Spacecraft crew procedures from paper to computers

Described here is a research project that uses human factors and computer systems knowledge to explore and help guide the design and creation of an effective Human-Computer Interface (HCI) for spacecraft crew procedures. By having a computer system behind the user interface, it is possible to have increased procedure automation, related system monitoring, and personalized annotation and help facilities. The research project includes the development of computer-based procedure system HCI prototypes and a testbed for experiments that measure the effectiveness of HCI alternatives in order to make design recommendations. The testbed will include a system for procedure authoring, editing, training, and execution. Progress on developing HCI prototypes for a middeck experiment performed on Space Shuttle Mission STS-34 and for upcoming medical experiments are discussed. The status of the experimental testbed is also discussed

The JPL Phase B interferometer testbed

Future NASA missions with large optical systems will require alignment stability at the nanometer level. However, design studies indicate that vibration resulting from on-board disturbances can cause jitter at levels three to four orders of magnitude greater than this. Feasibility studies have shown that a combination of three distinct control layers will be required for these missions, including disturbance isolation, active and passive structural vibration suppression, and active optical pathlength compensation. The CSI technology challenge is to develop these design and control approaches that can reduce vibrations in the optical train by a factor of 1000 to 10,000. The focus of the paper is on describing the Phase B Testbed structure and facility, as the experimental results are included in other papers presented at this same conference

Robotic planner expert system (RPLANES)

The Artificial Intelligence Section of the Mission Planning and Analysis of the Johnson Space Center has developed a prototype of an expert system for robotic planning. A robot is given a high level goal to perform an action (i.e., swap, adjust, or stow) on a component unit of an object such as a satellite and the Robotic Planner Expert System (RPLANES) generates the necessary goals for arm actions. RPLANES is designed using the Inference Corp. Automated Reasoning Tool (ART) development tool. It resides on a SYMBOLICS 3670. RPLANES and its evolution are described

Long Duration Exposure Facility: A general overview

The Long Duration Exposure Facility (LDEF) is a large, low-cost, reusable, unmanned, free-flying spacecraft which accommodates technology, science, and applications experiments for long-term exposure to the space environment. The LDEF was designed and built by the NASA Langley Research Center (LaRC) for NASA's Office of Aeronautics and Space Technology. Specifically, the LDEF was designed to transport experiments into space via the Space Shuttle, to free fly in Earth orbit for an extended period, and be retrieved on a later Space Shuttle flight allowing experiments to be returned to Earth for postflight analysis in the laboratory. The LDEF with a full complement of experiments was placed in Earth orbit in April 1984 by Challenger and retrieved from orbit in January 1990 by Columbia. A general overview of the LDEF, its mission, systems, experiments, and operations is presented. Excerpts from various NASA documents are extensively used

Investigation of fuselage acoustic treatment for a twin-engine turboprop aircraft in flight and laboratory tests

A flight and laboratory study of sidewall acoustic treatment for cabin noise control is described. In flight, cabin noise levels were measured at six locations with three treatment configurations. Noise levels from narrow-band analysis are reduced to one-third octave format and used to calculate insertion loss, IL, defined as the reduction of interior noise associated with the addition of a treatment. Laboratory tests used a specially constructed structural panel modeled after the propeller plane section of the aircraft sidewall, and acoustic treatments representing those used in flight. Lab measured transmission loss and absorption values were combined using classical acoustic procedures to obtain a prediction of IL. Comparison with IL values measured in flight for the boundary layer component of the noise indicated general agreement

Increased Coronary Artery Disease Severity in Black Women Undergoing Coronary Bypass Surgery

Race and sex disparities are believed to play an important role in heart disease. The purpose of this study was to examine the association between race, sex, and number of diseased vessels at the time of coronary artery bypass grafting (CABG), and subsequent postoperative outcomes. The 13,774 patients undergoing first-time, isolated CABG between 1992 and 2011 were included. Trend in the number of diseased vessels between black and white patients, stratified by sex, were analyzed using a Cochran-Armitage trend test. Models were adjusted for age, procedural status (elective vs. nonelective), and payor type (private vs. nonprivate insurance). Black female CABG patients presented with an increasingly greater number of diseased vessels than white female CABG patients (adjusted P(trend) = 0.0021). A similar trend was not observed between black and white male CABG patients (adjusted P(trend) = 0.18). Black female CABG patients were also more likely to have longer intensive care unit and hospital lengths of stay than other race-sex groups.Our findings suggest that black female CABG patients have more advanced coronary artery disease than white female CABG patients. Further research is needed to determine the benefit of targeted preventive care and preoperative workup for this high-risk group

