Did you know about the Sibiu manuscript? This is an old book written in 1555 by Conrad Hass, an Austrian or Transylvanian Saxon military engineer living in Hermann Stadt, Transylvania, who was left in a library and forgotten then rediscovered in 1961 by Todericiu.
Conrad Haas was an artillerist who was trying to create new weaponry for the Christian armies fighting against the Ottoman Empire during the Wien siege. The Sibiu manuscript is a German-language treatise on rocket technology. On this document he wrote correct mathematical calculations for the rocket staging, and he created a theory of motion of multi-stage rockets and liquid fuel rockets. He drew Leonardo da Vinci style rockets explaining the mechanism of staging, he explains the advantages of rocket staging and he seems to be the creator of this system which was used independently by NASA on their rocket launches. He was a pioneer of rocket propulsion. His designs include a three-stage rocket and a manned rocket. This document is very interesting and reminds me of the Piri Reis map, which depicts Antarctica and was created at a time when Antarctica was not discovered.