Urban Air Mobility (UAM) aircraft development, enabled by Distributed Electric Propulsion (DEP), is transforming the aerospace industry by providing on-demand, affordable, quiet, and fast passenger-carrying operations in metropolitan areas. Designing and producing safe reliable UAM aircraft is particularly challenging given the relative infancy of electric propulsion for aeronautical applications, and that the complex aeromechanics associated with multiple proprotors and lifting/nonlifting surfaces interacting with each other and the airframe impacts fatigue, performance, control and flying qualities. As UAM aircraft concepts start to mature to the point that sub-scale demonstrators and proof-of-concept aircraft are being developed, there is a need for improved analysis tools, to support more detailed design, control law and control system development and testing. Unfortunately, the current generation of CFD-based high fidelity tools is unsuitable for many daily design and analysis applications due to computational cost, expertise requirements and setup level of effort. Conversely, many current design tools rely upon look-up tables or empirical relationships to capture complex interactional aerodynamics, or viscous and compressible effects, and become increasingly inaccurate in regions where the strong wake/component interactions occur or wakes trailed and shed from aerodynamic component becomes highly distorted. To directly address this market need, the team of Continuum Dynamics, Inc. and Georgia Institute of Technology proposes to build upon ongoing nonoverlapping work for NASA and the Department of Defense to develop a suite of mid-fidelity aeromechanics tools that directly address modelling assumptions and limitations of current and emerging design tools without being as costly as contemporary high fidelity overset CFD-based approaches.
The proposed effort supports several of NASA ARMD’s Strategic Thrusts ( #3 - Ultra-Efficient Commercial Vehicles and #4 - Transition to Low-Carbon Propulsion) and ongoing Advanced Air Vehicle Program (AAVP) projects (the Advanced Air Transport Technologies (AATT) project, the Transformative Aeronautics Concepts Program (TACP), and the Revolutionary Vertical Lift Technologies (RVLT) project. The proposed analysis tool will be able to assist in the design and evaluation of new configurations.
The proposed effort will produce a CFD-level mid-fidelity aeromechanics analysis tool for DEP, STOL, VTOL and UAM aircraft, in addition to advanced rotorcraft. Commercialization opportunities are anticipated from licensing the new modeling tools and providing support and engineering services in support of Uber Elevate, DoD’s Future Vehicle Lift and other current and future development projects
In the STTR Phase I solicitation for Topic T13.01 Intelligent Sensor Systems, NASA called for development of sensor systems with capabilities to measure the health and accuracy of the sensor, to detect anomalies, and to function in extreme environments. Alphacore and its Research Partner, Arizona State University, developed a framework in Phase I for self-calibrating sensors, backed by artificial intelligence with in-field calibration capabilities. We proved the feasibility of our approach by modeling pressure sensor and a capacitive accelerometer, designing electrical tests to correlate with mechanical characteristics, developing an aging simulation framework for the sensors, and designing the parametrizable self-test IP.
Based on the success in achieving STTR Phase I objectives as summarized in this proposal and described in detail in the STTR Phase I final report, Alphacore proposes to continue its work to meet the goals outlined by NASA in its solicitation. In the STTR Phase II we will fabricate test and prototype circuits that implement and validate the work done in Phase I, as well as extend the concepts developed in Phase I to other types of sensors. The sensor system design framework will provide:
In-field sensor calibration does not require application of physical stimulus
Post-production calibration information is leveraged for fast and reliable calibration
Sensor health and accuracy will be gauged by an artificial intelligence framework and a confidence level will be assigned to the decisions made by sensor readings
When possible, electrical stimulus can be used to excite the sensor; when electrical stimulation is not possible, array-based solutions can be developed
A low-cost ASIC will embody the calibration tools and techniques, enabling sensor self-calibration across a range of sensors and sensor types
Reduced system maintenance time and expense
Improved system performance and reliability
NIST traceability
The initial application is to assist with NASA rocket engine testing. The tests create a harsh environment which affects sensor calibration and makes it difficult to access the sensors to check and adjust calibration. Alphacore’s sensor self-calibration solution will benefit the development and testing procedures for virtually all future missions, including Deep Space Gateway, the Moon to Mars missions, the Europa Clipper, and the Titan Saturn System Mission. The technology can be hardened for deployment on the missions themselves.
Sensors are used in aerospace and automobiles for safety, navigation and system health, and in defense for missile monitoring and launch warning systems and battle-space characterization. Alphacore’s solution will enable sensor self-calibration across a range of sensors and sensor types, and improve the reliability of measurements from these sensors to prevent accidents or system failure.
Our proposed concept is to use Blockchain Technology (BCT) to enhance the Model Based Systems Engineering (MBSE) team collaboration. Blockchains are a highly tamper-resistant Distributed Ledger Technology (DLT) in which all relevant transactions are immutably and identically recorded and stored in nodes of distributed networks to provide an authoritative Single Source of Truth (SST). Blockchains also support decentralized governance with nuanced privacy models. Smart Contracts (SC) are self-enforcing agreements realized by the automatic execution of agreed-upon computer code upon the endorsement of transactions between multiple parties. The benefits of our concept are SST, high security, improved trust, privacy preservation, transparency, accountability, traceability, and high cost effectiveness. The goal of our proposed concept is to provide the NASA MBSE teams with BCT tools to share models and implement collaborative processes in a secure, decentralized, and distributive environment.
