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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 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Dexterous Orbital Servicing System (DOSS)

The Dexterous Orbiter Servicing System (DOSS) is a dexterous robotic spaceflight system that is based on the manipulator designed as part of the Flight Telerobotics Servicer program for the Space Station Freedom and built during a 'technology capture' effort that was commissioned when the FTS was cancelled from the Space Station Freedom program. The FTS technology capture effort yielded one flight manipulator and the 1 g hydraulic simulator that had been designed as an integrated test tool and crew trainer. The DOSS concept was developed to satisfy needs of the telerobotics research community, the space shuttle, and the space station. As a flight testbed, DOSS would serve as a baseline reference for testing the performance of advanced telerobotics and intelligent robotics components. For shuttle, the DOSS, configured as a movable dexterous tool, would be used to provide operational flexibility for payload operations and contingency operations. As a risk mitigation flight demonstration, the DOSS would serve the International Space Station to characterize the end to end system performance of the Special Purpose Dexterous Manipulator performing assembly and maintenance tasks with actual ISSA orbital replacement units. Currently, the most likely entrance of the DOSS into spaceflight is a risk mitigation flight experiment for the International Space Station.

Price, Charles R.↗
NASA NTRS2012

Software Programs Derive Measurements from Photographs

Even under the most unfortunate circumstances, NASA continues on a path of innovation. After the Space Shuttle Columbia reentered the atmosphere on February 1, 2003, it experienced a catastrophic failure, and the entire crew and vehicle were lost. For the two weeks prior to the accident, Columbia STS-107 was on a mission to perform physical, life, and space sciences research in the unique environment of microgravity. Following the accident, the remaining shuttles - Endeavor, Atlantis, and Discovery - were grounded, and an intense investigation ensued. The Columbia Accident Investigation Board spent nearly 7 months examining the cause of the accident and determining what would ensure a safe return to flight. To this end, investigators performed an extensive review down five analytic paths: aerodynamic, thermodynamic, sensor data timeline, debris reconstruction, and imaging. As part of the evaluation of all the available imagery from Columbia's ascent, orbit, and entry, investigators needed a new method for analyzing still video images to determine the size of the material that fell from Columbia, as well as the distance that the material traveled. John Lane, a scientist at Kennedy Space Center, devised a software program to calculate the unknown dimension of the material in the images, and soon after the investigation was complete, continued to enhance the technology. Eventually, the program that assisted in the Columbia investigation became available for licensing.

Source record↗
NASA NTRSDate not supplied

The Ten Lockheed Martin Cyber-Physical Challenges: Formalized, Analyzed, and Explained

Capturing and analyzing requirements of Cyber-Physical Systems (CPS) can be challenging, since CPS models typically involve time-varying and real-valued variables, physical system dynamics, or even adaptive behavior. MATLAB/Simulinkis a development and simulation framework that is widely used in industry to capture such systems. In this paper, we report on the application of NASA Ames tools to perform end-to-end analysis of the Ten Lockheed Martin Challenge Problems (LMCPS). LMCPS is a set of industrial Simulink model benchmarks and natural language requirements developed by domain experts. Our framework, which integrates the tools FRET and COCOSIM, is used to: 1) elicit, explain, and formalize the semantics of the given natural language requirements; 2) generate verification code and monitors that can be automatically attached to the Simulink models; 3) perform verification by using SMT-based model checkers. FRET and COCOSIM are open source, and can be used by other researchers and practitioners to replicate our case study. We provide a categorization of recurring patterns in the formalization of the requirements and discuss the strengths and weaknesses of our automated verification approach.

