Age distribution among NASA scientists and engineers

The loss of technical expertise through attrition in NASA and the aerospace industry is discussed. This report documents historical age-related information for scientific and engineering personnel in general and the NASA Lewis Research Center in particular, for 1968 through 1987. Recommendations are made to promote discussion and to establish the groundwork for action

Flow visualization study of the effect of injection hole geometry on an inclined jet in crossflow

A flow visualization was studied by using neutrally buoyant, helium-filled soap bubbles, to determine the effect of injection hole geometry on the trajectory of an air jet in a crossflow and to investigate the mechanisms involved in jet deflection. Experimental variables were the blowing rate, and the injection hole geometry cusp facing upstream (CUS), cusp facing downstream (CDS), round, swirl passage, and oblong. It is indicated that jet deflection is governed by both the pressure drag forces and the entrainment of free-stream fluid into the jet flow. For injection hole geometries with similar cross-sectional areas and similar mass flow rates, the jet configuration with the larger aspect ratio experienced a greater deflection. Entrainment arises from lateral shearing forces on the sides of the jet, which set up a dual vortex motion within the jet and thereby cause some of the main-stream fluid momentum to be swept into the jet flow. This additional momentum forces the jet nearer the surface. Of the jet configurations, the oblong, CDS, and CUS configutations exhibited the largest deflections. The results correlate well with film cooling effectiveness data, which suggests a need to determine the jet exit configuration of optimum aspect ratio to provide maximum film cooling effectiveness

Luigi Gussalli - Italian Spaceflight Visionary

The purpose of this paper is to heighten awareness within the space history community of the contributions of Luigi Gussalli, an Italian inventor and spaceflight visionary

Oxidation and protection of fiberglass-epoxy composite masts for photovoltaic arrays in the low Earth orbital environment

Fiberglass-epoxy composites are considered for use as structural members for the mast of the space station solar array panel. The low Earth orbital environment in which space station is to operate is composed mainly of atomic oxygen, which has been shown to cause erosion of many organic materials and some metals. Ground based testing in a plasma asher was performed to determine the extent of degradation of fiberglass-epoxy composites when exposed to a simulated atomic oxygen environment. During exposure, the epoxy at the surface of the composite was oxidized, exposing individual glass fibers which could easily be removed. Several methods of protecting the composite were evaluated in an atomic oxygen environment and with thermal cycling and flexing. The protection techniques evaluated to date include an aluminum braid covering, an indium-tin eutectic and a silicone based paint. The open aluminum braid offered little protection while the CV-1144 coating offered some initial protection against atomic oxygen, but appears to develop cracks which accelerate degradation when flexed. Coatings such as the In-Sn eutectic may provide adequate protection by containing the glass fibers even though mass loss still occurs

Mast material test program (MAMATEP)

The Mast Material Test Program (MAMATEP) at NASA Lewis is discussed. Objectives include verifying the need for, and evaluating the performance of, various protection techniques for the Solar Array Assembly mast of the Space Station Photovoltaic Power Module. Mast material samples were evaluated in terms of mass and bending modulus, measured before and after environmental exposure. Test environments included atomic oxygen exposure (RF plasma asher), thermal cycling, and mechanical flexing. Protective coatings included CV-1144 silicon, a Ni/Au/InSn eutectic, and an open weave, Al braid. Results indicate that unprotected samples degrade in an atomic oxygen environment at a steady rate. Open weave, Al braid offers little protection for the fiberglass-epoxy sample in an asher environment. Ni/Au/InSn eutectic offers excellent protection in an asher environment prior to thermal cycling and mechanical flexing. Long duration asher results from unprotected samples indicate that, even though the fiberglass-epoxy degrades, a protection technique may not be necessary to ensure structural integrity. However, a protection technique may be desirable to limit or contain the amount of debris generated by the degradation of the fiberglass-epoxy

