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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 NTRS1992

Identification of aerodynamic models for maneuvering aircraft

The method based on Fourier functional analysis and indicial formulation for aerodynamic modeling as proposed by Chin and Lan is extensively examined and improved for the purpose of general applications to realistic airplane configurations. Improvement is made to automate the calculation of model coefficients, and to evaluate more accurately the indicial integral. Test data of large angle-of-attack ranges for two different models, a 70 deg. delta wing and an F-18 model, are used to further verify the applicability of Fourier functional analysis and validate the indicial formulation. The results show that the general expression for harmonic motions throughout a range of k is capable of accurately modeling the nonlinear responses with large phase lag except in the region where an inconsistent hysteresis behavior from one frequency to the other occurs. The results by the indicial formulation indicate that more accurate results can be obtained when the motion starts from a low angle of attack where hysteresis effect is not important.

Lan, C. Edward↗

NASA NTRS1992

High-speed civil transport issues and technology program

A strawman program plan is presented, consisting of technology developments and demonstrations required to support the construction of a high-speed civil transport. The plan includes a compilation of technology issues related to the development of a transport. The issues represent technical areas in which research and development are required to allow airframe manufacturers to pursue an HSCT development. The vast majority of technical issues presented require flight demonstrated and validated solutions before a transport development will be undertaken by the industry. The author believes that NASA is the agency best suited to address flight demonstration issues in a concentrated effort. The new Integrated Test Facility at NASA Dryden Flight Research Facility is considered ideally suited to the task of supporting ground validations of proof-of-concept and prototype system demonstrations before night demonstrations. An elaborate ground hardware-in-the-loop (iron bird) simulation supported in this facility provides a viable alternative to developing an expensive fill-scale prototype transport technology demonstrator. Drygen's SR-71 assets, modified appropriately, are a suitable test-bed for supporting flight demonstrations and validations of certain transport technology solutions. A subscale, manned or unmanned flight demonstrator is suitable for flight validation of transport technology solutions, if appropriate structural similarity relationships can be established. The author contends that developing a full-scale prototype transport technology demonstrator is the best alternative to ensuring that a positive decision to develop a transport is reached by the United States aerospace industry.

Hewett, Marle D.↗

NASA NTRS1992

Ground terminal expert (GTEX). Part 2: Expert system diagnostics for a 30/20 Gigahertz satellite transponder

A research effort was undertaken to investigate how expert system technology could be applied to a satellite communications system. The focus of the expert system is the satellite earth station. A proof of concept expert system called the Ground Terminal Expert (GTEX) was developed at the University of Akron in collaboration with the NASA Lewis Research Center. With the increasing demand for satellite earth stations, maintenance is becoming a vital issue. Vendors of such systems will be looking for cost effective means of maintaining such systems. The objective of GTEX is to aid in diagnosis of faults occurring with the digital earth station. GTEX was developed on a personal computer using the Automated Reasoning Tool for Information Management (ART-IM) developed by the Inference Corporation. Developed for the Phase 2 digital earth station, GTEX is a part of the Systems Integration Test and Evaluation (SITE) facility located at the NASA Lewis Research Center.

Durkin, John↗

NASA NTRS1992

Operational strategies for contamination control of composite materials

Composite materials, used on many instruments, are a potential contamination source for sensitive sensors, especially for sensors or detectors cooled below -80 C. It is a well known fact that composite materials absorb water during fabrication, integration, test, and launch activities and desorb this water under vacuum conditions. Water absorption can be divided into two types: shallow water and deep water. Shallow water is generally about 500 A thick on a clean material surface and is easily desorbed under vacuum conditions. Deep water is a function of the material and is absorbed into the bulk of the material. Deep water can outgas for weeks, months, or years, depending on the vent path, the amount of absorbed water, and the temperature of the material. Several operational strategies have been successfully employed on the Wide Field Planetary Camera. The operational strategies include ultradry gaseous nitrogen purge, dew point of less than -80 C, and vacuum bake-out with verification of outgassing rates. The nitrogen purge is instituted during the fabrication phase and is continued through launch activities. Great care is taken to avoid extended periods of time that the material is exposed to the ambient environment (50 percent relative humidity). On-orbit operational strategies include heat-up and cool-down scenarios which allow the deep water to be sufficiently outgassed before cooling the sensors or detectors.

Hansen, Patricia A.↗

NASA NTRS1993

The Fifth NASA/DOD Controls-Structures Interaction Technology Conference, part 1

This publication is a compilation of the papers presented at the Fifth NASA/DoD Controls-Structures Interaction (CSI) Technology Conference held in Lake Tahoe, Nevada, March 3-5, 1992. The conference, which was jointly sponsored by the NASA Office of Aeronautics and Space Technology and the Department of Defense, was organized by the NASA Langley Research Center. The purpose of this conference was to report to industry, academia, and government agencies on the current status of controls-structures interaction technology. The agenda covered ground testing, integrated design, analysis, flight experiments and concepts.

