IXPE Mission System Concept and Development Status

The Goal of the Imaging X-Ray Polarimetry Explorer (IXPE) Mi SMEX), is to expand understanding of high-energy astrophysical processes and sources, in support of NASAs first science objective in Astrophysics: Discover how the universe works. IXPE, an international collaboration, will conduct X-ray imaging polarimetry for multiple categories of cosmic X-ray sources such as neutron stars, stellar-mass black holes, supernova remnants and active galactic nuclei. The Observatory uses a single science operational mode capturing the X-ray data from the targets. The IXPE Observatory consists of spacecraft and payload modules built up in parallel to form the Observatory during system integration and test. The payload includes three X-ray telescopes each consisting of a polarization-sensitive, gas pixel X-ray detector, paired with its corresponding grazing incidence mirror module assembly (MMA). A deployable boom provides the correct separation (focal length) between the detector units (DU) and MMAs. These payload elements are supported by the IXPE spacecraft which is derived from the BCP-small spacecraft architecture. This paper summarizes the IXPE mission science objectives, updates the Observatory implementation concept including the payload and spacecraft ts and summarizes the mission status since last years conference

Arcus: exploring the formation and evolution of clusters, galaxies, and stars

Arcus, a Medium Explorer (MIDEX) mission, was selected by NASA for a Phase A study in August 2017. The observatory provides high-resolution soft X-ray spectroscopy in the 12-50Å bandpass with unprecedented sensitivity: effective areas of >450 cm^2 and spectral resolution >2500. The Arcus key science goals are (1) to measure the effects of structure formation imprinted upon the hot baryons that are predicted to lie in extended halos around galaxies, groups, and clusters, (2) to trace the propagation of outflowing mass, energy, and momentum from the vicinity of the black hole to extragalactic scales as a measure of their feedback and (3) to explore how stars, circumstellar disks and exoplanet atmospheres form and evolve. Arcus relies upon the same 12m focal length grazing-incidence silicon pore X-ray optics (SPO) that ESA has developed for the Athena mission; the focal length is achieved on orbit via an extendable optical bench. The focused X-rays from these optics are diffracted by high-efficiency Critical-Angle Transmission (CAT) gratings, and the results are imaged with flight-proven CCD detectors and electronics. The power and telemetry requirements on the spacecraft are modest. Mission operations are straightforward, as most observations will be long (~100 ksec), uninterrupted, and pre-planned, although there will be capabilities to observe sources such as tidal disruption events or supernovae with a ~3 day turnaround. Following the 2nd year of operation, Arcus will transition to a proposal-driven guest observatory facility

Air Force Institute of Technology Research Report 2018

This Research Report presents the FY18 research statistics and contributions of the Graduate School of Engineering and Management (EN) at AFIT. AFIT research interests and faculty expertise cover a broad spectrum of technical areas related to USAF needs, as reflected by the range of topics addressed in the faculty and student publications listed in this report. In most cases, the research work reported herein is directly sponsored by one or more USAF or DOD agencies. AFIT welcomes the opportunity to conduct research on additional topics of interest to the USAF, DOD, and other federal organizations when adequate manpower and financial resources are available and/or provided by a sponsor. In addition, AFIT provides research collaboration and technology transfer benefits to the public through Cooperative Research and Development Agreements (CRADAs). Interested individuals may discuss ideas for new research collaborations, potential CRADAs, or research proposals with individual faculty using the contact information in this document

Orbital Debris: A Chronology

This chronology covers the 37-year history of orbital debris concerns. It tracks orbital debris hazard creation, research, observation, experimentation, management, mitigation, protection, and policy. Included are debris-producing, events; U.N. orbital debris treaties, Space Shuttle and space station orbital debris issues; ASAT tests; milestones in theory and modeling; uncontrolled reentries; detection system development; shielding development; geosynchronous debris issues, including reboost policies: returned surfaces studies, seminar papers reports, conferences, and studies; the increasing effect of space activities on astronomy; and growing international awareness of the near-Earth environment

Arcus: exploring the formation and evolution of clusters, galaxies, and stars

Arcus, a Medium Explorer (MIDEX) mission, was selected by NASA for a Phase A study in August 2017. The observatory provides high-resolution soft X-ray spectroscopy in the 12-50Å bandpass with unprecedented sensitivity: effective areas of >450 cm^2 and spectral resolution >2500. The Arcus key science goals are (1) to measure the effects of structure formation imprinted upon the hot baryons that are predicted to lie in extended halos around galaxies, groups, and clusters, (2) to trace the propagation of outflowing mass, energy, and momentum from the vicinity of the black hole to extragalactic scales as a measure of their feedback and (3) to explore how stars, circumstellar disks and exoplanet atmospheres form and evolve. Arcus relies upon the same 12m focal length grazing-incidence silicon pore X-ray optics (SPO) that ESA has developed for the Athena mission; the focal length is achieved on orbit via an extendable optical bench. The focused X-rays from these optics are diffracted by high-efficiency Critical-Angle Transmission (CAT) gratings, and the results are imaged with flight-proven CCD detectors and electronics. The power and telemetry requirements on the spacecraft are modest. Mission operations are straightforward, as most observations will be long (~100 ksec), uninterrupted, and pre-planned, although there will be capabilities to observe sources such as tidal disruption events or supernovae with a ~3 day turnaround. Following the 2nd year of operation, Arcus will transition to a proposal-driven guest observatory facility

