The expansion of our civilization to the Moon and beyond is now within our reach. This book explores the importance of being a spacefaring nation. It proposes maximizing use of the Moon and shows ...that science and engineering fact are ahead of science fiction.
Space and time are both crucial characteristic dimensions of geographic events and phenomena. Although exploratory spatial data analysis (ESDA) can be used to visualize and summarize complex spatial ...patterns, it has limitations in capturing the temporal dynamics of geographic features. Efforts have been made to incorporate the time dimension into ESDA techniques to detect space-time clustering or trends. Localized space-time statistics that could help in exploratory space-time data analysis (ESTDA), however, are still lacking. Focusing on spatial panel data, our work extended Getis-Ord
and
statistics using a space-time contemporaneous weight matrix and a space-time lagged weight matrix to account for local space-time autocorrelation. Two applications in this article show that the newly developed method can be used to summarize space-time patterns from spatial panel data, identify changes of landscape more consistently, and lend the results readily to visualization.
Free space optical (FSO) communication technology, also known as optical wireless communications, has regained a great interest over the last few years. In some cases, FSO is seen as an alternative ...to existing technologies, such as radio frequency. In other cases, FSO is considered as a strong candidate to complement and integrate with next-generation technologies, such as 5G wireless networks. Accordingly, FSO technology is being widely deployed in various indoor (e.g., data centers), terrestrial (e.g., mobile networks), space (e.g., inter-satellite and deep space communication), and underwater systems (e.g., underwater sensing). As the application portfolio of FSO technology grows, so does the need for a clear classification for FSO link configurations. Most existing surveys and classifications are single-level classifications, and thus not inclusive enough to accommodate recent and emerging changes and developments of different FSO link configurations and systems. In this paper, we propose a multi-level classification framework to classify existing and future indoor, terrestrial, space, underwater, and heterogenous FSO links and systems using common and simple unified notation. We use the proposed classification to review and summarize major experimental work and systems in the area until 2017. Using the proposed classification and survey, we aim to give researchers a jump-start to tap into the growing and expanding realm of the FSO technology in different environments. The proposed classification can also help organize and systematically present the progress in the research on FSO technology. This makes the identification of the market needs for standards an easier task. Moreover, different entities involved in the standardization process including academic, industry, and regulatory organizations can use the proposed classification as a unified language to communicate during the early stages of standard development which require ambiguity-free discussions and exchange of ideas between different standardization entities. We use the proposed classification to review existing standards and recommendations in the field of FSO. It is also envisioned that the proposed classification can be used as a unified framework to define different FSO channel models for simulation tools.
INTRODUCTION: In the 1990s, Canada, member states of the European Space Agency, Japan, the Russian Federation, and the United States entered into an international agreement Concerning Cooperation on ...the Civil International Space Station. Among the many unique infrastructure challenges,
partners were to develop a comprehensive international medical system and related processes to enable crew medical certification and medical support for all phases of missions, in a framework to support a multilateral space program of unprecedented size, scope, and degree of integration. During
the Shuttle/Mir Program, physicians and specialized experts from the United States and Russia studied prototype systems and developed and operated collaborative mechanisms. The 1998 NASA Memoranda of Understanding with each of the other four partners established the Multilateral Medial Policy
Board, the Multilateral Space Medicine Board, and the Multilateral Medical Operations Panel as medical authority bodies to ensure International Space Station (ISS) crew health and performance. Since 1998, the medical system of the ISS Program has ensured health and excellent performance of
the international crewsan essential prerequisite for the construction and operation of the ISSand prevented mission-impacting medical events and adverse health outcomes. As the ISS is completing its second decade of crewed operation, it is prudent to appraise its established medical framework
for its utility moving forward in new space exploration initiatives. Not only the ISS Program participants, but other nations and space agencies as well, concomitant with commercial endeavors in human spaceflight, can benefit from this evidence for future human exploration programs.Doarn
CR, Polk JD, Grigoriev A, Comtois J-M, Shimada K, Weerts G, Dervay JP, Taddeo TA, Sargsyan A. A framework for multinational medical support for the International Space Station: a model for exploration. Aerosp Med Hum Perform. 2021; 92(2):129134.
If you have ever wondered about space travel, now you have the opportunity to understand it more fully than ever before. Traveling into space and even emigrating to nearby worlds may soon become part ...of the human experience. Scientists, engineers, and investors are working hard to make space tourism and colonization a reality. As astronauts can attest, extraterrestrial travel is incomparably thrilling. To make the most of the experience requires serious physical and mental adaptations in virtually every aspect of life, from eating to intimacy. Everyone who goes into space sees Earth and life on it from a profoundly different perspective than they had before liftoff. Astronomer and former NASA/ASEE scientist Neil F. Comins has written the go-to book for anyone interested in space exploration. He describes the wonders that travelers will encounter—weightlessness, unparalleled views of Earth and the cosmos, and the opportunity to walk on another world—as well as the dangers: radiation, projectiles, unbreathable atmospheres, and potential equipment failures. He also provides insights into specific trips to destinations including suborbital flights, space stations, the Moon, asteroids, comets, and Mars—the top candidate for colonization. Although many challenges are technical, Comins outlines them in clear language for all readers. He synthesizes key issues and cutting-edge research in astronomy, physics, biology, psychology, and sociology to create a complete manual for the ultimate voyage.