Newsom, Jerry R.↗

NASA NTRS1993

The Fifth NASA/DOD Controls-Structures Interaction Technology Conference, part 2

Newsom, Jerry R.↗

NASA NTRS1993

GEOTAIL Spacecraft historical data report

The purpose of this GEOTAIL Historical Report is to document ground processing operations information gathered on the GEOTAIL mission during processing activities at the Cape Canaveral Air Force Station (CCAFS). It is hoped that this report may aid management analysis, improve integration processing and forecasting of processing trends, and reduce real-time schedule changes. The GEOTAIL payload is the third Delta 2 Expendable Launch Vehicle (ELV) mission to document historical data. Comparisons of planned versus as-run schedule information are displayed. Information will generally fall into the following categories: (1) payload stay times (payload processing facility/hazardous processing facility/launch complex-17A); (2) payload processing times (planned, actual); (3) schedule delays; (4) integrated test times (experiments/launch vehicle); (5) unique customer support requirements; (6) modifications performed at facilities; (7) other appropriate information (Appendices A & B); and (8) lessons learned (reference Appendix C).

Boersig, George R.↗

NASA NTRS1992

A facility for training Space Station astronauts

The Space Station Training Facility (SSTF) will be the primary facility for training the Space Station Freedom astronauts and the Space Station Control Center ground support personnel. Conceptually, the SSTF will consist of two parts: a Student Environment and an Author Environment. The Student Environment will contain trainers, instructor stations, computers and other equipment necessary for training. The Author Environment will contain the systems that will be used to manage, develop, integrate, test and verify, operate and maintain the equipment and software in the Student Environment.

Hajare, Ankur R.↗

NASA NTRS1993

Simplified power processing for inert gas ion thrusters

Significant simplifications to power processors for inert gas ion thrusters in the 1 to 5 kW range have been identified. They include elimination of all but three power supplies - one each for the neutralizer, main discharge, and beam. The neutralizer and discharge power supplies would provide both cathode heating and plasma generating functions. This dual-use power supply concept was validated via integration tests with a 30 cm diameter xenon ion thruster. The beam/accelerator power supply would have positive and negative outputs to allow a single power supply to provide both functions. The discharge and beam power supplies would incorporate full-bridge inverters similar to those proven for flight-ready arcjet propulsion systems. Operation of this simplified power processing scheme at an inverter frequency of 50 kHz results in a projected power processor design with low mass and high efficiency. A 2 kW reference point design has estimated values of specific mass of 5.4 kg/kW and an efficiency of 93 percent.

Rawlin, V. K.↗

NASA NTRS1991

Overview of communications programs

The objective of the communications program is to advance critical areas of enabling and enhancing communication technologies that support commercial needs, science, and exploration missions for the 1990's and beyond. The technology program consists of research and technology development in the following areas: RF technology; digital technology; optical communications; mobile communications; and systems integration, test, and evaluation.

Depaula, Ramon P.↗

NASA NTRS1989

The design of a commercial space infrastructure

Space Services and Logistics, Inc. represents the complete engineering design of a technically and financially viable commercial space company. The final proposal offers an economically sound program of space vehicles and systems designed to substantially affect a variety of space markets and produce a vertically integrated structure within the next 20 years. Throughout this design process, particular stress has been placed on attaining the highest possible levels of safety and reliability. The final program financial design requires a considerable initial outlay, but promises a relatively quick return on invested capital, culminating in large annual profits by the end of the 20-year scope of the cost outlook. The overall design has been extensively researched and was primarily driven by the present and near-term projected market demands for services uniquely or competitively offered only by space-oriented operations. Heretofore, available capabilities, rather than these market demands, have determined the degree and type of commercial market access. Removing this limitation through extensive use of modularity and reconfigurability allows the company to gear itself to the market, while still remaining extremely competitive with existing systems. The markets identified as lucrative, and that have governed much of the design requirements, are: low-cost launch services to LEO over a wide range of payload masses and inclinations; upper stage payload delivery from LEO to GEO; manned space operations and human transport to and from orbit; EVA assembly and maintenance of large space structures; satellite servicing and repair by both humans and telerobotic operations; a line of customized satellites designed for extended life and capable of reconfiguration or technology upgrade on orbit; small-scale microgravity experimentation and manufacturing supported by spacecraft retrieval capabilities for experimental specimens and manufactured goods; and a full-range of payload integration, testing, design, and support services before launch and once in orbit.

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NASA NTRS1992

STGT program: Ada coding and architecture lessons learned

STGT (Second TDRSS Ground Terminal) is currently halfway through the System Integration Test phase (Level 4 Testing). To date, many software architecture and Ada language issues have been encountered and solved. This paper, which is the transcript of a presentation at the 3 Dec. meeting, attempts to define these lessons plus others learned regarding software project management and risk management issues, training, performance, reuse, and reliability. Observations are included regarding the use of particular Ada coding constructs, software architecture trade-offs during the prototyping, development and testing stages of the project, and dangers inherent in parallel or concurrent systems, software, hardware, and operations engineering.