Anastasia Mavridou↗
NASA NTRS1993

Control structural interaction testbed: A model for multiple flexible body verification

Conventional end-to-end ground tests for verification of control system performance become increasingly complicated with the development of large, multiple flexible body spacecraft structures. The expense of accurately reproducing the on-orbit dynamic environment and the attendant difficulties in reducing and accounting for ground test effects limits the value of these tests. TRW has developed a building block approach whereby a combination of analysis, simulation, and test has replaced end-to-end performance verification by ground test. Tests are performed at the component, subsystem, and system level on engineering testbeds. These tests are aimed at authenticating models to be used in end-to-end performance verification simulations: component and subassembly engineering tests and analyses establish models and critical parameters, unit level engineering and acceptance tests refine models, and subsystem level tests confirm the models' overall behavior. The Precision Control of Agile Spacecraft (PCAS) project has developed a control structural interaction testbed with a multibody flexible structure to investigate new methods of precision control. This testbed is a model for TRW's approach to verifying control system performance. This approach has several advantages: (1) no allocation for test measurement errors is required, increasing flight hardware design allocations; (2) the approach permits greater latitude in investigating off-nominal conditions and parametric sensitivities; and (3) the simulation approach is cost effective, because the investment is in understanding the root behavior of the flight hardware and not in the ground test equipment and environment.

Chory, M. A.↗
NASA NTRS1977

Discovery and repair of software anomalies

The average time required to discover and repair anomalies which appear randomly in the end-to-end tests performed after program completion is evaluated. A model which explains anomaly discovery and repair phenomena when applied to variations in work load and multiple-stage testing is presented. The theory shows that estimates of anomaly levels and team capability can be predicted after a significant fraction of the anomalies have been found, and indicates procedures for applying these figures to schedule estimation and work-load assignment. Of particular interest is the demonstration that end-to-end testing of programs in other than the operational environment is not generally cost effective.

Tausworthe, R. C.↗
NASA NTRS2012

NAND Flash Qualification Guideline

Better performing Forward Error Correction on the forward link along with adequate power in the data open an uplink operations trade space that enable missions to: Command to greater distances in deep space (increased uplink margin). Increase the size of the payload data (latency may be a factor). Provides space for the security header/trailer of the CCSDS Space Data Link Security Protocol. Note: These higher rates could be used for relief of emergency communication margins/rates and not limited to improving top-end rate performance. A higher performance uplink could also reduce the requirements on flight emergency antenna size and/or the performance required from ground stations. Use of a selective repeat ARQ protocol may increase the uplink design requirements but the resultant development is deemed acceptable, due the factor of 4 to 8 potential increase in uplink data rate.

Floating Gate Memory↗
NASA NTRS2012

Replacing the CCSDS Telecommand Protocol with Next Generation Uplink

Better performing Forward Error Correction on the forward link along with adequate power in the data open an uplink operations trade space that enable missions to: Command to greater distances in deep space (increased uplink margin) Increase the size of the payload data (latency may be a factor) Provides space for the security header/trailer of the CCSDS Space Data Link Security Protocol Note: These higher rates could be used for relief of emergency communication margins/rates and not limited to improving top-end rate performance. A higher performance uplink could also reduce the requirements on flight emergency antenna size and/or the performance required from ground stations. Use of a selective repeat ARQ protocol may increase the uplink design requirements but the resultant development is deemed acceptable, due the factor of 4 to 8 potential increase in uplink data rate.

