Advanced onboard propulsion benefits and status

Future commercial space systems may include geosynchronous-orbit communication satellites; Earth-observing satellites in polar, sun-synchronous orbits; and tended low-earth-orbit platforms. All such space systems require onboard propulsion for a variety of functions, including stationkeeping and drag makeup, apogee motors, and delivery and return. In many cases, the onboard propulsion exerts a major influence on the overall mission performance, lifetime, and integration. NASA has established a Low Thrust Propulsion Program, which is developing chemical and electric propulsion concepts that offer potential for significant benefits for onboard propulsion for the various classes of commercial spacecraft. The onboard propulsion requirements of future commercial space systems are briefly discussed, followed by a summary of the characteristics and status of relevant elements of the NASA Low Thrust program

The NASA Electric Propulsion Program

The NASA OAST Propulsion, Power, and Energy Division supports an electric propulsion program aimed at providing benefits to a broad class of missions. Concepts which have the potential to enable or significantly benefit space exploration and exploitation are identified and advanced toward application in the near and far term. This paper summarizes recent program progress in mission/system analysis; in electrothermal, electrostatic, and electromagnetic propulsion technologies; and in propulsion/spacecraft integration

What to Teach in an Information Systems Curriculum: Depends on Who You Ask!

Alumni surveys provide useful ways to evaluate the effectiveness of current programs and to provide direction for program modifications. A recent survey of alumni of a Pacific Northwest university undergraduate IS program reveals that they view communication skills and data communication, network and client server skills highly. Group Projects with Real Clients was the highest rated topic for the alumni respondents. Further analysis of the data shows that responses are highly tied to the current IS position and focus of the respondent. As schools evaluate their programs via alumni surveys, they should be aware of this influence

Enhancing space transportation: The NASA program to develop electric propulsion

The NASA Office of Aeronautics, Exploration, and Technology (OAET) supports a research and technology (R and T) program in electric propulsion to provide the basis for increased performance and life of electric thruster systems which can have a major impact on space system performance, including orbital transfer, stationkeeping, and planetary exploration. The program is oriented toward providing high-performance options that will be applicable to a broad range of near-term and far-term missions and vehicles. The program, which is being conducted through the Jet Propulsion Laboratory (JPL) and Lewis Research Center (LeRC) includes research on resistojet, arcjets, ion engines, magnetoplasmadynamic (MPD) thrusters, and electrodeless thrusters. Planning is also under way for nuclear electric propulsion (NEP) as part of the Space Exploration Initiative (SEI)

New Developments and Research Findings: NASA Hydrazine Arcjets

In 1984, the market for commercial geosynchronous communications satellites (comsats) was expanding and there was strong competition between spacecraft builders for market share. The propellant required for the north-south stationkeeping (NSSK) function was a major mission limiter, and the small chemical and resistojet systems then in use were at or near their physical limits. Thus, conditions were right for the development of a high performance NSSK system, and after an extensive survey of both propulsion technologies and the aerospace community, the NASA program chose hydrazine arcjets for development. A joint government/industry development program ensued which culminated in the acceptance of arcjet technology. NASA efforts included fundamental feasibility assessments, hardware development and verification, and multiple efforts aimed at the demonstration of critical operational characteristics of arcjet systems. Throughout the program, constant contact with the user community was maintained to determine system requirements. Both contracted and cooperative programs with industry were supported. First generation, kW-class arcjets are now operational for NSSK on the Telstar 401 satellite launched in December of 1993 and are baselined for use on multiple future satellite series (Intelsat 8, AsiaSat, Echostar). Arcjet development efforts are now focusing on the development of both high performance (600 s), 2 kW thrusters for application on next generation comsats and low power (Pe approximately 0.5 kW) for a variety of applications on power limited satellites. This paper presents a review of the NASA's role in the development of hydrazine arcjets with a focus on approaches, lessons learned, and the future

State Regulation of Franchising: The Washington Experience Revisited

Thirty-six years ago, and one year after Washington became the second state in the nation to enact a statute regulating franchise relationships, Professor Donald S. Chisum wrote the seminal article on franchising in Washington, State Regulation of Franchising: The Washington Experience. Professor Chisum\u27s article has been one of the few reference sources for Washington franchise law, and it has been the primary source relied on by courts addressing claims under Washington\u27s Franchise Investment Protection Act (FIPA). Since Professor Chisum originally published his article, the Federal Trade Commission (FTC) has promulgated and amended regulations governing the sale of franchises nationally, and two different groups have drafted uniform franchise acts. In Washington, the legislature significantly amended FIPA in 1991, and courts have addressed some of the unresolved issues under the statute. This Article assesses the changed state of franchise law in Washington. Part II considers the economic impact of franchising and the need for a review of franchising in Washington. Part III reviews the historical foundation for Washington\u27s current franchise laws, the context in which they were created, and the changes to franchise law that drive our modem understanding of FIPA today. Part IV addresses the current regulatory scheme in Washington, including practical considerations such as franchise registration, disclosure, and state enforcement powers. Finally, Part V addresses civil liability for violations of FIPA\u27s registration, disclosure, and relationship provisions

Knowledge and Use of Integrated Pest Management by Underserved Producers in Missouri and the Role of Extension

In Missouri, Plain producers (groups of conservative Anabaptist faith, including the Amish and Mennonites) are one type of underserved audience that has found a niche in vegetable production. The study reported here investigated the level of knowledge and use of Integrated Pest Management (IPM) gained over a 3-year period following implementation of Extension activities by the University of Missouri and Lincoln University, the two Missouri land-grant universities. Results indicate that Extension plays an important role in the observed increased use of IPM by the target audience and highlight the need to continue using traditional methods (e.g., printed documents, one-on-one interactions)

Increasing social complexity, climate change, and why societies might fail to cope

The PEOPLE 3000 working group focuses on integrating archaeological and paleoecological case studies with mathematical modeling. We seek to understand how coevolving human societies and ecosystems can successfully cope with the interrelated forces of population growth, increasing social complexity and climate change, and the diversity of trajectories of reorganization that social-ecological systems follow.Fil: Byers, David A.. State University of Utah; Estados UnidosFil: Lima, M.. State University of Utah; Estados UnidosFil: Gil, Adolfo Fabian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Universidad Tecnologica Nacional. Facultad Regional San Rafael; ArgentinaFil: Gayo, E.. Pontificia Universidad Católica de Chile; ChileFil: Latorre, C.. Pontificia Universidad Católica de Chile; ChileFil: Robinson, Erick. University Of Wyoming; Estados UnidosFil: Villalba, R.. Universidad Tecnologica Nacional. Facultad Regional San Rafael; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentin