Autonomous rendezvous and capture development infrastructure

In the development of the technology for autonomous rendezvous and docking, key infrastructure capabilities must be used for effective and economical development. This involves facility capabilities, both equipment and personnel, to devise, develop, qualify, and integrate ARD elements and subsystems into flight programs. One effective way of reducing technical risks in developing ARD technology is the use of the ultimate test facility, using a Shuttle-based reusable free-flying testbed to perform a Technology Demonstration Test Flight which can be structured to include a variety of additional sensors, control schemes, and operational approaches. This conceptual testbed and flight demonstration will be used to illustrate how technologies and facilities at MSFC can be used to develop and prove an ARD system

Periodic Atlas of the Metroscape: Lassoing Urban Sprawl

This issue\u27s atlas compares the metroscape with four other metropolitan areas (San Antonio, Columbus, Charlotte, and Orlando). Using 1990 and 2000 census block group data, density classifications were used to show patterns of urban (3 ,000+ persons/ sq.mi .), suburban (1 ,000 to 3,000 persons/sq.mi .), exurban (300 to 1,000 persons/sq .mi.) , and rural (/sq.mi.) growth. While the metroscape experienced significant population growth from 1990 to 2000, compared to the other four, it realized the smallest loss of rural lands and significantly less suburban and exurban style development as well. By comparison, Orlando - the other metro area in the sample using urban containment policies - realized significantly more outward development

Debunking the exurban myth: a comparison of suburban households

Journal ArticleAs American cities spill over their traditional boundaries into 'exurbia', the debate about whether this new growth is substantively different from what preceded is an important one. We disagree with the idea that the counterurbanization the United States is experiencing represents a dramatic break from previous growth patterns. Using parametric and nonparametric analysis, we examine whether or not the behavioral patterns and demographic characteristics of exurbanites differ from those of suburbanites. Is exurbanization really different from suburbanization and are exurbanites really different from suburbanites? Our research shows that the answer is no. Exurbia should not be defined separately from suburbia. Rather, the development on the metropolitan fringe is simply the latest incarnation of the continued suburbanization of American cities

Effectiveness of urban containment regimes in reducing exurban sprawl

Journal ArticleDuring the 1990s, the exurban landscape grew faster and added more people than urban, suburban, and rural landscapes. In many respects, exurbanization is the quintessential representation of urban sprawl and the problems it poses. More than 100 metropolitan areas across the US attempt to manage exurbanization through various forms of urban containment at regional or subregional scales. In this article, we assess the extent to which urban containment is effective in managing exurban sprawl in the 35 largest metropolitan areas in the US. Through simple cross-section analysis, we found that relative to metropolitan areas without urban containment, those pursuing "strong" containment efforts performed best in reducing exurbanization. Strong containment programs are those that direct urban development into areas defined by urban containment boundaries and restrict development outside the boundaries. Metropolitan areas with "natural" containment, i.e., where development is constrained because of oceans, mountains, public ownership, and water supply, did not perform as well but saw less exurbanization than noncontained metropolitan areas. Least effective relative to other forms of containment were metropolitan areas with weak containment efforts, principally because such approaches do not substantially restrict development outside containment boundaries. Strong urban containment appears to be effective in reigning in exurban sprawl but without apparently dampening population growth generally

SEGMENTING NICHE GOAT-MEAT MARKETS

This research report provides an examination of the ratings of an important sensory attribute of chevon (goat meat) with that of beef and pork. Results from an analysis of variance of comparative ratings of the flavor of chevon and that of beef and pork suggest that selected demographic characteristics of U.S. consumers influenced the ratings of chevon'Â’s flavor with that of beef and pork. The findings indicate that Hispanics, blacks, and females should not be treated as homogenous niche markets. The results suggest that there are distinct subdivision preferences within and between these consumer partitions.Agribusiness,

An experimental investigation of the flow physics of high-lift systems

This progress report, a series of viewgraphs, outlines experiments on the flow physics of confluent boundary layers for high lift systems. The design objective is to design high lift systems with improved C(sub Lmax) for landing approach and improved take-off L/D and simultaneously reduce acquisition and maintenance costs. In effect, achieve improved performance with simpler designs. The research objectives include: establish the role of confluent boundary layer flow physics in high-lift production; contrast confluent boundary layer structure for optimum and non-optimum C(sub L) cases; formation of a high quality, detailed archival data base for CFD/modeling; and examination of the role of relaminarization and streamline curvature

An Experimental Investigation of the Confluent Boundary Layer on a High-Lift System

This paper describes a fundamental experimental investigation of the confluent boundary layer generated by the interaction of a leading-edge slat wake with the boundary layer on the main element of a multi-element airfoil model. The slat and airfoil model geometry are both fully two-dimensional. The research reported in this paper is performed in an attempt to investigate the flow physics of confluent boundary layers and to build an archival data base on the interaction of the slat wake and the main element wall layer. In addition, an attempt is made to clearly identify the role that slat wake / airfoil boundary layer confluence has on lift production and how this occurs. Although complete LDV flow surveys were performed for a variety of slat gap and overhang settings, in this report the focus is on two cases representing both strong and weak wake boundary layer confluence

An experimental investigation of the flow physics of high-lift systems

This progress report is a series of overviews outlining experiments on the flow physics of confluent boundary layers for high-lift systems. The research objectives include establishing the role of confluent boundary layer flow physics in high-lift production; contrasting confluent boundary layer structures for optimum and non-optimum C(sub L) cases; forming a high quality, detailed archival data base for CFD/modelling; and examining the role of relaminarization and streamline curvature. Goals of this research include completing LDV study of an optimum C(sub L) case; performing detailed LDV confluent boundary layer surveys for multiple non-optimum C(sub L) cases; obtaining skin friction distributions for both optimum and non-optimum C(sub L) cases for scaling purposes; data analysis and inner and outer variable scaling; setting-up and performing relaminarization experiments; and a final report establishing the role of leading edge confluent boundary layer flow physics on high-lift performance

Vortex transport and voltage noise in disordered superconductors

We study, by means of three-dimensional Monte Carlo simulations, the current-voltage (IV) characteristics and the voltage noise spectrum at low temperatures of driven magnetic flux lines interacting with randomly placed point or columnar defects, as well as with periodically arranged linear pinning centers. Near the depinning current J_c, the voltage noise spectrum S(w) universally follows a 1/w^a power law. For currents J > J_c, distinct peaks appear in S(w) which are considerably more pronounced for extended as compared to point defects, and reflect the spatial distribution of the correlated pinning centers.Comment: 8 pages, latex, Elsevier style file and figures include