builder Friedrich Wilhelm Sander.[60] In 1928, Fritz von Opel drove a rocket car, the Opel-RAK.1 on the Opel raceway in Rüsselsheim, Germany. In 1928 the Lippisch Ente flew: rocket power launched the manned glider, although it was destroyed on its second flight. In 1929 von Opel started at the Frankfurt-Rebstock airport with the Opel-Sander RAK 1-airplane, which was damaged beyond repair during a hard landing after its first flight.