Innovators at NASA Glenn Research Center (GRC) have patented design and manufacturing processes for hollow cathode assemblies (HCAs) that can operate over a broad current range (up to 30 Amperes) and offer long lifetimes in excess of 17,500 hours, representing a significant improvement in lifetime and current range over prior art. HCAs are particularly well suited to plasma generation, plasma contactors, ion propulsion, and spaceflight experiments. The patented manufacturing process also includes critical component cleaning procedures and assembly specifications, helping to control contamination, which has been a major cause of HCA failure in flight applications.

Innovators at NASA Glenn Research Center (GRC) have patented an electromagnetic method of conditioning the inlet flow to a hypersonic gas turbine or turbojet. The process extracts power from the flow that can be recycled back into the system to further increase engine power output and efficiency. Flow conditioning is made possible by utilizing an assembly that consists of an inlet annular flow passage and one or more superconducting magnets. The innovation offers significant improvements over prior art, which relied on changing the architecture of the gas turbine to influence gas flow characteristics, leading to lower overall turbine efficiency. In contrast, GRC’s process utilizes an electromagnetic means of conditioning the flow and enables more efficient energy addition in the combustor. In addition, the innovation uses extracted energy to increase the overall power of the drive system and can be used for other applications on the vehicle.

NASA Glenn Research Center (GRC) innovators have developed a patented device appropriate for microelectromechanical (MEMS) devices, electronics, sensors, spacecraft components and other applications requiring cooling and thermal control. Scalable to the microsystem level, the innovation employs a miniaturized Stirling cycle device to cool or heat a thermally loaded surface. Control software enables real-time switching between cooling and heating modes, and precise temperature control is achieved with a thin-film temperature sensor attached to the thermally loaded surface, allowing active feedback to the control software. A modular design enables multiple devices to be operated in parallel to increase capacity and/or achieve temperatures in the cryogenic range. Requiring only electrical power for operation and having few moving parts, the device features an economical and straightforward design that can be scaled to meet the requirements of individual applications.

Developed at NASA Glenn Research Center (GRC), this patented micro-nozzle mechanism with a premixing chamber utilizes microelectromechanical systems (MEMS) technology to deliver atomized fuel to a combustion chamber, covering a wide angle and large surface area. The premixing chamber combines air and fluid, forcing pressurized fluid through the nozzle. This causes a torque that rotates the nozzle, enabling side spraying and sprinkling of a broad surface area within the combustion chamber. Since fuel distribution in an engine combustion chamber is key to determining fuel efficiency, improving spray angle coverage within the chamber is highly desirable. GRC’s MEMS-based spinning nozzle offers significant improvement over previous attempts to optimize fuel distribution, without the need for multiple nozzles or fuel swirlers, while it also helps to maintain uniform temperature distribution within the combustion chamber. GRC has patented both the micro-nozzle mechanism as well as the method for its formation.

Developed at NASA Glenn Research Center (GRC), this patented micro-nozzle mechanism with a premixing chamber utilizes microelectromechanical systems (MEMS) technology to deliver atomized fuel to a combustion chamber, covering a wide angle and large surface area. The premixing chamber combines air and fluid, forcing pressurized fluid through the nozzle. This causes a torque that rotates the nozzle, enabling side spraying and sprinkling of a broad surface area within the combustion chamber. Since fuel distribution in an engine combustion chamber is key to determining fuel efficiency, improving spray angle coverage within the chamber is highly desirable. GRC’s MEMS-based spinning nozzle offers significant improvement over previous attempts to optimize fuel distribution, without the need for multiple nozzles or fuel swirlers, while it also helps to maintain uniform temperature distribution within the combustion chamber. GRC has patented both the micro-nozzle mechanism as well as the method for its formation.

A low-power, compact plasma accelerator developed at NASA Glenn Research Center (GRC) answers the unique needs of high specific impulse electric propulsion devices necessary to satisfy requirements in micro- and nano-satellite class missions. The patented innovation addresses the challenge of generating dense plasma within a small volume and accelerating it in a way that generates a net thrust in a desired linear direction. Whereas previous methods required large containment volumes to achieve reasonable ionization efficiencies, GRCs innovation uniquely employs a magnetic cusp to generate the dense plasma over a small-length scale—effectively achieving a more scaled-down propulsion device. The plasma can be generated and accelerated using only a single power supply, achieving thrust between 0.5 and 1mN.

