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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 307 records · Page 17
All sourcesNASA NTRSDOE OSTI
NASA NTRS1974

The Atmosphere Explorer power subsystem

The design and operation of the power subsystem for the Atmospheric Explorer spacecraft are discussed. The additional functional redundancy which was added in several component areas to improve the overall subsystem reliability is analyzed. The battery charging technique has been modified to include third electrode overcharge control. The automatic removal of all battery charge is provided to correct abnormally high battery voltages. An undervoltage detector has been added which removes all nonessential spacecraft loads when the battery voltage falls below a given level. All automatic functions can be over-ridden by ground command.

Obenschain, A.↗
NASA NTRS1982

100 kWe MPD thruster system design

A MPD thruster subsystem point design is presented that may be applicable to a wide variety of NASA/DoD missions. The system is electrically matched to a 100 kWe thermoelectric-nuclear supply and operates the thruster in a pulsed, quasi-steady mode on cryogenically stored argon. The overall system efficiency is 52% which includes efficiencies of the electrolytic capacitor energy store, constant power charging unit, thyristor switch, and assumes a 60% thruster efficiency. The system specific mass is 21.6 kg/kWe. Various technology improvements are discussed which could reduce the specific mass to under 10 kg/kWe, while simultaneously increasing the efficiency and reducing the overall subsystem complexity.

King, D. Q.↗
NASA NTRS1983

Simplified power processing for ion-thruster subsystems

A design for a greatly simplified power-processing unit (SPPU) for the 8-cm diameter mercury-ion-thruster subsystem is discussed. This SPPU design will provide a tenfold reduction in parts count, a decrease in system mass and cost, and an increase in system reliability compared to the existing power-processing unit (PPU) used in the Hughes/NASA Lewis Research Center Ion Auxiliary Propulsion Subsystem. The simplifications achieved in this design will greatly increase the attractiveness of ion propulsion in near-term and future spacecraft propulsion applications. A description of a typical ion-thruster subsystem is given. An overview of the thruster/power-processor interface requirements is given. Simplified thruster power processing is discussed.

Wessel, F. J.↗
NASA NTRS1972

Apollo experience report: Lunar module instrumentation subsystem

The design concepts and philosophies of the lunar module instrumentation subsystem are discussed along with manufacturing and systems integration. The experience gained from the program is discussed, and recommendations are made for making the subsystem more compatible and flexible in system usage. Characteristics of lunar module caution and warning circuits are presented.

Obrien, D. E., III↗
NASA NTRS1978

Flight performance of the High Energy Astronomy Observatory /HEAO 1/ power subsystem

The design and flight performance of the HEAO-1 power subsystem is described. Solar array power analysis and test data are compared to orbital performance. The batteries are described along with parametric cell tests which led to the temperature-compensated voltage limits used in the charge controls. Battery life test results, used for verification of battery charger temperature-compensated voltage limits, are compared with orbital performance. The control electronics are

Reppucci, G. M.↗
NASA NTRS1996

Image Processing In Laser-Beam-Steering Subsystem

Conceptual design of image-processing circuitry developed for proposed tracking apparatus described in "Beam-Steering Subsystem For Laser Communication" (NPO-19069). In proposed system, desired frame rate achieved by "windowed" readout scheme in which only pixels containing and surrounding two spots read out and others skipped without being read. Image data processed rapidly and efficiently to achieve high frequency response.

Lesh, James R.↗
NASA NTRS1994

The design of a petabyte archive and distribution system for the NASA ECS project

The NASA EOS Data and Information System (EOSDIS) Core System (ECS) will contain one of the largest data management systems ever built - the ECS Science and Data Processing System (SDPS). SDPS is designed to support long term Global Change Research by acquiring, producing, and storing earth science data, and by providing efficient means for accessing and manipulating that data. The first two releases of SDPS, Release A and Release B, will be operational in 1997 and 1998, respectively. Release B will be deployed at eight Distributed Active Archiving Centers (DAAC's). Individual DAAC's will archive different collections of earth science data, and will vary in archive capacity. The storage and management of these data collections is the responsibility of the SDPS Data Server subsystem. It is anticipated that by the year 2001, the Data Server subsystem at the Goddard DAAC must support a near-line data storage capacity of one petabyte. The development of SDPS is a system integration effort in which COTS products will be used in favor of custom components in very possible way. Some software and hardware capabilities required to meet ECS data volume and storage management requirements beyond 1999 are not yet supported by available COTS products. The ECS project will not undertake major custom development efforts to provide these capabilities. Instead, SDPS and its Data Server subsystem are designed to support initial implementations with current products, and provide an evolutionary framework that facilitates the introduction of advanced COTS products as they become available. This paper provides a high-level description of the Data Server subsystem design from a COTS integration standpoint, and discussed some of the major issues driving the design. The paper focuses on features of the design that will make the system scalable and adaptable to changing technologies.

