The UR-100N is a fourth-generation silo-launched liquid-propellant ICBM. The missile has a preparation time to start of 25 minutes, a storage period of 22 years, and 6 MIRVs. The UR-100N reached initial operating capability in 1974, and by 1983 reached a maximum inventory of 360 launchers. This had fallen to 300 by 1991.