El arte como un espacio de intervención desde la articulación

Durante el proceso socio-histórico del Trabajo Social como profesión, se han ido configurando espacios de intervención desde las problemáticas sociales emergentes, en donde se inclina, mayormente, por el control, asistencia y focalización de las demandas. Por esta razón, es un desafío para nuestro ejercicio profesional, replantear estas formas, lo que implica un proceso de reconocimiento de otros posibles espacios de intervención, como un aporte a los ya legitimados y “gastados" por los asuntos burocráticos e institucionales. Y tanto reflexionar sobre esta situación, surge como tema de esta tesina el “Arte como espacio alternativo de intervención de problemáticas sociales desde la articulación de diversas disciplinas", estableciendo el siguiente objetivo general: “Reflexionar sobre el Arte como un posible espacio pertinente al Trabajo Social, en donde se articulan diferentes disciplinas desde lo social como de lo artístico". Pero ¿por que el pensar el Arte como un posible espacio de intervención? Porque aunque UD no lo crea, el Arte “tiene en si mismo la potencialidad de transformar lo diferente en singular y valioso, de abrir canales para establecer lazos sociales en torno a las producciones de cada sujeto y de estimular procesos de comunicación e intercambio. En este sentido, los proyectos artístico-culturales pueden constituirse en espacios de participación, capaces de promover el desarrollo de la ciudadanía". Partiendo desde este punto se reflexionará sobre: · Conceptualización del Arte y aportes que produce en la intervención de problemáticas sociales. · Posibilidades de encuentro entre el Trabajo Social y el Arte. · Posibles elementos que pueden generar y determinar la elaboración de esta construcción teórica metodológica. · Multidisciplinariedad y sus aportes en el espacio de intervención social. · Capitales que se ponen en juego dentro del trabajo multidisciplinario.Fil: Ciancone, Andrea María. Universidad Nacional de Cuyo. Facultad de Ciencias Políticas y Sociales

Spaceflight Safety on the North Coast of America

Spaceflight Safety (SFS) engineers at NASA Lewis Research Center (LeRC) are responsible for evaluating the microgravity fluids and combustion experiments, payloads and facilities developed at NASA LeRC which are manifested for spaceflight on the Space Shuttle, the Russian space station Mir, and/or the International Space Station (ISS). An ongoing activity at NASA LeRC is the comprehensive training of its SFS engineers through the creation and use of safety tools and processes. Teams of SFS engineers worked on the development of an Internet website (containing a spaceflight safety knowledge database and electronic templates of safety products) and the establishment of a technical peer review process (known as the Safety Assurance for Lewis Spaceflight Activities (SALSA) review)

Challenges and Opportunities of International Cooperation for Safety & Mission Assurance (SMA) on the European Service Module (ESM) of the Orion Program

ESA is providing the ESM to NASA for the Orion Program in accordance with the Implementing Arrangement (IA) established between the two Agencies in 2012. This IA is a barter agreement, in which ESA provides Service Module vehicles for the first two flights of Orion in exchange for two servicing missions to the ISS. This arrangement has provided opportunities and challenges to both communities. It represents an important opportunity for ESA to build on its experience in the development and operations of ATV and play an active role in the development and flight of a manned space vehicle. This paper will explore some of the unique aspects of this arrangement as it affects Safety & Mission Assurance (SMA).The assessment of ESM compliance with applicable safety requirements is the responsibility of the Joint Safety and Engineering Review Panel (JSERP). The JSERP has two features that are relatively unique amongst NASA safety panels. First, NASA Engineering and SMA organizations co-chair this Panel. Previously, Safety has chaired, with Engineering as a member of the Panel. Inclusion of Engineering as a co-chair has offered greater leverage within the technical community. Second, the JSERP includes a second set of co-chairs from ESA Engineering and ESA Product Assurance and Safety (PA/S) organizations. This recognizes the international arrangement as one of partnership.Another source of both opportunity and challenge is the differing experience base of ESA and NASA. NASA has decades of experience in manned spaceflight, dating back to the Mercury program and following through Gemini, Apollo, Apollo-Soyuz, Skylab, Shuttle and the International Space Station. The risk posture for manned missions is much more rigorous than for unmanned missions. ESA brings a wealth of knowledge as well, with their flights of Ariane and Automated Transfer Vehicle (ATV), development and operation of the Columbus module on ISS, and satellite programs. The result is that both parties have developed paradigms related to risk and failure that contribute to ESM discussions.Orion represents humanity's first venture beyond Low-Earth Orbit (LEO) in over fifty years. Much of that experience is captured in program documents, but first-hand knowledge is limited to a few spaceflight veterans. Missions to LEO have offered the opportunity of direct, near-instantaneous communications and assistance, and the ability to return to Earth within a matter of hours in case of emergency. Outward-bound missions do not have these features and will require a more autonomous spacecraft with attendant safety-related issues.This paper will explore these and other challenges as we approach the flight of the first Orion vehicle

