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With the rapid development of space technology and the exponential growth of data generated by a large number of space satellite equipment every day, these huge spatio-temporal data have the characteristics of complex information, heterogeneous, real-time receiving and receiving, scattered storage and long storage period. Based on this situation, spatio-temporal data networks are facing the severe challenges of confusion and complexity of data management and uncertainties in network topology structure. Therefore, it is very important to manage spatio-temporal data effectively and to solve the problem of topological change caused by node movement in spatio-temporal data network. In this paper, we will construct the network of spatio-temporal data based on the improved Tyson polygon topology algorithm. In the construction, we mainly use Hadoop architecture as the processing architecture of massive spatial large data. At the same time, we construct the cluster structure of the network based on the improved Tyson polygon theory, and creatively propose a hierarchical spatio-temporal data network architecture. In the last part of the experiment, a number of experiments are carried out to verify and analyze the proposed architecture. The experimental results show that the proposed architecture and algorithm have obvious advantages in the management of spatio-temporal large data network and in solving the problem of network topology change. [ABSTRACT FROM AUTHOR]

This paper proposes a parallel computing analysis model HPM and analyzes the parallel architecture of CPU–GPU based on this model. On this basis, we study the parallel optimization of the ray-tracing algorithm on the CPU–GPU parallel architecture and give full play to the parallelism between nodes, the parallelism of the multi-core CPU inside the node, and the parallelism of the GPU, which improve the calculation speed of the ray-tracing algorithm. This paper uses the space division technology to divide the ground data, constructs the KD-tree organization structure, and improves the construction method of KD-tree to reduce the time complexity of the algorithm. The ground data is evenly distributed to each computing node, and the computing nodes use a combination of CPU–GPU for parallel optimization. This method dramatically improves the drawing speed while ensuring the image quality and provides an effective means for quickly generating photorealistic images. [ABSTRACT FROM AUTHOR]

Modern astronautics problems require methods of tractable uncertainty quantification for problems with data in a variety of mathematical spaces. Polynomial Chaos Expansions (PCEs) enable tractable uncertainty propagation, sensitivity analysis, and provide a surrogate model to efficiently solve stochastic optimization problems. Existing PCE methods are mostly isolated to bases defined via tensor products of univariate functions over subdomains of the real line or integers. The goal of this work is to incorporate random vectors on the n-dimensional sphere, thereby extending the use of PCEs to problems that include spacecraft attitude uncertainty. Random inputs with probability densities on the n-sphere are generally correlated. When directional random inputs are independent, products of univariate functions fail to produce an orthogonal basis. Basis functions must preserve the periodic response of the system produced by the underlying structure of the domain. This paper presents an approach to generating an orthogonal basis with respect to a density function on the n-sphere by combining hyperspherical harmonics with an orthogonalization procedure based on the raw moments of the harmonic functions. For highly concentrated densities on the unit sphere, the spherical cap harmonics provide a more numerically stable solution while preserving periodicity. Numeric errors in the proposed procedure are presented for multiple cases. Performance of the PCEs is quantified when propagating uncertainty for a highly eccentric orbit with a random translational maneuver error, and a second case based on rigid-body dynamics with the attitude state parameterized as a quaternion. [ABSTRACT FROM AUTHOR]

Recent research on space technology applications has revealed a growing demand for deployable structures with large apertures. Numerous deployable structures that can form a single closed loop have been developed with a total weight limitation. The main purpose of this paper is to present an equivalent parameterized mechanical modeling method that is appropriate for an annular tensegrity structure, which is a tensioned structure that is intended for antenna applications with an aperture range of 30–100 m. In this model, the solutions of geometrically nonlinear problems for the cables and beams of the hoop are presented. Both the kinetic energy and potential energy are identified, which are represented by the velocity of the node component and strain component, respectively, of the beam members in the hoop unit of the parameterized hoop structure. Then, the behaviors of the eigenvalues and vibration modes for this tensegrity structure based on dynamic analysis are also investigated. Additionally, the effect on dynamic performance is demonstrated when the structural parameters are changed. The sensitivity of the structural parameters to dynamic characteristics is separately analyzed. The priority approaches to improving the overall stiffness of the structure when employing different hoop configurations are proposed. [ABSTRACT FROM AUTHOR]

Based on a historical case study, this contribution develops a framework for studying the industrial dynamics of complex products and systems (CoPS). The case study focuses on the spacecraft industry from 1957 to 2011. It is suggested that the main drivers of the dynamics of this typical CoPS industry are changes in long-term demand behavior. The main hypothesis formulated in this contribution states that customers' purchasing policies are underpinned by a set of heterogeneous motives (i.e., defense and security, political prestige, science and technology, macroeconomic benefits and profit-seeking) that evolve over time in response to changes in contextual variables. Within this framework, the paper examines the long-term relationships between customer motives on the one hand and the size (i.e., number of spacecraft launched) and segmentation (i.e., application domains of space technology) of the spacecraft market on the other hand. It shows that the dynamics of spacecraft industry resides on changes affecting customers' motives, the latter behaving as lead users of a particular type. Indeed, customers are organizations and institutions which contribution to technological development goes far beyond bringing technical and non-technical, market-oriented, knowledge and competencies through collaboration with firms. In doing so, the paper proposes a conceptual framework based on the characterization of customer motives to study how demand behaviors affect the dynamics of CoPS industries. [ABSTRACT FROM AUTHOR]

