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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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At least 145 records · Page 8

Thermal Protection Systems for Future NASA Space Vehicles

The proposed first through fourth generation of future NASA Reusable Launch Vehicles (RLV) within NASA will be described, in general, along with their relative goals for improvement in performance (i.e., cost, safety, life, and turnaround time). A brief description of Spaceliner 100 activities representing a means to achieve those goals will be included. Some of the families of thermal protection materials with widely varying characteristics that are being developed for first generation space vehicles at Ames Research Center will be described as well as potential materials and composites for second and third generation applications as systems. These families of materials include functionally gradient material composites that are made from a variety of low-density substrates and moderate to fully dense surface treatments providing the resultant material with both toughness and higher temperature capability opening the envelope of Thermal Protection Systems (TPS) capabilities. Some of the materials truly represent enabling technologies that are required to achieve substantially enhanced thermal protection system performance thereby reducing vehicle risk. Finally the needs for integrated vehicle health monitoring (IVHM) of future vehicles thermal protection systems relative to achieving the goals for third generation reusable launch vehicles and for improving vehicle performance and capabilities reducing risk will be described along with the state of the art in TPS.

Leiser, Daniel B.↗

Modeling of Detached Solidification

Our long term goal is to develop techniques to achieve detached solidification reliably and reproducibly, in order to produce crystals with fewer defects. To achieve this goal it is necessary to understand thoroughly the physics of detached solidification. It was the primary objective of the current project to make progress toward this complete understanding. 'Me products of this grant are attached. These include 4 papers and a preliminary survey of the observations of detached solidification in space. We have successfully modeled steady state detached solidification, examined the stability of detachment, and determined the influence of buoyancy-driven convection under different conditions. Directional solidification in microgravity has often led to ingots that grew with little or no contact with the ampoule wall. When this occurred, crystallographic perfection was usually greatly improved -- often by several orders of magnitude. Indeed, under the Soviet microgravity program the major objective was to achieve detached solidification with its resulting improvement in perfection and properties. Unfortunately, until recently the true mechanisms underlying detached solidification were unknown. As a consequence, flight experiments yielded erratic results. Within the past three years, we have developed a new theoretical model that explains many of the flight results. This model gives rise to predictions of the conditions required to yield detached solidification.

Regel, Liya L.↗

Citadels Final Report (GMLC 2.2.1: Citadels)

This is the final project report for the Grid Modernization Laboratory Consortium (GMLC) Resilient Distribution System (RDS) Citadels project. The primary goal of this GMLC project was to increase the operational flexibly of power systems by engaging microgrids distributedly, coordinated using consensus algorithms. The primary goal was successfully achieved. The primary goal was divided into three areas: Implement peer-to-peer control between microgrid controllers using the Open Field Message Bus (OpenFMB) approach; Develop and implement consensus algorithms on commercially available hardware that allows a group of microgrids to distributedly implement operational controls; Develop the architectures and controls to enable groups of microgrids to coordinate their operations to support the bulk power system during abnormal events, and end-use loads in the event the bulk power systems fail.

24 POWER TRANSMISSION AND DISTRIBUTION↗

Higher education institutions can do more to lead society toward resilience and sustainability

Higher education institutions (HEIs) are beginning to recognize their role as leading societal institutions in the movement toward resilience and sustainability by empowering their students as sustainability stakeholders and leaders and recognizing the value of faculty and staff as facilitators in this mobilization toward a more sustainable future. This chapter identifies seven goals derived from academic research that can be used to foster student leadership in sustainability and support faculty and staff in facilitatory roles. To date, however, most research has focused on sustainability in the classroom environment or the establishment of living labs. To illuminate how these seven goals can be achieved, the chapter adopts stakeholder theory and conducts an integrated case study assessment. Overall, the chapter helps to (i) develop a stronger understanding of sustainability and resilience, (ii) identify best practices for empowering student leaders and to better understand the facilitatory role played by faculty and staff in achieving the seven goals, and (ii) offer further insights through a reflective case study.

Sustainability and Resilience, Sustainability Syst↗

Learning reliable manipulation strategies without initial physical models

A description is given of a robot, possessing limited sensory and effectory capabilities but no initial model of the effects of its actions on the world, that acquires such a model through exploration, practice, and observation. By acquiring an increasingly correct model of its actions, it generates increasingly successful plans to achieve its goals. In an apparently nondeterministic world, achieving reliability requires the identification of reliable actions and a preference for using such actions. Furthermore, by selecting its training actions carefully, the robot can significantly improve its learning rate.

