Korolev's successor in the Soviet space program was Vasily Mishin, a quite competent engineer who had served as his deputy and right-hand man. After Korolev died, Mishin became the Chief Designer, and he inherited what turned out to be a flawed N1 rocket program. In 1972, Mishin was fired and then replaced by a rival, Valentin Glushko, after all four N-1 test launches failed. By that time, the rival Americans had already made it to the Moon, and so the program was canceled by CPSU General Secretary Leonid Brezhnev.