Abstract—The paper covers historical events related to the launch of the Luna-10 automated interplanetary station in 1966, which for the first time in the world became an artificial satellite of the Moon and performed a number of scientific studies and made discoveries in global astronautics. [ABSTRACT FROM AUTHOR]

Psychological support to the crew is crucial for space mission accomplishment and cosmonauts' professional longevity. In advance of remote space exploration missions we need to sum up and organize the accumulated experience of psychological support at the current stage of astronautic development. The paper gives a retrospect of the psychological support to space crews of piloted space systems/vehicles and highlights its basic goals and methods. [ABSTRACT FROM AUTHOR]

PM2.5 is a bad output of China's improved industrialization and rapid economic development, which seriously threatens people's health and greatly hinders the sustainable economic development. Studying the socio-economic driving factors of PM2.5 emissions is of great significance for reducing air pollution and realizing green development. Therefore, based on the simultaneous consideration of space technology differences and time technology progress, this paper constructs an index decomposition analysis-production-theoretical decomposition analysis decomposition model under the global meta-frontier-production theory. Then, we decompose the PM2.5 emission concentration of 30 provinces in China from 2005 to 2018 into nine driving factors and discuss the impact of different factors from the national, regional, and provincial levels. The results reveal that economic activity is still the main factor to promote the increase of PM2.5 emission, but its effect decreases, while the inhibitory effect of catch-up effect on PM2.5 concentration increases gradually. In addition, economic activities have the greatest impact on the East China, while the time catch-up effect has a more significant impact on the Central and Western China. Moreover, the influence of energy intensity effect, space technology catch-up effect, and time technology catch-up effect is gradually increasing, which have become important factors to inhibit the PM2.5 emission. Based on the above results, we put forward relevant policy suggestions. [ABSTRACT FROM AUTHOR]

The paper investigates the evolution of the first manned international space mission – a rendezvous and docking between a US and a Soviet spacecraft in 1975 known as the Apollo-Soyuz Test Project (ASTP). The aim is to reconsider the rationales behind the ASTP from both a conceptual and an empirical perspective in order to get a better understanding of the evolution of international cooperation in the highly competitive and strategic field of space technology. Based on archival sources from Moscow, it sheds some light on those factors that led to a change in the previous reluctance of Soviets to cooperate with the US in the manned spaceflight. From the theoretical point of view, it argues that the ASTP was as much a tool of competition as one of cooperation and resulted from an interplay between cooperative and competitive logics. To explain the turn towards cooperative practices, the article looks at the complex constellation of competitive relations that existed within the national and international context of space exploration and changed in the late 1960s and early 1970s. The decisive role in those changes was played by factors that can be subsumed under the notion of the so-called "third." [ABSTRACT FROM AUTHOR]

Abstract—The paper analyzes the Russian scientific and technological capabilities to manufacture a space-borne observation platform for high-precision monitoring of the Earth's gravitational field. It is shown that some Russian space systems manufacturing technologies may well be used for this purpose; however, in general, the level of the domestic technologies must be substantially improved so as to meet stringent requirements of such a project. Nevertheless, it can be confidently stated that it is quite feasible to carry out this project using Russian technologies. [ABSTRACT FROM AUTHOR]

A review of the latest journal and book publications on the problems of technogenic clogging of near-Earth space and methods for solving them is carried out. Based on the results of publications, we analyze international standards, present space debris classification, analyze the main sources of space debris formation and methods for clearing debris from space, estimate the evolution of technogenic clogging of low-Earth orbits, and the implementation of the process of removing space debris. The papers for modeling space technology systems designed for recording and evaluating fluxes of space debris in spacecraft orbits are analyzed. [ABSTRACT FROM AUTHOR]

A powerful set of projections has constructed post-apartheid higher education in South Africa. Among these is the expectation that technikons (institutions similar to the British polytechnics) would become universities of technology, with a mission to drive the technology of national reconstruction and development. In this paper, one of the new universities of technology serves as a case study to explore organizational structure and to highlight the ethics of university management and leadership. Building a new university provides the opportunity to place ethics "upfront", rather than as an afterthought, by constructing an organizational framework that makes ethical issues integral to management and decision-making processes. In imagining the structure of a university of technology, the authors were inspired by future scripting methods developed by Bastiaan De Laat, and by Duncan Den Boer, Arie Rip and Sandra Speller. The research process firstly involved the identification of themes related to values and ethics through an analysis of the environment. These themes were incorporated into three scenarios of possible futures for this new university type. Using these scenarios, the ethical issues that emerged (according to how the university of technology might choose to organise itself), are compared with the original themes. Conclusions are then drawn with regard to management structures that are hierarchical and entrench compliance, or that are traditionally collegiate and expertise-based, or that might enable mutual appreciation and allow for leaders to emerge within any functional space at a university of technology. [ABSTRACT FROM AUTHOR]