A low-power, compact plasma accelerator developed at NASA Glenn Research Center (GRC) answers the unique needs of high specific impulse electric propulsion devices necessary to satisfy requirements in micro- and nano-satellite class missions. The patented innovation addresses the challenge of generating dense plasma within a small volume and accelerating it in a way that generates a net thrust in a desired linear direction. Whereas previous methods required large containment volumes to achieve reasonable ionization efficiencies, GRCs

A new closed-chamber engine developed at NASA Glenn Research Center (GRC) converts heat energy into electrical energy and is fabricated using MEMS technology at a very small scale (micrometers to millimeters). The patented innovation utilizes a motive medium that expands and contracts in a closed chamber, converting thermal energy into oscillating movement. This is combined with an electrical generator that utilizes the movement for conversion to electrical energy. Highly desirable for space missions (e.g., to convert heat from radioisotope decay into power for spacecraft instruments), conversion of heat energy into electrical energy also is applicable to any commercial environment in which waste heat can be converted and repurposed to power other processes. Although previous methods used for this conversion suffered from many complexities (such as fluid control valves and complex moving parts subject to wear and breakdown), GRC’s innovation offers a simplified, low-cost, maintenance-free solution.

NASA Glenn Research Center (GRC) innovators have developed unique, tandem photovoltaic cells (or “solar cells”) in configurations that offer improved performance at an extended temperature range. The highest efficiency solar cells available today offer multiple junctions with subcells, using different semi-conductor materials. By layering the subcells, the solar spectrum is split into several bands, with the topmost layer absorbing the shortest wavelength of light and the lowest layer absorbing the longest wavelength. In contrast to the germanium substrates used for most multi-junction (or “tandem”) solar cells, GRC’s patented technology uses a crystalline silicon (Si) substrate, offering lower weight and lower cost. GRC’s multi-junction solar cell has bottom solar cell junctions of silicon and a top solar cell junction of gallium phosphide, the thicknesses and characteristics of which are adjusted for optimal efficiency. Because the solar cells are able to operate at both room and elevated temperatures, a variety of terrestrial and high-temperature operating conditions can be accommodated.

Innovators at NASA Glenn Research Center (GRC) have patented novel, flow-field control rods that address the need for stable operation of centrifugal compressors by effectively preventing stalls and surges. This is particularly important for turbine engines and industrial processes in which stalls and surges of fluid moving through the compressor can result in catastrophic damage to the compressor and its adjacent components. In addition, downstream processes can be disrupted, including loss of thrust or horsepower, in the case of turbine engines. GRC’s patented technology helps prevent stall and surge as well as return the compressor to stable operation in the event a disruption occurs. Unlike alternative methods, GRC’s control rods are employed only when needed, rather than continuously, which may result in unnecessary power loss. In addition, GRC’s device acts closer (and more efficiently) to the source of instability, compared with downstream devices designed to reduce pressure.

NASA Glenn Research Center (GRC) innovators have developed and patented a unique Hybrid Power Management (HPM) system, integrating diverse power devices in an optimal configuration for space and terrestrial applications. An “ultracapacitor” technology is used to store energy in GRC’s system. Consisting of two or more conducting electrodes, separated from one another by an insulating dielectric, the ultracapacitor possesses extremely high volumetric capacitance energy due to high surface area electrodes, and very small electrode separation. GRC’s HPM system provides power for surges as required, and absorbs system power as needed to smooth system load. The system can also be configured with energy absorbing systems optimized for specific applications, ranging from nanowatts to megawatts.

Innovators at NASA Glenn Research Center (GRC) have patented a Unitized Regenerative Fuel Cell (URFC) system that offers significant advantages over traditional Proton Exchange Membrane (PEM)-based RFC systems. In particular, the URFC performs both the process of electrolysis of water as well as the process of recombining of the hydrogen and oxygen gas byproducts to produce electricity. This enables a one-cell stack of the URFC system, replacing the one electrolysis cell stack and one fuel cell stack of traditional RFC systems, saving a substantial amount of weight since the cell stacks are the major component of an RFC system. In addition, traditional RFC systems use dedicated fuel cells or electrolysis cells with reactants that circulate through the cell stack via a circulation pump to remove fuel cell reaction byproducts or for cooling of the cell stack. GRC’s system eliminates the need for circulating reactants (eliminating the need for a circulation pump) by using heat pipes to convey waste heat from the fuel cell stack to reactant storage tanks that act as heat sinks/sources and as passive radiators of the waste heat. The URFC offers an effective energy storage system, charging through the electrolysis process and discharging through the fuel cell process to produce electricity.