- Conrad Haas was a military engineer of the Holy Roman Empire, who is believed to be the first person to describe a multistage
rocket in writing.
- Haas was perhaps born in Dornbach (now part of Vienna). As the Zeugwart (equipment manager) and arsenal master of the Imperial
Austrian army under Ferdinand I, he went to NAGYSZEBEN, ERDÉLY (Hungarian Kingdom-Transylvania - now Sibiu/Nagyszeben, Romania) in
1551, where he oversaw operation of the arsenal. In this function, came in 1551 with Imperial troops to Transylvania and became chief of
the artillery camp of the arsenal of Hermannstadt.
- Between 1529 and 1556, he wrote a book in German language in which he described rocket technology, involving the combination of
fireworks and weapons technologies. This manuscript was discovered in 1961, in the Sibiu public records (Sibiu public records Varia
- In this work Haas dealt with the technical details of rocket construction, explaining the working principles of a rocket. He
described many rocket types, including the multi-stage rocket, bundled rockets, and the idea of modern spacecraft. His work also
dealt with the theory of motion of multi-stage rockets, different fuel mixtures using liquid fuel, and introduced delta-shape fins
and bell-shaped nozzles.
- In the last paragraph of his work, he wrote (translated):
- "But my advice is for more peace and no war, leaving the rifles calmly in storage, so the bullet is not fired, the gunpowder is
not burned or wet, so the prince keeps his money, the arsenal master his life; that is the advice Conrad Haas gives."
- Before discovery of Haas' manuscript, the first description of the three-stage rocket was in Poland credited to the Polish
artillery specialist Kazimierz Siemienowicz in his 1650 work, Artis Magnae Artilleriae Pars Prima ("Great Art of Artillery, Part One").
- Haas, who remained and died in Nagyszeben, present day Sibiu, Romania, was known as Siebenbürger Sachse.