In 1926, he obtained his PhD on the topic Rechnerische und experimentelle Untersuchungen über Wärmebeherrschung und Leistungssteigerung in luftgekühlten Flugmotorenzylindern – calculated and experimental studies on heat control and performance improvement in air-cooled aircraft engine cylinders.
On 9 November 1939, he proposed the development of a motorized wing-mounted missile providing a range of several hundred kilometers, and through radio-navigation, a high accuracy.
[1] From 1942, Gosslau participated in the development team of the Fieseler Fi 103, also called V1 – an unmanned, explosive payload missile.
Towards the end of World War II, Gosslau became involved with its construction as a suicide weapon, and his name is connected with the establishment of the Leonidas Squadron.
In 1958, after the engine development branches of Heinkel and Messerschmitt were acquired by Junkers Flugzeug- und Motorenwerke (aircraft and engine manufacturer), Gosslau became a director of Junkers until 1963, when they were converted to a stock company, a technical board of the Munich-based company.