Post-hoc motion correction for coronary computed tomography angiography without additional radiation dose - Improved image quality and interpretability for “free”

Objective To evaluate the impact of a motion-correction (MC) algorithm, applicable post-hoc and not dependent on extended padding, on the image quality and interpretability of coronary computed tomography angiography (CCTA). Methods Ninety consecutive patients undergoing CCTA on a latest-generation 256-slice CT device were prospectively included. CCTA was performed with prospective electrocardiogram-triggering and the shortest possible acquisition window (without padding) at 75% of the R-R-interval. All datasets were reconstructed without and with MC of the coronaries. The latter exploits the minimal padding inherent in cardiac CT scans with this device due to data acquisition also during the short time interval needed for the tube to reach target currents and voltage (“free” multiphase). Two blinded readers independently assessed image quality on a 4-point Likert scale for all segments. Results A total of 1,030 coronary segments were evaluated. Application of MC both with automatic and manual coronary centerline tracking resulted in a significant improvement in image quality as compared to the standard reconstruction without MC (mean Likert score 3.67 [3.50;3.81] vs 3.58 [3.40;3.73], P = 0.005, and 3.7 [3.55;3.82] vs 3.58 [3.40;3.73], P < 0.001, respectively). Furthermore, MC significantly reduced the proportion of non-evaluable segments and patients with at least one non-evaluable coronary segment from 2% to as low as 0.3%, and from 14% to as low as 3%. Reduction of motion artifacts was predominantly observed in the right coronary artery. Conclusions A post-hoc device-specific MC algorithm improves image quality and interpretability of prospectively electrocardiogram-triggered CCTA and reduces the proportion of non-evaluable scans without any additional radiation dose exposure

Radiomics for the detection of diffusely impaired myocardial perfusion: A proof-of-concept study using 13N-ammonia positron emission tomography

AIM The current proof-of-concept study investigates the value of radiomic features from normal 13N-ammonia positron emission tomography (PET) myocardial retention images to identify patients with reduced global myocardial flow reserve (MFR). METHODS Data from 100 patients with normal retention 13N-ammonia PET scans were divided into two groups, according to global MFR (i.e., < 2 and ≥ 2), as derived from quantitative PET analysis. We extracted radiomic features from retention images at each of five different gray-level (GL) discretization (8, 16, 32, 64, and 128 bins). Outcome independent and dependent feature selection and subsequent univariate and multivariate analyses was performed to identify image features predicting reduced global MFR. RESULTS A total of 475 radiomic features were extracted per patient. Outcome independent and dependent feature selection resulted in a remainder of 35 features. Discretization at 16 bins (GL16) yielded the highest number of significant predictors of reduced MFR and was chosen for the final analysis. GLRLM_GLNU was the most robust parameter and at a cut-off of 948 yielded an accuracy, sensitivity, specificity, negative and positive predictive value of 67%, 74%, 58%, 64%, and 69%, respectively, to detect diffusely impaired myocardial perfusion. CONCLUSION A single radiomic feature (GLRLM_GLNU) extracted from visually normal 13N-ammonia PET retention images independently predicts reduced global MFR with moderate accuracy. This concept could potentially be applied to other myocardial perfusion imaging modalities based purely on relative distribution patterns to allow for better detection of diffuse disease