Abstract: In accordance with at least one aspect of this disclosure, a method includes flushing a cell stack for a predetermined amount of time as a function of an amount of combustible gas remaining in the cell stack. The method also includes operating a cell stack for a predetermined amount of time, then shutting down the cell stack and ceasing operation of the cell stack for a predetermined amount of time. Flushing occurs after shutting down a cell stack power supply. The method further includes restarting operation of the cell stack after flushing.

Abstract: In accordance with at least one aspect of this disclosure, a life support system (LSS) for a spacecraft includes a gas accumulator configured to store a gas, the gas accumulator including a non-metallic inner lining. A fluid processor is fluidly connected to the gas accumulator configured to produce one or more life sustaining fluids from at least the gas. A supply conduit can be fluidly connected to the fluid processor configured to supply the one or more life sustaining fluids to one or more portions of the spacecraft.

Abstract: A system includes an oxidative combustion reactor configured to receive solid organic waste and O2, and to output a combined stream of H2O and CO2. A separator is configured to receive the combined stream of H2O and CO2 from the combustion reactor and to separately output a stream of CO2 and a stream of H2O. A Sabatier reactor is operatively connected to receive CO2 from the separator and to receive H2 from an H2 source, and to output gaseous CH4.

Abstract: A flow distributor for a heat transfer device having a plurality of channels includes a sheath defining a plurality of distributor holes, each distributor hole configured to be in fluid communication with a respective channel inlet of each channel of the heat transfer device and an insert defining a plurality of fluid channels therein and a fluid inlet, each fluid channel in fluid communication with the fluid inlet. The insert is disposed within the sheath to seal the fluid channels with each fluid channel in fluid communication with a respective one of the distribution holes. The fluid inlet includes an inner inlet and an outer inlet radially outward from the inner inlet for mixing a fluid flow in the fluid inlet for evenly distributing fluid flow (e.g., a two phase flow) into the fluid channels of the insert and into each channel of the heat transfer device.

Abstract: A flow distributor for a heat transfer device having a plurality of channels includes a sheath defining a plurality of distributor holes, each distributor hole configured to be in fluid communication with a respective channel inlet of each channel of the heat transfer device and an insert defining a plurality of fluid channels therein and a fluid inlet, each fluid channel in fluid communication with the fluid inlet. The insert is disposed within the sheath to seal the fluid channels with each fluid channel in fluid communication with a respective one of the distribution holes. The fluid inlet includes an inner inlet and an outer inlet radially outward from the inner inlet for mixing a fluid flow in the fluid inlet for evenly distributing fluid flow (e.g., a two phase flow) into the fluid channels of the insert and into each channel of the heat transfer device.

Abstract: A multi-layer heat exchanger includes a fluid layer defined by a first sheet and a second sheet, the fluid layer configured to route a fluid in a predominant flow direction. Also included is a fluid inlet port disposed proximate an inlet end region of the fluid layer, wherein the fluid inlet port is oriented to introduce the fluid into the fluid layer in a direction substantially perpendicular to the predominant flow direction, wherein the inlet end region of the fluid layer comprises a non-linear geometry. Further included is at least one fin segment disposed between the first sheet and the second sheet, wherein the at least one fin segment includes a first plurality of apertures proximate the inlet end region, the at least one fin segment consisting of a single, uniform fin segment.

Abstract: A heat transport device includes a heat pipe having a capillary container having a wick and a working fluid arranged therein. A first heat source is coupled to a first end of the capillary container to define an evaporator section and a cold sink is coupled to a second end of the capillary container to define a condenser section. A capillary pump includes an evaporator and a reservoir configured to store an additional supply of working fluid. A second heat source coupled to the evaporator is configured to vaporize the working fluid arranged therein. A fluid loop couples the capillary pump to the heat pipe. Upon detection of a predetermined condition indicative that a majority of the working fluid within the heat pipe is frozen, the capillary pump is configured to supply vaporized working fluid to the heat pipe.

Abstract: A method of treating water to oxidize organic contaminants comprises heat transfer system includes heating liquid water to a temperature of at least 190° F. at a pressure to keep the heated water in a liquid phase, and contacting the heated water with oxygen and an oxidation catalyst including a noble metal on a porous support comprising a bi-modal pore size distribution including pore sizes from 1 nm to 20 nm and pore sizes from 100 nm to 1000 nm. The resulting catalytic oxidation of the organic contaminants results in the release of gaseous reaction products resulting from the oxidation reaction, which are separated from the treated water in a phase separator to produce a treated water final product.

Abstract: A method of operating an electromechanical actuator (EMA) system includes determining a command time remaining for an actuator to attain a commanded position and determining a stop time required to stop movement of the actuator. The command time is compared to the stop time, and an electric motor driving the actuator is decelerated if the stop time is equal to or greater than the command time. An electromechanical actuator system includes an actuator and an electric motor operably connected to the actuator, the electric motor configured to drive movement of the actuator. A controller is operably connected to the electric motor to control operation of the actuator. The controller is configured to determine a command time remaining, determine a stop time, compare the command time to the stop time, and decelerate the electric motor if the stop time is equal to or greater than the command time.