This paper illustrates an indirect method to optimize multiple-impulse trajectories from circular lunar orbit to Earth. Optimization is performed in the circular restricted three-body problem, and the necessary optimality conditions are found through optimal control theory. In order to overcome the difficulty of initial adjoints estimation, a homotopic approach, which is based on an auxiliary optimization problem with known solution, is developed; this approach proves to be robust and efficient. Examples are presented for a range of lunar orbit orientations to assess the impact on velocity impulse requirements. Optimization results for trajectories with different number of impulses are also compared. The developed procedure can support fast and accurate evaluation of the transfer costs for Moon-to-Earth trajectories both in nominal conditions and for contingency plans. [ABSTRACT FROM AUTHOR]

The zero-propellant maneuver is an advanced concept of the spacecraft attitude control. The problem of zero-propellant maneuver using single gimbal control moment gyroscopes is researched in this paper. The saturation and singularity problems of single gimbal control moment gyroscopes are analyzed, and the performance indexes to measure saturation and singularity are proposed. The path planning model considering the gimbal steering law is established using modified rodrigues parameter. Then, a hybrid approach combining the pseudospectral method and direct shooting method is proposed to solve the nonlinear path planning problem with complicated constraints. Finally, the numerical simulation is executed to validate the effectiveness of the proposed method. It is shown that an optimized attitude maneuver path satisfying the saturation and singularity constraints can be obtained and the zero-propellant maneuver using single gimbal control moment gyroscopes can be successfully achieved. [ABSTRACT FROM AUTHOR]

The X-ray Telescope (XRT) of the Hinode mission provides an unprecedented combination of spatial and temporal resolution in solar coronal studies. The high sensitivity and broad dynamic range of XRT, coupled with the spacecraft’s onboard memory capacity and the planned downlink capability will permit a broad range of coronal studies over an extended period of time, for targets ranging from quiet Sun to X-flares. This paper discusses in detail the design, calibration, and measured performance of the XRT instrument up to the focal plane. The CCD camera and data handling are discussed separately in a companion paper. [ABSTRACT FROM AUTHOR]

Numerous papers are devoted to studying the motion of a system (coupling) of two bodies in the Earth’s satellite orbit ([1–4] and others). The problem on the planar inertial motion of three bodies, coupled by a non-extensible weightless string having the form of an unfastened chain, is considered in the paper. Such a configuration can be represented, for example, by a system of two coupled spacecraft rotating around their common center of mass (in order to simulate the gravity force) in long-term space missions, when the third body (the lift) is located on a connecting cable. The bodies are considered to be the material points (particles). [ABSTRACT FROM AUTHOR]

The SPICAM experiment onboard the Mars-Express spacecraft includes sounding the Martian atmosphere in the ultra-violet (118–320 nm) and near IR (1–1.7 μm) ranges. The infrared spectrometer operates in the range of 1–1.7 μm with a resolution of 3.5 cm−1 in the mode of nadir observations and solar and stellar occulations. This paper is devoted to analyzing the basic results of nadir observations of the infra-red SPICAM channel during the first Martian year of the instrument operation: from January 2004 to November 2005. One of the primary goals of SPICAM-IR is water vapor monitoring in the atmosphere of Mars in the band of 1.37 μm and ozone abundance determination from the day-time airglow of molecular oxygen O2( a 1Δg) in the band of 1.27 μm. Simultaneous measurements of these minor constituents of the planet are necessary for understanding photochemical processes in the Martian atmosphere. The degree of their anticorrelation and a comparison with the results of photochemical modeling of the atmosphere will contribute to our knowledge of the Martian atmosphere stability. [ABSTRACT FROM AUTHOR]

The goal of this paper is to summarize the experimental data on the atmosphere of Venus obtained after 1985, when the VIRA (Venus International Reference Atmosphere) or COSPAR model was published. Among the most important results that have appeared since then are the following: measurements of the vertical temperature profile by the VEGA spacecraft with high precision and high altitude resolution; measurements made with balloons of the VEGA spacecraft; radio occultation measurements of Magellan, Venera-15, and Venera-16; and temperature profiles derived from the data of infrared spectrometry obtained by Venera-15. The new result as compared to VIRA is the creation of a model of the atmosphere in the altitude range 55 to 100 km dependent on local time. This model is presented in our paper in tabulated form. [ABSTRACT FROM AUTHOR]

In this paper we consider a large-scale enhancement of the intensity of solar protons (E = 1–20 MeV) observed in June 1991 for 26 days at different points of interplanetary space, onboard ULYSSES (in the time period under consideration it was located at a heliocentric distance of 3 AU, at an angular distance of ∼70° to the East of the Sun–Earth line and 3° to the South of the ecliptic plane) and GRANAT (which was orbiting around the Earth spending most of its flight time outside the Earth's magnetosphere). An approximation is made of the complex time profile of the enhancement of the solar cosmic ray (SCR) intensity on the basis of the reflection model of their propagation in the heliosphere. It has been established that, in this event, the transport of SCR particles in the interplanetary space was mainly carried out in the traps made up by the fronts of radially moving flare disturbances. The parameters of these fronts obtained when modeling this enhancement of SCR allow one to estimate the characteristic dimensions of the regions of effective capture of SCR. Comparison of the results of approximations obtained for the data from GRANAT and ULYSSES spacecraft demonstrated an increase in the regions of capture of SCR when the radial distance from the Sun increases. [ABSTRACT FROM AUTHOR]

An asteroid exploration probe 'Hayabusa2', that was developed by Japan Aerospace Exploration Agency (JAXA), was launched on December 3rd, 2014 to challenge complicated and accurate operations during the mission phase around the C-type asteroid 162137 Ryugu (1999 JU3) (Tsuda et al. in Acta Astron. 91:356-362, 2013). An impact experiment on a surface of the asteroid will be conducted using the Small Carry-on Impactor (SCI) system, which will be the world's first artificial crater creation experiment on asteroids (Saiki et al. in Proc. International Astronautical Congress, IAC-12.A3.4.8, 2012, Acta Astron. 84:227-236, 2013a; Proc. International Symposium on Space Technology and Science, 2013b). We developed a new micro Deployable CAMera (DCAM3) system for remote observations of the impact phenomenon applying our conventional DCAM technology that is one of the smallest probes in space missions and gained a great success in past Japanese mission IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun). DCAM3 is a miniaturized separable unit that contains two cameras and radio communication devices for transmission image data to the mothership 'Hayabusa2', and it observes the impact experiment at an unsafe region in where the 'Hayabusa2' is difficult to stay because of a risk of exploding and impacting debris hitting. In this paper, we report details of the DCAM3 system and development results as well as our mission plan for the DCAM3 observation during the SCI experiment. [ABSTRACT FROM AUTHOR]

The design space of mapping multimedia applications on an architectural platform is complex and many parameters are needed to be considered in order to find the optimum mapping. Conventionally, architectural parameters are varied to find different design points and the application side parameters are considered fixed and unchanged, while multimedia applications are equipped with several configurations to control the complexity and quality of the output. In this paper, we experimentally investigate joint application-architecture design space exploration of multimedia applications on many-core platforms. The joint exploration is conducted on two state of the art video coding standards and STHorm many-core platform as the underlying architecture. In the first case study, MPEG4-SP decoder is mapped on STHorm with varying buffer size and variable number of Processing Elements (PEs). In the second case study, HEVC (High Efficiency Video Coding) decoder with variable Quantization Parameter (QP) is mapped on STHorm with variable PE number. The application is characterized with representative parameters on the basis of high level dataflow representation of the application. It is demonstrated that joint exploration of these parameters outperforms that of their separate exploration in terms of well-established combinatory metrics such as space-time product and energy-time product metrics while achieving performance constraints. [ABSTRACT FROM AUTHOR]

Aiming at the influence of satellite motion on the inter-satellite two-way clock offset measurement, this paper proposed a correction method to eliminate the influence of satellite motion. Firstly, the measuring principle for the inter-satellite two-way clock offset was offered, and then specific influences of satellite motion on the measurement of inter-satellite two-way clock offset were analyzed in details when the mutual closing and far-away motions were conducted among the satellites. Finally, this paper integrated the specific influences of two motions on the measurement of inter-satellite clock offset, and put forward the correction method of inter-satellite clock offset with the smallest error after the polynomial fitting of measured clock offset. Satellite tool kit (STK) was used for the simulation of two-way clock offset measurement, and the result indicated that the accuracy of measurement for the inter-satellite clock offset with the length of 8 min containing the simulation error was better than 1 ns. The clock offset correction method can be used for the autonomous and high-accuracy measurement of inter-satellite clock offset. [ABSTRACT FROM AUTHOR]

In recent years, great experience has been accumulated in manned flight astronautics for rendezvous in near-Earth orbit. During flights of Apollo spacecraft with crews that landed on the surface of the Moon, the problem of docking a landing module launched from the Moon's surface with the Apollo spacecraft's command module in a circumlunar orbit was successfully solved. A return to the Moon declared by leading space agencies requires a scheme for rendezvous of a spacecraft launched from an earth-based cosmodromee with a lunar orbital station. This paper considers some ballistic schemes making it possible to solve this problem with minimum fuel expenditures. [ABSTRACT FROM AUTHOR]

This paper is dedicated to the creative activities of the outstanding designer of space technologies G.N. Babakin, who worked at the Lavochkin Association. Under Babakin's leadership, domestic automatic spacecraft were developed for research of near-Earth space, the Moon, planets of the Solar System, and for astrophysical observations. The short-term prospects of the national space program are presented. [ABSTRACT FROM AUTHOR]

For many industrial, medical and space technologies, cryogenic fluids play irreplaceable roles. When any cryogenic system is initially started, it must go through a transient chill down period prior to normal operation. Chilldown is the process of introducing the cryogenic liquid into the system, and allowing the system components to cool down to several hundred degrees below the ambient temperature. The chilldown process is an important initial stage before a system begins functioning. The objective of this paper is to investigate the chilldown process associated with a flexible hose that was simulated by a channel with saw-teeth inner wall surface structure in the current study. We have investigated the fundamental physics of the two-phase flow and quenching heat transfer during cryogenic chilldown inside the simulated flexible hose through flow visualization, data measurement and analysis. The flow pattern developed inside the channel was recorded by a high speed camera for flow pattern investigation. The experimental results indicate that the chilldown process that is composed of unsteady vapor-liquid two-phase flow and phase-change heat transfer is modified by the inner wall surface wavy structure. Based on the measurement of the channel wall temperature, the teeth structure and the associated cavities generally reduce the heat transfer efficiency compared to the straight hose. Furthermore, based on the measured data, a complete series of correlations on the heat transfer coefficient for each heat transfer regime was developed and reported. [ABSTRACT FROM AUTHOR]