Low Density Parity Check (LDPC)↗
NASA NTRS2019

Overview of NASA's Solar Electric Propulsion Project

NASA is continuing to develop and qualify a state of the art 13 kW-class Advanced Electric Propulsion System (AEPS) for NASA exploration missions through a contract with Aerojet Rocketdyne. An objective of the AEPS project is to empower the US space industry to accelerate the adoption of high power electric propulsion technologies by reducing the risk and uncertainty of integrating Solar Electric Propulsion (SEP) technologies into space flight systems. NASA and AEPS contract has recently initiated engineering hardware testing of the Hall Current Thruster (HCT), Power Processing Unit (PPU), and Xenon Flow Controller (XFC) at both the component and system levels. The successful completion of these tests will provide the required information to advance the AEPS system towards Critical Design Review. In support of the AEPS contract, NASA and JPL have been performing risk reduction activities to address specific concerns of the state of the art higher power Hall thruster propulsion system. These risk reduction activities have included long duration wear testing of the Technology Demonstration Unit (TDU) Hall thruster and cathode hardware, thermal cycling testing of TDU cathode heaters and coils, plasma plume measurements, and investigating PPU design. In addition to NASA propulsion development, the SEP project is developing the Plasma Diagnostic Package (PDP) and the SEP Testbed. The PDP is designed for use in conjunction with a high powered EP system to characterize in-space operation. The SEP Testbed system is developed for demonstration of Abstract: NASA is continuing to develop and qualify a state of the art 13 kW-class Advanced Electric Propulsion System (AEPS) for NASA exploration missions through a contract with Aerojet Rocketdyne. An objective of the AEPS project is to empower the US space industry to accelerate the adoption of high power electric propulsion technologies by reducing the risk and uncertainty of integrating Solar Electric Propulsion (SEP) technologies into space flight systems. NASA and AEPS contract has recently initiated engineering hardware testing of the Hall Current Thruster (HCT), Power Processing Unit (PPU), and Xenon Flow Controller (XFC) at both the component and system levels. The successful completion of these tests will provide the required information to advance the AEPS system towards Critical Design Review. In support of the AEPS contract, NASA and JPL have been performing risk reduction activities to address specific concerns of the state of the art higher power Hall thruster propulsion system. These risk reduction activities have included long duration wear testing of the Technology Demonstration Unit (TDU) Hall thruster and cathode hardware, thermal cycling testing of TDU cathode heaters and coils, plasma plume measurements, and investigating PPU design. In addition to NASA propulsion development, the SEP project is developing the Plasma Diagnostic Package (PDP) and the SEP Testbed. The PDP is designed for use in conjunction with a high powered EP system to characterize in-space operation. The SEP Testbed system is developed for demonstration of an integrated SEP end-to-end system performance. The paper will present an overview of the NASA and the AEPS contract activities and a summary of the associated NASA in-house activities.

Plasma Diagnostics Package↗
NASA NTRSDate not supplied

Metallic Environmentally Resistant Coating Rapid Innovation Initiative

Lightweight alloys such as aluminum (Al) and titanium (Ti) are often specified for space systems to minimize mass while maintaining structural integrity [1,2]. Such alloys however, have poor tribological response (high friction and wear), especially in extreme space environments, which becomes worse with the additional presence of lunar regolith. This leads to short lifetimes and premature failures that will ultimately limit long term operations on the lunar surface [2]. This project is addressing this technology gap by developing advanced wear- and radiation-resistant coatings for lightweight parts to extend the life-time and sustainability of both lunar and Martian assets. Ceramics were considered for their high wear resistance, but were rejected because of their low fracture toughness, which would be especially problematic for structural components. The novel and existing coating technologies and deposition methods are being tested in this project. The coating materials are Boron Nitride-Aluminum (BN-Al), Nickle Titanium (NiTi), Aluminum Oxide (AlO3), Ti64 with hBN at 2 and 10 vol percent (Ti-2vol%hBN and Ti-10vol%hBN), and the deposition techniques are high pressure cold-spray (CS) and ambient and vacuum plasma-spray (APS and VPS) [3,4,5]. BN-Al, NiTi, Ti-2vol%hBN, and Ti-10vol%hBN were applied with all three deposition techniques, and AlO3 was applied only using the APS deposition technique. A tungstenite (WS2) film was applied to the NiTi VPS coating. The coating and deposition technique configurations are being tested against several key end-use performance parameters. The parameters include the capabilities of the coatings under wear environments such as regolith simulant, thermal cycling from high (120°C) to cryogenic (-173°C), high vacuum (~10-7 torr), and pre- and post-exposure to ionizing particle radiation. Wear tests include pin on disk, three-body abrasion, and surface erosion by high velocity regolith impacts. The initial down selection is being performed using on virgin and environmental exposure samples using pin on disk and three body abrasion wear tests. From preliminary assessment of this testing, a few configurations were eliminated. Ti-10vol%hBN could not be applied using CS application and NiTi could not be applied using APS or CS application so these configurations did not get tested. Early pin on disk wear tests showed poor wear performance of BN-Al so this coating was eliminated early in the testing process. AlO3 on Al substrate did not survive thermal cycling, but wear testing is continuing for AlO3 on Ti substrate. A more detailed analysis is being con-ducted to further reduce the number of configuration for phase II and III. Phase II testing will include conventionally and additively manufactured substrates with surface erosion testing. In phase III, the coatings will be applied to three mechanism types: channel and slot, ball and socket, and a hinge joint. Each will demonstrate a different type of wear incidence. The mechanisms and their base materials are of direct interest to the end users and infusion points: the Human Landing System (HLS) and the Lunar Surface Innovation Initiative (sustained lunar surface operations). The technology development project is based out of Marshall Space Flight Center, has partnered with Florida International University (Miami, FL) and Plasma Processes (Huntsville, Al), and is supported by a group of NASA mentors from different centers.

