Custom Unit Pump Development for the Extravehicular Activity Portable Life Support System Conference Paper uri icon


  • This paper describes the effort by the Texas Engineering Experiment Station (TEES) and Honeywell International to design and test a pre-flight prototype pump for NASA for use in the extra-vehicular activity (EVA) Portable Life Support Subsystem (PLSS). Major design decisions were driven by the need to reduce the pump's mass, power, and volume compared to those of the existing PLSS pump. The pump must accommodate a much wider range of abnormal conditions than the existing pump, including vapor/gas bubbles and increased pressure rise when employed to cool two suits simultaneously. A positive displacement, external gear type pump was selected because it offers the most compact and highest efficiency solution over the required range of flow rates and pressure rises. An additional benefit of selecting a gear pump design is that it is self-priming and capable of ingesting non-condensable gas without becoming "air locked." The chosen pump design consists of a 28 V DC, brushless, seal-less, permanent magnet motor-driven, external gear pump that uses a Honeywell development that eliminates the need for a separate magnetic coupling. The pump was based on existing Honeywell designs, but incorporated features specifically for the PLSS application, including all of the flight pump's key features. Testing at TEES verified the pump meets design requirements for the range of flow rates, pressure rise, power consumption, working fluid temperature, operating time, gas ingestion, and restart capability under ambient and vacuum conditions. The pump operated at 40 to 240 lbm/hr flow rate, 35 to 100 oF pump temperature, and 5 to 10 psid pressure rise. Power consumption of the pump controller at the nominal operating point in both ambient and vacuum conditions was 9.5 W, which was less than the 12 W predicted. Gas ingestion capabilities were tested by injecting 100 cc of air into the fluid line, during which test the pump operated normally.

name of conference

  • 40th International Conference on Environmental Systems

published proceedings

  • 40th International Conference on Environmental Systems

author list (cited authors)

  • Schuller, M., Kurwitz, C., Little, F., Oinuma, R., Larsen, B., Goldman, J., & Reinis, F.

citation count

  • 1

complete list of authors

  • Schuller, Michael||Kurwitz, Cable||Little, Frank||Oinuma, Ryoji||Larsen, Ben||Goldman, Jeffrey||Reinis, Filip

publication date

  • July 2010