REACH最新文献

This year is remarkable for the Chinese space industry, as it marks the 60th anniversary of its establishment, and also coincides with the expiration of the National High-Tech Research and Development Program of China (also widely known as the 863 Program) after three decades. As full participants and the chief scientist of this milestone program for the last decade, we are strongly inspired by the profound role of modern astrodynamics in Chinese space practices. Sharing a common starting point with planetary science, astrodynamics is rooted in the findings of Kepler and Galileo, and its theory was first formulated by Newton. This paper aims to tell the story of the progress and development of astrodynamics in the context of China’s space technology reflected throughout the 30-year-long National Space High-Tech Program: the explosive growth of recent Chinese space missions has been strongly encouraged by the progressing of modern astrodynamics. As the plotline of this article, the milestones of Chinese space flight, most of which were supported by the 863 Program, were collected and organized within the framework of the main achievements in modern astrodynamics, and as it will be demonstrated, these amazing space activities paint a clear picture that can be understood as a part of the great journey of human space exploration.

In recent years, NASA has renewed its focus on manned missions beyond low Earth orbit. These missions will take astronauts to asteroids, the moon, or to Mars. As mission designs become more concrete, it is clear that they will differ from current missions to the International Space Station (ISS) in many ways, including duration, real-time communication with ground, evacuation options, crew rotations, and distance from Earth. These differences will add new challenges to maintaining human health and performance on long-duration exploratory missions (LDEMs). Given the integral nature of teamwork to the success of space missions, differences from current ISS missions will also pose new risk factors to strong team performance over the course of the missions. Factors influencing team performance have previously been identified on past space missions and studies in analogous environments (e.g., submarines, Antarctic research stations). These existing risk factors that affect team performance may be exacerbated on longer space missions in closer quarters, and new risk factors are likely to emerge. Selecting astronauts with the “right stuff” for the new LDEM teams becomes an essential first step in promoting mission success.

With this in mind, the purpose of this review is to identify the critical psychological factors, especially those relevant to functioning in a team-based mission, to consider during the astronaut selection process that may mitigate risk factors and enhance team performance. First, a review of the risk factors that have an identified impact on team performance will serve as context for the critical psychological factors to consider in selection. Second, this review will examine the psychological factors to consider in the selection process to best mitigate the risk factors previously identified. Third, selection methods and measures used to evaluate these psychological factors will be identified. Fourth and finally, we will list recommendations for current operations and future research.

Many features of the space environment cause physical ailments for human explorers, some which are truly unique. For example, the long-term health effects of living and working in a microgravity environment can currently only be experienced in an orbiting spacecraft. Radiation exposure, however, is a significant concern in space but is also an issue in certain terrestrial environments. Despite similarities with terrestrial radiation, space-based radiation is rarely encountered in an Earth environment. In fact, there are only a few locations around the world where space radiation can even be produced for research purposes. Although many long-term studies on the health effects of terrestrial radiation have been performed, there remain significant uncertainties as to whether or not Earth-based radiation can be used as a model for space-based radiation. Some of this uncertainty rests with the limited human-applicable radiation data acquired in space environments beyond Low Earth Orbit. Recent publications documenting radiation measurements from NASA’s Mars Science Laboratory have significantly added to the understanding of estimated total radiation exposure doses during a human Mars mission. Despite the uncertainties regarding these estimates and the use of Earth-based radiation as a model, it is known that there are unquestionable health risks associated with long-term exposure to space radiation including tissue damage, increased cancer risk, acute radiation syndrome, central nervous system defects, and many others. This paper will discuss these health risks, the differences between terrestrial and space radiation, recent knowledge developments regarding space radiation, and also potential countermeasures for protecting future human spaceflight explorers.

This review article highlights the importance of human systems integration (HSI) in human space exploration. One may think of these terms as common sense, some companies even have some regulations in place for something that sounds similar. However, there is still some work to do in order to fully incorporate the human aspect into our aerospace systems, especially today when we are working with complex and multidisciplinary system of systems. For that reason, this article brings the concepts that different programs are using and integrates them, to put into perspective how different disciplines have similar concepts and goals, bringing opportunities for collaboration. Definition of system, system of systems, systems engineering, human systems integration, human error are provided, and how all these come together. Then an assessment is made of various human reliability analysis techniques used in non-aerospace industries, and how they can be applicable to space systems. The use of error prevention HSI tools is discussed, including human in the loop evaluations, usability tests, and workload evaluations. The article dives into the human systems integration domains at the Department of Defense (DoD) and at the National Aeronautics and Space Administration (NASA). A comparison graph was created showing HSI activity across mission lifecycle phases and reviews for a commercial product, the DoD, and NASA, using the SEBoK System Life Cycle Process Model, ISO/IEC/IEEE 15288 Systems and Software Engineering International Standard for System Life Cycle Processes, NRC Human-System Integration in the System Development Process, and the Human Systems Integration Practitioner’s Guide NASA/SP-2015-3709. Learning about these tools and processes will aid the architecting and engineering of habitats, vehicles, and simply put systems for deep space missions, for which human limitations and capabilities must be accounted during the design phase and continue throughout the product lifecycle to help minimize human error, hence increasing human and product safety.

