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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Demand on Space Shuttle general-purpose computers reduced. Simulations Testbed and Scenario Pre-processor (STB&SPP) system reduces need for use of GPC's in hardware and software development and testing. System consists of computer program, SPP, and set of utility subroutines, STB, which incorporates Interface Simulator (ISIM). STB&SPP system written in FORTRAN V and Assembler.
Understanding the fundamental forces and symmetries of nature has long been a central goal of particle physics. While the Standard Model (SM) provides a successful framework, it does not guarantee the conservation of baryon number B or lepton number L, thus motivating searches for their violation. Proton decay, a fundamental process violating B, has been at the forefront of experimental searches for decades.The discovery of the weak neutral current in 1973 unified the electromagnetic and weak forces and inspired the creation of Grand Unified Theories (GUTs) that also unify the strong force. In 1974, the first-ever GUT, proposed by Georgi and Glashow, naturally predicted proton decay. This prediction led to an experimental push to validate these theories, and a large underground detector boom was born. Initially designed for proton decay searches, these detectors later proved invaluable to neutrino physics.Although no evidence for proton decay has yet been observed, next-generation large detectors, such as the Deep Underground Neutrino Experiment (DUNE), offer the opportunity to improve on current experimental limits. Utilizing its Liquid Argon Time Projection Chamber (LArTPC) technology, DUNE is positioned to probe rare processes such as proton decay with increased sensitivity.This thesis presents a sensitivity study for the dominant proton decay mode predicted by Supersymmetric GUTs, p → K+ν, utilizing machine learning approaches. Two methods are explored in this thesis: a Boosted Decision Tree (BDT) analysis and a Graphical Neural Network (GNN) analysis with NuGraph. A lifetime limit of 5.36 ± 0.69 × 1033 years for 400 kt-yrs is found using the BDT, while the GNN achieves a lifetime limit of 6.19±1.26×1033 years for 400-kt-yrs. The NuGraph result offers better sensitivity compared to the current limit set by Super-Kamiokande of 5.90 × 1033 while the BDT result offers a slightly lower sensitivity.Additionally, this thesis discusses cross-section work, a first-ever foray into proton decay and atmospheric neutrinos in a vertical drift (VD) DUNE detector, and extensive hardware contributions to the DUNE Far Detector (FD) 1 Module-0, ProtoDUNE-2, which serves as a testbed for the final detector design and installation.
Advanced nuclear reactors are crucial to the future of energy both in the United States and around the globe. In contrast to the current operating fleet, they are characterized as being deployable in remote locations and able to operate in semi-autonomous or autonomous fashion. This leap forward necessitates a new reactor control paradigm. Because advanced nuclear reactors are still under development in the United States, the creation of new control methods to achieve autonomous operations has been based on systems modeling and simulation. However, an important factor in successfully deploying these new control methods is the ability to seamlessly transition from simulation environments to real-world settings. Control methods tested in both simulation and experimental settings need to be investigated in the context of advanced reactor applications. This work developed a series of simple controllers for Idaho National Laboratory (INL)’s Microreactor Applications Research Validation and Evaluation (MARVEL) microreactor operating in load-following scenarios. These controllers were tested in both simulation and experimental settings, and a comparative performance analysis was performed. The simulation tests leveraged the Control and Optimization Modular Modeling Application for Nuclear Deployment (COMMAND) software developed in a previous stage of the current effort, along with the MARVEL Reactor Excursion and Leak Analysis Program (RELAP5-3D) and Monte Carlo N-Particle (MCNP) models. The experimental tests leveraged the COMMAND software, MARVEL models, and the U.S. Department of Energy Microreactor Program’s Microreactor Automated Control System (MACS). MACS was developed to serve as a control method testbed. It was customized to mirror the MARVEL microreactor, and COMMAND enabled MACS to emulate the physics of MARVEL. The load-following controller was developed using the simulation platform, with efforts to emulate real systems by introducing actuator saturation and noise. These factors were incrementally accounted for in the controller design. After finalizing the controller design, it was implemented with the experimental setup. The experimental conditions tested included an initial test under conditions similar to the final simulation test, and two additional scenarios. The first scenario introduced additional actuator saturation to account for equipment aging over time, which was unknown to the controller. The second scenario introduced sensor delay, a phenomenon anticipated with the use of remote operations or wireless communication in advanced reactors. These tests revealed several notable differences. While the controller performed well in simulation, it exhibited several limitations when transitioning to hardware. The main challenges involved maintaining the steady-state target power, as evidenced by larger error values between the true reactor power and setpoint power, as well as persistent oscillations in controlled reactor power. These issues could lead to unacceptable transient conditions in real reactor testing. Introducing actuator aging and stochastic delays in the experimental setup significantly impacted controller performance, resulting in increased overshoot and undershoot, and exacerbated error and oscillations previously mentioned. These findings underscore the importance of experimental testbeds for testing and validating control methods, as controllers developed using only theory and/or simulation may perform unexpectedly when applied to actual hardware. This research emphasizes the need for an experimental testbed for achieving such validation.