This paper proposes a novel observer-based fault diagnosis method, incorporating an online control allocation scheme, for an orbiting spacecraft in the presence of actuator failures/faults, unexpected disturbances and input saturation. The proposed scheme solves a difficult problem in spacecraft fault tolerant control design by compensating for the loss in effectiveness and time-varying faults using redundant actuators, so that the overall system is stable, despite external disturbances and input saturation. This is accomplished by developing an observer-based fault diagnosis mechanism to reconstruct or estimate the actuator faults/failures. An online control allocation scheme is then used to redistribute the control signals to the healthy actuators in the case of faults/failures, without reconfiguring the controller, so that the control signal distribution is based on the reconstructed actuator effectiveness level. Simulation results using a rigid spacecraft model show good performance in the presence of faults, including total actuator failure scenarios, external disturbances and actuator input saturation, which validates the effectiveness and feasibility of the proposed scheme. [ABSTRACT FROM AUTHOR]

Venus Express is the first European (ESA) mission to the planet Venus. Its main science goal is to carry out a global survey of the atmosphere, the plasma environment, and the surface of Venus from orbit. The payload consists of seven experiments. It includes a powerful suite of remote sensing imagers and spectrometers, instruments for in-situ investigation of the circumplanetary plasma and magnetic field, and a radio science experiment. The spacecraft, based on the Mars Express bus modified for the conditions at Venus, provides a versatile platform for nadir and limb observations as well as solar, stellar, and radio occultations. In April 2006 Venus Express was inserted in an elliptical polar orbit around Venus, with a pericentre height of ∼250 km and apocentre distance of ∼66000 km and an orbital period of 24 hours. The nominal mission lasted from June 4, 2006 till October 2, 2007, which corresponds to about two Venus sidereal days. Here we present an overview of the main results of the nominal mission, based on a set of papers recently published in Nature, Icarus, Planetary and Space Science, and Geophysical Research Letters. [ABSTRACT FROM AUTHOR]

This paper introduces Raman spectroscopy and discusses various scenarios where it might be applied to in situ planetary missions. We demonstrate the extensive capabilities of Raman spectroscopy for planetary investigations and argue that this technique is essential for future planetary missions. [ABSTRACT FROM AUTHOR]

Non-convex and non-affine parameterizations of uncertainty are intrinsic within every attitude estimation problem given the fact that minimal and/or nonsingular representations of the attitude matrix are invariably nonlinear functions of the unknown attitude variables. Of course, this fact remains true for rotation matrices both in the 2-D plane (flatland) and in higher dimensional spaces (otherlands). Therefore, estimation problems involving minimal nonsingular representations of unknown attitude matrices bring significant challenges to the adaptive estimation community. This paper develops a novel algorithm for attitude estimation. The proposed algorithm relies upon the design of an adaptive update law for the attitude estimate while preserving its inherent orthogonal structure. The underlying approach borrows from the classical Poisson differential equation in rigid-body rotational kinematics and endows certain manifold attractivity features within the adaptive estimation algorithm. Consequently, we are not only able to efficiently handle the non-affine and non-convex nature of the parameter uncertainty, but are also ensured of estimation algorithm stability and robustness under bounded measurement noise. In addition to a rigorous discussion on the overall methodology, the paper provides example simulations that help demonstrate the effectiveness of the attracting manifolds design. [ABSTRACT FROM AUTHOR]

A suite of three optical instruments has been developed to observe Comet 9P/Tempel 1, the impact of a dedicated impactor spacecraft, and the resulting crater formation for the Deep Impact mission. The high-resolution instrument (HRI) consists of an f/35 telescope with 10.5 m focal length, and a combined filtered CCD camera and IR spectrometer. The medium-resolution instrument (MRI) consists of an f/17.5 telescope with a 2.1 m focal length feeding a filtered CCD camera. The HRI and MRI are mounted on an instrument platform on the flyby spacecraft, along with the spacecraft star trackers and inertial reference unit. The third instrument is a simple unfiltered CCD camera with the same telescope as MRI, mounted within the impactor spacecraft. All three instruments use a Fairchild split-frame-transfer CCD with 1,024× 1,024 active pixels. The IR spectrometer is a two-prism (CaF2 and ZnSe) imaging spectrometer imaged on a Rockwell HAWAII-1R HgCdTe MWIR array. The CCDs and IR FPA are read out and digitized to 14 bits by a set of dedicated instrument electronics, one set per instrument. Each electronics box is controlled by a radiation-hard TSC695F microprocessor. Software running on the microprocessor executes imaging commands from a sequence engine on the spacecraft. Commands and telemetry are transmitted via a MIL-STD-1553 interface, while image data are transmitted to the spacecraft via a low-voltage differential signaling (LVDS) interface standard. The instruments are used as the science instruments and are used for the optical navigation of both spacecraft. This paper presents an overview of the instrument suite designs, functionality, calibration and operational considerations. [ABSTRACT FROM AUTHOR]