BCT for MBSE provides data sharing and executing process in a secure decentralized and distributive environment. Each organization has its intellectual property. Sharing data while protecting the proprietary information using blockchain technology has numerous applications in NASA programs which involves contractors from different companies.
Other Government agencies like DoD and DoE have programs that requires multiple contractors to collaborate and share data. Each party has intellectual property. Sharing data while protecting the proprietary information is crucial to the success of the program. This applies to every industry in the commercial sector.
NASA is seeking propulsive capability for SmallSats and modular CubeSats for several lunar, interplanetary, and deep space missions. Because of their small size, CubeSats can be transported into orbit, using excess capacity of large launch vehicles ridesharing as secondary payloads. A downside of ridesharing is that satellites are often released into unfavorable trajectories/orbits that require high-precision and high-thrust chemical propulsion capability for orbital changes and other maneuvers. In the Phase I effort, a 5N low-cost ASCENT thruster was developed, and a propulsion module that included thrusters for both high-thrust and also low thrust with higher specific impulse in a dual mode propulsion system was designed. The focus of the Phase II effort is to develop a flight design for the 5N thruster and to design, fabricate, test, and deliver propellant tanks, manifold, and propulsion controller for a prototype flight unit propulsion module. The 5N thrusters will be tested to enable reaching TRL-6, and the CubeSat dual mode propulsion system will be designed, built, and tested. Georgia Tech will support the overall effort to design, build, and test a CubeSat propulsion system for performing impulsive maneuvers on small spacecraft. Georgia Tech will use its heritage CubeSat propulsion system experience and make limited changes as necessary to satisfy the unique dual mode requirements. This activity includes detailed design, fabrication, and delivery of two mechanical units: a structural test (burst) unit and a prototype field unit.
The Phase II project will provide a dual mode green propulsion system for a technology demonstrator mission. PLASMA’s 100 mN thruster will be creating flight heritage and will be a product for commercial and government buyers. A flight design 5N thruster will be made commercially available. NASA applications include any satellite requiring attitude and orbit control, reaction control, formation flying, and controlled reentry.
There are tremendous commercial applications for STTR dual mode green propulsion system, 100 mN thruster and 5N thruster. Applications include all commercial and government satellites requiring attitude and orbit control, reaction control, formation flying, controlled reentry, and military applications such as divert and attitude control.
Future human extraterrestrial missions will require export and landing of countless payloads on the lunar and Martian surfaces. Such a quantity and rate of payload delivery will require cost-effective and rapid manufacturing of many large Thermal Protection Systems (TPS). Intelligent Optical Systems proposes to develop a modular system for in-situ bonding and curing of thermoset resin to the spacecraft to facilitate automated manufacturing of TPS. This system is compatible with additive manufacturing techniques, high-temperature thermoset resins, and composite substrates currently in use and under development by NASA, SpaceX, and others. Our in-situ resin curing system will eliminate the need for large ovens or autoclaves. By leveraging advances in out of autoclave curing methods, our system will enable curing of additively manufactured high temperature thermoset resin based TPS in-situ. An infrared heat source mounted directly on the print head will rapidly stiffen the extrudate as it leaves the nozzle, enabling multi-layer printing. Upon completion of the printing process, a modular system of conductive heat blankets, conforming to the surface contours of the structure, will control final cure of the thermoset. The system will measure the temperature of the resin, and provide feedback control and log thermal history during curing. In-line surface activation with a corona generator will ensure strong bonding to the underlying substrate and at layer interfaces.
Validation of the system will be performed by measuring the degree of cure of in-situ cured samples and measurement of bond strength. We have already demonstrated in Phase I that in-situ cured samples achieve a high degree of cure, char yield, glass transition temperature, and bond strength, comparable to traditionally cured resins. The target end point for Phase II work is scaling the system by 10x with performance deviation of no more than 5% between in-situ cured and control cured resins.
Potential applications for NASA include human missions to the moon and Mars. Such missions will require TPS to protect both crew and cargo from heat during hypersonic flight. The advanced TPS production technology developed in this project will be applicable to the Human Exploration and Operations Mission Directorate's (HEO) Orion spacecraft and commercial spaceflight. Further development of the technique will enable 3D printing and automated production of high temperature resilient parts and molds on Earth, the moon, and Mars.
Commercial Space programs like SpaceX will benefit from advanced TPS manufacturing processes being developed by NASA. The proposed system will enable the parallelized and rapid production of heat shields required for interplanetary colonization. Additionally, this technology could enable commercial thermoset resin 3D printing technology, and impact the advanced manufacturing market as a whole.
