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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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NASA NTRS2013

Geolab Results from Three Years of Analog Mission Tests

GeoLab is a prototype glovebox for geological sample examination that was, until November 2012, fully integrated into NASA's Deep Space Habitat Analog Testbed [1,2]. GeoLab allowed us to test science operations related to contained sample examination during simulated exploration missions. The facility, shown in Figure 1 and described elsewhere [1-4], was designed for fostering the development of both instrument technology and operational concepts for sample handling and examination during future missions [3-5]. Even though we recently deintegrated the glovebox from the Deep Space Habitat (Fig. 2), it continues to provide a high-fidelity workspace for testing instruments that could be used for sample characterization. As a testbed, GeoLab supports the development of future science operations that will enhance the early scientific returns from exploration missions, and will help ensure selection of the best samples for Earth return.

Evans, Cindy A.↗
NASA NTRS1990

Autonomous power expert system

The Autonomous Power Expert (APEX) system was designed to monitor and diagnose fault conditions that occur within the Space Station Freedom Electrical Power System (SSF/EPS) Testbed. APEX is designed to interface with SSF/EPS testbed power management controllers to provide enhanced autonomous operation and control capability. The APEX architecture consists of three components: (1) a rule-based expert system, (2) a testbed data acquisition interface, and (3) a power scheduler interface. Fault detection, fault isolation, justification of probable causes, recommended actions, and incipient fault analysis are the main functions of the expert system component. The data acquisition component requests and receives pertinent parametric values from the EPS testbed and asserts the values into a knowledge base. Power load profile information is obtained from a remote scheduler through the power scheduler interface component. The current APEX design and development work is discussed. Operation and use of APEX by way of the user interface screens is also covered.

Walters, Jerry L.↗
NASA NTRS2004

Model validation of SIM external metrology at the sub-nanometer level

In order to achieve micro-arcsecond astrometry, SIM must make measurements of various optical path lengths at the picometer level. In this regime of precision, nearly every simplifying assumption in optics must be reexamined as a potential source of systematic error. SIM makes extensive use of physics-based models to predict the form and level of systematic errors affecting instrument performance. Since many of the modeling areas represent new frontiers in optical modeling, the validation of these physical models is a significant challenge that SIM must meet. In the case of the external metrology truss, the model must account for the imperfections in the corner cubes as well as the distance measuring interferometers ("beam launchers"). This model is being validated using the Kite testbed, a 2-D metrology truss with picometer-level accuracy in displacement measurements. We present the model and the results of the model validation tests on the Kite testbed.

Kuan, Gary M.↗
NASA NTRS2002

Status of Brayton Cycle Power Conversion Development at NASA GRC

The NASA Glenn Research Center (GRC) is pursuing the development of Brayton cycle power conversion for various NASA initiatives. Brayton cycle power systems offer numerous advantages for space power generation including high efficiency, long life, high maturity, and broad scalability. Candidate mission applications include surface rovers and bases, advanced propulsion vehicles, and earth orbiting satellites. A key advantage is the ability for Brayton converters to span the wide range of power demands of future missions from several kilowatts to multi-megawatts using either solar, isotope, or reactor heat sources. Brayton technology has been under development by NASA since the early 1960's resulting in engine prototypes in the 2 to 15 kW-class that have demonstrated conversion efficiency of almost 30% and cumulative operation in excess of 40,000 hours. Present efforts at GRC are focusing on a 2 kW testbed as a proving ground for future component advances and operational strategies, and a 25 kW engine design as a modular building block for 100 kW-class electric propulsion and Mars surface power applications.

