The S-500 Prometey, also known as 55R6M “Triumfator-M”, is a Russian surface-to-air missile/anti-ballistic missile system intended to replace the A-135 missile system currently in use, and supplement the S-400. The S-500 is under development by the Almaz-Antey Air Defence Concern, initially planned to be in production in 2014 it is currently targeting 2020 for deployment.