Study on effects of powder and flake chemistry and morphology on the properties of Al-Cu-Mg-X-X-X powder metallurgy advanced aluminum alloys

The effects of alloy chemistry and particulate morphology on consolidation behavior and consolidated product properties in rapid solidification processed, powder-metallurgical Al-3Li-1.5Cu-1Mg-0.5Co-0.2Zr and Al-4.4Cu-1.5Mg-Fe-Ni-0.2Zr extrusions and forgings were studied. Microstructures and mechanical properties of both alloys are largely unaffected by particulate production method (vacuum atomization, ultrasonic atomization, or twin-roller quenching) and by particulate solidification rates between 1000 and 100,000 K/s. Consolidation processing by canning, cold compaction, degassing, and hot extrusion is sufficient to yield mechanical properties in the non-Li-containing alloy extrusions which are similar to those of 7075-Al, but ductilities and fracture toughnesses are inferior owing to poor interparticle bonding caused by lack of a vacuum-hot-pressing step during consolidation. Mechanical properties of extrusions are superior to those of forgings owing to the stronger textures produced by the more severe hot working during extrusion. The effects on mechanical properties of dispersoid size and volume fraction, substructural refinement, solid solution strengthening by Mg, and precipitate size and distribution are elucidated for both alloy types

The Effects of the Security Environment on Military Expenditures: Pooled Analyses of 165 Countries, 1950-2000

Countries' military expenditures differ greatly across both space and time. This study examines the determinants of military spending, with particular reference to the importance of the external security environment. Using the liberal-realist model of international relations, we first estimate the probability that two countries will be involved in a fatal militarized interstate dispute. We then aggregate these ex ante estimates of the likelihood of dyadic conflict, calculating the annual joint probability that a country will be involved in a fatal dispute. This is our measure of the external threat. We then estimate the level of military spending by country and year as a function of the security environment, arms races with foes and the defense expenditures of friendly countries, states' involvement in actual military conflict, economic output, and various other political variables. In analyses of a panel of 165 countries, 1950 to 2000, we find that the security environment is a powerful determinant of military spending. Indeed, our prospectively measured estimate of the external threat is more influential than any of several influences known only ex post. Our best estimate is that a one percentage point rise in the probability of a fatal dispute leads to a 3 percent increase in military spending.Military spending, Security threat, Arms race, Militarized disputes, Democracy, Alliances

The effect of foreign investment on economic development and income inequality

In this paper, we assess the effect of globalization on the distribution of income within countries, focussing on the influence of foreign direct investment. We analyze data for 72 countries, 1970-90. We incorporate in our tests the Kuznets (1955) curve, measures of the character of political institutions, and various aspects of the economy and society that have been emphasized in recent research. Our results are easy to summarize. Globalization has little effect on income inequality within countries. The ratio of foreign direct investment stock to gross domestic product is unrelated to the distribution of income. Income inequality in developing and developed countries is unaffected by the presence of multinational corporations. Nor are alternative measures of economic openness - the trade-to-GDP ratio and Sachs and Warner's (1995) measure of free trade policy - associated with greater inequality. The share of income received by the poorest 20% of society in particular is not influenced by the economic importance of foreign investment. If foreign investment increases average incomes in developing countries, as we confirm here, and does not affect the distribution of income, it must benefit all segments of society in developing countries

Effect of microgravity on several visual functions during STS shuttle missions

Changes in the acuity of astronaut vision during flight are discussed. Parameters such as critical flicker vision, stereopsis to 10 seconds of arc, visual acuity in small steps to 20/7.7, cyclophoria, lateral and vertical phoria and retinal rivalry were tested using a visual function tester. Twenty-three Space Transportation System (STS) astronauts participated in the experiments. Their vision was assessed twice before launch and after landing, and three to four times while on-orbit and landing. No significant differences during space flight were observed for any of the visual parameters tested. In some cases, slight changes in acuity and stereopsis were observed with a subsequent return to normal vision after flight