Christiansen, Alan D.↗

Creating a foundation for a synergistic approach to program management

In order to accelerate the movement of humans into space within reasonable budgetary constraints, NASA must develop an organizational structure that will allow the agency to efficiently use all the resources it has available for the development of any program the nation decides to undertake. This work considers the entire set of tasks involved in the successful development of any program. Areas that hold the greatest promise of accelerating programmatic development and/or increasing the efficiency of the use of available resources by being dealt with in a centralized manner rather than being handled by each program individually are identified. Using this information, an agency organizational structure is developed that will allow NASA to promote interprogram synergisms. In order for NASA to efficiently manage its programs in a manner that will allow programs to benefit from one another and thereby accelerate the movement of humans into space, several steps must be taken. First, NASA must develop an organizational structure that will allow potential interprogram synergisms to be identified and promoted. Key features of the organizational structure are recommended in this paper. Second, NASA must begin to develop the requirements for a program in a manner that will promote overall space program goals rather than achieving only the goals that apply to the program for which the requirements are being developed. Finally, NASA must consider organizing the agency around the functions required to support NASA's goals and objectives rather than around geographic locations.

Knoll, Karyn T.↗

Three-D Flow Analysis of the Alternate SSME HPOT TAD

This paper describes the results of numerical flow analyses performed in support of design development of the Space Shuttle Main Engine Alternate High Pressure Oxidizer Turbine Turn-around duct (TAD). The flow domain has been modeled using a 3D, Navier-Stokes, general purpose flow solver. The goal of this effort is to achieve an alternate TAD exit flow distribution which closely matches that of the baseline configuration. 3D Navier Stokes CFD analyses were employed to evaluate numerous candidate geometry modifications to the TAD flowpath in order to achieve this goal. The design iterations are summarized, as well as a description of the computational model, numerical results and the conclusions based on these calculations.

Kubinski, Cheryl A.↗

Presentation to International Space University Students on g-LIMIT and STABLE-ATD Projects and Related Microgravity Vibration Isolation Topics

Vibration isolation is a necessity in the development of science in space and especially those experiments destined for operation on the International Space Station (ISS). The premise of microgravity scientific research is that in space, disturbances are minimized and experiments can be conducted in the absence of gravity. Although microgravity conditions exist in space, disturbances are still present in various forms and can be detrimental to the success of a microgravity experiment. Due to the plethora of disturbances and the various types that will occur on the space station, the microgravity community has elected to incorporate various means of isolating scientific payloads from these unwanted vibrations. Designing these vibration isolators is a crucial task to achieve true microgravity science. Since conventional methods of isolating payloads can achieve only limited isolation, new technologies are being developed to achieve the goal of designing a generic vibration isolation system. One such system being developed for the Microgravity Science Glovebox (MSG) is called g-LIMIT which stands for Glovebox Integrated Microgravity Isolation Technology. The g-LIMIT system is a miniaturized active vibration isolator for glovebox experiments. Although the system is initially developed for glovebox experiments, the g-LIMIT technology is designed to be upwardly scaleable to provide isolation for a broad range of users. The g-LIMIT system is scheduled to be flown on the UF-2 mission in August of the year 2000 and will be tested shortly thereafter. Once the system has been fully qualified, the hardware will become available for other researchers and will provide a platform upon which the goal of microgravity science can be achieved.

Alhorn, Dean↗

Surface Texturing Investigated for a High Solar Absorptance Low Infrared Emittance Solar Collector

The objective of this work was to design, build, and vacuum test a high solar absorptance, low infrared emittance solar collector for heat engine and thermal switching applications. Mini-satellites proposed by the Applied Physics Laboratory for operation in environments that are subject to radiation threat may utilize a heat engine for power and a thermal bus for thermal control. To achieve this goal, a surface having high solar absorptance and low infrared emittance is needed. At the NASA Glenn Research Center, one concept being pursued to achieve this goal is texturing high thermal conductivity graphite epoxy composites using a directed atomic oxygen beam and then coating the textured surface with a reflective metallic coating. Coupons were successfully textured, coated, and evaluated. A variety of texturing conditions were explored, and textures were documented by scanning electron microscopy. Copper, gold, silver, iridium, and aluminum coatings were applied, and the highest solar absorptance to infrared emittance ratio was found to be 1.3. A full-sized solar collector was manufactured with this ratio, and the amount of heat collected was observed using an Inconel calorimeter installed in a bench-top vacuum chamber equipped with a solar simulator. Results to date indicate good heat flow through the system, with 9 W of heat flow measured by the calorimeter.