The engineering goal of the Deep Impact mission is to impact comet Tempel 1 on July 4, 2005, with a 370 kg active Impactor spacecraft (s/c). The impact velocity will be just over 10 km/s and is expected to excavate a crater approximately 20 m deep and 100 m wide. The Impactor s/c will be delivered to the vicinity of Tempel 1 by the Flyby s/c, which is also the key observing platform for the event. Following Impactor release, the Flyby will change course to pass the nucleus at an altitude of 500 km and at the same time slow down in order to allow approximately 800 s of observation of the impact event, ejecta plume expansion, and crater formation. Deep Impact will use the autonomous optical navigation (AutoNav) software system to guide the Impactor s/c to intercept the nucleus of Tempel 1 at a location that is illuminated and viewable from the Flyby. The Flyby s/c uses identical software to determine its comet-relative trajectory and provide the attitude determination and control system (ADCS) with the relative position information necessary to point the High Resolution Imager (HRI) and Medium Resolution Imager (MRI) instruments at the impact site during the encounter. This paper describes the Impactor s/c autonomous targeting design and the Flyby s/c autonomous tracking design, including image processing and navigation (trajectory estimation and maneuver computation). We also discuss the analysis that led to the current design, the expected system performance as compared to the key mission requirements and the sensitivity to various s/c subsystems and Tempel 1 environmental factors. [ABSTRACT FROM AUTHOR]

In this paper, we review the results from numerical simulations that investigate the evolution of molecular cores into stars and brown dwarfs. We begin by discussing the four main processes involved in this evolution, fragmentation, accretion, interactions with discs, and stellar dynamical interactions. We then discuss large-scale calculations in which all of these processes are model simultaneously. Finally, we review results that have been obtained from past magnetohydrodynamical (MHD) calculations of fragmentation and look towards future MHD calculations. [ABSTRACT FROM AUTHOR]

The problems of investigation and optimization of the motion of spacecraft are extensively discussed in the literature. Nevertheless, in many cases a large variety of qualitative characteristics of their motion and of the form of their trajectories are still unclear. In this paper we consider a plane equiangular acceleration of a spacecraft both in a Newtonian field and in its absence (at a large distance from the center of attraction). The general equation of a trajectory of plane acceleration is presented with the introduction of a new variable, an index of an exponent, which allows one to obtain convenient solutions at different values of the time-independent angle of inclination of the vector of thrust to the spacecraft's radius vector (i.e., when equiangular acceleration takes place). Asymptotic solutions are constructed and an interesting fact is revealed. Namely, it is shown that when the center of attraction exists or is absent, for all initial conditions the trajectories appearing at the above equiangular acceleration of a material point tend to the standard logarithmic spirals at a large distance from the center. Specifically, when the value of transverse (perpendicular to the radius vector) thrust is constant, there appears a logarithmic spiral with an angle of inclination to the radius vector equal to 35.264°. Different forms of the trajectory of equiangular acceleration of spacecraft at a low thrust are also studied. The results obtained can be useful for the investigation and choice of optimum space trajectories. [ABSTRACT FROM AUTHOR]

The aim of this paper is to apply the Autonomous Adaptive Control method to the problem of stabilization of a spacecraft's angular motion. The method is being developed at the Department of Simulation Systems of the Institute for System Programming, Russian Academy of Sciences. As applied to the problem under study, the main advantages of this method lie in the fact that there is no need to construct and incorporate into the control system a mathematical model of the controlled object, while it provides high-quality control, which cannot be ensured by a traditional control system. By optimizing the system with the use of genetic algorithms, one can save computational and hardware resources without losses in the quality of control and in the adaptive properties of the control system. [ABSTRACT FROM AUTHOR]

The International Space Station (ISS) already serves as a laboratory for experiments in fundamental physics. It could be used for a much wider range of experiments if the operational concept of the ISS will be changed. Operational constraints set limits for the precision level of experiments. Free-flying platforms with high precision attitude and orbit control (drag-free control) could co-orbit with the ISS and improve the experimental conditions. The paper summarizes the main constraints and discusses concepts for improvement. [ABSTRACT FROM AUTHOR]

This study analyzes for the first time the interaction between a rigid and a deformable vehicle in formation. In this paper we investigate the interaction between an orbiting system of two tethered spacecraft and a single separated spacecraft. This problem arises when a distributed sensor array formed by connected vehicles is being commanded to reconfigure from a remote location by another remote vehicle. In another example, a free-flying robotic inspector vehicle flies around a deployed large space structure, such as a tethered spacecraft, deployed membrane or solar reflector, with the intent of monitoring the structural integrity of the larger vehicle prior to docking and possibly servicing it. This paper points out that even if the additional internal dynamics of the system caused by flexibility is considered, high pointing precision can be achieved when a fictitious rigid frame is used to track the tethered system. Even higher precision can be achieved when one specific point on the deformable structure is directly tracked. The results show that accuracy to the sub centimeter level or less in relative positioning and to the arc second level in relative angle can also be achieved with this novel architecture. [ABSTRACT FROM AUTHOR]

