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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 253 records · Page 14

Towards a knowledge-based system to assist the Brazilian data-collecting system operation

A study is reported which was carried out to show how a knowledge-based approach would lead to a flexible tool to assist the operation task in a satellite-based environmental data collection system. Some characteristics of a hypothesized system comprised of a satellite and a network of Interrogable Data Collecting Platforms (IDCPs) are pointed out. The Knowledge-Based Planning Assistant System (KBPAS) and some aspects about how knowledge is organized in the IDCP's domain are briefly described.

Rodrigues, Valter↗

NASA Langley WINN System Operational Assessment

An operational assessment of the NASA Langley Weather Information Network (WINN) System is presented. The objectives of this program include: 1) Determine if near real-time weather information presented on the flight deck improves pilot situational awareness of weather; and 2) Identify pilot interface issues related to the use of WINN system during test flights. This paper is in viewgraph form.

Jonsson, Jon↗

Dynamics Explorer spacecraft and ground operations systems

The Dynamics Explorer program of NASA is designed to study the coupling of energy, electric currents, electric fields, and plasmas between the atmosphere, ionosphere, and the magnetosphere. The program is composed of two well instrumented polar orbiting satellites and ground operations and data handling systems which have been designed to acquire, process, and make readily available to the scientists of the program the data sets necessary for analysis to accomplish the science objectives. These systems are described with emphasis placed on the relationship of the two instrumented spacecraft and the ground systems to their roles in meeting the program requirements. In addition, the characteristics of the orbits selected are specified.

Hoffman, R. A.↗

Photovoltaic power system operation in the Mars environment

Detailed information on the environmental conditions on Mars are very desirable for the design of photovoltaic systems for establishing outposts on the Martian surface. The variation of solar insolation (global, direct, and diffuse) at the Viking lander's locations is addressed. It can be used, to a first approximation, for other latitudes. The radiation data is based on measured optical depth of the Martian atmosphere derived from images taken of the sun with a special diode on the Viking cameras; and computation based on multiple wavelength and multiple scattering of the solar radiation. The data are used to make estimates of photovoltaic system power, area and mass for a surface power system using regenerative fuel cells for storage and nighttime operation.

Appelbaum, Joseph↗

Photovoltaic power system operation in the Mars environment

Detailed information on the environmental conditions on Mars are very desirable for the design of photovoltaic systems for establishing outposts on the Martian surface. The variation of solar insolation (global, direct, and diffuse) at the Viking lander's locations is addressed. It can be used, to a first approximation, for other latitudes. The radiation data is based on measured optical depth of the Martian atmosphere derived from images taken of the sun with a special diode on the Viking cameras; and computation based on multiple wavelength and multiple scattering of the solar radiation. The data are used to make estimates of photovoltaic system power, area and mass for a surface power system using regenerative fuel cells for storage and nighttime operation.

Appelbaum, Joseph↗

Space system operations and support cost analysis using Markov chains

This paper evaluates the use of Markov chain process in probabilistic life cycle cost analysis and suggests further uses of the process as a design aid tool. A methodology is developed for estimating operations and support cost and expected life for reusable space transportation systems. Application of the methodology is demonstrated for the case of a hypothetical space transportation vehicle. A sensitivity analysis is carried out to explore the effects of uncertainty in key model inputs.

Unal, Resit↗

Real-time operating system for a multi-laser/multi-detector system

The laser-one hazard detector system, used on the Rensselaer Mars rover, is reviewed briefly with respect to the hardware subsystems, the operation, and the results obtained. A multidetector scanning system was designed to improve on the original system. Interactive support software was designed and programmed to implement real time control of the rover or platform with the elevation scanning mast. The formats of both the raw data and the post-run data files were selected. In addition, the interface requirements were selected and some initial hardware-software testing was completed.

Coles, G.↗

Simulation of mass storage systems operating in a large data processing facility

A mass storage simulation program was written to aid system designers in the design of a data processing facility. It acts as a tool for measuring the overall effect on the facility of on-line mass storage systems, and it provides the means of measuring and comparing the performance of competing mass storage systems. The performance of the simulation program is demonstrated.

