Better Commissioning through Simulation: How to Trust your Satellite Pointing Faster

The on-orbit satellite commissioning period serves to incrementally build trust in the orbital asset, from first contact to calibration of specialized payloads

Gary Snyder\u27s idiosyncratic Buddhist poetics and the razoredge .

Gary Snyder\u27s poetry conveys Zen states of consciousness through unconventional grammar and syntax. From his first book Riprap in 1959 to his last collection of poems, Mountains and Rivers Without End in 1996, he has confronted the challenge of transforming Buddhist philosophy and discourse into Western poetics. Snyder\u27s syncretism pertaining to Buddhist and Native American beliefs form a unique view of Zen that suggests his precise involvement with the meditative self-discipline may be unstable and elusive. A close reading of Snyder\u27s idiosyncratic Buddhist poetics reveals an impasse between a non-verbal realm, where the Cartesian duality of subject and object dissolves, and the Western outlook that consciousness can\u27t escape language and thought; Snyder\u27s term razoredge corresponds to this juncture. Viewing his works from a Buddhist perspective, which emphasizes Eastern forms such as haiku and the Zen koan, shows how the disruption of ordinary dualistic thinking potentially improves the aesthetic of nonduality

Bot Contracts

In this Article, we explain why the transactions commonly known as “smart contracts” are better understood as “bot contracts.” Taking an interdisciplinary approach, we show why the “smart contracts” moniker is misdescriptive in two important ways. First, these transactions are automated, not smart. Second, they do not afford parties many enforcement rights and defenses that one expects from common law contractual relationships. To fully understand these transactions, it is important to appreciate how the term “smart contracts” differs from what the technology delivers. Our review of the technology explains that these transactions have tremendous practical utility in reducing risk and avoiding the uncertainty and expense of seeking judicial enforcement. However, the electronic processes that occur in this category are not smart in the sense of being thoughtful, creative, or even amenable to change. They are programmed to follow preset instructions and execute automatically. Once the conditions for performance under a smart contract occur, performance cannot be stopped. Because these transactions are automated, they lack features and defenses available to those who enter into typical contractual relationships. Common law contracts are sets of promises or obligations that may be enforced by a court. However, once a smart contract is set in motion, no person or court can reverse the transaction. In this way, smart contracts differ fundamentally from traditional contracts because they leave no room for judicial intervention. By design, they evade the risk of what a court may do in fashioning a remedy. Courts have no power to set the transaction aside if it was induced by fraud or if another common law defense would, under other circumstances, render the transaction void or voidable. Although the term “smart contract” appears to have taken hold, we propose that these transactions are better thought of as “bot” or “automated” agreements. Reframing these transactions in this way would reset expectations in line with what the technology can deliver. Adopting this more encompassing terminology will send a strong informational signal that avoids misrepresenting the abilities of these agreements by more accurately communicating that they execute automatically and eliminate both the risks and benefits that accompany traditional common law contracts

The Small Isolated Gas-rich Irregular Dwarf (SIGRID) Galaxy Sample: Description and First Results

Using an optically unbiased selection process based on the HIPASS neutral hydrogen survey, we have selected a sample of 83 spatially isolated, gas-rich dwarf galaxies in the southern hemisphere with cz between 350 and 1650kms -1, and with R-band luminosities and H I masses less than that of the Small Magellanic Cloud. The sample is an important population of dwarf galaxies in the local universe, all with ongoing star formation, and most of which have no existing spectroscopic data. We are measuring the chemical abundances of these galaxies, using the integral-field spectrograph on the Australian National University 2.3m telescope, the Wide-Field Spectrograph. This paper describes our survey criteria and procedures, lists the survey sample, and reports on initial observations

Immune Mechanisms of Plaque Instability

Inflammation crucially drives atherosclerosis from disease initiation to the emergence of clinical complications. Targeting pivotal inflammatory pathways without compromising the host defense could compliment therapy with lipid-lowering agents, anti-hypertensive treatment, and lifestyle interventions to address the substantial residual cardiovascular risk that remains beyond classical risk factor control. Detailed understanding of the intricate immune mechanisms that propel plaque instability and disruption is indispensable for the development of novel therapeutic concepts. In this review, we provide an overview on the role of key immune cells in plaque inception and progression, and discuss recently identified maladaptive immune phenomena that contribute to plaque destabilization, including epigenetically programmed trained immunity in myeloid cells, pathogenic conversion of autoreactive regulatory T-cells and expansion of altered leukocytes due to clonal hematopoiesis. From a more global perspective, the article discusses how systemic crises such as acute mental stress or infection abruptly raise plaque vulnerability and summarizes recent advances in understanding the increased cardiovascular risk associated with COVID-19 disease. Stepping outside the box, we highlight the role of gut dysbiosis in atherosclerosis progression and plaque vulnerability. The emerging differential role of the immune system in plaque rupture and plaque erosion as well as the limitations of animal models in studying plaque disruption are reviewed