Bacteria in water and surface-attached biofilms pose health and operational challenges in human support systems. Current biofilm control technologies (i.e., hydrophobic surfaces, biocide-impregnated plastic coatings, chemical biocides, mercury-based lamps or light emitting diodes (LEDs)) either work for a very short duration, lead to residual chemical by-products of concern, have impractical physical designs, or limited light irradiation capacity. We propose a means of increasing the irradiation area of a UV-C LED by >100x by launching its light into side-emitting optical fibers (SEOFs), essentially creating germicidal flexible glowsticks. Currently only visible light SEOFs are commercially available. However, we discovered a technology (patent-pending) using silica nanoparticles (NPs) permanently attached to optical fibers that achieve side-emission of UV-C light along the entire optical fiber length. This is achieved using our dual-layer SEOF that includes 1) tunable shape-, size-, and surface chemistry-modified silica NPs that create photon and energy-scattering centers on the fiber surface and 2) UV-C transparent polymer coating over the NPs that protects the SEOF while allowing light to enter the water. Flexible individual or bundled SEOFs can deliver light from UV-C LED(s) to large surface areas. Our SEOF technology targets biofilm control in water or air, including narrow channels in potable water devices or tubing, biomedical devices or surface disinfection. Research performed during the Phase I STTR successfully 1) optimized the SEOF NP coating, 2) advanced development of desirable light profiles along SEOF, 3) developed a proprietary first-principle optical fiber light scattering mathematical model to engineer the SEOF and 4) demonstrated bacterial inactivation in water or on surfaces. This Phase II STTR proposal advances research initiated in Phase I and develops prototype devices for technology demonstration (TRL 5).
Microbial control in potable water systems; air/surface disinfection applications
Biofilm control in major home appliances/water appliances; biomedical devices; legionella control; air/surface disinfection applications
The Controls and Load Alleviation Simulation Platform (CLASP) framework was developed in the NASA STTR Phase I activity preceding this Phase II proposal. CLASP has been created to perform time-domain simulations of gust and turbulence encounters with a focus on UAM and VTOL aircraft concepts. The centerpiece of CLASP is a Simulink flight simulation model that has been developed with significant modularity and modeling flexibility with regard to aircraft aero-propulsive, control system, and structural dynamics models as well as the definition of gust and turbulence characteristics. The NASA LA-8 configuration was used to demonstrate the developed capabilities of the CLASP framework. Phase I simulations were limited to considering the configuration’s forward flight mode, while Phase II will extend the framework capabilities to vertical flight mode as well.
The CLASP framework utilizes a hybrid aero-propulsive modeling approach in which strip theory is used to develop the loads on the fore and aft wings while lookup tables are used to represent the aerodynamic loads on the rest of the airframe. FlightStream® is used extensively for the aero-propulsive analysis within CLASP. A prototype semi-automated FlightStream® Reduced Order Model (ROM) was developed in Phase I and will be automated in this Phase II activity. This feature enables the data reduction necessary to integrate the flow solver into the CLASP framework with very high computational efficiency.
The modal approximation method is used to model the structural dynamics of the flexible fore and aft wings. Control system modeling in CLASP includes inner loop controllers for pitch-hold, bank-hold, and yaw damping; an altitude-hold autopilot function, and a proportional-derivative Gust Load Alleviation (GLA) control law operating on estimated gust-induced angle of attack
Li–S/Li-O2 batteries have great potential to meet energy storage requirements for Electrified Aircraft propulsion applications. However, due to the need for oxygen storage and supply systems, the complicit balance of plant significantly decreases both the gravimetric and volumetric energy density of Li-O2 battery systems. For the Li-S battery, however, the main obstacle – “rapid capacity fade on cycling” due to shuttling effects and volumetric change, has to be resolved. In phase I, collaborating with the University of Utah, Chemtronergy developed a unique all solid-state Li-S battery (ASSLSB) consisting a novel highly conductive thin polymer composite electrolyte and a highly-performing sulfur cathode, potentially capable of integrating with an industrial roll-to-roll battery manufacturing process readily for scaling-up. The composite solid polymer electrolyte (SPE) showed a conductivity as high as 2.2x10-4 S/cm and electrochemical window > 6.26 V at room temperature. Coin cells constructed with the novel SPE and unique sulfur cathode showed initial discharge specific capacity as high as 1500 mAh/g at room temperature, while capable of maintaining at 510 mAg/g after 100 cycles. In Phase II, a prototype Li-S battery pouch cell will be developed, followed by proof-of-concept demonstration. Successful development of the SPE and high-performance sulfur cathode will eliminate the use of flammable organic substances in the electrolyte while suppressing the polysulfide dissolution and lithium dendrite formation, thus making the Li-S batteries safer and durable.
Through improving cycle life and safety, the proposed all solid state Li-S battery will address the key limitation for space applications. With high safety and long cycle life, ASSLSB would meet multi-use or cross platform space energy storage applications, and result in significant mass and volume savings and operational flexibility, including Electrical Aircraft propulsion (EAP), EVA space suits and tools, human example, lunar and martian landers, science platforms and surface solar arrays.
The proposed ASSLSB can be widely used in consumer electronic, electric vehicles and charging stations, tourist coaches, yachts, wind and solar energy storage power, traffic signals, solar hybrid street lighting, UPS power supply, home energy storage, coal miner, disaster relief emergency, communication base stations, telecommunications, etc.