The Sun’s outer atmosphere is heated to temperatures of millions of degrees, and solar plasma flows out into interplanetary space at supersonic speeds. This paper reviews our current understanding of ...these interrelated problems: coronal heating and the acceleration of the ambient solar wind. We also discuss where the community stands in its ability to forecast how variations in the solar wind (i.e., fast and slow wind streams) impact the Earth. Although the last few decades have seen significant progress in observations and modeling, we still do not have a complete understanding of the relevant physical processes, nor do we have a quantitatively precise census of which coronal structures contribute to specific types of solar wind. Fast streams are known to be connected to the central regions of large coronal holes. Slow streams, however, appear to come from a wide range of sources, including streamers, pseudostreamers, coronal loops, active regions, and coronal hole boundaries. Complicating our understanding even more is the fact that processes such as turbulence, stream-stream interactions, and Coulomb collisions can make it difficult to unambiguously map a parcel measured at 1 AU back down to its coronal source. We also review recent progress—in theoretical modeling, observational data analysis, and forecasting techniques that sit at the interface between data and theory—that gives us hope that the above problems are indeed solvable.
The new computer program SHELXT employs a novel dual‐space algorithm to solve the phase problem for single‐crystal reflection data expanded to the space group P1. Missing data are taken into account ...and the resolution extended if necessary. All space groups in the specified Laue group are tested to find which are consistent with the P1 phases. After applying the resulting origin shifts and space‐group symmetry, the solutions are subject to further dual‐space recycling followed by a peak search and summation of the electron density around each peak. Elements are assigned to give the best fit to the integrated peak densities and if necessary additional elements are considered. An isotropic refinement is followed for non‐centrosymmetric space groups by the calculation of a Flack parameter and, if appropriate, inversion of the structure. The structure is assembled to maximize its connectivity and centred optimally in the unit cell. SHELXT has already solved many thousand structures with a high success rate, and is optimized for multiprocessor computers. It is, however, unsuitable for severely disordered and twinned structures because it is based on the assumption that the structure consists of atoms.
Progress in spaceflight research has led to the introduction of various manned and unmanned reusable space vehicle concepts, opening up uncharted opportunities for the newborn space transport ...industry. For future space transport operations to be technically and commercially viable, it is critical that an acceptable level of safety is provided, requiring the development of novel mission planning and decision support tools that utilize advanced Communication, Navigation and Surveillance (CNS) technologies, and allowing a seamless integration of space operations in the current Air Traffic Management (ATM) network. A review of emerging platform operational concepts is conducted, highlighting both the challenges and the opportunities brought in by the integration with conventional atmospheric air transport. Common launch and re-entry planning methodologies are then discussed, where the physical and computational limitations of these approaches are identified and applicability to future commercial space transport operations is assessed. Attention is then turned to the on-orbit phase, where the unique hazards of the space environment are examined, followed by an overview to the necessary elements required for space object de-confliction and collision avoidance modelling. The regulatory framework evolutions required for spacecraft operations are then discussed, with a focus on space debris mitigation strategies and operational risk assessment. Within the atmospheric domain, possible extensions and alternatives to the conventional airspace segregation approaches are identified including promising Air Traffic Flow Management (ATFM) techniques to facilitate the integration of new-entrant platforms. Lastly, recent modelling approaches to meet on-orbit risk criteria are discussed and evolutionary requirements to improve current operational procedures are identified. These insights will inform future research on CNS/ATM and Avionics (CNS + A) systems and associated cyber-physical architectures for Space Traffic Management (STM).
From Space debris to asteroid strikes to anti-satellite weapons, humanity's rapid expansion into Space raises major environmental, safety, and security challenges. In this book, Michael Byers and ...Aaron Boley, an international lawyer and an astrophysicist, identify and interrogate these challenges and propose actionable solutions. They explore essential questions from, 'How do we ensure all of humanity benefits from the development of Space, and not just the world's richest people?' to 'Is it possible to avoid war in Space?' Byers and Boley explain the essential aspects of Space science, international law, and global governance in a fully transdisciplinary and highly accessible way. Addressing the latest and emerging developments in Space, they equip readers with the knowledge and tools to engage in current and critically important legal, policy, and scientific debates concerning the future development of Space. This title is also available as Open Access on Cambridge Core.
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