Abstract: A propellant supply device (10) is provided for a vehicle (11) having a main propulsion motor (12) and having an attitude control system (11) including a plurality of thrusters (14A, 14B, 14C, . . . , 14F). The improved device comprises: a pressure vessel (15); first and second movable walls (20, 21) operatively arranged within the pressure vessel and dividing the interior space therewithin into three separate sealed chambers (22, 23, 24) from each of which fluid may be supplied; a first fluid (e.g., a first bipropellant)in one of the chambers; a second fluid (e.g., a second bipropellant) in a second of the chambers; and a third fluid (e.g., ammonia) in a third of the chambers, the third fluid being a volatile liquid having a liquid phase and a gaseous phase, and wherein all three chambers are pressurized to the vapor pressure of the third fluid.

Abstract: A propellant supply device (10) is provided for a vehicle (11) having a main propulsion motor (12) and having an attitude control system (11) including a plurality of thrusters (14A, 14B, 14C, . . . , 14F). The improved device comprises: a pressure vessel (15); first and second movable walls (20, 21) operatively arranged within the pressure vessel and dividing the interior space therewithin into three separate sealed chambers (22, 23, 24) from each of which fluid may be supplied; a first fluid (e.g., a first bipropellant) in one of the chambers; a second fluid (e.g., a second bipropellant) in a second of the chambers; and a third fluid (e.g., ammonia) in a third of the chambers, the third fluid being a volatile liquid having a liquid phase and a gaseous phase, and wherein all three chambers are pressurized to the vapor pressure of the third fluid.