Radioisotope power systems utilising americium-241 as a source of heat have been under development in Europe as part of a European Space Agency funded programme since 2009. The aim is to develop all ...of the building blocks that would enable Europe to launch and operate deep space and planetary missions in environments where use of solar power or alternative power generation technologies is challenging. Although some technical and policy work activity predate the ESA programme, the maturity of the technology has now reached a level that it can be incorporated in mission studies and roadmaps targeting the period from the mid 2020s onwards. This paper describes the state of the art in European radioisotope thermoelectric generators and radioisotope heater units. This paper includes: the evolution of the technical programme in detail; descriptions of the design; evolution of RTG and RHU devices from laboratory prototypes to more advanced fully functional systems; and experimental data obtained to date. This paper also outlines the technical challenges and multidisciplinary skills required to develop what is a world leading, original, significant and transformative technology solution for planetary science and exploration missions from the mid 2020s onwards.
Galactic Astronomy James Binney, Michael Merrifield
2021, 1998, 2021-07-13, Letnik:
9
eBook
This is the definitive treatment of the phenomenology of galaxies--a clear and comprehensive volume that takes full account of the extraordinary recent advances in the field. The book supersedes the ...classic text Galactic Astronomy that James Binney wrote with Dimitri Mihalas, and complements Galactic Dynamics by Binney and Scott Tremaine. It will be invaluable to researchers and is accessible to any student who has a background in undergraduate physics. The book draws on observations both of our own galaxy, the Milky Way, and of external galaxies. The two sources are complementary, since the former tends to be highly detailed but difficult to interpret, while the latter is typically poorer in quality but conceptually simpler to understand. Binney and Merrifield introduce all astronomical concepts necessary to understand the properties of galaxies, including coordinate systems, magnitudes and colors, the phenomenology of stars, the theory of stellar and chemical evolution, and the measurement of astronomical distances. The book's core covers the phenomenology of external galaxies, star clusters in the Milky Way, the interstellar media of external galaxies, gas in the Milky Way, the structure and kinematics of the stellar components of the Milky Way, and the kinematics of external galaxies. Throughout, the book emphasizes the observational basis for current understanding of galactic astronomy, with references to the original literature. Offering both new information and a comprehensive view of its subject, it will be an indispensable source for professionals, as well as for graduate students and advanced undergraduates.
Radioisotope thermoelectric generators (RTG) and heater units (RHU) systems are being developed in Europe as part of a European Space Agency (ESA) funded program. Aimed at enabling or significantly ...enhancing space science and exploration missions, these systems rely on the cost-effective production of americium-241 for the fuel. The use of an iterative approach and the application of lean methodologies for the development these systems have been the focus of this technology program. Isotope containment architectures and, in the case of RTG systems, bismuth telluride based thermoelectric generators are under development. At the small end of the scale, the RHU configuration is based on a 3 W thermal power output. The first version of this system has been designed and analysed. Electrically-heated and mechanical models have been produced and tested. The RTG heat source configuration is designed to deliver 200 W of thermal power output while minimizing the volume occupied by the fuel. A 5% total system conversion efficiency and a modular scalable design imply that electrical power output can range between 10 W and 50 W. Each RTG system could house up to 5 heat sources. An electrically-heated RTG system based on the 200 W heat source architecture has been designed, analysed and tested. The advancement in the design of the heat source for both RTGs and RHUs is currently the focus of the programme with the aim of advancing the technology readiness level of the containment structures. The most recent results of the programme will be presented.
The subject of the thesis is anti-Americanism in the British Labour Party between 1960 and 1997. The 'Introduction' examines the conceptual questions, as well as the historical heritage, of Socialist ...anti-Americanism. The body of the thesis is split into three case studies, each case study dealing with one of three selected 'eras' in Labour politics. The three case studies take a uniform approach to examining anti- Americanism, studying three proposed forms of Socialist anti-Americanism antiimperialist, pacifist and anti-capitalist anti-Americanism. The first case study examines anti-Americanism in the British Labour Party during the 1960s, beginning with Harold Wilson's installation as Party leader in 1963. The first case study specifically focuses on Socialist anti-Americanism between 1964 and 1967, when the Vietnam War dominated British Labour politics. The second case study examines Socialist anti-Americanism during the 1980s, though the case study does also consider the influence of developments in Labour politics in the late-1970s. Such a time frame has been chosen for the second case study because of the extent of left-wing control in Labour politics at this time. The third case study examines Socialist anti-Americanism throughout the 1990s, the years of reformation and rehabilitation for the Labour Party. The influence of political developments in the late-1980s are also considered in the third case study. The 'Conclusions' highlight the most significant discoveries made during the examination of Socialist anti-Americanism. The 'Bibliography' details the various primary and secondary sources used in the researching and writing of the thesis.
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