Cornerstone Research Group Inc. (CRG) in partnership with The University of Delaware Center for Composites Manufacturing (UD-CCM) proposes to advance the state-of-the-art in space vehicle thermal protection systems (TPS) with a combined multi-layer approach. The multi-layer approach will consist of an outer ablative layer followed by an internal insulation layer. The outer, ablative layer will be produced using automated composite fabrication techniques with continuous fiber reinforcement. These techniques are already common to the aerospace industry, but have not yet been adapted to high temperature materials that are often needed for re-entry conditions. Behind the ablative layer will be an insulation system that may be a single composition or functionally graded with varying composition to ensure compatibility with the continuous fiber layer on the outside surface. Traditional TPS fabrication is labor intensive, specialized work, with size limitations; and as such, is expensive, slow, and modular. By contrast, others are now regularly producing wings sections, fuselage components, and a variety of other large parts with automated processing. This work seeks to combine the value of automated processing that is already well understood within the aerospace community and apply it to materials that are capable of enduring the extreme environments of atmospheric entry in support of manned missions to Mars as well as re-entry to Earth from low-earth orbit (LEO), with the latter need taking on renewed interest as the US is returning to the moon in the next decade. This is possible due to a new class of material invented by CRG called MG Resin. The resins are being explored with for a range of applications including C/C hot structures, TPS, syntactic insulation, and elastomeric rocket motor insulation among others. The materials have demonstrated high char yield, low erosion, and good mechanical performance, and are compatible with a wide variety of processing methods.
Thermal Protection Systems (TPS): Aeroshells, Hypersonics, Leading Edges, Nose Cones
High Temperature Composites: Aircraft Engine Components, Control Surfaces, Nozzles, Fins
Foundry Refractory Materials: Furnace liners, Ladle liners
Fire Smoke and Toxicity Compliant Materials: Aircraft and marine interiors
Industrial Insulation: Furnaces and boilers, Reactors and piping
Automotive: Engine, Exhaust
Energy Industries: Turbines, Diesel Generators, Fuel Cells, Transformers, Batteries
Thermal Protection Systems (TPS): Aeroshells, Hot Structures
The use of COTS (Commercial Off-The-Shelf) parts in space for electronics is increasingly becoming a significant enabler for many capabilities during a mission. This STTR project will provide a better understanding of the feasibility of COTS electronics for High Performance Computing (HPC) in space environments which are already heavily shielded. This STTR team (Alphacore + Vanderbilt University) proposes innovative strategies, based on a complete system analysis of HPC COTS that include, but are not limited to, identifying the vulnerable aspects of COTS-based HPC systems, failure modes and their propagation through the system, as well as selected parts radiation testing, to mitigate radiation induced impacts to potential HPC systems in those highly shielded space environments, such as manned missions and human habitats.
This proposal aims to (i) evaluate radiation performance of sub-systems of an HPC system, (ii) develop mitigation techniques for each sub-system, and (iii) determine if NASA specs for space deployment can be met by the redesigned system using COTS components.
The radiation effects model has two aspects: systems modeling language (SysML), and goal structuring notation (GSN), from which it can produce reliability objects for evaluating mission reliability of spacecraft: discrete Bayesian Nets (BN) and Fault Trees (FT). Using SysML, the target system is modeled via functional decomposition diagrams, architectural diagrams via block diagram models, fault propagation diagrams, which constitute a complete description of a spacecraft (or subsystem) with multiple functions. GSN is used to create a visual argument structure highlighting goals and strategies to achieve required top-level function in given space environment for mission life. These goals and strategies are supported by solutions such as radiation testing or mitigation strategies. The methods will be extensively verified and validated by multiple irradiation tests (neutron, proton, alpha).
The results from this project will be relevant to any NASA mission or project and any space mission that intends to send humans beyond LEO (Low Earth Orbit) with a High-Performance Computing (HPC) system. An HPC ecosystem is also of interest to Science Mission Directorate (SMD). Immediate infusion targets include Mars Fetch Rover, WFIRST/Chronograph, Gateway, SPLICE/Lunar Lander. This proposal addresses NASA needs described in the latest 2015 NASA Technology Roadmaps such as Space Weather Forecasting.
Private enterprises that have based their business on spaceflight can make use of this technology to reduce their loads when embarking on missions to space. Future constellations of small communications satellites will blanket the Earth with Internet connectivity as well. Other countries are also participating in space exploration driving the global market for radiation hardened electronics.
A phase II effort will build on the success of the phase I effort and move from demonstrating a passive antenna to an electronically steered 2D dynamically metasurface aperture (DMA). By appropriately tuning each element on the metasurface, using metasurface-specific algorithms, we will demonstrate a high gain electronically steered beam with fast switching speeds. This approach lends itself to minimize total power consumption, and by association, cooling requirements. A DMA will uses inexpensive components (e.g., varactors and DACs at a few $ each) and unlike an AESA, the DMA does not require phase shifters or densely packed transmission/receiver modules. As a result, production DMA antennas are expected to have a bill of materials (BOM) of around $100k per square meter, or less, making it possible to build large, high-performance—but relatively inexpensive—apertures. Further, in exploring the DMA for very large aperture systems, the Duke team has discovered a variation of the metasurface architecture that minimizes the number of components needed to achieve the requisite beam forming and beam steering performance, further reducing antenna costs. Ultimately, the DMA design maintains the advantages of a sparse phased array, but with the extreme field of regard associated with advanced active electronic scanned arrays (AESA) systems.
