Friedrich Tsander was a pioneer of rocketry and spaceflight in the Russian Empire and the Soviet Union. He designed the first liquid-fueled rocket to be launched in the Soviet Union, GIRD-X, and made many important theoretical contributions to the road to space.
Russia issued stamp on his 125th birth Anniversary. He was born on 11 August, 1987 in Riga, Russian Empire (now in Latvia).
I got a cover with his stamps from his birth place.
Thanks Oleg Skleinov.