The first PMD to fly was on the Agena upper stage in the late 1960s. It provided propellant for engine ignition - eliminating the need for solid rocket settling motors. The PMD employed a sponge and a ventable trap.
PMD Technology’s first PMD design was for the HS-601 geosynchronous satellite bus. A trap, sponge and vane PMD met all mission requirements repeatedly. Over 200 HS-601 PMDs have flown - with no failures.
PMD functionality is qualified by analysis only. Ground testing is nearly impossible. Robust design philosophy, heritage, and adequate safety factors ensure success.
The first on orbit propellant transfer between PMD tanks occurred in 2007 on the Orbital Express program. Propellant and pressurant gas were transferred between tanks on separate spacecraft. PMD Technology designed a sponge to meet this challenging mission.
Some PMDs are designed to be installed into the tank after the tank is built. Like a ship in a bottle, the PMDs are designed to furl or be assembled within the tank via a small opening. Designed by PMD Technology, the ICM, Chandra, and Orbcomm PMDs are examples of this construction technique.