Mason, Lee S.↗
NASA NTRS2016

Phase Retrieval Implementation for the WFIRST Coronagraph Development Testbed

The Wide-Field Infrared Survey Telescope (WFIRST) is a 2.4m diameter space telescope NASA program. The payload will include two instruments, including a coronagraph instrument (CGI). The CGI will be the first active, high-contrast stellar coronagraph in space intended for imaging, discovery, and spectral characterization of exoplanets and debris discs. The CGI designs under development use deformable mirrors (DM) to create a point spread function (PSF) with a dark region around the obscured star object. Each DM consists of an array of actuators, and each actuator causes a local displacement to a thin, mirror-coated, glass face sheet. The actuator displacements are designed to create the PSF. Typically, phase retrieval is used to set the DM actuator displacements to their designed pattern, and then the actuators are further modified by an iterative control loop to correct for system non-idealities. To observe an exoplanet near the star object, the contrast in the annular region must be better than 10^8 (10^9 after post processing) relative to the unobstructed image of the star [1,2]. The coronagraph testbed at Jet Propulsion Laboratory is used to test coronagraph design and control algorithms. The optical system (Fig. 1) is maintained in a vacuum tank so that the PSF is stable for long integration times. Phase retrieval is an important tool for the testbed and serves several purposes, in addition to setting initial DM actuator displacements. Other uses include evaluation of systematic wavefront error introduced by system components, and alignment of the DMs and pupil masks. For example, the location of specific DM actuators relative to the Lyot mask can be determined by displacing the actuator, then measuring the location of the phase disturbance in the pupil plane with phase retrieval. In the next section we further describe the optical train of the testbed and the collection of source and pupil images available as inputs for phase retrieval, as well as one phase retrieval algorithm employed. Section 3 shows example phase retrieval results.

Marx, David↗
NASA NTRS1994

Regular Topologies for Gigabit Wide-Area Networks

In general terms, this project aimed at the analysis and design of techniques for very high-speed networking. The formal objectives of the project were to: (1) Identify switch and network technologies for wide-area networks that interconnect a large number of users and can provide individual data paths at gigabit/s rates; (2) Quantitatively evaluate and compare existing and proposed architectures and protocols, identify their strength and growth potentials, and ascertain the compatibility of competing technologies; and (3) Propose new approaches to existing architectures and protocols, and identify opportunities for research to overcome deficiencies and enhance performance. The project was organized into two parts: 1. The design, analysis, and specification of techniques and protocols for very-high-speed network environments. In this part, SRI has focused on several key high-speed networking areas, including Forward Error Control (FEC) for high-speed networks in which data distortion is the result of packet loss, and the distribution of broadband, real-time traffic in multiple user sessions. 2. Congestion Avoidance Testbed Experiment (CATE). This part of the project was done within the framework of the DARTnet experimental T1 national network. The aim of the work was to advance the state of the art in benchmarking DARTnet's performance and traffic control by developing support tools for network experimentation, by designing benchmarks that allow various algorithms to be meaningfully compared, and by investigating new queueing techniques that better satisfy the needs of best-effort and reserved-resource traffic. This document is the final technical report describing the results obtained by SRI under this project. The report consists of three volumes: Volume 1 contains a technical description of the network techniques developed by SRI in the areas of FEC and multicast of real-time traffic. Volume 2 describes the work performed under CATE. Volume 3 contains the source code of all software developed under CATE.

Shacham, Nachum↗
NASA NTRS2007

Phoenix Missile Hypersonic Testbed (PMHT): System Concept Overview

A viewgraph presentation of the Phoenix Missile Hypersonic Testbed (PMHT) is shown. The contents include: 1) Need and Goals; 2) Phoenix Missile Hypersonic Testbed; 3) PMHT Concept; 4) Development Objectives; 5) Possible Research Payloads; 6) Possible Research Program Participants; 7) PMHT Configuration; 8) AIM-54 Internal Hardware Schematic; 9) PMHT Configuration; 10) New Guidance and Armament Section Profiles; 11) Nomenclature; 12) PMHT Stack; 13) Systems Concept; 14) PMHT Preflight Activities; 15) Notional Ground Path; and 16) Sample Theoretical Trajectories.

Jones, Thomas P.↗
NASA NTRS1985

Computational structural mechanics: A new activity at the NASA Langley Research Center

Complex structures considered for the late 1980's and early 1990's include composite primary aircraft structures and the space station. These structures are much more difficult to analyze than today's structures and necessitate a major upgrade in computerized structural analysis technology. A major research activity in computational structural mechanics (CSM) was initiated. The objective of the CSM activity is develop advanced structural analysis technology that will exploit modern and emerging computers such as computers with vector and/or parallel processing capabilities. The three main research activities underway in CSM include: (1) structural analysis methods development; (2) a software testbed for evaluating the methods; and (3) numerical techniques for parallel processing computers. The motivation and objectives of the CSM activity are presented and CSM activity is described. The current CSM research thrusts, and near and long term CSM research thrusts are outlined.

