48,501 research outputs found
Study of sample drilling techniques for Mars sample return missions
To demonstrate the feasibility of acquiring various surface samples for a Mars sample return mission the following tasks were performed: (1) design of a Mars rover-mounted drill system capable of acquiring crystalline rock cores; prediction of performance, mass, and power requirements for various size systems, and the generation of engineering drawings; (2) performance of simulated permafrost coring tests using a residual Apollo lunar surface drill, (3) design of a rock breaker system which can be used to produce small samples of rock chips from rocks which are too large to return to Earth, but too small to be cored with the Rover-mounted drill; (4)design of sample containers for the selected regolith cores, rock cores, and small particulate or rock samples; and (5) design of sample handling and transfer techniques which will be required through all phase of sample acquisition, processing, and stowage on-board the Earth return vehicle. A preliminary design of a light-weight Rover-mounted sampling scoop was also developed
Advanced expander test bed program
The Advanced Expander Test Bed (AETB) is a key element in NASA's Space Chemical Engine Technology Program for development and demonstration of expander cycle oxygen/hydrogen engine and advanced component technologies applicable to space engines as well as launch vehicle upper stage engines. The AETB will be used to validate the high-pressure expander cycle concept, investigate system interactions, and conduct investigations of advanced mission focused components and new health monitoring techniques in an engine system environment. The split expander cycle AETB will operate at combustion chamber pressures up to 1200 psia with propellant flow rates equivalent to 20,000 lbf vacuum thrust. Contract work began 27 Apr. 1990. During 1992, a major milestone was achieved with the review of the final design of the oxidizer turbopump in Sep. 1992
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For cooperation and assistance in the work reported here, we gratefully acknowledge Dr.
William Burgoyne, State of Alaska Division of Environmental Conservation and Mr. Delon
Brown, USDA, Alaska Crop and Livestock Reporting Service. We especially appreciate the efforts
of numerous pesticide manufacturers, distributors, dealers, and users who took the necessary
time to provide information essential for this compilation. Richard Maxwell, Agricultural Chemicals
Specialist, Cooperative Extension Service, Washington State University, provided difficult to
locate pesticide label information. The editors of Farm Chemicals Handbook, 1980, provided the
list of preferred names as well as information regarding general application of pesticide products.Acknowledgments -- Introduction -- Reference -- Pesticide Use in Alaska, 197
Middle atmosphere measurements of small-scale electron density irregularities and ion properties during the MAC/Epsilon campaign
Rocket payloads designed to measure small scale electron density irregularities and ion properties in the middle atmosphere were flown with each of the three main salvos of the MAC/Epsilon campaign conducted at the Andoya Rocket Range, Norway, during October to November 1987. Fixed bias, hemispheric nose tip probes measured small scale electron density irregularities, indicative of neutral air turbulence, during the rocket's ascent; and subsequently, parachute-borne Gerdien condensers measured the region's polar electrical conductivity, ion mobility and density. One rocket was launched during daylight (October 15, 1052:20 UT), and the other two launches occurred at night (October 21, 2134 UT: November 12, 0021:40 UT) under moderately disturbed conditions which enhanced the detection and measurement of turbulence structures. A preliminary analysis of the real time data displays indicates the presence of small scale electron density irregularities in the altitude range of 60 to 90 km. Ongoing data reduction will determine turbulence parameters and also the region's electrical properties below 90 km
A human factors methodology for real-time support applications
A general approach to the human factors (HF) analysis of new or existing projects at NASA/Goddard is delineated. Because the methodology evolved from HF evaluations of the Mission Planning Terminal (MPT) and the Earth Radiation Budget Satellite Mission Operations Room (ERBS MOR), it is directed specifically to the HF analysis of real-time support applications. Major topics included for discussion are the process of establishing a working relationship between the Human Factors Group (HFG) and the project, orientation of HF analysts to the project, human factors analysis and review, and coordination with major cycles of system development. Sub-topics include specific areas for analysis and appropriate HF tools. Management support functions are outlined. References provide a guide to sources of further information
Human Factors Considerations in System Design
Human factors considerations in systems design was examined. Human factors in automated command and control, in the efficiency of the human computer interface and system effectiveness are outlined. The following topics are discussed: human factors aspects of control room design; design of interactive systems; human computer dialogue, interaction tasks and techniques; guidelines on ergonomic aspects of control rooms and highly automated environments; system engineering for control by humans; conceptual models of information processing; information display and interaction in real time environments
Aerodynamic data on a large semispan tilting wing with 0.5-diameter chord, double-slotted flap, and both left-hand and right-hand rotation of a single propeller
Longitudinal aerodynamic data on large-scale semispan V/STOL tilt-wing configuration having single propeller with left and right hand rotatio
Decision-making under future uncertainty: Developing adaptive urban water strategies
Copyright © 2014 Inderscience Enterprises Ltd. This paper describes a decision-making framework created to develop long term adaptive water supply and demand strategies to respond to future contextual uncertainties, such as climate change and urbanisation. Whilst there are various theoretical methods for decision making under uncertainty, they generally have not been applied to the water sector. Nor have they been brought together in an integrated, practically-grounded process to guide strategic planning and project level decisions, such as the approach proposed in this paper. This approach avoids predictions of the future or modelling intensive analysis, rather it integrates the fundamental characteristics of uncertain system influences (trends and shocks) with two additional thinking tools: The use of scenarios based on a number of uncertainties to describe potential futures, and the focus on investment approaches to guide the packaging of potential response measures
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