Space transportation systems, launch systems, and propulsion for the Space Exploration Initiative: Results from Project Outreach

A number of transportation and propulsion options for Mars exploration missions are analyzed. As part of Project Outreach, RAND received and evaluated 350 submissions in the launch vehicle, space transportation, and propulsion areas. After screening submissions, aggregating those that proposed identical or nearly identical concepts, and eliminating from further consideration those that violated known physical princples, we had reduced the total number of viable submissions to 213. In order to avoid comparing such disparate things as launch vehicles and electric propulsion systems, six broad technical areas were selected to categorize the submissions: space transportation systems; earth-to-orbit (ETO) launch systems; chemical propulsion; nuclear propulsion; low-thrust propulsion; and other. To provide an appropriate background for analyzing the submissions, an extensive survey was made of the various technologies relevant to the six broad areas listed above. We discuss these technologies with the intent of providing the reader with an indication of the current state of the art, as well as the advances that might be expected within the next 10 to 20 years

Linguistic incompetence: giving an account of researching multilingually

This paper considers the place of linguistic competence and incompetence in the context of researching multilingually. It offers a critique of the concept of competence and explores the performative dimensions of multilingual research and its narration, through the philosophy of Judith Butler, and in particular her study Giving an account of oneself. It explores aspects of risk, justice, narrative limit and a morality of multilingualism in emergent multilingual research frameworks. These theoretical dimensions are explored through consideration of ‘linguistically incompetent’ ethnographic work with refugees and asylum seekers, in contexts of hospitality and in life long learning research in the Gaza Strip, and of early attempts to learn new languages. The paper offers a prospect of a relational approach to researching multilingually and affirms the vulnerability at the heart of linguistic hospitality

Color/magnitude calibration for National Aeronautics and Space Administration (NASA) standard Fixed-Head Star Trackers (FHST)

This paper characterizes and analyzes the spectral response of Ball Aerospace fixed-head star trackers, (FHST's) currently in use on some three-axis stabilized spacecraft. The FHST output is a function of the frequency and intensity of the incident light and the position of the star image in the field of view. The FHST's on board the Extreme Ultraviolet Explorer (EUVE) have had occasional problems identifying stars with a high B-V value. These problems are characterized by inaccurate intensity counts observed by the tracker. The inaccuracies are due to errors in the observed star magnitude values. These errors are unique to each individual FHST. For this reason, data were also collected and analyzed from the Upper Atmosphere Research Satellite (UARS). As a consequence of this work, the Goddard Space Flight Center (GSFC) Flight Dynamics Division (FDD) hopes to improve the attitude accuracy on these missions and to adopt better star selection procedures for catalogs

In vitro fermentation of different ratios of alfalfa and starch or inulin incubated with an equine faecal inoculum

The aim of this work was to assess the impact of substituting starch (S) or inulin (I) with high-temperature dried alfalfa (HTDA) as substrates for in vitro fermentation with an equine faecal inoculum. A series of experiments were conducted to assess the fermentation kinetics of HTDA (chopped [CA] or ground [GA]) and either S or I mixed in the following ratios; 100:0, 80:20, 60:40, 40:60 and 20:80S/I: CA/GA, respectively. For each experiment, a further set of bottles containing identical ratios of S/I: CA/GA were also prepared, with the exception that the alfalfa received a simulated foregut digestion treatment (SFD) as prior to incubation. Total gas production increased (P<0.05) as the ratio of S/I to alfalfa increased. Total gas production was lower in bottles containing SFD-treated alfalfa (P<0.001). Dry matter loss decreased proportionately with increasing level of alfalfa substitution of S/I (P<0.001). Values for pH were lower in bottles containing S or I, with pH values in bottles containing S alone falling to almost 6 and those with I dropping to pH 5 and under. However, the substitution of S or I with 40% alfalfa produced pH values above 6.7, which is within physiological levels encountered in the large intestine of the horse. Consequently, there appears to be considerable potential to buffer the deleterious effects of high-starch/fructan diets with the substitution of these substrates with high-temperature dried alfalfa

Liquidus Phases of the Richardson H5 Chondrite at High Pressures and Temperatures