Knight, N. F., Jr.↗
NASA NTRS1995

A study of space-rated connectors using a robot end-effector

The main research activities have been directed toward the study of the Robot Operated Materials Processing System (ROMPS), developed at GSFC under a flight project to investigate commercially promising in-space material processes and to design reflyable robot automated systems to be used in the above processes for low-cost operations. The research activities can be divided into two phases. Phase 1 dealt with testing of ROMPS robot mechanical interfaces and compliant device using a Stewart Platform testbed and Phase 2 with computer simulation study of the ROMPS robot control system. This report provides a summary of the results obtained in Phase 1 and Phase 2.

Nguyen, Charles C.↗
NASA NTRS2001

Engine With Regression and Neural Network Approximators Designed

At the NASA Glenn Research Center, the NASA engine performance program (NEPP, ref. 1) and the design optimization testbed COMETBOARDS (ref. 2) with regression and neural network analysis-approximators have been coupled to obtain a preliminary engine design methodology. The solution to a high-bypass-ratio subsonic waverotor-topped turbofan engine, which is shown in the preceding figure, was obtained by the simulation depicted in the following figure. This engine is made of 16 components mounted on two shafts with 21 flow stations. The engine is designed for a flight envelope with 47 operating points. The design optimization utilized both neural network and regression approximations, along with the cascade strategy (ref. 3). The cascade used three algorithms in sequence: the method of feasible directions, the sequence of unconstrained minimizations technique, and sequential quadratic programming. The normalized optimum thrusts obtained by the three methods are shown in the following figure: the cascade algorithm with regression approximation is represented by a triangle, a circle is shown for the neural network solution, and a solid line indicates original NEPP results. The solutions obtained from both approximate methods lie within one standard deviation of the benchmark solution for each operating point. The simulation improved the maximum thrust by 5 percent. The performance of the linear regression and neural network methods as alternate engine analyzers was found to be satisfactory for the analysis and operation optimization of air-breathing propulsion engines (ref. 4).

Patnaik, Surya N.↗
NASA NTRS2019

Psyche Early Project Verification & Validation Planning Development

The Psyche mission to the asteroid (16) Psyche was selected as the fourteenth mission in the Discovery program in January 2017. The Psyche mission will determine if (16) Psyche is the core of a larger differentiated body. As part of the development of this mission a Verification and Validation (V&V) engineer was assigned early in the project’s design Phase B. This paper will discuss some of the strategies that the Psyche team is using to take full advantage of the early planning for V&V on flight projects and specifically how the Psyche mission is approaching these tasks. This paper will discuss the effects of having a V&V mindset on: 1) The Psyche requirements development process, and how focusing not only on how the team will verify these requirements but also on developing the tools necessary to track and monitor that verification feeds back into the requirement development process. 2) The Psyche testbed development, and how using a verification mindset is useful for identifying holes in the testbed development process, including the required testbed speed and how to think about testbed certification early in the process while encouraging trades and developing relationships with the testbed team. 3) Developing new V&V Tools for Psyche, and how developing tools early in the project development process means that they can influence the development of other requirement and scheduling tools. 4) Verification Activity Planning, which is typically done to a preliminary level during Phase B of the project, and is important for understanding the major testing that is needed to ensure that the system as built represents the design. On Psyche we are not only focused on bringing this planning to a preliminary level, we are also developing a V&V focused schedule to help us de-conflict V&V activities that may require similar resources early on in the program’s development. 5) Validation Planning, for which we are working with the testbed and model development teams to ensure that their models can be effectively validated and that the plans to do so are in place. In this paper we will describe how the Psyche mission is approaching each of these V&V areas and identify lessons that can be taken by other space missions trying to decide how much effort should be put into V&V early in the project lifecycle.

Solish, Benjamin↗
NASA NTRS1986

Data Management System (DMS) testbed user's manual development, volumes 1 and 2

A critical review of the network communication services contained in the Tinman User's Manual for Data Management System Test Bed (Tinman DMS User's Manual) is presented. The review is from the perspective of applying modern software engineering principles and using the Ada language effectively to ensure the test bed network communication services provide a robust capability. Overall the material on network communication services reflects a reasonably good grasp of the Ada language. Language features are appropriately used for most services. Design alternatives are offered to provide improved system performance and a basis for better application software development. Section two contains a review and suggests clarifications of the Statement of Policies and Services contained in Appendix B of the Tinman DMS User's Manual. Section three contains a review of the Network Communication Services and section four contains concluding comments.