In this paper, we quantify the effect of random noise on the probability of misclassification of images produced by multi-spacecraft interferometric imaging systems (MSIIS). We consider two metrics for the noise corrupting the image: the mean squared error (MSE) and the worst-case error (WCE). We show that these are consistent with the goal of image classification in that, as the MSE or WCE tends to zero, the probability of misclassifying an image also tends to zero. Given a feature map, i.e., a real-valued function of an image variable, we assume that classification is done by applying a threshold to the feature map. In this feature-based classification, we find bounds on the MSE and the WCE such that the probability of misclassifying the image is guaranteed to be less than some pre-specified value. We illustrate the theory through an example where the banded appearance of the image of a planet is detected. The results of this paper could be used for the reliable characterization of exo-solar planets and similar astronomical studies. [ABSTRACT FROM AUTHOR]

A problem of optimal turn of a spacecraft is considered. The time of turn is minimized, as well as the functional having a meaning of the propellant consumption. An analytical solution to the problem stated is derived. It is demonstrated that the solution optimal in this sense belongs to a class of two-impulse controls, under which a spacecraft executes the turn along the trajectory of its free motion. The solution obtained in this paper differs from earlier available solutions considerably. The estimations of the propellant consumption for a realization of the programmed turn are made. [ABSTRACT FROM AUTHOR]

This review deals with the selection of the electric propulsion system (EPS) for the internationally developed and designed, primary nuclear-electric space tug International Nuclear Power and Propulsion System (INPPS). INPPS is scheduled for interplanetary missions to Mars and Jupiter moon Europa missions by the end of decade 2020. Regarding specific technical and mission parameters preselected electric thruster (ET) types, developed by international companies and institutions, are analysed, evaluated and investigated for a possible application as propulsion system (PS), the so-called CET (Cluster of Electric Thrusters). It is analysed whether solely electric thrusters, combined in an adequate CET, enable the envisaged interplanetary missions—robotic and astronautic/crewed with the INPPS flagship. Thruster clusters with strategic consortium considerations are analysed as a feasible PS of the INPPS. The studied CET consists of the following: (a) only European ETs, (b) combination of German and European ETs, (c) Japanese and European ETs or at least (d) Japanese, European and US thrusters. The main results are (1) Robotic and crewed INPPS mission to Mars/Europa are realizable with EPS only (no chemical propulsion is needed), (2) that every CET, except (c) of only Japanese and part of European thrusters, is capable to perform the main part of envisaged INPPS flagship mission orbit to Mars, back to Earth and to Jupiter/Europa moon. [ABSTRACT FROM AUTHOR]

Profiles scientist in aeromechanics and space research Mikhail Yakovlevich Marov, editor-in-chief of the journal and corresponding member of the Russian Academy of Sciences, who has made a tremendous contribution to the study of outer space and related areas of contemporary science. Career background; Educational history; Achievements and awards.

The International Centre on Space Technologies for Natural and Cultural Heritage (HIST) under the auspices of UNESCO was proposed to UNESCO by the Chinese Academy of Sciences (CAS) in May 2007. Since its inauguration in July 2011, HIST has played a vital role in assisting UNESCO and its Member States in the conservation of UNESCO-designated sites. World Heritage sites, Biosphere reserves and UNESCO Global Geoparks are three primary categories of UNESCO-designated sites. [Extracted from the article]

An attitude determination covariance measurement model for unit vector sensors with a wide field-of-view is analyzed and compared to the classic QUEST covariance model. The wide field-of-view model has been previously proposed as a more realistic alternative for sensors where measurement accuracy depends on angular distance from the boresight axis. Both QUEST and the wide field-of-view models are evaluated relative to a measurement model that uses the two-dimensional sensor focal plane measurements directly, rather than first converting them to unit vectors. The Fisher information matrix is derived for attitude determination based on such direct sensor measurements, and the wide field-of-view measurement model is shown to have the same Fisher information matrix. Numerical simulations confirm that an extended Kalman filter based on the wide field-of-view model outperforms a filter based on the QUEST measurement model, and also that the wide field-of-view 3 σ bounds are effectively identical to those of a filter based on the direct two-dimensional sensor measurements. [ABSTRACT FROM AUTHOR]

The article introduces a series of articles on astronautics published within the issue that were presented during the American Astronautical Society (AAS) F. Landis Markley Astronautics Symposium held in Cambridge, Maryland from June 29 to July 2, 2008.

