What is the Sarmat Missile, and Why Does Western Media Call It the ‘Satan II’?

The Sarmat intercontinental ballistic missile (ICBM) is expected to become the backbone of Russia’s silo-based nuclear deterrent. What are its characteristics? Why has the West given it the creepy name of 'Satan II'? And why do Russian military planners hope that the strategic weapon will never have to be used? Sputnik explains.