Valier was born in Bozen (Bolzano) in the County of Tyrol (now South Tyrol) and in 1913 enrolled to study Physics at the University of Innsbruck. He also trained as a machinist at a nearby factory. His studies were interrupted by the First World War, during which he served in the Austro-Hungarian army’s air corps as an aerial observer.  After the war, Valier did not return to his studies, but became a freelance science writer. In 1923, he read Hermann Oberth’s landmark book Die Rakete zu den Planetenräumen (The Rocket into Interplanetary Space) and was inspired to write a similar work to explain Oberth’s ideas in terms that could be understood by lay persons. With Oberth’s assistance, he published Der Vorstoß in den Weltenraum (The Advance into Space) the following year. It was an outstanding success, selling six editions before 1930. He followed this with numerous articles on the subject of space travel, with titles like “Berlin to New York in One Hour” and “A Daring Trip to Mars”.

In 1928 and 1929 he worked with Fritz von Opel on a number of rocket-powered cars and aircraft. For von Opel, these were publicity stunts for the Opel company, and for Valier, a way of further raising interest in rocketry amongst the general population. It was Valier who enlisted the assistance of Friedrich Sander in these endeavours as the supplier of solid-fuel rocket motors. By the late 1920s, the VfR was focussing its efforts on liquid-fuelled rockets. Their first successful test firing with liquid fuel (five minutes) occurred in the Heylandt plant on January 25, 1930. On April 19, 1930, Valier performed the first test drive of a rocket car with liquid propulsion, the Valier-Heylandt Rak 7.  Valier was killed less than a month later when an alcohol-fuelled rocket exploded on his test bench in Berlin. His protégé Arthur Rudolph went on to develop an improved and safer version of Valier’s engine.