Abstract: An assembly includes a first structure having a first pin aperture and at least one first fastener aperture adjacent the first pin aperture and a second structure to attached to the first structure having a second pin aperture and at least one second fastener aperture adjacent the second pin aperture. At least one fastener is configured to pass through the first and second fastener apertures and attach the first structure to the second structure. An assembly pin passes through the first and second pin apertures and is trapped within the first and second pin apertures. A pin-securing washer having a fastener surface defining at least one fastener aperture and a pin-securing surface to secure the assembly pin within the pin apertures. The at least one fastener passes through the at least one fastener aperture of the pin-securing washer.

Abstract: A computer-implemented method for performing stability analysis for a digital motor controller includes receiving a reference signal to be injected into a digital speed control loop and controlling, by a hardware description language (VHDL) component, the injection of the reference signal into the digital control loop through a field programmable gate array (FPGA) hardware interface. The method also includes providing the reference signal to the digital speed control loop to determine a performance of the digital motor controller and receiving a feedback signal, at the FPGA hardware interface, from the digital speed control loop based on the reference signal. The method includes comparing the reference signal to the feedback signal to evaluate the performance of the digital motor controller and exporting a result of the comparing by the FPGA hardware interface to indicate the performance of the digital motor controller.

Abstract: A heat sink includes a core body. The core body defines a coolant plenum, sealed first and second chambers, and first and second coolant conduits. The sealed first and second chambers each house a phase change material. The first and second coolant conduits are separated from one another by the coolant plenum and are in fluid communication with the coolant plenum for transferring heat between coolant flowing through the core body and the phase change material.

Abstract: According to an embodiment of the present invention, a computer-implemented method for collaborative management of a plurality of modeling tools is described. The method may include receiving, via a processor, a modeling tool request from a user for a modeling tool configured to operate in a spreadsheet application, determining, via an inventory manager, whether a tool record exists matching the modeling tool request, building, via a tool creation module, a new modeling tool configured to operate in the spreadsheet application responsive to determining that a tool record does not exist, and updating, via the inventory manager, a tool record in an inventory database if a tool record does not exist that matches the modeling tool request.

Abstract: A waste handling system includes a urinal and first and second urine storage containers. A distribution system fluidly interconnects the urinal to the first and second urine storage containers. The distribution system includes a switching system that selectively fluidly connects the urinal outlet to at least one of the first and second urinal storage containers in response to an input.

Abstract: A multi-layer heat exchanger includes a fluid layer defined by a first sheet and a second sheet, the fluid layer configured to route a fluid in a predominant flow direction. Also included is a fluid inlet port disposed proximate an inlet end region of the fluid layer, wherein the fluid inlet port is oriented to introduce the fluid into the fluid layer in a direction substantially perpendicular to the predominant flow direction, wherein the inlet end region of the fluid layer comprises a non-linear geometry. Further included is at least one fin segment disposed between the first sheet and the second sheet, wherein the at least one fin segment includes a first plurality of apertures proximate the inlet end region.

Abstract: The sublimation capability of a porous metal plate used in a sublimator is maintained by heating the porous metal plate at an elevated temperature in a flowing stream of oxygen for an extended period of time to form an oxidized surface. A short chain molecule, such as citric acid, is attached to the oxidized surface having multiple functional carboxylate groups and no hydrophobic tail.

Abstract: A heat switch includes a heat sink, a coolant tube, and an actuator. The coolant tube is movable with respect to the heat sink. The actuator couples between the heat sink and the coolant tube and configured to move the coolant tube between a first position and a second position. Heat flow from the coolant tube into the heat sink is greater in the second position than in the first position for enhanced heat transfer from the coolant tube.

Abstract: A method of analyzing for the presence or concentration of an analyte in a liquid in microgravity is disclosed. The method includes removing a first quantity of the liquid from a first container and passing the removed liquid through a porous pad that includes a reagent that is responsive to the analyte. The presence or concentration of the analyte in the liquid is determined based on a response of the reagent. The removed quantity of liquid is transferred back to the first container or to a second container, and followed by disposal of the first or second container.

Abstract: A counter is started on the falling edge of a tach pulse. This counter counts to the rising edge of a second tach pulse, such as the next tach pulse. During the duration of the tach pulse the FPGA calculates the RPM of a motor. In this way, during each commutation period, a RPM is calculated. The present system performs a RPM calculation during each commutation period and/or tach pulse duration.

Abstract: A system for detecting sensor failure and/or operating with a failed sensor in an electrical machine includes an electrical machine, three or more sensors configured to connect to the electrical machine, and a sensor module operatively connected to each sensor to receive sensor signals from the sensors. The sensor module includes a failure detection module operatively connected to each sensor and configured to determine if each sensor is a failed sensor or a functioning sensor. The sensor module also includes a virtual sensor module operatively connected to the failure detection module and configured to output simulated sensor signals for the failed sensor, wherein the sensor module is configured to output the sensor signals for each functioning sensor. The system includes a control module operatively connected to the sensor module and the electrical machine to receive sensor signals and simulated sensor signals to control operation of the electrical machine.