Johannes Winkler (May 29, 1897 – December 27, 1947) was a German rocket pioneer who founded the first German rocket society and launched the first successful liquid-fuelled rocket in Europe.
In 1915 during World War I, he joined the German army and was wounded in action the following year, leading to a lengthy hospitalisation. After his recovery, he studied as a machinist at the Danzig technical college and found a job at Junkers.
On July 5, 1927, he was one of the founders the Verein für Raumschiffahrt (VfR - "Spaceflight Society"). He also was the society's first president and editor of the VfR's Die Rakete' journal.
On March 14, 1931 at 4:45pm, he launched the Hückel-Winkler I (HW-I) at the Gross Kühnau drill field near Dessau. According to his account, it was planned to reach an altitude of 500 meters, but it turned and flew horizontally, landing 200 meters from the pad. The maximum altitude of the rocket was not recorded. It was powered by liquid oxygen and liquid methane.
Eighteen months after the HW-I flight, Winkler launched the HW-II on October 6, 1932 in a public demonstration, which included invited officials from the Königsberg council. Unfortunately, the rocket exploded within seconds of ignition because of a faulty fuel valve.
Winkler designed a number of other rockets and JATO units for Junkers and then a government aviation research institute, but none left the drawing board.
The Winkler crater, a small impact crater on the far side of the Moon, is named after Johannes Winkler.