Cubesat Constellation Design for Air Traffic Monitoring

Suitably equipped global and local air traffic can be tracked. The tracking information may then be used for control from ground-based stations by receiving the Automatic Dependent Surveillance-Broadcast (ADS-B) signal. The ADS-B signal, emitted from the aircraft's Mode-S transponder, is currently tracked by terrestrial based receivers but not over remote oceans or sparsely populated regions such as Alaska or the Pacific Ocean. Lack of real-time aircraft time/location information in remote areas significantly hinders optimal planning and control because bigger "safety bubbles" (lateral and vertical separation) are required around the aircraft until they reach radar-controlled airspace. Moreover, it presents a search-and-rescue bottleneck. Aircraft in distress, e.g. Air France AF449 that crashed in 2009, take days to be located or cannot be located at all, e.g. Malaysia Airlines MH370 in 2014. In this paper, we describe a tool for designing a constellation of small satellites which demonstrates, through high-fidelity modeling based on simulated air traffic data, the value of space-based ADS-B monitoring and provides recommendations for cost-efficient deployment of a constellation of small satellites to increase safety and situational awareness in the currently poorly-served surveillance area of Alaska. Air traffic data has been obtained from the Future ATM Concepts Evaluation Tool (FACET), developed at NASA Ames Research Center, simulated over the Alaskan airspace over a period of one day. The simulation is driven by MATLAB with satellites propagated and coverage calculated using AGI's Satellite ToolKit(STK10)

The Metal-Enriched Outer Disk of NGC 2915

We present optical emission-line spectra for outlying HII regions in the extended neutral gas disk surrounding the blue compact dwarf galaxy NGC 2915. Using a combination of strong-line R23 and direct oxygen abundance measurements, we report a flat, possibly increasing, metallicity gradient out to 1.2 times the Holmberg radius. We find the outer-disk of NGC 2915 to be enriched to a metallicity of 0.4 Z_solar. An analysis of the metal yields shows that the outer disk of NGC 2915 is overabundant for its gas fraction, while the central star-foming core is similarly under-abundant for its gas fraction. Star formation rates derived from very deep ~14 ks GALEX FUV exposures indicate that the low-level of star formation observed at large radii is not sufficient to have produced the measured oxygen abundances at these galactocentric distances. We consider 3 plausible mechanisms that may explain the metal-enriched outer gaseous disk of NGC 2915: radial redistribution of centrally generated metals, strong galactic winds with subsequent fallback, and galaxy accretion. Our results have implications for the physical origin of the mass-metallicity relation for gas-rich dwarf galaxies.Comment: 11 pages, 4 figures, accepted to ApJ April 8th, 201

Paper Session III-C - Earth Dividends From the Development of Space Vehicle Robotics: Technologies and Techniques

This paper identifies and describes advanced robotics technologies and novel applications of state-of-the-art techniques which presently focus on space-related missions but which could result in other dividends on Earth. The paper has three sections. The first section focuses on the development of technology to help NASA automate the reprocessing of low-Earth-orbit vehicles. These advanced technologies include vibration isolation for robot arms and end-effectors, automated handling of fuels and other hazardous materials, and automated safety systems for process control. The second section describes the use of state-of-the-art solid modeling techniques to assist in the design of a robot arm, camera systems, sensors, and platforms for characterizing and exploring a planetary terrain. The third section discusses the use of these advanced technologies and novel applications to provide dividends on Earth in both space- and nonspacerelated applications. Vibration isolation could improve the performance of long manipulator arms used for vehicle processing and cleaning Department of Energy waste tanks. Automated handling of hazardous fluids could help automate the fueling of commercial and passenger vehicles. The advanced safety circuit could enhance many chemical process control operations. Modeling techniques for designing terrain exploration systems could assist the design of vehicles for exploring the many sites on Earth where human entry may be unsafe or inefficient, such as nuclear waste sites, military sites with unexploded ordnance, and widespread geological and agricultural surveys