The antenna platform we envision here will harness commercial printed circuit board (PCB) manufacturing techniques to produce the top metasurface layer. A multilayer waveguide feed will be fabricated with additive 3D printing methods and uses a conductive polymer that can be electroplated for low loss. This, advantageously, supports a very lightweight antenna and great flexibility in its geometry, traits that reduce launch costs in a satellite environment.
Metasurface antennas is promising for its excellent SWaP-C characteristics. It promises to achieve light weight due to its polymeric nature and low power consumption due to the use of metasurface technology. Its development costs and cost per antenna are also likely to be low due to the standard additively manufacturing approaches. We see applications in NASA efforts towards lower cost synthetic aperture mission for Earth science objectives, lunar, and interplanetary missions. These antennas can be used from L-band to millimeter wave.
This proposed technology enables rapid prototyping of light, conformal, flexible, and embedded electronics for the defense sectors and electronics industry in general. The lower weight afforded by using conductive polymers, will find additional applications in weight constrained applications such as aerospace and in applications that require customized integration.
The proposed innovation is a new software tool that overcomes the present obstacles to simulation-based tailoring of EMC environment specifications for all space flight electronics.
NASA’s baseline EMC qualification process is for all electronics systems, subsystems and components to be test-qualified to a single, universal MIL-STD-461 specification. However, this is not necessarily a safe or cost-effective process. The MIL STD may underestimate some known threats specific to a NASA mission. Successive revisions to MIL-STD-461 have increased radiation susceptibility levels by more than 40dB to accommodate the rapidly evolving EMC threats from ever-higher frequency digital electronics. But this in turn means that the MIL STD may substantially overstate the maximum expected environment for other NASA missions, precluding the use of lower cost, commercial-of-the-shelf (COTS) electronics.
The proposed innovation uses asymptotic statistics to greatly reduce the simulation task complexity, making it feasible for NASA engineers to predict and mitigate cable harness currents induced by coupling with strong cavity electric fields for all spacecraft and launch vehicle programs. Phase II will deliver a customization of RobustPhysics’ hybrid electromagnetic field modelling software for NASA electromagnetic compatibility (EMC) applications. The hybrid solution uses rigorous physics to couple a statistical model of the 3D electric field in cavities with a deterministic transmission line / transfer matrix model of currents in a cable harness. The reduced order, statistical power balance model for 3D electric fields in complex connected cavities – including launch vehicle fairings - was validated in the Phase I STTR.
The new simulation tool has application to all NASA spacecraft designed to withstand EMC environment threats such as unwanted wireless and radar transmitters, on-board electronics aggressors, electrostatic discharge (ESD), lightning and high intensity radio frequency (HIRF) threats. EMC specialists at Marshall Space Flight Center confirmed application to launch vehicle avionics and possibly more immediate application to critical cable harnesses in the complex enclosed electromagnetic fields within the International Space Station modules.
Non-NASA applications include commercial and military aircraft, as well as EMC engineering for Navy ship, submarine, UUV and torpedo systems. There are equally clear applications in large markets outside aerospace-defense, the most significant being automotive and consumer electronics.
The central thrust of this program is to provide NASA with higher performance components that can engender large advances in performance of satellite thruster systems while also introducing large SWaP savings and improved reliability as to meet the needs of the rapidly increasing smaller satellite market. QorTek is proposing a revolutionary design of a subcompact solid-state (textured ceramic actuated) flow control systems for electric propulsion system thrusters (cathode tubes) such as envisaged Xe, Ar, Kr, He, or I. At under 12 cu-cm volume, and operating at under 2mW, these new flow control components will introduce large power savings for most EP thruster systems being designed for small satellites and other mission equipment (included landed equipment). Designed to be the first ever EP flow controllers that can function to high temperatures (> 300°C) opening a new design where the controller is directly mated to the thruster as to reduce downstream tubing, reduce propellant waste, and accelerate acceptance testing as well as they are readily amenable to radhard implementation – including their subcompact drive/control electronics employing recent advances at QorTek. Although the initial system is targeted toward NASA Class D missions, the extremely high reliability of our solid-state drive technology will enable all many NASA and commercial space missions to benefit from its use. Because this is a direct drive solution, the first such for propulsion flow control on spacecraft, these can apply fast valve open/close rates (estimated >1.2KHz) and deliver true linear proportional flow control. The large reduction in power cost and mass, combined with ability for radhard implementation would make these new components and ideal selection for on-board prop. systems and other equipment for small spacecraft are now envisaged for Moon-Mars (Artemis) and other deep space missions that will have immediate applications to the booming market in LEO/GEO small satellites.
The proposed technology targets Electric Propulsion systems, that are becoming foundational to many key NASA mission goals, in particular Moon-Mars (Artemis) and other Deep Space missions. Compared to legacy solenoid-based systems, the proposed solid-state valves will drastically reduce power, size/weight, and also provide multi-use, and enable elevated operating temperatures, which will enable this technology to be integrated close to the thruster. Integrated components are expected to be rapidly fielded to drastically decrease mission costs.
“New Space”, is looking for simplified system for cost reduction and to open up more space for fuel for extended operation period. Phase I demonstrated high pressure valve is very attractive to eliminate pressure regulator. The compact, high-pressure direct-drive valves are in direct interest of low-cost propulsion and feed-system developers for the fleet of light and agile vehicles.