Despite tremendous progress in the development of untethered soft robots in recent years, existing systems lack the mobility, model‐based control, and motion planning capabilities of their piecewise rigid counterparts. As in conventional robotic systems, the development of versatile locomotion of soft robots is aided by the integration of hardware design and control with modeling tools that account for their unique mechanics and environmental interactions. Here, a framework for physics‐based modeling, motion planning, and control of a fully untethered swimming soft robot is introduced. This framework enables offline co‐design in the simulation of robot parameters and gaits to produce effective open‐loop behaviors and enables closed‐loop planning over motion primitives for feedback control of a frog‐inspired soft robot testbed. This pipeline uses a discrete elastic rods (DERs) physics engine that discretizes the soft robot as many stretchable and bendable rods. On hardware, an untethered aquatic soft robot that performs frog‐like rowing behaviors is engineered. Hardware validation verifies that the simulation has sufficient accuracy to find the best candidates for sets of parameters offline. The simulator is then used to generate a trajectory library of the robot's motion in simulation that is used in real‐time closed‐loop path following experiments on hardware.
We report the design, construction, and operation of a multi-axis heterodyne interferometry (MAHI) system operating at MHz heterodyne frequencies, which provides a testbed for technologies to be used in the Laser Interferometer Space Antenna (LISA) space-based gravitational wave mission. The system was calibrated for measurement of the piston, pitch, and yaw of a three-axis piezo-actuated mirror, giving measured calibration values that closely match those predicted by a simulation based on Gaussian beam tracing. The piston sensitivity of the MAHI system in the LISA band was measured to be below 10pmHz 1/2 10pmHz1/2 for frequencies above 4 mHz and below 1pmHz 1/2 1pmHz1/2 for frequencies above 35 mHz. The sensitivity is limited above 2 Hz by the mechanical vibrations of the apparatus and below 1 mHz by dimensional changes caused by temperature fluctuations. Evidence points towards scattered light as the limiting noise source at intermediate frequencies. The angular sensitivity of the MAHI system was measured to be close to or below 10nradHz 1/2 10nradHz1/2 for frequencies above 4 mHz and below 1nradHz 1/2 1nradHz1/2 for frequencies above 100 mHz. Noise budgets for both length and angle were determined, indicating the areas in which improvements must be made in order to reach increased sensitivity. The current operating sensitivity already provides a useful testbed for LISA technologies and a potential blueprint for future ground segment equipment.
As part of the technology validation strategy of the next generation space telescope (NGST), a system testbed is being developed at GSFC, in partnership with JPL and Marshall Space Flight Center (MSFC), which will include all of the component functions envisioned in an NGST active optical system. The system will include an actively controlled, segmented primary mirror, actively controlled secondary, deformable, and fast steering mirrors, wavefront sensing optics, wavefront control algorithms, a telescope simulator module, and an interferometric wavefront sensor for use in comparing final obtained wavefronts from different tests. The developmental. cryogenic active telescope testbed (DCATT) will be implemented in three phases. Phase 1 will focus on operating the testbed at ambient temperature. During Phase 2, a cryocapable segmented telescope will be developed and cooled to cryogenic temperature to investigate the impact on the ability to correct the wavefront and stabilize the image. In Phase 3, it is planned to incorporate industry developed flight-like components, such as figure controlled mirror segments, cryogenic, low hold power actuators, or different wavefront sensing and control hardware or software. A very important element of the program is the development and subsequent validation of the integrated multidisciplinary models. The Phase 1 testbed objectives, plans, configuration, and design will be discussed.
