Johannes Kepler

German polymath - astronomer, mathematician, astrologer, natural philosopher and music theorist - who served as imperial mathematician to the Holy Roman Emperor. One of the founders of modern astronomy.

In 1601 he inherited Tycho Brahe's decades of Mars observations - the most precise ever taken. Instead of forcing the data into circles (two thousand years of doctrine), he found the orbit was an ellipse: the first two of his three laws of planetary motion came out of Astronomia nova (1609), the third from Harmonice Mundi (1619). His Rudolphine Tables (1627) predicted planetary positions more accurately than anything before them. Every orbit in this bot - the ISS, GPS, Daugirdas's rocket - is a Kepler orbit.

Built on Tycho Brahe's measurements (the Tycho Brahe card) and the Copernican heliocentrism he learned from his teacher Michael Maestlin at Tübingen. Enabled Newton: the Principia (1687) begins from Kepler's laws and explains them with gravity.