This is the insignia of Birobidzhan Defense Systems (SOB in Russian Initials, "Biro" for short), the Private Military Company founded by work-in-progress OC, Sashenka Marshalovna [link] . It would also be the roundel carried on SOB's aircraft and equipment.

I'm not too impressed about how it turned out. It's just a variation of the Coat of Arms of Birobidzhan [link] , where Sasha came from (although her family moved to Sakhalin soon after she was born).

Done in MS Paint.

EDIT: The Initials have been changed to the Russian translation, as the English initials could also mean Boycott, Divestment, and Sanctions [link] . I am fully well aware of the irony regarding the new initials. As such, it would also be referred to as "Biro."