Usavage, Paul↗

NASA NTRS1993

Payload/GSE/data system interface: Users guide for the VPF (Vertical Processing Facility)

Payload/GSE/data system interface users guide for the Vertical Processing Facility is presented. The purpose of the document is three fold. First, the simulated Payload and Ground Support Equipment (GSE) Data System Interface, which is also known as the payload T-0 (T-Zero) System is described. This simulated system is located with the Cargo Integration Test Equipment (CITE) in the Vertical Processing Facility (VPF) that is located in the KSC Industrial Area. The actual Payload T-0 System consists of the Orbiter, Mobile Launch Platforms (MLPs), and Launch Complex (LC) 39A and B. This is referred to as the Pad Payload T-0 System (Refer to KSC-DL-116 for Pad Payload T-0 System description). Secondly, information is provided to the payload customer of differences between this simulated system and the actual system. Thirdly, a reference guide of the VPF Payload T-0 System for both KSC and payload customer personnel is provided.

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NASA NTRS1992

OASIS-CC presentation

The Operations and Science Instrument Support (OASIS) project is a long-term effort to help produce operations capabilities that can support space science missions of the next century. Portions of the OASIS concept in software have been implemented under the general name OASIS-R/T. OASIS-CC is the OASIS Command and Control, for monitoring and controlling science instruments and spacecraft during test, integration, launch and on-orbit operations. Viewgraphs are presented on the OASIS-CC functionality description, OASIS-CC support, and OASIS-CC as a tool.

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NASA NTRS1994

Nickel cadmium battery operations on-orbit: Trials, tribulations, and success on the Upper Atmosphere Research Satellite

The Upper Atmosphere Research Satellite (UARS), designed, built, integrated, tested, and operated by NASA and Martin Marietta is a low-Earth orbiting, Earth-observing spacecraft which was launched via Space Shuttle Discovery on September 12, 1991 and deployed three days later. The Modular Power Subsystem (MPS) onboard the satellite is equipped with three NASA Standard 50 Ampere-hour (Ah) nickel-cadmium (NiCd) batteries. McDonnell Douglas Electronics Systems Company fabricated the MPS, and batteries from Gates Aerospace Batteries cells. Nominal battery performance was achieved for the first four months of spacecraft operation. First evidence of anomalous battery performance was observed in January 1992, after the first maximum beta angle (low Depth of Discharge) period. Since then, the Flight Operations Team (FOT), under the direction of Goddard Space Flight Center's UARS Project and Space Power Application Branch, has monitored and managed battery performance by adjusting solar array offset angle, conducting periodic deep discharge, and controlling battery recharge ratio. This paper covers a brief overview of the UARS, the FOT's operational battery management, and the observed spacecraft battery performance.

Rao, Gopalakrishna M.↗

NASA NTRS1994

NASA Johnson Space Center Life Sciences Data System

The Life Sciences Project Division (LSPD) at JSC, which manages human life sciences flight experiments for the NASA Life Sciences Division, augmented its Life Sciences Data System (LSDS) in support of the Spacelab Life Sciences-2 (SLS-2) mission, October 1993. The LSDS is a portable ground system supporting Shuttle, Spacelab, and Mir based life sciences experiments. The LSDS supports acquisition, processing, display, and storage of real-time experiment telemetry in a workstation environment. The system may acquire digital or analog data, storing the data in experiment packet format. Data packets from any acquisition source are archived and meta-parameters are derived through the application of mathematical and logical operators. Parameters may be displayed in text and/or graphical form, or output to analog devices. Experiment data packets may be retransmitted through the network interface and database applications may be developed to support virtually any data packet format. The user interface provides menu- and icon-driven program control and the LSDS system can be integrated with other workstations to perform a variety of functions. The generic capabilities, adaptability, and ease of use make the LSDS a cost-effective solution to many experiment data processing requirements. The same system is used for experiment systems functional and integration tests, flight crew training sessions and mission simulations. In addition, the system has provided the infrastructure for the development of the JSC Life Sciences Data Archive System scheduled for completion in December 1994.

Rahman, Hasan↗

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 NTRS1993

COMET: First mission progress

The COMmercial Experiment Transporter (COMET) is a set of hardware and related infrastructure used to support orbital experiments of the Commerical Centers for the Development of Space (CCDS's) and their industrial partners. During the three years since the program started, contracts have been signed, design reviews conducted on all components, experiments selected for the first mission, all hardware has been manufactured, the first phase of integrated testing of the satellite, the experiments, and the Launch Facility have all been completed. The program experienced several delays in 1993. A component failure in the Service Module during preparation for environmental testing in January resulted in an eight-week delay for the Service Module part of the FreeFlyer. Discovery of large overruns of the mass budget required a major revision of the mission profile for COMET 1. In the spring of 1993, Space Industries Incorporated (SII) and Westinghouse stopped work because of a lack of funds. EER continued to work toward completion of their launch systems. SII and Westinghouse resumed work in September 1993. Since resumption of work, a technical review of all systems to ascertain their state of readiness has been completed. No major problems were discovered. All systems are proceeding toward a launch date in the first quarter of 1994.

Pawlick, Joseph F., Jr.↗