Caulk, Parris M.↗
NASA NTRS1987

GTOSS: Generalized Tethered Object Simulation System

GTOSS represents a tether analysis complex which is described by addressing its family of modules. TOSS is a portable software subsystem specifically designed to be introduced into the environment of any existing vehicle dynamics simulation to add the capability of simulating multiple interacting objects (via multiple tethers). These objects may interact with each other as well as with the vehicle into whose environment TOSS is introduced. GTOSS is a stand alone tethered system analysis program, representing an example of TOSS having been married to a host simulation. RTOSS is the Results Data Base (RDB) subsystem designed to archive TOSS simulation results for future display processing. DTOSS is a display post processors designed to utilize the RDB. DTOSS extracts data from the RDB for multi-page printed time history displays. CTOSS is similar to DTOSS, but is designed to create ASCII plot files. The same time history data formats provided for DTOSS (for printing) are available via CTOSS for plotting. How these and other modules interact with each other is discussed.

Lang, David D.↗
NASA NTRS1978

System design package for solar heating and cooling site data acquisition subsystem

The Site Data Acquisition Subsystem (SDAS) designed to collect data from sensors located on residential or commercial buildings using a solar heating and/or cooling system is described. It takes the data obtained from sensors located on the solar system, processes the data into suitable format, stores the data for a period of time, and provides the capability for either telephone retrieval by the central data processing system or manual retrieval of the data for transfer to a central site. The SDAS is also designed so that it will not degrade the operation of the solar heating/cooling system which it is monitoring.

Source record↗
NASA NTRS1986

Shuttle Imaging Radar-B/C instruments

The successfully flown Shuttle Imaging Radar-B (SIR-B) instrument is described, giving details of the hardware, the subsystem functions, and the Shuttle interfaces. The preliminary design of the SIR-C instrument is described, giving an overview of the preliminary hardware design, the subsystem functional design, and the Shuttle interfaces.

Huneycutt, Bryan L.↗
NASA NTRS1991

IMPAC: An Integrated Methodology for Propulsion and Airframe Control

The National Aeronautics and Space Administration is actively involved in the development of enabling technologies that will lead towards aircraft with new/enhanced maneuver capabilities such as Short Take-Off Vertical Landing (STOVL) and high angle of attack performance. Because of the high degree of dynamic coupling between the airframe and propulsion systems of these types of aircraft, one key technology is the integration of the flight and propulsion control. The NASA Lewis Research Center approach to developing Integrated Flight Propulsion Control (IFPC) technologies is an in-house research program referred to as IMPAC (Integrated Methodology for Propulsion and Airframe Control). The goals of IMPAC are to develop a viable alternative to the existing integrated control design methodologies that will allow for improved system performance and simplicity of control law synthesis and implementation, and to demonstrate the applicability of the methodology to a supersonic STOVL fighter aircraft. Based on some preliminary control design studies that included evaluation of the existing methodologies, the IFPC design methodology that is emerging at the Lewis Research Center consists of considering the airframe and propulsion system as one integrated system for an initial centralized controller design and then partitioning the centralized controller into separate airframe and propulsion system subcontrollers to ease implementation and to set meaningful design requirements for detailed subsystem control design and evaluation. An overview of IMPAC is provided and detailed discussion of the various important design and evaluation steps in the methodology are included.

Garg, Sanjay↗
NASA NTRS2012

Modular, Autonomous Command and Data Handling Software with Built-In Simulation and Test

The spacecraft system that plays the greatest role throughout the program lifecycle is the Command and Data Handling System (C&DH), along with the associated algorithms and software. The C&DH takes on this role as cost driver because it is the brains of the spacecraft and is the element of the system that is primarily responsible for the integration and interoperability of all spacecraft subsystems. During design and development, many activities associated with mission design, system engineering, and subsystem development result in products that are directly supported by the C&DH, such as interfaces, algorithms, flight software (FSW), and parameter sets. A modular system architecture has been developed that provides a means for rapid spacecraft assembly, test, and integration. This modular C&DH software architecture, which can be targeted and adapted to a wide variety of spacecraft architectures, payloads, and mission requirements, eliminates the current practice of rewriting the spacecraft software and test environment for every mission. This software allows missionspecific software and algorithms to be rapidly integrated and tested, significantly decreasing time involved in the software development cycle. Additionally, the FSW includes an Onboard Dynamic Simulation System (ODySSy) that allows the C&DH software to support rapid integration and test. With this solution, the C&DH software capabilities will encompass all phases of the spacecraft lifecycle. ODySSy is an on-board simulation capability built directly into the FSW that provides dynamic built-in test capabilities as soon as the FSW image is loaded onto the processor. It includes a six-degrees- of-freedom, high-fidelity simulation that allows complete closed-loop and hardware-in-the-loop testing of a spacecraft in a ground processing environment without any additional external stimuli. ODySSy can intercept and modify sensor inputs using mathematical sensor models, and can intercept and respond to actuator commands. ODySSy integration is unique in that it allows testing of actual mission sequences on the flight vehicle while the spacecraft is in various stages of assembly, test, and launch operations all without any external support equipment or simulators. The ODySSy component of the FSW significantly decreases the time required for integration and test by providing an automated, standardized, and modular approach to integrated avionics and component interface and functional verification. ODySSy further provides the capability for on-orbit support in the form of autonomous mission planning and fault protection.

Cuseo, John↗