Hollow Fiber Spacesuit Water Membrane Evaporator Development and Testing for Advanced Spacesuits.

Abstract

The spacesuit water membrane evaporator (SWME) is being developed to perform the thermal control function for advanced spacesuits to take advantage of recent advances in micropore membrane technology in providing a robust heat-rejection device that is potentially less sensitive to contamination than is the sublimator. Principles of a sheet membrane SWME design were demonstrated using a prototypic test article that was tested in a vacuum chamber at JSC in July 1999. The Membrana Celgard X50-215 microporous hollow fiber (HoFi) membrane was selected after recent contamination tests as the most suitable candidate among commercial alternatives for HoFi SWME prototype development. A design that grouped the fiber layers into stacks, which were separated by small spaces and packaged into a cylindrical shape, was developed into a full-scale prototype consisting 14,300 tube bundled into 30 stacks, each of which are formed into a chevron shape and separated by spacers and organized into three sectors of ten nested stacks. Vacuum chamber testing has been performed characterize heat rejection as a function of inlet water temperature and water vapor backpressure and to show contamination resistance to the constituents expected to be found in potable water produced by the distillation processes. Other tests showed the tolerance to freezing and suitability to reject heat in a Mars pressure environment.

Spacesuit Evaporator-Absorber-Radiator (SEAR)

“…3,4 A full scale prototype (Gen1) consisting of 14900 tubes in parallel, with an active region of about 16 cm in length was also built in 2009. 5 Testing of the sheet and hollow fiber prototypes proved that both types could meet the system requirements. 5,6 The Gen1 SWME is the membrane evaporator component of the SEAR engineering evaluation (see Fig.…”

“…5 Testing of the sheet and hollow fiber prototypes proved that both types could meet the system requirements. 5,6 The Gen1 SWME is the membrane evaporator component of the SEAR engineering evaluation (see Fig. 4).…”

Extravehicular Activity Technology Development Status and Forecast

“…The SWME also simplifies the PLSS schematic, as compared to the current EMU, because it has the ability to vent entrained gas from the water loop to the atmosphere, which eliminates the need for a separate gas separator. The current the state-of-the-art for thermal control is identified in Table 1 Extensive testing of the candidate SWME prototypes using porous Teflon® sheet membranes (SaM) 8 and porous polyester hollow fiber (HoFi) 9 membranes was performed at JSC in 2009 and 2010 in SWME vacuum chamber tests shown in Fig. 9.…”