All earth-orbiting spacecraft are susceptible to impacts by orbital debris particles, which can occur at extremely high speeds and can damage flight- and mission-critical systems. The traditional damage mitigating shield design for this threat consists of a “bumper” that is placed at a relatively small distance away from the main “inner wall” of the spacecraft. The performance of a hypervelocity impact shield is typically characterized by its ballistic limit equation, which is typically drawn as a line of demarcation between regions of rear-wall perforation and no perforation; when graphically represented, it is often referred to as a ballistic limit curve. Once developed, these equations and curves can be used to optimize the design of spacecraft wall parameters so that the resulting shields can withstand a wide variety of high-speed impacts by orbital debris. This paper presents some comments and observations on the development of the three-part ballistic limit equation used to predict the response of dual-wall structural systems under hypervelocity projectile impact. The paper concludes with some insights into the limitations of NASA’s current MMOD risk analysis code, and offers several suggestions regarding how it could be modified so that, for example, it could be used as an integral part of a probabilistic risk assessment exercise.

The study of the crew communications with Mission Control Center (MCC) is a standard procedure of remote medical and psychological monitoring of space crews in Federal Space Agency of Russia. The main purpose of this analysis can be considered as obtaining of diagnostic data on the psycho-neurological status affected by space flight factors. The article presents an overview of the results of 20 years investigations of the crew communications with MCC in the series of ground experiments with isolation and confinement, and in the pilot study aboard the International State Station (ISS), as well. The special attention was paid to the evolution of methodological approaches to the study of speech. The main results of the crew communications studies under the effects of space flight factors are presented, the basic phenomena of its dynamics under the conditions of long-term isolation, sensory deprivation, monotony, autonomy and communication delay are considered. The prospects of studying the space crew communications within the frame of onboard experiment “Content” are discussed.

We propose a search for sources of directed energy systems such as those now becoming technologically feasible on Earth. Recent advances in our own abilities allow us to foresee our own capability that will radically change our ability to broadcast our presence. We show that systems of this type have the ability to be detected at vast distances and indeed can be detected across the entire horizon. This profoundly changes the possibilities for searches for extra-terrestrial technology advanced civilizations. We show that even modest searches can be extremely effective at detecting or limiting many civilization classes. We propose a search strategy, using small Earth based telescopes, that will observe more than 10¹² stellar and planetary systems with possible extensions to more than 10²⁰ systems allowing us to test the hypothesis that other similarly or more advanced civilization with this same capability, and are broadcasting, exist. We show that such searches have unity probability of detecting even a single comparably advanced civilization anywhere in our galaxy within a relatively short search time (few years) IF that civilization adopts a simple beacon strategy we call “intelligent targeting”, IF that civilization is beaconing at a wavelength we can detect and IF that civilization left the beacon on long enough for the light to reach us now. In this blind beacon and blind search strategy the civilization does not need to know where we are nor do we need to know where they are. This same basic strategy can be extended to extragalactic distances.

Aircraft parabolic flights provide repetitively periods of reduced gravity whose duration depends on the target reduced gravity level and on the type of aircraft used. Typical durations for a large aircraft varies between approximately 20 s for a 0 g environment and 32 s for a Martian g level environment. This paper presents the European parabolic flights, their objectives, the aircraft presently used and results of some experiments.

In the past 15 years, several group studies have identified the need to validate the role of artificial gravity (AG) as countermeasure to physiological deconditioning during long duration space missions. AG during centrifugation can be adjusted by varying the rotation rate of the vehicle or the distance of the habitat relative to the axis or rotation. These AG parameters have an impact on vehicle design and on human activities associated with the mission. Mission designers are presently reviewing the technologies and habitats necessary to maintain optimal health, safety, and performance of the crewmembers for missions to destinations beyond the Earth–Moon system. New health concerns during space flight have now emerged, such as the Vision Impairment and Intracranial Pressure (VIIP) syndrome, which appears to be caused by prolonged cranial fluid shifts that persist in the presence of currently available countermeasures. The notion of AG research therefore needed to be revisited to consider what role, if any, AG should play in these missions. This paper describes the engineering aspects of human spacecraft providing AG, what is known of the effects of AG on humans, and the research needed to answer the questions raised by mission designers.