Mcbride, John G.↗
NASA NTRS1988

A methodology for automation and robotics evaluation applied to the space station telerobotic servicer

The efforts of a recent study aimed at identifying key issues and trade-offs associated with using a Flight Telerobotic Servicer (FTS) to aid in Space Station assembly-phase tasks is described. The use of automation and robotic (A and R) technologies for large space systems would involve a substitution of automation capabilities for human extravehicular or intravehicular activities (EVA, IVA). A methodology is presented that incorporates assessment of candidate assembly-phase tasks, telerobotic performance capabilities, development costs, and effect of operational constraints (space transportation system (STS), attached payload, and proximity operations). Changes in the region of cost-effectiveness are examined under a variety of systems design assumptions. A discussion of issues is presented with focus on three roles the FTS might serve: (1) as a research-oriented testbed to learn more about space usage of telerobotics; (2) as a research based testbed having an experimental demonstration orientation with limited assembly and servicing applications; or (3) as an operational system to augment EVA and to aid the construction of the Space Station and to reduce the programmatic (schedule) risk by increasing the flexibility of mission operations.

Smith, Jeffrey H.↗
NASA NTRS1989

Assessment of SPAR elements and formulation of some basic 2-D and 3-D elements for use with testbed generic element processor

The initial Computational Structural Mechanics (CSM) Testbed was based on Level 13 of the SPAR finite element computer program. Until recently, the element library of the Testbed has been limited to those elements in Level 13 of SPAR. The development of a generic element processor has enabled element researchers to develop, implement and assess element formulations with relative ease. An assessment of new elements as well as the existing SPAR Level 13 elements has revealed some definite shortcomings with the SPAR Level 13 2-D and 3-D elements. The SPAR S81 solid element does not pass the patch test problem proposed by MacNeal-Harder. These deficiencies are identified here. The 2-D elements, however, seem to perform well taking into account the limitations imposed by the theory used to formulate them, (i.e., thin plates only). Common deficiencies of the 2-D and 3-D elements in SPAR have to do with their adaptability to the nonlinear analysis utilities developed by Lockheed Palo Alto Research Lab. Also, the EFIL format of the SPAR element data does not conform to the standard format of the Testbed.

Aminpour, Mohammad A.↗
NASA NTRS1988

Hypersonic drone vehicle design: A multidisciplinary experience

UCLA's Advanced Aeronautic Design group focussed their efforts on design problems of an unmanned hypersonic vehicle. It is felt that a scaled hypersonic drone is necesary to bridge the gap between present theory on hypersonics and the future reality of the National Aerospace Plane (NASP) for two reasons: (1) to fulfill a need for experimental data in the hypersonic regime, and (2) to provide a testbed for the scramjet engine which is to be the primary mode of propulsion for the NASP. The group concentrated on three areas of great concern to NASP design: propulsion, thermal management, and flight systems. Problem solving in these areas was directed toward design of the drone with the idea that the same design techniques could be applied to the NASP. A 70 deg swept double-delta wing configuration, developed in the 70's at the NASA Langley, was chosen as the aerodynamic and geometric model for the drone. This vehicle would be air launched from a B-1 at Mach 0.8 and 48,000 feet, rocket boosted by two internal engines to Mach 10 and 100,000 feet, and allowed to cruise under power of the scramjet engine until burnout. It would then return to base for an unpowered landing. Preliminary energy calculations based on flight requirements give the drone a gross launch weight of 134,000 pounds and an overall length of 85 feet.

Source record↗
NASA NTRSDate not supplied

Experimental Verification of the Parabolic Deformable Mirror for the ExoSpec Project

For the Habitable Worlds Observatory (HWO), it is essential to broaden the controllable wavelength bandwidth for high-contrast imaging and spectroscopy to increase the exoEarth yield and characterization. The Parabolic Deformable Mirrors (PDM) subpackage, under the NASA Headquarters-directed Exoplanet Spectroscopy (ExoSpec) Work Package, is specifically tailored to do so. We have successfully procured a first-generation (Gen 1) PDM device and completed in-depth characterization of the device. This robust evaluation has become instrumental in informing subsequent stages of development, particularly in shaping the design and specifying requirements for the next generation, Gen 2, PDM device. We have built a testbed in an environmentally controlled cleanroom to experimentally demonstrate the use of a PDM in a coronagraph instrument with an integral field spectrograph (IFS). This versatile testbed is designed to test different DM architectures, low-order wavefront sensing schemes, and a lenslet-based IFS. This provides us with a basis for comparison with different DM configurations: 1) flat DM, 2) PDMs, and 3) a flat DM and PDMs. In this communication, we will discuss the testbed design and updates, PDM characterization, and Gen 2 requirement definitions.