Arcus: The X-ray Grating Spectrometer Explorer

Arcus, a Medium Explorer (MIDEX) mission, was selected by NASA for a Phase A study in August 2017. The observatory provides high-resolution soft X-ray spectroscopy in the 12-50Å bandpass with unprecedented sensitivity: effective areas of >450 cm^2 and spectral resolution >2500. The Arcus key science goals are (1) to measure the effects of structure formation imprinted upon the hot baryons that are predicted to lie in extended halos around galaxies, groups, and clusters, (2) to trace the propagation of outflowing mass, energy, and momentum from the vicinity of the black hole to extragalactic scales as a measure of their feedback and (3) to explore how stars, circumstellar disks and exoplanet atmospheres form and evolve. Arcus relies upon the same 12m focal length grazing-incidence silicon pore X-ray optics (SPO) that ESA has developed for the Athena mission; the focal length is achieved on orbit via an extendable optical bench. The focused X-rays from these optics are diffracted by high-efficiency Critical-Angle Transmission (CAT) gratings, and the results are imaged with flight-proven CCD detectors and electronics. The power and telemetry requirements on the spacecraft are modest. Mission operations are straightforward, as most observations will be long (~100 ksec), uninterrupted, and pre-planned, although there will be capabilities to observe sources such as tidal disruption events or supernovae with a ~3 day turnaround. Following the 2nd year of operation, Arcus will transition to a proposal-driven guest observatory facility

