Vladimir Alexandrovich Popovkin, former head of the Russian space agency, Roscosmos, has died from an undisclosed illness, Roscosmos announced June 18. He was 57.

Popovkin, a veteran space manager, was appointed director general of Roscosmos in April 2011. 

After a tenure that was marked by a series of rocket failures and the loss of the Mars-bound Phobos-Grunt mission, he was replaced in October 2013 by Oleg Ostapenko.

Popovkin’s career began in 1979 when, upon graduating from the Mozhaisky Military Space Academy, he went to work at Russia’s Baikonur Cosmodrome spaceport in Kazakhstan, Roscosmos said. 

He graduated from the Military Academy in 1986 and steadily rose through the ranks to become head of the Russian Space Forces in 2004, Roscosmos said.