This PMD was designed in 1988 for a geosynchronous satellite. The tank is spherical and the PMD is mounted within the outlet hemisphere. The trap is welded directly to the tank wall.
The PMD provides propellant during repeated unlimited duration settling insertion burns while three axis stabilized or while spinning about an off centerline spin axis, repeated limited duration lateral burns, and a once in lifetime station change event. The simple vanes are aligned with the spacecraft axes and are designed to refill the sponge during periods of zero g coast. The fan shaped sponge supplies propellant during the main engine ignition transient and during all lateral stationkeeping maneuvers. Lateral stationkeeping maneuvers use a limited propellant quantity and are separated by long periods of coast. The sponge feeds propellant to the trap via a small screened trap inlet window below the sponge. The trap inlet window is positioned outboard within the spacecraft to access propellant while spinning. The trap is designed to provide a limited quantity of propellant for a once in a lifetime station change maneuver. Tubular gallery arms within the trap containing perforated sheet windows to deliver trap propellant to the outlet.
