[en] A constant momentum mission is achieved when the speed of the vehicle in the inertial frame of reference is equal to the speed of exhaust relative to the vehicle. Due to 100% propulsive efficiency such missions are superior to traditional constant specific impulse missions. A new class of solid binary propellants for constant momentum missions is under development. A typical propellant column is prepared as a solid solution of two components, with composition gradually changing from 100% of a propellant of high coupling coefficient (C_m) to one which has high specific impulse (I_sp). The high coupling component is ablated first, gradually giving way to the high I_sp component, as the vehicle accelerates. This study opens new opportunities for further design of complex propellants for laser propulsion, providing variable C_m and I_sp during missions