The Mars 2020 Sampling and Caching Subsystem(SCS) is the most complex robotic system ever fielded on a MarsRover. It includes a 5 degree-of-freedom Robotic Arm, coringdrill, gas Dust Removal Tool, interfaces for two turret-mountedinstruments, and an Adaptive Caching Assembly (ACA). TheACA is itself a complex robotic system, containing hardware tosupport docking and bit exchange, a 3 degree-of-freedomSample Handling Assembly for manipulating sample tubes,storage for several drill bits and sample tubes, and mechanismsto support observing and sealing samples collected by the drill.To successfully verify and validate the SCS hardware andsoftware and its integration with the Mars 2020 flight systemseveral key strategies were employed.The SCS Verification and Validation (V&V) program utilizedmultiple test venues with tiered levels of fidelity. These includedsimulation and visualization software environments, low fidelitydevelopment testbeds, testbeds with high fidelity SCS hardwareand commercial off-the shelf avionics, integrated systemtestbeds with flight-like avionics, and environmental testbedscapable of simulating Martian surface temperature andpressure. Multiple units of each SCS hardware componentmoved fluidly between test venues to accomplish myriadstandalone and coordinated test objectives. Test preparationand executions were performed by a diverse team of engineerswith training and technical ownership tailored for individualexperience and role. Despite significant differences between testvenues, the SCS V&V team established efficient and consistentprocesses and tools for procedure development, test execution,and data review that enabled personnel, as well as technicalproducts such as sequences and parameter configurations, toflow between venues effectively. A series of benchmark testsprovided evidence of performance consistency as elements weretransferred between venues and as system capability evolved.This paper provides an overview of the SCS V&V program andexplores several overarching strategies that enabled successfuloperation in the face of unprecedented complexity. Keyoutcomes of the SCS validation effort are summarized, alongwith lessons learned and beneficial integrations of validationtool and process innovations into Mars surface operations.
A network of virtual machines at cloud server sites connected over virtual IO connections is a flexible, easily deployable, and cost-effective alternative to a physical network infrastructure with dedicated servers connected over leased fiber lines. We study the throughput performance of such a cloud network by collecting measurements over Google Cloud infrastructure spanning multiple continents. To study its ideal performance and impact of packet losses, we utilize its emulation using dedicated servers and connection hardware emulation devices. We compare the measurements over the cloud network to those over its emulation on a testbed. We examine the throughput profiles of both networks as a function of the round trip time and their utilization-concavity coefficients, estimated using measurements for common TCP versions. The throughput profile's concave-convex shape and its coefficient are critical indicators of the network performance, qualitatively and quantitatively, respectively. The results indicate their overall agreement between the production cloud network and its emulation using dedicated connections, and a near optimal throughput performance of the former except for a few under-performing connections. Also, the number of parallel flows is found to be a dominant factor in optimizing the throughput across various conditions and TCP versions.
Concepts for missions of distributed spacecraft flying in formation abound. From high resolution interferometry to spatially distributed in-situ measurements, these mission concepts levy a myriad of guidance, navigation, and control (GNC) requirements on the spacecraft/formation as a single system. A critical step toward assessing and meeting these challenges lies in realistically simulating distributed spacecraft systems. The Formation Flying TestBed (FFTB) at NASA Goddard Space Flight Center's (GSFC) Guidance, Navigation, and Control Center is a hardware-in-the-loop simulation and development facility focused on GNC issues relevant to formation flying systems. The FFTB provides a realistic simulation of the vehicle dynamics and control for formation flying missions in order to: (1) conduct feasibility analyses of mission requirements, (2) conduct and answer mission and spacecraft design trades, and (3) serve as a host for GNC software and hardware development and testing. The initial capabilities of the FFTB are based upon an integration of high fidelity hardware and software simulation, emulation, and test platforms developed or employed at GSFC in recent years, including a high-fidelity Global Positioning System (GPS) simulator which has been a fundamental component of the GNC Center's GPS Test Facility. The FFTB will be continuously evolving over the next several years from a tool with capabilities in GPS navigation hardware/software-in-the-loop analysis and closed loop GPS-based orbit control algorithm assessment. Eventually, it will include full capability to support all aspects of multi-sensor, absolute and relative state determination and control, in all (attitude and orbit) degrees of freedom, as well as information management for satellite clusters and constellations. A detailed description of the FFTB architecture is presented in the paper.
