Fritz Adam Hermann von Opel, was the only child of Wilhelm von Opel and a grandson of Adam Opel, founder of the Opel company. He is remembered mostly for his spectacular demonstrations of rocket propulsion that earned him the nickname "Rocket Fritz". Opel was born in Rüsselsheim and educated at the technical university of Darmstadt. After graduation, he was made director of testing for the Opel company and also put in charge of publicity. In the 1920s, he became interested in using rockets in publicity stunts for the company and sought advice from Max Valier of the newly formed Verein für Raumschiffahrt and Friedrich Sander, a pyrotechnics manufacturer from Bremerhaven. On 15 March 1928 Opel tested his first rocket-powered car, the RAK.1, and achieved a top speed of 75 km/h in it, proving the feasibility of the concept of rocket propulsion. Less than two months later, he reached a speed of 230 km/h in the RAK.2, driven by 24 solid-fuel rockets. Later that same year, he purchased a sailplane named the "Lippisch Ente" from Alexander Lippisch and attached rocket motors to it, creating the world's first rocket plane on 11 June. The aircraft exploded on its second test flight, before Opel had had a chance to pilot it himself, so he commissioned a new aircraft, also called the RAK.1, from Julius Hatry, and flew it at Frankfurt-am-Main on 30 September 1929. In the meantime, another mishap had claimed the RAK.3, a rocket-powered railway car powered by 30 solid-fuel rockets which had reached a speed of 254 km/h. Also in 1928, Opel built and test ran a rocket-powered motorcycle called the Monster. Opel left the family firm and Germany after 1929. On 25 April 1940 Fritz von Opel was taken off the Italian liner Conte di Savoia by the British authorities at Gibraltar. After being detained at Gibraltar for sixteen days, he was allowed to proceed to the United States. In 1947 Opel married Emita Herrán Olózaga and became the father of Formula One driver Rikky von Opel, born later the same year. He died at Samedan in Switzerland in 1971.

https://en.wikipedia.org/wiki/Fritz_von_Opel