Touchstone produced carbon foam (CFOAM), graphite foam (GFOAM) composite core tool materials for evaluating heat transfer characteristics. In addition a high in-plane heat spreader was evaluated along with fiber reinforced bismaleimide (BMI) composite that is the tool surface. The heat source were 300 and 600 W flexible heaters manufactured from glass reinforced silicone and polyimide. The thermal results were collected and submitted to Clemson University and used for validating a 2D model that they developed. After completing the flat panel test a graphite core having DCB geometry was constructed and evaluated for thermal gradients. It was concluded that future development work would be on a tool having GFOAM core and BMI composite surface. The technology readiness level for Phase I started at TRL-1 and ended at TRL-5 based upon a BMI-GFOAM system and that has bottom mount heaters. It is proposed in Phase II to build a segmented 12ft span DCB self-heating composite tool prototype that may be used to validate the technology and provide thin ply composite booms with corrugated geometry in support of NASA LaRC thin-ply composites research.
NASA has expressed interest in improving materials and processes. The intent of this technology development is to provide NASA with a more adaptable, or logistically favorable, process for curing large composite structures. A composite tool that can heat cure large composite structures without autoclave pressure and large ovens is a potential game changer for onsite production needs. The proposed Touchstone self-heating composite tool technology is modular, thus allowing for disassembly, storage, and transportation.
The general approach and specific technologies developed in this STTR can also be applied to other commercial applications such as Airbus A340 & A380 fixed wing leading edges, keel beam ribs, and Boeing 787 pressure bulkheads. Other military Aerospace and Wind applications that demand high stiffness are also potential candidates.
For this STTR Phase II project, Applied NanoFemto Technologies (ANFT) and MIT aim to develop a prototype of a miniature urine test system and extend its application to more general applications in testing and screening. In Phase I of the project, we have designed and optimized the on-chip digital Fourier Transform spectrometer (dFT) technology for the SWIR spectrum test system, developed the light coupling technologies, and refined the SWIR LED and photodetector growth parameters. The waveguide design and coupling simulation as well as the SWIR LED and photodetector development has demonstrated the feasibility of the proposed PIC-based chip-scale urine test platform. In Phase II, we will develop a prototype of the miniature PIC-based broadband spectroscopic urine test system with ultra-low SWaP, high sensitivity and high accuracy will be demonstrated. Clinical application and extension to the COVID-19 diagnostic test will be explored as well.
A top candidate “green” monopropellant proposed as a safe replacement for hydrazine in spacecraft systems is also shown in tests to be a high performance propellant for ion electrospray thrusters. The proposed effort is to take full advantage of these remarkable characteristics to develop an efficient bimodal ion-chemical thruster system using a common propellant supply tank. This proposal responds directly to the Dual Mode Propulsion focus area in the T2.03 STTR topic.
The expected mass and volume savings, increased propellant use efficiency and the added flexibility in thrusting options (high thrust with moderate Isp and lower thrust with high Isp) will significantly augment the operational propulsion and attitude control ranges, especially in small spacecraft applications.
Phase I demonstrated and tested an efficient propellant management system interfacing the high pressure monopropellant tank with the ion electrospray thruster arrays. This allows the development in Phase II of a complete protoflight system, including multiple thruster arrays and control electronics, that can be integrated into a space mission. The Phase II development will leverage the existing ion electrospray thruster technology, and integrate it with the new propellant management system to provide a multi-thruster ion propulsion system. The assembly will be designed to interface with an existing compact chemical thruster to achieve a complete proto-flight bi-modal propulsion system, ready for integration and flight testing on a space platform.
NASA applications are many, as most space system designs attempt to minimize bus mass and volume budgets to maximize payload capacity, and are concerned about propulsion. The combined capability for agile maneuvering, precision attitude control and thrusting and extended mission lifetime applies to missions in earth orbits or lunar and interplanetary space, and also fractionated observatories requiring multiple platforms with good control performances. Geosciences, heliophysics, astrophysics and lunar or interplanetary exploration will benefit.
Non-NASA space systems, from commercial or government organizations will also benefit from the bimodal propulsion advantages in performance ranges, mass and volume budget savings and extended lifetime. The potential applications are numerous and include earth observation, monitoring and communication systems, satellite constellations, robotic systems to assemble in space or retrieve debris.
We propose to construct a multispectral MWIR light source consisting of a single silicon chip which will generate and combine
light from a wide MWIR spectral range. Compared to existing conventional MWIR emitters, we will double the available wavelength emission range and combine light on-chip, removing the need for free-space optics.
Front-end laser source for: trace gas sensors (in situ or remote sensing), LIDAR, spectrometers (in situ or remote sensing), lab- on-a-chip chemical analysis systems, and atmospheric monitoring
This source will significantly reduce the size, weight, and power (SWaP) of existing systems and is ideal for instruments deployed on platforms requiring very low SWaP: cube sat, landers, satellites, and aircraft.
Commercial: trace-gas sensors for commercial or industrial applications, including vehicle and factory emissions monitoring.
Scientific: laser source as scientific instrumentation for laboratory use
Military: counter-measures and scene illumination.
