27 research outputs found

    Target evaluation and low-thrust trajectory planning for near-Earth asteroid mining

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    Near-Earth Asteroids (NEAs) are abundant with minerals that would be undoubtedly beneficial for future space exploration, as the utilization of these in-space resources could enable otherwise unaffordable missions. This thesis aims to address several remaining issues in asteroid mining mission planning, including target selection and ranking, multi-return low thrust trajectory design, NEA mining season determination, asteroid mining campaign designs, and other considerations. This study starts with a comprehensive asteroid resource investigation and an impulsive roundtrip accessibility analysis for the known 29,266 NEAs and 46% of them are found accessible. By combining the two studies, a NEA resource map is created, providing key knowledge of resource locations, types, reserves, and minimum delta-V requirements to retrieve the resources. Mining missions are then preliminarily constructed using impulsive trajectories for 13,481 NEAs, and a series of Figures of Merit (FoMs) are proposed. In total, over 900 accessible and known targets for mining water, Platinum Group Metals (PGMs) and silicates are ranked. Low-thrust mining missions are then studied. New Deep Neural Network (DNN) based models are constructed as the surrogate of the conventional optimization process. The new method reduces by 99.94% the low-thrust trajectory design time. Typical Solar Electric Propulsion (SEP) spacecraft configurations are used to design trajectories for supply delivery and resource transportation. The transportation capabilities of different spacecraft configurations are quantified. An asteroid mining campaign design framework is proposed, which integrates all the developed models, algorithms, and asteroid data. An example mining campaign on Bennu is presented, and an economic analysis is performed. The sensitivity analysis shows the low thrust mining missions are more resistant to changing economic parameters. Campaigns are then numerically designed and optimized for 76 known water-bearing and 58 potential PGM-bearing targets, using both impulsive and low thrust trajectories. The “NEA mining season”, which was an abstract concept, is validated. The mining seasons are categorized into three major types based on their feasibility for mining. Two 35-year water mining and PGM mining plans are generated. It is found the current known targets can form a 21,000billionPGMminingindustryanda21,000 billion PGM mining industry and a 13,000 billion water mining industry. It is found that low thrust-based mining is the key to a successful mining campaign, and that it may increase the profit by 2.8 ~ 8.7 times

    Cyber Law and Espionage Law as Communicating Vessels

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    Professor Lubin\u27s contribution is Cyber Law and Espionage Law as Communicating Vessels, pp. 203-225. Existing legal literature would have us assume that espionage operations and “below-the-threshold” cyber operations are doctrinally distinct. Whereas one is subject to the scant, amorphous, and under-developed legal framework of espionage law, the other is subject to an emerging, ever-evolving body of legal rules, known cumulatively as cyber law. This dichotomy, however, is erroneous and misleading. In practice, espionage and cyber law function as communicating vessels, and so are better conceived as two elements of a complex system, Information Warfare (IW). This paper therefore first draws attention to the similarities between the practices – the fact that the actors, technologies, and targets are interchangeable, as are the knee-jerk legal reactions of the international community. In light of the convergence between peacetime Low-Intensity Cyber Operations (LICOs) and peacetime Espionage Operations (EOs) the two should be subjected to a single regulatory framework, one which recognizes the role intelligence plays in our public world order and which adopts a contextual and consequential method of inquiry. The paper proceeds in the following order: Part 2 provides a descriptive account of the unique symbiotic relationship between espionage and cyber law, and further explains the reasons for this dynamic. Part 3 places the discussion surrounding this relationship within the broader discourse on IW, making the claim that the convergence between EOs and LICOs, as described in Part 2, could further be explained by an even larger convergence across all the various elements of the informational environment. Parts 2 and 3 then serve as the backdrop for Part 4, which details the attempt of the drafters of the Tallinn Manual 2.0 to compartmentalize espionage law and cyber law, and the deficits of their approach. The paper concludes by proposing an alternative holistic understanding of espionage law, grounded in general principles of law, which is more practically transferable to the cyber realmhttps://www.repository.law.indiana.edu/facbooks/1220/thumbnail.jp

    Shielding Strategies for Human Space Exploration

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    A group of twenty-nine scientists and engineers convened a 'Workshop on Shielding Strategies for Human Space Exploration' at the Lyndon B. Johnson Space Center in Houston, Texas. The provision of shielding for a Mars mission or a Lunar base from the hazards of space radiations is a critical technology since astronaut radiation safety depends on it and shielding safety factors to control risk uncertainty appear to be great. The purpose of the workshop was to define requirements for the development and evaluation of high performance shield materials and designs and to develop ideas regarding approaches to radiation shielding. The workshop was organized to review the recent experience on shielding strategies gained in studies of the 'Space Exploration Initiative (SEI),' to review the current knowledge base for making shield assessment, to examine a basis for new shielding strategies, and to recommend a strategy for developing the required technologies for a return to the moon or for Mars exploration. The uniqueness of the current workshop arises from the expected long duration of the missions without the protective cover of the geomagnetic field in which the usually small and even neglected effects of the galactic cosmic rays (GCR) can no longer be ignored. It is the peculiarity of these radiations for which the inter-action physics and biological action are yet to be fully understood

    Social work with airports passengers

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    Social work at the airport is in to offer to passengers social services. The main methodological position is that people are under stress, which characterized by a particular set of characteristics in appearance and behavior. In such circumstances passenger attracts in his actions some attention. Only person whom he trusts can help him with the documents or psychologically

    The Final Proceedings of the DOE/NASA Solar Power Satellite Program Review

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    The solar power satellite (SPS) concept defined as 'placing gigantic satellites in geosynchronous orbit to capture sunlight, changing the energy into an appropriate form for transmission to Earth, and introducing the energy into the electric power grid' is evaluated in terms of costs and benefits. The concept development and evaluation program is reviewed in four general areas: systems definition; environmental; societal; and comparative assessments. Specific factors addressed include: transportation, construction in space, methods of conversion of sunlight into energy, transmission to Earth, maintenance in orbit and decommissioning of satellites; environmental, political, and economic effects; and comparison of SPS to other forms of power generation, both terrestrial and in space

    Applications of Monte Carlo Methods in Biology, Medicine and Other Fields of Science

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    This volume is an eclectic mix of applications of Monte Carlo methods in many fields of research should not be surprising, because of the ubiquitous use of these methods in many fields of human endeavor. In an attempt to focus attention on a manageable set of applications, the main thrust of this book is to emphasize applications of Monte Carlo simulation methods in biology and medicine

    Deep space communication and navigation study. Volume 2 - Communication technology Final report

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    Alternative types of communication systems for deep space probes and extent of aid spacecraft can provide for deep space navigatio
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