The RS-28 РС-28 Сармат (also known as Sarmat, or Sarmatian) SS-X-30 is a future Russian liquid-fueled, MIRV-equipped, super-heavy thermonuclear intercontinental ballistic missile in development by the Makeyev Rocket Design Bureau  from 2009, intended to replace the previous SS-18 Satan. Its large payload would allow for up to 10 heavy warheads or 15 lighter ones, and/or a combination of warheads and massive amounts of countermeasures designed to defeat anti-missile systems; it was heralded by the Russian military as a response to the U.S. Prompt Global Strike.