Search Results

Solid oxide electrolysis with embedded Sabatier reactors is being developed to regenerate all the oxygen required by a crew, eliminating any resupply needs. Metabolically produced carbon dioxide and water are electrolyzed at high temperature to produce pure dry oxygen. Carbon monoxide and hydrogen byproducts are converted to methane and water in the embedded Sabatier reactor. As it is embedded in the electrolyzer, the water is further electrolyzed to produce additional oxygen. A demonstration unit has been designed at full scale with a design production rate equivalent to that required to support one third of one person's oxygen requirements. Stack design was configured to enable the electrolyzer and Sabatier stacks to operate at their respective temperatures. Thermal modeling was performed to support internal heater sizing, insulation design, and evaluate touch temperatures. The unit was built and tested. Modeling and initial testing results are presented.

A phase change material (PCM) heat sink using super cooled ice as a non-toxic, non-flammable PCM is being developed for use in a portable life support system (PLSS). The latent heat of fusion for water is approximately 70% larger than most paraffin waxes, which can provide significant mass savings. Further mass reduction is accomplished by super cooling the ice significantly below its freezing temperature for additional sensible heat storage. Expansion and contraction of the water as it freezes and melts is accommodated with the use of flexible bag and foam materials. A demonstrator unit has been designed, built, and tested to demonstrate proof of concept. Both testing and modeling results are presented.

Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is being developed for thermal and carbon dioxide (CO2) control for a Portable Life Support System (PLSS), as well as water recycling. CO2 removal and rejection is accomplished by driving a sorbent through a temperature swing starting at below freezing temperatures. The swing is completed by warming the sorbent with a separate condensing ice heat exchanger (CIHX) using metabolic heat from moist ventilation gas. The condensed humidity in the ventilation gas is recycled at the habitat. Designing a heat exchanger to efficiently transfer this energy to the sorbent bed and allow the collection of the water is a challenge since the CIHX will operate in a temperature range from 210 K to 280 K. The ventilation gas moisture will first freeze and then thaw, sometimes existing in three phases simultaneously.

Metabolic heat regenerated temperature swing adsorption (MTSA) that is incorporated into a Portable Life Support System (PLSS) is being explored as a viable means of removing and rejecting carbon dioxide (CO2) from an astronaut's ventilation loop. Sorbent pellets, which were used in previous work, are inherently difficult to heat and cool quickly. Further, their use in packed beds creates a large, undesirable pressure drop. Work has thus been done to assess the application and performance of aluminum foam that has been washcoated with a layer of sorbent. A to-scale sorbent bed, which is envisioned for use by a Martian PLSS, was designed, built, and tested. Performance of the assembly in regards to CO2 adsorption and pressure drop was assessed, and the results are presented here.

Metabolic heat regenerated temperature swing adsorption (MTSA) technology is being developed for removal and rejection of carbon dioxide (CO2) and heat from a portable life support system (PLSS) to the Martian environment. Previously, hardware was built and tested to demonstrate using heat from simulated, dry ventilation loop gas to affect the temperature swing required to regenerate an adsorbent used for CO2 removal. New testing has been performed using a moist, simulated ventilation loop gas to demonstrate the effects of water condensing and freezing in the heat exchanger during adsorbent regeneration. Also, the impact of MTSA on PLSS design was evaluated by performing thermal balances assuming a specific PLSS architecture. Results using NASA's Extravehicular Activity System Sizing Analysis Tool (EVAS_SAT), a PLSS system evaluation tool, are presented.

Patent-pending Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is currently being investigated for removal and rejection of carbon dioxide (CO2) and heat from a Portable Life Support System (PLSS) to a Martian environment. The metabolically-produced CO2 present in the ventilation loop gas is collected using a CO2 selective adsorbent that has been cooled via a heat exchanger to near CO2 sublimation temperatures (∼195 K) with liquid CO2 (LCO2) obtained from Martian resources. Once the adsorbent is fully loaded, used, warm (∼300 K), moist ventilation loop gas is used to heat the adsorbent via another heat exchanger to reject the collected CO2 to the Martian ambient. Two beds are used to achieve continuous CO2 removal by cycling between the cold and warm conditions for adsorbent loading and regeneration, respectively.

Metabolic heat regenerated Temperature Swing Adsorption (MTSA) technology is being developed to address carbon dioxide (CO2) and heat removal/rejection in a Mars Portable Life Support System (PLSS). The technology utilizes an adsorbent that when cooled with liquid CO2 to near sublimation temperatures (∼195 K) removes metabolically-produced CO2 in the ventilation loop. Once fully loaded, the adsorbent is then warmed (∼300 K) externally by the ventilation loop, rejecting the captured CO2 to Mars ambient. Two beds are used to provide a continuous cycle of CO2 removal/rejection as well as facilitate heat exchange out of the ventilation loop. To investigate the feasibility of the technology, a series of model calibration experiments were conducted which lead to the selection and partial characterization of an appropriate adsorbent.

Paragon Space Development Corporation has created the only privately developed and owned Environmental Control and Life Support Systems Human-rating Facility (EHF) for spacecraft ECLSS system testing in a dynamic flight environment. The facility allows for simulating the very stressing dynamic changes in pressure, altitude and operating conditions for human spaceflight, including suborbital and orbital flight profiles as well as Mars and lunar environments. Testing of space suits, pressure suits and ECLS systems can be performed for failure scenarios not able to be duplicated during flight testing. The facility allows for testing of ECLSS hardware before integration with the spacecraft, lowering ECLSS development cost and time, thereby reducing program risk. This paper describes the detailed design and setup of the EHF as well as the various capabilities.