CIRA annual report FY 2014/2015

Reporting period July 1, 2014-March 31, 2015

El urban sprawl : un modelo de urbanización insostenible

Tesi en modalitat de compendi de publicacions, amb diferents articles retallats per drets de l'editor.(English) he present thesis consists in a PhD thesis by compendium of publications. The general objective of the thesis is the analysis of the phenomenon of the Urban Sprawl, on a planetary scale, starting from the hypothesis that it is an unsustainable process. For the development, specific objectives were set that include the evolution of the research through a selection of 20 papers. The objectives are: a) Analyzing the Urban Sprawl urbanization model, by reviewing the specialized literature; b) Studying the genesis and evolution c) Quantify the Urban Sprawl from databases of local, regional and global, raising the question: is the Sprawl a phenomenon of planetary scope? d) Verify the hypothesis that in Europe, despite having a relatively dense metropolitan structure, there is a pronounced process of Urban Sprawl in the peripheries of large cities e) Define the “city” in the Sprawl era, defining urban and metropolitan systems based on morphological, economic and functional criteria f) Develop a methodology for the analysis of the internal structure of metropolises, capable of contrasting the degree of monocentrism and polycentrism of urban and metropolitan systems and verify the hypothesis that a higher degree of polycentrism reduces the degree of Sprawl (+ Polycentrism =-Sprawl) g) Apply this methodology to the analysis of specific cases, such as the Spanish urban system h) Apply the above methodology to analyze the efficiency in land consumption of the metropolitan systems of Madrid and Barcelona, Los Angeles and Chicago i) Analyze the process of urbanization through the land impacted by urbanization on a global scale, through images of night lights, delimiting metropolitan and megalopolitan areas and defining the different landscapes of human settlements j) Assess suitability of nighttime images to identify urban areas (in relation to rural settlements), and especially the Urban Sprawl, as well as, quantify the retrospective (and prospective) dynamics of the urbanization process (with special attention to China) k) Evaluate the climatic behavior of dispersed and low-density fabrics in comparison to the rest of urban and rural fabrics and uses; l) Study the daytime and nighttime Urban Heat Island (UHI), its spatial distribution and climatic performance of the different types of land covers; m) Study the urban factors that increase the adaptation of cities to global warming, specifically, urban parks as islands of cold in the context of the UHI n) Analyze the effects of heat waves on health, as well as the effect of urban greenery. The thesis, on the one hand, confirms the hypothesis of the unsustainability of the Urban Sprawl, since it implies a high consumption of land, in addition to generating unsustainable mobility. In the same way, it implies a fragmented and dispersed urbanization model, higher energy consumption and promotes social segregation. On the other hand, from the perspective of adaptation to climate change, the Urban Sprawl undoubtedly has a better performance, mainly due to the quality and quantity of green areas present in this type of urban fabric (absent in the central and dense city) and its proximity to those rural or forest areas, which are spaces that produce fresh air. The great challenge of spatial and urban planning is to stop this process of urban expansion without compromising the quality of life, comfort and human health. In this sense, it is necessary to proceed with a radical regeneration of the inherited urban fabrics. The compact city model cannot simply be considered the paradigm of sustainability. It must learn from the green spaces per inhabitant present in the Sprawl. Therefore, it can be concluded that green compactness is the new paradigm of 21st century cities.(Español) La tesis consiste en una tesis por compendio de publicaciones y el objetivo central es el análisis del fenómeno de la dispersión de la urbanización llamado Urban Sprawl a escala planetaria, partiendo de la hipótesis de que se trata de un proceso insostenible. Para el desarrollo de la misma se plantearon objetivos específicos que han sido desarrollados a través de artículos. Estos objetivos son: a) analizar el modelo del Urban Sprawl, mediante la revisión de la literatura especializada b) estudiar su génesis y evolución c) cuantificar el Urban Sprawl a partir de bases de datos de alcance local, regional y mundial, planteando la interrogante ¿es el Sprawl un fenómeno de alcance planetario? d) verificar la hipótesis de que en Europa, a pesar de tener una estructura metropolitana relativamente densa, existe un acusado proceso de Urban Sprawl en las periferias de las grandes ciudades e) delimitar la “ciudad” en la era del Sprawl, definiendo los sistemas urbanos y metropolitanos a partir de criterios morfológicos, económicos y funcionales f) desarrollar una metodología para el análisis de la estructura interna de las metrópolis, capaz de contrastar el grado de monocentrismo y policentrismo de los sistemas urbanos y metropolitanos y verificar la hipótesis de que un mayor grado de policentrismo atenúa el grado de Sprawl (+ Policentrismo = - Sprawl) g) aplicar dicha metodología al análisis de casos concretos, como es el sistema urbano español h) aplicar la anterior metodología para analizar la eficiencia en el consumo de suelo de los sistemas metropolitanos de Madrid y Barcelona, Los Ángeles y Chicago i) Analizar el proceso de urbanización a través del suelo impactado por la urbanización a escala mundial, por medio de imágenes de luces nocturnas, delimitando áreas metropolitanas y megalopolitanas a escala mundial y definiendo en las mismas los diferentes paisajes de los asentamientos humanos j) evaluar la capacidad de las luces nocturnas para identificar las áreas urbanas y muy especialmente el Urban Sprawl, así como cuantificar la dinámica retrospectiva (y prospectiva) del proceso de urbanización (con especial atención a China); k) evaluar el comportamiento climático de los tejidos dispersos y de baja densidad en comparación al resto de tejidos y usos urbanos y rurales; l) Estudiar la Isla de Calor Urbana (UHI) diurna y nocturna, su distribución espacial y comportamiento climático de los diferentes tipos de cubiertas de suelo; m) estudiar los factores urbanísticos que incrementan la adaptación de las ciudades al calentamiento global, específicamente, los parques urbanos como islas de frío en el contexto de la UHI; y n) analizar los efectos que tienen las olas de calor en la salud, así como el efecto del verde urbano. La tesis, por un lado, confirma la hipótesis de la insostenibilidad del Urban Sprawl, dado que implica un alto consumo de suelo, además de generar una movilidad insostenible. Del mismo modo, implica un modelo de urbanización fragmentado y disperso, un mayor consumo energético y promueve la segregación social. Por otro lado, desde la perspectiva de la adaptación al cambio climático, el Urban Sprawl tiene sin duda un mejor comportamiento, principalmente por la calidad y cantidad de espacio verde presente en este tipo de tejido urbano (ausente en la ciudad central y densa) y su proximidad a aquellas zonas rurales o forestales, que son espacios que producen aire fresco. El gran desafío de la planificación territorial y urbana es detener este proceso de expansión urbana sin comprometer la calidad de vida, el confort y la salud humana. En este sentido, es necesario proceder a una reforma radical de los tejidos urbanos heredados. El modelo de ciudad compacta no puede ser considerado simplemente el paradigma de la sostenibilidad. Debe aprender de la mayor cantidad de espacios verdes por habitante presente en el Sprawl. Por tanto, concluir que la compacidad verde es el nuevo paradigma de las ciudades del siglo XXI.Postprint (published version

Annual Research Report, 2010-2011

Annual report of collaborative research projects of Old Dominion University faculty and students in partnership with business, industry and government.https://digitalcommons.odu.edu/or_researchreports/1000/thumbnail.jp