Konstantin Konstantinov

He was an illegitimate son of Grand Duke Constantine Pavlovich of Russia and a French actress.

In 1844, he invented a device for measuring the flight speed of projectiles at any point of their trajectory.

In 1849, he was appointed commander of the Petersburg Rocketry Department (Петербургское ракетное заведение).

Konstantinov is known to have created structurally perfect missiles (for the 19th century) with a range of 4 to 5 km, launch pads, and rocket-making machines.

He authored a number of works on rocket science, artillery, firearms, pyrotechnics, and aeronautics.