Jaworske, Donald A.↗

Ares V and Future Very Large Launch Vehicles to Enable Major Astronomical Missions

The current NASA architecture planned to return humans to the lunar surface includes the Ares V heavy lift launch vehicle designed primarily to carry the Altair lunar lander and to be available before about 2020. However. the capabilities of this system (and its variants) are such that adapting the vehicle to launch very large optical systems could achieve major scientific goals that are not otherwise possible. For example, an 8-m monolith UV/visual/IR telescope appears able to be launched to the Sun-Earth L2 location by an Ares V with a 10-m fairing. Even larger apertures that are deployed or assembled in space seem possible, which may take advantage of other elements of NASA's future human spaceflight architecture. Alternatively. multiple elements of a spatial array or two or three astronomical observatories might he launched simultaneously. That is, Ares V appears to offer the astronomy communities an opportunity to put into orbit extremely capable observatories, in addition to being a key element of NASA's current architecture for human spaceflight. For the past year, a number of scientists and engineers have been eva1uating concepts for astronomical observatories that take advantage of future large launch vehicles, including the science goals of such missions and design modifications to the vehicle to enable the observatories. In parallel, members of the Solar System science communities have likewise been considering what major science goals can be achieved if new, extremely capable launch systems become available.

Thronson, Harley↗

Aircraft Configuration and Flight Crew Compliance with Procedures While Conducting Flight Deck Based Interval Management (FIM) Operations

Flight deck based Interval Management (FIM) applications using ADS-B are being developed to improve both the safety and capacity of the National Airspace System (NAS). FIM is expected to improve the safety and efficiency of the NAS by giving pilots the technology and procedures to precisely achieve an interval behind the preceding aircraft by a specific point. Concurrently but independently, Optimized Profile Descents (OPD) are being developed to help reduce fuel consumption and noise, however, the range of speeds available when flying an OPD results in a decrease in the delivery precision of aircraft to the runway. This requires the addition of a spacing buffer between aircraft, reducing system throughput. FIM addresses this problem by providing pilots with speed guidance to achieve a precise interval behind another aircraft, even while flying optimized descents. The Interval Management with Spacing to Parallel Dependent Runways (IMSPiDR) human-in-the-loop experiment employed 24 commercial pilots to explore the use of FIM equipment to conduct spacing operations behind two aircraft arriving to parallel runways, while flying an OPD during high-density operations. This paper describes the impact of variations in pilot operations; in particular configuring the aircraft, their compliance with FIM operating procedures, and their response to changes of the FIM speed. An example of the displayed FIM speeds used incorrectly by a pilot is also discussed. Finally, this paper examines the relationship between achieving airline operational goals for individual aircraft and the need for ATC to deliver aircraft to the runway with greater precision. The results show that aircraft can fly an OPD and conduct FIM operations to dependent parallel runways, enabling operational goals to be achieved efficiently while maintaining system throughput.

Shay, Rick↗

A Solar-assisted Voltage Optimization Method for Transmission Solar Network Power System

This paper proposes a new formulation and solution algorithm that uses transmission level solar inverters to address the security-constrained optimal power flow (SCOPF) problem. The goal is to stabilize voltage fluctuations in transmission networks in base case and contingency scenarios, by using bulk solar power plant with a minimal number of post-contingency corrections. To achieve this goal, a two-stage volt/var optimization method is proposed to first correct all voltage violations with the volt-var alternating current optimal power flow (ACOPF) algorithm for a base case. Then a linearized SCOPF volt-var control algorithm is proposed to identify the corrective actions for all potential voltage violations in all contingency scenarios. The proposed method was tested and validated on a modified IEEE 118-bus system with solar photovoltaic (PV) data.

Photovoltaic, Volt/Var Control↗

SOLPOL: A Solar Polarimeter for Hard X-Rays and Gamma-Rays

Th goal of this project was to continue the development of a hard X-ray polarimeter for studying solar flares. In earlier work (funded by a previous SR&T grant), we had already achieved several goals, including the following: 1) development of a means of producing a polarized radiation source in the lab that could be used for prototype development; 2) demonstrated the basic Compton scatter polarimeter concept using a simple laboratory setup; 3) used the laboratory results to verify our Monte Carlo simulations; and 4) investigated various detector technologies that could be incorporated into the polarimeter design. For the current one-year program, we wanted to fabricate and test a laboratory science model based on our SOLPOL (Solar Polarimeter) design. The long-term goal of this effort is to develop and test a prototype design that could be used to study flare emissions from either a balloon- or space-borne platform. The current program has achieved its goal of fabricating and testing a science model of the SOLPOL design, although additional testing of the design (and detailed comparison with Monte Carlo simulations) is still desired. This one-year program was extended by six months (no-cost extension) to cover the summer of 1999, when undergraduate student support was available to complete some of the laboratory testing.

