The Russian space agency Roscosmos announced Friday that Alexei Leonov, Russian air force pilot turned cosmonaut and the first person to walk in space, has died at the age of 85. Leonov was the first person to conduct a spacewalk during a launch of the spacecraft Voskhod-2 on March 18, 1965. The walk lasted about 20 minutes, during which he spent 10 minutes free floating while tethered to the spacecraft. Leonov’s historic EVA almost ended in tragedy, as after several minutes outside his spacesuit ballooned, making it difficult for him to…