Hari B. Subedi↗
NASA NTRS2021

New Observing Strategies Testbed (NOS-T)

The New Observing Strategies (NOS) initiative within the NASA Earth Science Technology Office(ESTO)Advanced Information Systems Technology(AIST) program envisions future Earth science missions with distributed sensors(nodes) interconnected by a communications fabric that enables dynamic and intelligent operations [1].Some NOS concepts resemble systems-of-systems or collaborative systems where operational authority is distributed among multiple systems, necessitating new methods for systems engineering and design to cope with more decentralized control over constituent systems[2].The New Observing Strategies Testbed (NOS-T, verbalized as "enoh es tee") is a computational environment to develop, test, mature, and socialize new operating concepts and technology for NOS. NOS-T provides infrastructure to integrate and orchestrate user-contributed applications for system-of-systems test cases with true distributed control over constituent systems. The overall concept, illustrated in Figure 1, interconnects individual user applications and a NOS-T manager application via common information system infrastructure to coordinate the execution of virtual Earth science missions. NOS-T enables principal investigators to conduct test runs in the same environment, systematically changing variables to assess the overall efficacy of the proposed new observing strategies. Recorded data and outcomes provide evidence to advance technology readiness level and improve or innovate upon existing Earth science measurement techniques

Paul Grogan↗
NASA NTRS2003

Brayton Power Conversion Unit Tested: Provides a Path to Future High-Power Electric Propulsion Missions

Closed-Brayton-cycle conversion technology has been identified as an excellent candidate for nuclear electric propulsion (NEP) power conversion systems. Advantages include high efficiency, long life, and high power density for power levels from about 10 kWe to 1 MWe, and beyond. An additional benefit for Brayton is the potential for the alternator to deliver very high voltage as required by the electric thrusters, minimizing the mass and power losses associated with the power management and distribution (PMAD). To accelerate Brayton technology development for NEP, the NASA Glenn Research Center is developing a low-power NEP power systems testbed that utilizes an existing 2- kWe Brayton power conversion unit (PCU) from previous solar dynamic technology efforts. The PCU includes a turboalternator, a recuperator, and a gas cooler connected by gas ducts. The rotating assembly is supported by gas foil bearings and consists of a turbine, a compressor, a thrust rotor, and an alternator on a single shaft. The alternator produces alternating-current power that is rectified to 120-V direct-current power by the PMAD unit. The NEP power systems testbed will be utilized to conduct future investigations of operational control methods, high-voltage PMAD, electric thruster interactions, and advanced heat rejection techniques. The PCU was tested in Glenn s Vacuum Facility 6. The Brayton PCU was modified from its original solar dynamic configuration by the removal of the heat receiver and retrofitting of the electrical resistance gas heater to simulate the thermal input of a steady-state nuclear source. Then, the Brayton PCU was installed in the 3-m test port of Vacuum Facility 6, as shown. A series of tests were performed between June and August of 2002 that resulted in a total PCU operational time of about 24 hr. An initial test sequence on June 17 determined that the reconfigured unit was fully operational. Ensuing tests provided the operational data needed to characterize PCU performance over its full operating range. The primary test variables used in operating the Brayton PCU were heater input power and rotor speed. Testing demonstrated a maximum steady-state alternating-current power output of 1835 W at a gas heater power of 9000 W and a rotor speed of 52000 rpm. The corresponding measured turbine inlet gas temperature was 1076 K, and the compressor inlet gas temperature was 282 K. When insulation losses from the gas heater were neglected, the Brayton cycle efficiency for the maximum power point was calculated to be 24 percent. The net direct-current power output was 1750 W, indicating a PMAD efficiency of about 95 percent.

Mason, Lee S.↗