dust mitigation↗
NASA NTRS2017

ExEP Yield Modeling Tool and Validation Test Results

EXOSIMS is an open-source simulation tool for parametric modeling of the detection yield and characterization of exoplanets. EXOSIMS has been adopted by the Exoplanet Exploration Programs Standards De nition and Evaluation Team (ExSDET) as a common mechanism for comparison of exoplanet mission concept studies. To ensure trustworthiness of the tool, we developed a validation test plan that leverages the Python-language unit-test framework, utilizes integration tests for selected module interactions, and performs end-to-end cross- validation with other yield tools. This paper presents the test methods and results, with the physics-based tests such as photometry and integration time calculation treated in detail and the functional tests treated summarily. The test case utilized a 4m unobscured telescope with an idealized coronagraph and an exoplanet population from the IPAC radial velocity (RV) exoplanet catalog. The known RV planets were set at quadrature to allow deterministic validation of the calculation of physical parameters, such as working angle, photon counts and integration time. The observing keepout region was tested by generating plots and movies of the targets and the keepout zone over a year. Although the keepout integration test required the interpretation of a user, the test revealed problems in the L2 halo orbit and the parameterization of keepout applied to some solar system bodies, which the development team was able to address. The validation testing of EXOSIMS was performed iteratively with the developers of EXOSIMS and resulted in a more robust, stable, and trustworthy tool that the exoplanet community can use to simulate exoplanet direct-detection missions from probe class, to WFIRST, up to large mission concepts such as HabEx and LUVOIR.

Nunez, Paul↗
NASA NTRS2010

L-Band Digital Aeronautical Communications System Engineering - Concepts of Use, Systems Performance, Requirements, and Architectures

This NASA Contractor Report summarizes and documents the work performed to develop concepts of use (ConUse) and high-level system requirements and architecture for the proposed L-band (960 to 1164 MHz) terrestrial en route communications system. This work was completed as a follow-on to the technology assessment conducted by NASA Glenn Research Center and ITT for the Future Communications Study (FCS). ITT assessed air-to-ground (A/G) communications concepts of use and operations presented in relevant NAS-level, international, and NAS-system-level documents to derive the appropriate ConUse relevant to potential A/G communications applications and services for domestic continental airspace. ITT also leveraged prior concepts of use developed during the earlier phases of the FCS. A middle-out functional architecture was adopted by merging the functional system requirements identified in the bottom-up assessment of existing requirements with those derived as a result of the top-down analysis of ConUse and higher level functional requirements. Initial end-to-end system performance requirements were derived to define system capabilities based on the functional requirements and on NAS-SR-1000 and the Operational Performance Assessment conducted as part of the COCR. A high-level notional architecture of the L-DACS supporting A/G communication was derived from the functional architecture and requirements.

Zelkin, Natalie↗
NASA NTRS2021

NASA’s Surface Deformation and Change Mission Study

The National Academies of Science, Engineering and Medicine 2017 Decadal Survey of Earth Science and Applications identified geodetic measurements of surface deformation and related change as one of the top five “observables” to be prioritized in NASA’s future program. In response, NASA commissioned a multi-center Surface Deformation and Change(SDC) team to perform a five year study of mission architectures that would support SDC observables and provide the most value to the diverse science and applications communities it serves. The study is being conducted in phases, in which the science and applications capabilities identified in the Decadal Survey are refined, candidate architectures and associated technologies to support these needs are identified, architectures are assessed against a science value framework specific to SDC, and recommendations to NASA are made. Ultimately, NASA will decide which amongst these recommendations will proceed to mission formulation. As synthetic aperture radar (SAR) was identified as the prime sensor technology to satisfy SDC observational needs, a key component of the SDC study is to assess the current state of the art in SAR sensor and supporting technology. The number of SAR systems, both civil and commercial, is growing rapidly, requiring that mission architectures not only consider technology, but availability of data from other missions, possible partnerships or collaborations, and even data purchase. The mechanism for assessment involves development of an end-to-end science performance evaluation tool for multi-satellite con-stellations, which feeds into a science value framework that con-siders science performance, technological programmatic risks, and cost. This paper will present an overview of the ongoing study including the candidate architectures and the technology road map needed to achieve the objectives of the mission.