High resolution spectrographs with spectral resolution R = λ/∆λ > 5,000 are one of the most important tools for nearly every discipline in astronomy, but the design of high resolution spectrographs have not experienced significant changes in last several decades. A conventional high resolution spectrograph usually contains a collimator, echelle grating, cross disperser, and finally a camera and science detector—both typically semiconductor detectors. Here we propose developing a spectrometer where the light is separated and channelized by a photonic circuit and is then detected by an energy-resolving superconducting detector. The instrument would be a radical new type of high resolution spectrograph applicable for both multiobject and integral field unit (IFU) spectroscopy and other fiber fed light applications. Our goal is to create a high resolution multi-object spectrograph by marrying two breakthrough technologies, ultra-low loss arrayed waveguide gratings (AWG) and Microwave Kinetic Inductance Detectors, or MKIDs. MKIDs can determine the energy of each arriving photon without read noise or dark current, and with high temporal resolution. The AWG allows us to disperse light from the telescope, in a compact way and to position the dispersed light into numerous output channels which we can conveniently position (i.e. dispersed not just by the angle at which it diffracts off a prism or grating). The MKID allows us to distinguish between the orders in the disperse light contained within the channels, eliminated the need for a cross-disperser. In other words, the energy resolution of the MKID allows us to determine from which echelle order the photon came.
The most promising application for the High Resolution Photonic MKIDS Spectrograph is for High Dispersion Coronagraphy (HDC) for the detection and characterization of exoplanets. Having many fibers in a high-resolution spectrograph instead of one allows HDC to go from being a follow-up technique only to an incredibly powerful tool for both detection and characterization. Another science application is looking at resolved stellar populations with adaptive optics across the local group but increasing the observational efficiency by 100×.
The development of broadband high-resolution visible wavelengths spectrometers finds increasing applications in the life sciences and medical field, including spectral tissue sensing and optical coherence tomography. In addition, the PICs developed in this program operating at cryogenic temperatures can also be fundamental building blocks for quantum computing and communications.
Silver nanoparticles (Ag NPs) are used for the functionalization of surfaces in order to achieve antimicrobial properties and control biofilm growth. The antimicrobial activity of Ag NPs is attributed to the release of Ag + ion, which means that Ag NPs need to be soluble to achieve microbial inactivation. However, because of this constant silver release, Ag NPs rapidly dissolve away from the surface,
depleting the biocidal activity and limiting the use of Ag NPs for long term biofouling control. In Phase I of this project, the team led by Cactus Materials Inc. demonstrated that Ag NPs can be passivated with less soluble forms of silver, such as Ag 2 S, AgBr, or AgI, to slow down silver release and extend the lifetime of Ag NPs-based antimicrobial coatings. When different passivation chemistries were compared, sulfidation of Ag NPs was found to have the best performance in terms of both slow silver release and high antimicrobial performance. The improved anti-biofouling performance is attributed to the higher retention of silver on the surface over time. A green chemistry approach was developed to functionalize surfaces in situ using a flow through system with reagents of Toxicity Class II or lower. The passivated silver coatings were shown to be compatible with the current use of aqueous AgF for water treatment and storage in the International Space Station. Phase II of this project will evaluate how to coat surfaces comprised of different materials or having complex morphologies with the passivated silver coating developed in Phase I. Long term anti-biofouling performance will be assessed in a dormancy scenario of up to a year. Release of chemicals and particles during the dormancy period will be assessed to identify any risk to the water quality from long term exposure to the passivated silver coatings. The results of this research will establish the capacity of the
proposed innovation to control biofilm in a wide variety of structures for extended periods of time.
U.S. space exploration missions have long considered returning to the Moon and exploration of Mars that challenge life support systems. A potable water treatment process is needed to prevent microbial growth in the long duration missions. Silver have been proven by NASA to be effective for microbial control, however, there remain significant challenges on its fast dissolution rate for an effective solution at preventing biofilm formation. In addition to, another application is in water processor assembly (WPA) here biofoulings are persistent
There are unmet needs in current pandemic environment to disinfect tough surfaces including vehicles, air transportation, mass transits and many others. This coating system is expected to antimicrobial at the surface and maintain antimicrobial activity despite wear and environmental exposure. Other applications are included water membranes, textile cloths, and medicals metallic coatings
Dynamic gust encounters are a design factor for Distributed Electric Propulsion (DEP) aircraft operating in Urban Air Mobility (UAM) environments. Gust response is important for safety of operations and ride qualities, which affect community acceptance. Notional UAM aircraft configurations differ significantly from conventional helicopters with different gust response characteristics due to aerodynamic interactions between the rotor system, airframe, and environment. These differences may require alternate flight control strategies. The proposed effort will develop an assessment tool suite based on variable fidelity modeling for the aircraft response and operating environment including minimum complexity flight dynamics and canonical urban airwake models, in addition to high-fidelity analyses of coupled rotor-airframe and free wake dynamics. Novel flight control methods will be used to perform gust alleviation and optimize ride qualities that leverage the distributed control nature of UAM vehicle concepts. The assessment tool suite will be integrated with preliminary design and analysis tools used by NASA and the industry, providing design feedback for handling / ride qualities optimization. The use of higher fidelity models will permit more accurate assessment of flight controller margins and performance prior to flight test activities. Minimum complexity models also may be used for vertiport site assessment and flight path / trajectory optimization.