Holmes, R.↗

Verification and Validation of Safety-Critical Aircraft Systems Operating under Off-Nominal, Contingency, and Emergency Conditions

Verification and validation (V&V) of safety-critical technologies developed for loss of control (LOC) prevention and recovery and other aviation safety concerns pose significant challenges. Aircraft LOC can result from a wide spectrum of hazards, often occurring in combination, which cannot be fully replicated during evaluation. Technologies developed for LOC prevention and recovery must therefore be effective under a wide variety of hazardous and uncertain conditions, and the verification and validation of these technologies must provide some measure of assurance that the new vehicle safety technologies do no harm (i.e., that they themselves do not introduce new safety risks). V&V technologies must also enable the identification of system limitations and constraints, as well as enable the identification of safe and unsafe operating conditions (and their boundaries). Additionally, the V&V of complex, increasingly autonomous systems is a fundamental concern. Scalable, reproducible and cost-effective techniques for the assurance of safety critical systems during their design and operation is a key barrier to fielding new systems or updating current systems. Moreover, these techniques need to provide artifacts that enable a comprehensive evidence-based approach to certification. This briefing summarizes research performed under NASA’s Aviation Safety Program and follow-on research for the V&V of safety-critical aircraft system technologies developed for LOC prevention and recovery and increasingly autonomous systems, and for a broad assurance capability in both current and emerging aviation applications. Note that, in this briefing, the term “validation” refers to a confirmation that the system implementation (e.g., algorithms etc.) is performing the intended function(s), as well as an affirmation of effectiveness in these functions. “Verification” refers to a confirmation that the system implementation in the software and hardware meets its (hopefully validated) specifications (e.g., correctly executes algorithms as designed).

Validation↗

Giving the Public a Perspective into Unmanned Aircraft Systems' Operations

NASA is currently engaged in research to safely enable large-scale commercial applications of small Unmanned Aerial Systems (UAS) in low altitude airspace. This research effort, referred to as UAS Traffic Management (UTM), encompasses the concepts and technologies needed to accommodate the projected demand of UAS operating in the national airspace. One aspect related to the successful implementation of UTM in the future is public acceptance. Transparency will heavily influence this acceptance, and a public portal will provide much of that transparency through ease of access to information about the operations - mainly who, why, and where such operations are taking place. Related concerns to the public are individual privacy, security, and accountability of the operators. Providing the aforementioned information about operations can mitigate these concerns, but a balance will have to be achieved between the need for transparency from the public and the privacy of the operators. The proper balance and the needs of the various UTM stakeholders with regard to information access will be explored through the development and testing of a public portal as part of NASA's Technical Capability 3 (TCL 3) demonstration. Additionally, various approaches to the display of information and user interfaces will be surveyed through the development of a public portal by multiple UTM industry partners across different test sites.

UAS↗

A Simulation Based Approach for Contingency Planning for Aircraft Turnaround Operation System Activities in Airline Hubs

Commercial aircraft undergo a significant number of maintenance and logistical activities during the turnaround operation at the departure gate. By analyzing the sequencing of these activities, more effective turnaround contingency plans may be developed for logistical and maintenance disruptions. Turnaround contingency plans are particularly important as any kind of delay in a hub based system may cascade into further delays with subsequent connections. The contingency sequencing of the maintenance and logistical turnaround activities were analyzed using a combined network and computer simulation modeling approach. Experimental analysis of both current and alternative policies provides a framework to aid in more effective tactical decision making.

Adeleye, Sanya↗

Measured performance of a 3 ton LiBr absorption water chiller and its effect on cooling system operation

A three ton lithium bromide absorption water chiller was tested for a number of conditions involving hot water input, chilled water, and the cooling water. The primary influences on chiller capacity were the hot water inlet temperature and the cooling water inlet temperature. One combination of these two parameters extended the output to as much as 125% of design capacity, but no combination could lower the capacity to below 60% of design. A cooling system was conceptually designed so that it could provide several modes of operation. Such flexibility is needed for any solar cooling system to be able to accommodate the varying solar energy collection and the varying building demand. It was concluded that a three-ton absorption water chiller with the kind of performance that was measured can be incorporated into a cooling system such as that proposed, to provide efficient cooling over the specified ranges of operating conditions.

Namkoong, D.↗

Measured performance of a 3-ton LiBr absorption water chiller and its effect on cooling system operation

A 3-ton lithium bromide absorption water chiller was tested for a number of conditions involving hot-water input, chilled water, and the cooling water. The primary influences on chiller capacity were the hot water inlet temperature and the cooling water inlet temperature. One combination of these two parameters extended the output to as much as 125% of design capacity, but no combination could lower the capacity to below 60% of design. A cooling system was conceptually designed so that it could provide several modes of operation. Such flexibility is needed for any solar cooling system to be able to accommodate the varying solar energy collection and the varying building demand. It is concluded that a 3-ton absorption water chiller with the kind of performance that was measured can be incorporated into a cooling system such as that proposed, to provide efficient cooling over the specified ranges of operating conditions.

Namkoong, D.↗

Statement of Chester M. Lee, Director, Space Transportation Systems Operations, NASA, and Phillip E. Culbertson, Assistant Administrator of Planning and Program Integration, NASA

Payloads for the Space Transportation System 560 flights, particularly the NASA payloads, are discussed. NASA payloads will make up approximately 50% of total payloads in these flights. Proposed Spacelab experiments are listed and discussed; plans for accommodating commercial user payloads are then outlined, including price schedules.

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