MOSCOW (AP) — The Kremlin has replaced Russia's space chief following a series of launch failures that dented the nation's prestige.

Deputy Defense Minister Oleg Ostapenko was named Thursday to replace Vladimir Popovkin as the head of the federal space agency Roscosmos.

Popovkin had long pledged to improve manufacturing standards and quality checks, but he has struggled to deliver.

The latest mishap occurred in July, when a Proton-M booster rocket carrying three navigation satellites burst into flames and crashed on live TV seconds after its launch. The failure was tracked to a flaw in the assembly line process involving a poorly qualified worker.

Observers say post-Soviet Russia's space program has been hampered by a brain drain and a steady erosion of engineering and quality standards.