Part of early mantle evolution may include a magma ocean, where core formation began before the proto-Earth reached half of its present radius. Temperatures were high and bombardment and accretion were still occurring, suggesting that the proto-Earth consisted of a core and an at least partially liquid mantle, the magma ocean. As the Earth accreted, pressure near the core increased and the magma ocean decreased in volume and became shallower as it began to cool and solidify. As crystals settled, or floated, the composition of the magma ocean could change significantly and begin to crystallize different minerals from the residual liquid. Therefore, the mantle may be stratified following the P-T phase diagram for the bulk silicate Earth. To understand mantle evolution, it is necessary to know liquidus phase relations at high pressures and temperatures. In order to model the evolution of the magma ocean, high pressure and temperature experiments have been conducted to simulate the crystallization process using a range of materials that most likely resemble the bulk composition of the early Earth

Physical aspects of oracles for randomness, and Hadamard's conjecture

We analyze the physical aspects and origins of currently proposed oracles for (absolute) randomness.Comment: 10 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:1405.140

Implementation of GDPR: Learning with a local administration case study

The General Data Protection Regulation has come into force in the European Union in May 2018 in order to meet current challenges related to personal data protection and to help harmonise the data protection across the EU. Although the GDPR was expected to benefit companies, being private or public, by offering consistency in data protection activities and liabilities across the EU countries and by enabling more integrated EU wide data protection policies, it poses new challenges to companies. However, if we take a step back and think that this regulation has been in transit for more than 2 years, and that only after the implementation of this regulation has begun the real concern is: are companies ready to make this leap?This work has been supported by national funds through FCT – Fundação para a Ciência e Tecnologia within the Project Scope: UID/CEC/00319/2019

Quality of Life and Menopause in Women with Physical Disabilities

Objective: The goal of this cross-sectional study was to explore quality of life (QOL) in a sample of postmenopausal women with physical disabilities due to polio contracted in childhood. A structural equation model was used to confirm that menopause symptoms will have a minimal effect on QOL when disability-related variables are taken into account. Methods: A sample of 752 women who were postmenopausal completed a written survey. The structural equation model contained two measured predictors (age, severity of postpolio sequelae) and one latent predictor (menopause symptoms defined by four measured indicators). Functional status (defined by two measured indicators) was included as a mediator, with QOL (defined by three measured indicators) as the outcome. Results: The original model yielded acceptable fit indices (CFI = 0.96, RMSEA = 0.055) but resulted in a number of unexpected relationships that proved to be artifacts after model respecification. The respecified model yielded a nonsignificant chi-square value, which indicated no significant discrepancy between the proposed model and the observed data (chisquare = 18.5, dƒ = 13, p = 0.138). All fit indices indicated a good fit: CFI = 0.997, NNFI = 0.987, chi-square/dƒ = 1.43, and RMSEA = 0.024. Conclusions: When the effects of postpolio sequelae and functional status are included in the structural equation model, only the psychological symptoms of menopause play a prominent role in explaining QOL in this sample. The clinical implications of these findings suggest that attention to psychological symptoms and an exclusive focus on the physical aspects of menopause to the exclusion of other midlife life stressors and influences on a woman’s psychological well-being ignore the larger context of life in which they live. In particular, many women with disabilities may contend with additional or exacerbated stressors related to their disability.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63153/1/jwh.2006.15.1014.pd

Exploring the Unknown: Selected Documents in the History of the US Civilian Space Program

One of the most important developments of the twentieth century has been the movement of humanity into space with machines and people. The underpinnings of that movement -why it took the shape it did; which individuals and organizations were involved; what factors drove a particular choice of scientific objectives and technologies to be used; and the political, economic, managerial, and international contexts in which the events of the space age unfolded- are all important ingredients of this epoch transition from an earthbound to spacefaring people. This desire to understand the development of spaceflight in the United States sparked this documentary history series. 'Exploring the Unknown' is a multi-volume series containing a selection of key documents in history of the U.S. civil space program. This current volume, Volume III, focusing on the use of space for practical applications, prints 112 key documents on the history of satellite communications, remote sensing of earth, and space as an investment in economic growth, edited for ease of use. Each is introduced by a headnote providing context, bibliographical information, and background information necessary to understanding the document