The proposed UAM safety / ride quality assessment tool will provide a critical component for analysis of vehicle control requirements and gust rejection in terminal area operations, supporting NASA Aeronautics Research Mission Directorate Strategic Thrust 4 for Safe, Quiet, and Affordable Vertical Lift Air Vehicles. The technology will allow air vehicles to be developed with handling / ride qualities factored into the design process, which will be critical to community acceptance and more widespread adoption into the UAM transportation system.
CDI collaborates with air vehicle developers building components of the UAM transportation system and provides analysis tools that support performance prediction and flight dynamics evaluations. Technology developed here will naturally transition to these end users. CDI also will transition models to UAM traffic management (UTM) applications to support path planning and airspace use optimization.
The rocket rotating detonation engine (RDE) is a promising technology for its potential large improvement over state-of-the-art alternatives. NASA has identified the RDE as a technology of interest for its in-space propulsion applications such as orbital transfer or planetary lander engines. However, a technology feasibility assessment is not currently possible since the dynamics of the key fluid-combustion-system processes are not well understood for relevant conditions. To achieve a reliable and efficient RDE, various processes must be understood and/or optimized including the fuel-oxidizer propellant mixing, injection of fresh propellants with minimal pressure losses, and the interaction of fresh propellants with combustion products while avoiding deflagration losses. For liquid RDE combustion, measurements simply do not exist that provide detailed characterization of liquid breakup, atomization, vaporization, and burning during the interaction of liquid propellants with shocks and detonation waves. The proposed research focuses on transitioning state-of-the-art, time-resolved measurement techniques to liquid-fueled RDEs to provide information critical for understanding these systems and their design. The proposed research will provide ultra-high-speed (100 kHz–5 MHz) in-situ spatially and temporally resolved imaging of the gaseous oxidizer-liquid fuel mixing, species concentrations, and combustion to anchor and improve numerical modeling predictive capability. The proposed imaging measurements will characterize and measure the gaseous oxygen-liquid fuel mixing, combustion processes, flowfield structure, and dynamics in the liquid-fueled RDEs. Concurrent simulations will be performed at two fidelity levels (a lower fidelity Unsteady Reynolds Averaged Navier Stokes model and a higher fidelity shock-physics/multiphase-combustion mode), enabling improved interpretation of the measurement data and RDE physics, and anchored modeling and simulations.
The proposed R&D work seeks to modernize the measurement technology in RDEs for rocket applications. This includes time and space resolved measurements inside the RDE leveraging new technological developments such as the burst-mode laser. Detailed measurements of the mixing, O/F ratio, quantified deflagration versus detonation, and other key RDE phenomena will be directly compared to numerical simulations to provide boundary conditions and anchor current and future RDE modeling efforts.
Non-NASA applications of the proposed efforts include high-fidelity, spatiotemporal analysis of highly dynamic phenomena and validated modeling. Commercial applications include air-breathing propulsion, stationary power generation, and fundamental research in a wide range of aerothermal flows.
CU Aerospace (CUA) and the Univ. of Michigan (UM) propose the continued development of the Cycle Automated Mass Flow (CAMFlow) system for reliable and well-regulated flow control. CAMFlow uses an innovative control scheme that enables stable operation using only Boolean valve states, even for the low flow rates necessary for sub-kW Hall thrusters. This methodology removes system complexity and places the onus of reliability almost entirely on valve cycle life. Throttling, open and closed-loop operation, as well as hard startup/shutdown in closed loop mode were all successfully demonstrated with the CAMFlow system with a Hall thruster at UM facilities during the Phase I effort. Phase II CAMFlow units will be focused towards smaller Hall-effect or gridded-ion electric propulsion systems having a flow rate in the 0 – 5 mg/s range, however the technology is applicable over a larger range of flow rates for a broader commercial market. The system will be designed and fabricated with size, functionality, risk tolerance, and cost considerations appropriate for NASA Class-D missions. The Phase II effort has the dual focus of extensive reliability/performance testing and the design, assembly, acceptance testing, and delivery of a compact integrated Phase II system ready for flight integration. The successful Phase I demonstrations of stable operation at target performance levels lead to the design of the Phase II CAMFlow system test hardware, thermal modeling, production, acceptance testing, environmental validation testing, and delivery of a flight-like CAMFlow system (TRL 6) at the end of Phase II. CUA will also develop a brassboard Propellant Management Assembly (PMA) with a best effort goal of achieving a flight-like PMA.
CAMFlow systems can support NASA applications by directly enabling compact gas fed systems including lower power Hall effect thrusters in Class-D missions. NASA missions that could potentially benefit from our compact CAMFlow systems would generally require very high total impulse using Hall or ion thrusters. Such missions include near-Earth objects, inner Solar System, and Outer Solar System. A good example is the Psyche mission. The compact CAMFlow system designed for CubeSats and small satellites is easily scalable to larger sizes.
Aside from the general application of gas-fed propulsion systems, CAMFlow can also enable some unique ground testing opportunities. With open and closed loop control, along with the potential to use process variables aside from pressure, CAMFlow can help aid in the development of alternative control schemes a wide variety of fluid flow systems.