On August 9th, 2012, the Morpheus 1.5 Vertical Testbed (VTB) crashed during Free Flight 2 (FF2) at KSC SLF, resulting in the loss of 1.5 VTB hardware. JSC/KSC Morpheus team immediately executed the pre‐rehearsed Emergency Action Plan to protect personnel and property, so damage was limited to 1.5 VTB hardware. JSC/KSC Morpheus team secured data and mapped & recovered debris. Project had pre‐declared loss of VTB to be a test failure, not a mishap.
ESA and NASA conducted a joint Galileo/GPS space receiver experiment on-board the International Space Station (ISS). The objectives (Enderle 2017) of the joint project were to demonstrate the robustness of a combined Galileo/GPS waveform uploaded to NASA hardware already operating in the challenging space environment - the SCaN (Space Communications and Navigation) software defined radio (SDR) testbed (FPGA) - on-board the ISS. These activities data included the analysis of the Galileo/GPS signal and on-board Position/Velocity/Time (PVT) performance, processing of the Galileo/GPS raw data (code- and carrier phase) for Precise Orbit Determination (POD), and validate the added value of a space-borne dual GNSS receiver compared to a single-system GNSS receiver operating under the same conditions. This paper will provide a general overview of the Galileo/GPS experiment – called GARISS - on-board the ISS, describe design, test and validation and also the operations of the experiment. Further, the various analysis conducted in the con is joint project and also the results obtained will be presented with a focus on the (Precise) Orbit Determination results.
Outlined here is a procedure for evaluating network interface units (NIUs) produced for the Space Station program. The procedures should be equally applicable to the data management system (DMS) testbed NIUs produced by Honeywell and IBM. The evaluation procedures are divided into four areas. Performance measurement tools are hardware and software that must be developed in order to evaluate NIU performance. Performance tests are a series of tests, each of which documents some specific characteristic of NIU and/or network performance. In general, these performance tests quantify the speed, capacity, latency, and reliability of message transmission under a wide variety of conditions. Functionality tests are a series of tests and code inspections that demonstrate the functionality of the particular subset of ISO protocols which have been implemented in a given NIU. Conformance tests are a series of tests which would expose whether or not selected features within the ISO protocols are present and interoperable.
An industry-led collaborative project, called the National Storage Laboratory, was organized to investigate technology for storage systems that will be the future repositories for our national information assets. Industry participants are IBM Federal Systems Company, Ampex Recording Systems Corporation, General Atomics DISCOS Division, IBM ADSTAR, Maximum Strategy Corporation, Network Systems Corporation, and Zitel Corporation. Industry members of the collaborative project are funding their own participation. Lawrence Livermore National Laboratory through its National Energy Research Supercomputer Center (NERSC) will participate in the project as the operational site and the provider of applications. The expected result is an evaluation of a high performance storage architecture assembled from commercially available hardware and software, with some software enhancements to meet the project's goals. It is anticipated that the integrated testbed system will represent a significant advance in the technology for distributed storage systems capable of handling gigabyte class files at gigabit-per-second data rates. The National Storage Laboratory was officially launched on 27 May 1992.
In 2018, the Cognitive Communications and Propagation projects completed installation and checkout testing of a new Ka-Band ground station at the NASA Glenn Research Center in Cleveland, Ohio. The Cognitive Algorithms Demonstration Testbed (CADeT) was developed to provide a fully characterized and controllable dynamic link environment to researchers looking to demonstrate hardware and software aligned with atmospheric sensing and cognitive algorithms. CADeT integrates a host of precision control and measurement systems in addition to repurposing a 5.5 meter beam-waveguide dish platform previously used with the Advanced Communications Technology Satellite (ACTS). This paper will discuss the laboratory testing of ground station components with a emphasis on elements vital to achieving link budget requirements including characterization of the new Gallium Nitride (GaN) Solid State Power Amplifier (SSPA) and far-field measurements of the new antenna feed. Finally, the paper discusses in-situ tests conducted with CADeT and the Tracking and Data Relay Satellite System (TDRSS) to validate laboratory results and make necessary link budget adjustments before reviewing the lessons learned.
