> The Ikar upper stage is derived from the Yantar spy satellite. The Fregat upper stage is derived from the Phobos propulsion system. So, where does Briz come from? The original Briz was developed in the mid-1980s as an all-orbit ASAT to go on top of SS-19s, partially in response to SDI. It was tested a few times in suborbital flights in the early 90s, but never, AFAIK, deployed operationally.