Development of cosmonautics and preparation to the first manned space flights are briefly observed. Details of the development of the first Soviet intercontinental ballistic missile R-7, which served as a basis for creating Sputnik, Vostok, Voskhod, Molniya, and Soyuz launchers, are given. The contributions of the outstanding designers of space engineering, W. von Braun, S.P. Korolev, V.P. Glushko, and academician M.V. Keldysh, to the development of astronautics and first manned space missions are demonstrated. A list of test launches and manned flights of Vostok and Mercury spacecrafts and the basic characteristics of Vostok, Redstone, Atlas-D, Voskhod, and Soyuz launchers are presented. [ABSTRACT FROM AUTHOR]

Abstract  In this paper we give a statistical description of the phase space of a Fermi–Pasta–Ulam chain using the Fast Lyapunov Indicator, looking for properties valid in the thermodynamic limit. [ABSTRACT FROM AUTHOR]

Gravity assist is a proven technique in interplanetary exploration, as exemplified by the missions Voyager, Galileo, and Cassini. In the present paper, based in this well-known technique, an algorithm is developed to optimize missions to the outer planets. Then, this algorithm is applied to a mission to Neptune for the mid-term (2008-2020). The following schemes are analyzed: Earth-Jupiter-Neptune, Earth-Venus-Earth-Jupiter-Neptune, Earth-Venus-Earth-Jupiter-Saturn-Neptune. Transfer trajectories that provide a good compromise between the delta-V and the time of flight to Neptune are presented. In particular, the effects of the pericenter height for the gravity assist with Jupiter are studied in detail, since the final results have a strong dependence on this variable. [ABSTRACT FROM AUTHOR]

We used more than 250 000 high-precision American and Russian radar observations of the inner planets and spacecraft obtained in the period 1961–2003 to test the relativistic parameters and to estimate the solar oblateness. Our analysis of the observations was based on the EPM ephemerides of the Institute of Applied Astronomy, Russian Academy of Sciences, constructed by the simultaneous numerical integration of the equations of motion for the nine major planets, the Sun, and the Moon in the post-Newtonian approximation. The gravitational noise introduced by asteroids into the orbits of the inner planets was reduced significantly by including 301 large asteroids and the perturbations from the massive ring of small asteroids in the simultaneous integration of the equations of motion. Since the post-Newtonian parameters and the solar oblateness produce various secular and periodic effects in the orbital elements of all planets, these were estimated from the simultaneous solution: the post-Newtonian parameters are β=1.0000±0.0001 and γ=0.9999±0.0002, the gravitational quadrupole moment of the Sun is J2=(1.9±0.3)×10–7, and the variation of the gravitational constant is Ġ/G=(–2±5)×10–14 yr-1. The results obtained show a remarkable correspondence of the planetary motions and the propagation of light to General Relativity and narrow significantly the range of possible values for alternative theories of gravitation.© 2005 Pleiades Publishing, Inc. [ABSTRACT FROM AUTHOR]

This paper revisits a class of Earth-orbiting interferometric observatories introduced previously and reviews the general procedures to achieve wave-number plane coverage. The effect of eccentric spacecraft trajectories and gravity field J2 perturbations on wave-number plane coverage are considered. Conditions for complete wave-number plane coverage are found for certain classes of orbit perturbations. This analysis leads to design criteria for interferometric observatories that ensure wave-number plane coverage as a function of perturbation strength. [ABSTRACT FROM AUTHOR]

The Deep Impact mission will provide the first data on the interior of a cometary nucleus and a comparison of those data with data on the surface. Two spacecraft, an impactor and a flyby spacecraft, will arrive at comet 9P/Tempel 1 on 4 July 2005 to create and observe the formation and final properties of a large crater that is predicted to be approximately 30-m deep with the dimensions of a football stadium. The flyby and impactor instruments will yield images and near infrared spectra (1–5 μm) of the surface at unprecedented spatial resolutions both before and after the impact of a 350-kg spacecraft at 10.2 km/s. These data will provide unique information on the structure of the nucleus near the surface and its chemical composition. They will also used to interpret the evolutionary effects on remote sensing data and will indicate how those data can be used to better constrain conditions in the early solar system. [ABSTRACT FROM AUTHOR]

A fundamental study of indirect adaptive control addressed towards a class of uncertain mechanical and aerospace systems is the subject of this paper. We utilize and build upon certain recent techniques within adaptive control that permit nonlinear parameterization of uncertainty, thereby amounting to a significant shift from the classical certainty equivalence methodology. Instead of the more popular direct adaptive control formulations, our focus is restricted to the indirect methods because imposing prior information on properties of physically meaningful plant parameters is convenient within this framework. For two different types of uncertainty parameterizations, namely scalar parameters and proper orthogonal matrix parameters, we present smooth, non-overparameterized (lower order), and stable adaptive control algorithms that provide improved transient performance while at the same time utilize all the available prior information on the unknown parameters. In the particular case when there exists a single scalar uncertain parameter, the most novel attribute of the proposed controller is that adaptation gets automatically frozen once the parameter estimate reaches the corresponding true value, a highly desirable feature that is clearly missing within all existing certainty equivalence adaptive control schemes. Through both analysis and simulations, we have been able to confirm that this "nice" feature amounts to having a proportional term within the parameter update law; and is in fact enabled by a crucial role played by the introduction of certain design functions that are embedded within the new controller. All technical descriptions will be further elaborated by illustrative physical examples as well as numerical simulations of the resulting closed-loop dynamics to demonstrate the potential advantages of this new approach. [ABSTRACT FROM AUTHOR]