This slide presentation reviews the use of the High Contrast Imaging Testbed (HCIT) in the design and improvement of space coronagraphs. The objectives of the work are to: (1) Advance the technology readiness of space coronagraph hardware, techniques, algorithms, and predictive models; (2) Provide proof-of-concept demonstrations of coronagraph techniques; and (3) Support collaborations across the exoplanet community in pursuit of the optimal space coronagraph architecture.
In support of aviation fuel burn and emission reduction goals, NASA is pursuing high-payoff research investments that promise to transform aviation. This includes investments in Electrified Aircraft Propulsion (EAP). Multiple technology challenges must be addressed to unlock the full potential of EAP. This includes addressing challenges related to propulsion controls, which will be vital for ensuring efficient coordinated operation of EAP subsystems. This paper presents results from real-time hardware-in-the-loop testing of a control design for a single aisle partially-turboelectric aircraft propulsion concept conducted at the NASA Electric Aircraft Testbed (NEAT) facility. The control system under test is designed for a propulsion concept consisting of two wing-mounted turbofan engines that produce thrust and generate electrical power to drive a boundary layer ingesting tailfan propulsor via an electrical motor. An integrated control strategy is applied to ensure coordinated operation of the turbofan and tailfan subsystems during steady-state and transient operation throughout the flight envelope. The NEAT test of this integrated control design consists of a partially hardware-in-the-loop, partially simulated configuration. A subscale representation of the electrical system design is implemented in hardware and mechanically coupled to electric machines that emulate turbomachinery and propulsor shaft dynamics. The hardware configuration is then operated under the control of a real-time computer application that runs a simulation of the propulsion system and the developed control logic. The NEAT facility test campaign includes a series of experiments that subject the control design to throttle transients conducted throughout the flight envelope and full-flight mission profiles. Testing under simulated performance degradation is also conducted to evaluate control design robustness. This includes constant and abrupt changes in degradation levels. Results from the hardware-in-the-loop test are presented and shown to be in good agreement with pre-test simulation predictions demonstrating the efficacy of the integrated control design approach.
In support of aviation fuel burn and emission reduction goals, NASA is pursuing high-payoff research investments that promise to transform aviation. This includes investments in Electrified Aircraft Propulsion (EAP). Multiple technology challenges must be addressed to unlock the full potential of EAP. This includes addressing challenges related to propulsion controls, which will be vital for ensuring efficient coordinated operation of EAP subsystems. This paper presents results from real-time hardware-in-the-loop testing of a control design for a single aisle partially-turboelectric aircraft propulsion concept conducted at the NASA Electric Aircraft Testbed (NEAT) facility. The control system under test is designed for a propulsion concept consisting of two wing-mounted turbofan engines that produce thrust and generate electrical power to drive a boundary layer ingesting tailfan propulsor via an electrical motor. An integrated control strategy is applied to ensure coordinated operation of the turbofan and tailfan subsystems during steady-state and transient operation throughout the flight envelope. The NEAT test of this integrated control design consists of a partially hardware-in-the-loop, partially simulated configuration. A subscale representation of the electrical system design is implemented in hardware and mechanically coupled to electric machines that emulate turbomachinery and propulsor shaft dynamics. The hardware configuration is then operated under the control of a real-time computer application that runs a simulation of the propulsion system and the developed control logic. The NEAT facility test campaign includes a series of experiments that subject the control design to throttle transients conducted throughout the flight envelope and full-flight mission profiles. Testing under simulated performance degradation is also conducted to evaluate control design robustness. This includes constant and abrupt changes in degradation levels. Results from the hardware-in-the-loop test are presented and shown to be in good agreement with pre-test simulation predictions demonstrating the efficacy of the integrated control design approach.
Topics concerning the Robot-Operated Material Processing in Space (ROMPS) Program are presented in viewgraph form and include the following: a systems overview; servocontrol and servomechanisms; testbed and simulation results; system V controller; robot module; furnace module; SCL experiment supervisor; SCL script sample processing control; SCL experiment supervisor fault handling; block diagrams; hitchhiker interfaces; battery systems; watchdog timers; mechanical/thermal systems; and fault conditions and recovery.