Stephen Horst↗
NASA NTRS2021

NASA's Surface Deformation and Change Mission Study

The National Academies of Science, Engineering and Medicine 2017 Decadal Survey of Earth Science and Applications identified geodetic measurements of surface deformation and related change as one of the top five "observables" to be prioritized in NASA's program going forward. In response, NASA commissioned a multi-center Surface Deformation and Change (SDC) team to perform a five year study of mission architectures that would support SDC observables and provide the most value to the diverse science and applications communities it serves. The study is being conducted in phases, in which the science and applications capabilities identified in the Decadal Survey are interpreted and refined, candidate mission architectures and associated technologies to support these needs are identified, architectures are assessed against a science value framework specific to SDC, and recommendations to NASA are made. Ultimately, NASA will decide which amongst these recommendations will proceed to mission formulation. As synthetic aperture radar (SAR) was identified as the prime sensor technology to satisfy SDC observational needs, a key component of the SDC study is to assess the current state of the art in SAR sensor and spacecraft systems and components. The number of SAR systems, both civil and commercial, is growing rapidly, requiring that mission architectures not only consider technology, but availability of data from other missions, possible partnerships or collaborations, and even data purchase. The mechanism for assessment involves development of an end-to-end science performance evaluation tool for multi-satellite constellations, which feeds into a science value framework that considers science performance, technological programmatic risks, and cost. This paper will present an overview of the ongoing study including the architectures under consideration and the technology road map needed to achieve the objectives of the mission.

Rosen, Paul↗
NASA NTRS1975

Zinc depolarized electrochemical CO2 concentration

Two zinc depolarized electrochemical carbon dioxide concentrator concepts were analytically and experimentally evaluated for portable life support system carbon dioxide (CO2) removal application. The first concept, referred to as the zinc hydrogen generator electrochemical depolarized CO2 concentrator, uses a ZHG to generate hydrogen for direct use in an EDC. The second concept, referred to as the zinc/electrochemical depolarized concentrator, uses a standard EDC cell construction modified for use with the Zn anode. The Zn anode is consumed and subsequently regenerated, thereby eliminating the need to supply H2 to the EDC for the CO2 removal process. The evaluation was based primarily on an analytical evaluation of the two ZnDCs at projected end item performance and hardware design levels. Both ZnDC concepts for PLSS CO2 removal application were found to be noncompetitive in both total equivalent launch weight and individual extravehicular activity mission volume when compared to other candidate regenerable PLSS CO2 scrubbers.

Woods, R. R.↗
NASA NTRS1977

Low-cost high-performance VLF receiver front-end

A VLF receiver front end has been designed using standard linear IC's. The basic methods have been evaluated extensively on the omega 10.2-kHz channel but are readily adaptable to any other VLF frequency in the 10.2-20 kHz region. Applications for the modules exist in position location, time-frequency measurements, and signal propagation. The set provides control gates, zero-crossing signals, and analog outputs to interface with any type of digital logic, microprocessor, or analog signal processor.

Burhans, R. W.↗
NASA NTRS1978

A versatile microprocessor-controlled hybrid receiver

A hybrid receiver has been designed for the Galileo Project. The receiver, located on the Galileo Orbiter, will autonomously acquire and track signals from the first atmospheric probe of Jupiter as well as demodulate, bit-synchronize, and buffer the telemetry data. The receiver has a conventional RF and LF front end but performs multiple functions digitally under firmware control. It will be a self-acquiring receiver that operates under a large frequency uncertainty; it can accommodate different modulation types, bit rates, and other parameter changes via reprogramming. A breadboard receiver and test set demonstrate a preliminary version of the sequential detection process and verify the hypothesis that a fading channel does not reduce the probability of detection.

Grant, T. L.↗