McConnell, Michael L.↗

Global Energy Policy to Achieve the United States’ Nationally Determined Contributions: Potential Pathway

In 2021, the United States declared its Nationally Determined Contribution (NDC) in preparation for the COP26 climate summit, setting goals to achieve zero emission electricity by 2035, and reducing net emissions by 50–52% compared to 2005 levels. The current U.S. energy policies were found to not be adequate to meet these goals, thus it is necessary to draft a pathway to achieving these goals through policy changes. This study focused on foreign energy policies to analyze the most effective policies in a host of sectors. By identifying the most ambitious and effective policies from around the world in each sector, this study was able to suggest a policy pathway that can potentially achieve both of goals set in the NDC. In guiding the development of the proposed policy pathway, this study analyzed policies from Australia, Canada, California, China, Denmark, France, Germany, Japan, Russia, South Korea, Sweden, the United Kingdom, and the United States. This study found that the most drastic CO2 reductions came from low-carbon electricity policy, but contributions were also made from carbon capture, reforestation, hydrogen, energy efficiency, and climate smart agriculture.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Automating CPM-GOMS

CPM-GOMS is a modeling method that combines the task decomposition of a GOMS analysis with a model of human resource usage at the level of cognitive, perceptual, and motor operations. CPM-GOMS models have made accurate predictions about skilled user behavior in routine tasks, but developing such models is tedious and error-prone. We describe a process for automatically generating CPM-GOMS models from a hierarchical task decomposition expressed in a cognitive modeling tool called Apex. Resource scheduling in Apex automates the difficult task of interleaving the cognitive, perceptual, and motor resources underlying common task operators (e.g. mouse move-and-click). Apex's UI automatically generates PERT charts, which allow modelers to visualize a model's complex parallel behavior. Because interleaving and visualization is now automated, it is feasible to construct arbitrarily long sequences of behavior. To demonstrate the process, we present a model of automated teller interactions in Apex and discuss implications for user modeling. available to model human users, the Goals, Operators, Methods, and Selection (GOMS) method [6, 21] has been the most widely used, providing accurate, often zero-parameter, predictions of the routine performance of skilled users in a wide range of procedural tasks [6, 13, 15, 27, 28]. GOMS is meant to model routine behavior. The user is assumed to have methods that apply sequences of operators and to achieve a goal. Selection rules are applied when there is more than one method to achieve a goal. Many routine tasks lend themselves well to such decomposition. Decomposition produces a representation of the task as a set of nested goal states that include an initial state and a final state. The iterative decomposition into goals and nested subgoals can terminate in primitives of any desired granularity, the choice of level of detail dependent on the predictions required. Although GOMS has proven useful in HCI, tools to support the construction of GOMS models have not yet come into general use.

GOMS↗

Puerto Rico Grid Resilience and Transitions to 100% Renewable Energy Study (PR100): Final Report

The Puerto Rico Grid Resilience and Transitions to 100% Renewable Energy Study (PR100) is a comprehensive analysis based on extensive stakeholder input of possible pathways for Puerto Rico to achieve its goal of 100% renewable energy by 2050. PR100 was an integrated effort drawing on expertise and capabilities of the contributing national laboratories that explored possible pathways for Puerto Rico to achieve its goal of 100% renewable energy in the long term (by 2050), increase reliability and resilience in the immediate term (within the next few years), and work toward energy justice. The purpose of the study is to provide decision support and inform investment decisions for implementers of Puerto Rico's energy transition. See NREL/TP-6A20-88614 for the Spanish translation of this report.

100% renewable energy target↗

Kinematically redundant robot manipulators

Research on control, design and programming of kinematically redundant robot manipulators (KRRM) is discussed. These are devices in which there are more joint space degrees of freedom than are required to achieve every position and orientation of the end-effector necessary for a given task in a given workspace. The technological developments described here deal with: kinematic programming techniques for automatically generating joint-space trajectories to execute prescribed tasks; control of redundant manipulators to optimize dynamic criteria (e.g., applications of forces and moments at the end-effector that optimally distribute the loading of actuators); and design of KRRMs to optimize functionality in congested work environments or to achieve other goals unattainable with non-redundant manipulators. Kinematic programming techniques are discussed, which show that some pseudo-inverse techniques that have been proposed for redundant manipulator control fail to achieve the goals of avoiding kinematic singularities and also generating closed joint-space paths corresponding to close paths of the end effector in the workspace. The extended Jacobian is proposed as an alternative to pseudo-inverse techniques.

Baillieul, J.↗