Search

The global community, with coordination from the United Nations, is energized to pursue the Sustainable Development Goals (SDGs), a list of 17 important aspirations that summarize the key challenges of our era. The SDGs apply to every nation and represent an international effort to eliminate extreme poverty, ensure access to safe drinking water, strengthen food security, and produce clean and reliable energy, among other pursuits. Space technology is already being used around the world to advance progress toward the SDGs and monitor their related Indicators. This paper explores how six technologies related to space—satellite Earth observation, satellite communication, satellite navigation and positioning, human spaceflight and microgravity research, space technology transfer, and basic scientific research—are being used to realize the vision that the SDGs represent. The paper also discusses the obstacles that limit the application of these technologies for the SDGs and provides an overview of potential paths to overcome these barriers. The paper finally studies the historical and potential roles that four distinct types of entities involved in global sustainable development—governments, non- and inter-governmental organizations, entrepreneurial companies, and universities— have played or may play in the application of space technologies towards the SDGs. • Six space technology areas are shown to support the U.N. Sustainable Development Goals. • Examples of space projects that support the SDGs are found in many sectors. • New designs for technology are needed to improve effectiveness of space applications for the SDGS. [ABSTRACT FROM AUTHOR]

In some geographically challenging areas (such as deserts, seas, and forests) where direct connectivity to a terrestrial network is difficult, space communication is the only option. In these remote locations, Internet of Space Things (IoST) applications can also be used successfully. In this paper, the proposed payload for IoST applications demonstrates how an Automatic Identification System (AIS) and a fire detection system can be used effectively. A space mission based on efficient and low-cost communication can use a constellation of nanosatellites to better meet this need. These two applications, which use a constellation of nanosatellites, can provide relevant university-level data in several countries as an effective policy for the transfer of space technology in an educational initiative project. To enhance educational participation and interest in space technology, this paper shares the lessons learned from the project feasibility study based on an in-depth design of a nanosatellite with several analyses (data budget, link budget, power budget, and lifetime estimation). Lastly, this paper highlights by experiments the development and application of a cost-effective sensor node for fire detection and the use of GPS to enable AIS capabilities in the IoST framework. [ABSTRACT FROM AUTHOR]

The satellite technology proves its impact in the modern era with its wide benefits and applications. However, the cost of the development in this field presents gaps in many countries, almost the developed countries. Therefore, this paper provides a rich platform around low-cost sensors in order to improve maturity in space technology, mostly the system of attitude determination and control. The development of this knowledge turns out to be very interesting in order to achieve a space mission which leads to the progression of the spatial technology readiness level (TRL) defined by the international measurement scale which is able to estimate the technological maturity. Thus, the idea is carried out for the development of low-cost sensors' system for attitude determination around an Arduino board. A sensor fusion method was applied on three types of sensors: accelerometer, magnetometer, and gyroscope in order to detect the reliable orientation. It is aimed to apply quaternion based Kalman filter on different platform than previous systems. It is succeeded therefore to improve measurement accuracy around low-cost sensor to achieve the main goal of this paper. [ABSTRACT FROM AUTHOR]

With the development of commercial space technology, low-orbit large-scale satellite constellation has shown great development potential in communication services and military applications due to its advantages of low delay, strong signal, high coverage rate, fast communication rate, and low cost of mass production. It has become an urgent problem in the field of satellite constellations to study the perturbation evolution law of low-orbit large-scale constellation initialization and orbit maintenance, and how to maintain and control the deployment and initialization of low-orbit satellite constellations efficiently, economically, and stably. In this paper, the satellite motion law, constellation configuration evolution characteristics, and constellation initialization control strategy are analyzed considering the perturbation of earth's nonspherical gravity and atmospheric drag under the orbit deviation of satellite orbit elements. Firstly, MonteCarlo simulation was used to simulate the deviation of satellite initial orbit elements, and the evolution law of ascending ascension point and phase angle of different constellations was analyzed and, secondly, establish the initialization phase constellation deployment and the ascending node right ascension deployment of mathematical equations, using Starlink constellation (V1.0-L3, 8) satellite TLE data; initialization of Leo constellation orbit plane is analyzed, by considering the orbit bias satellite simulation data; the same orbital plane satellite initialization phase deployment method is analyzed; finally, this paper provides some suggestions for the future deployment and maintenance control strategy of low-orbit constellation. [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]

Copyright of Railway Signalling & Communication Engineering is the property of Railway Signalling & Communication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, a reconstruction approach for simulating the output performance of a satellite's solar array (SA) is proposed. This approach introduces an Earth-reflected irradiance and a degradation model that affect the performance in-orbit to reconstruct a typical single diode model. The main feature of this reconstruction is that the computational procedure is convenient and can be programmed to the microcomputer system for real-time performance monitoring. Based on limited information from the manufacturer's datasheet, the single diode model is parameterized. In addition, an effective method of determining initial values is presented to avoid nonconvergence in the parameterization. Moreover, Earth-reflected irradiance on a body-mounted SA is simulated analytically with the parallel and perpendicular view factors. The degradation of the SA performance is modeled by a nonlinear regression method. Finally, the reconstructed model is applied to simulate the SA performance of microsatellite Tianxun-1 (TX-1) developed by Nanjing University of Aeronautics and Astronautics. The measured results over four years in space verify the validity of the proposed reconstruction approach. [ABSTRACT FROM AUTHOR]

This paper describes the "2016 KOSEN Space Camp," which is a introductory education program on space technology for students enrolled at the various KOSEN colleges of technology in Japan. The camp was conducted twice, the first time on September 3-6, 2015 and the second time on September 1-4, 2016 at the Marine Park Niihama. Approximately 40 students and more than 10 teachers participated in the camp on each of the two occasions when it was held. The activities in the camp included a lecture by an eminent scientist; the study of basic rocket theory; model rocket experiments; and the development, analysis, and presentation of CanSat satellite model experiments. This unique education program provided by aerospace scientists and engineers is a KOSEN concept and product. [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 Floating Potential Measurement Unit (FPMU) is a multiprobe package designed to measure the floating potential of the International Space Station (ISS) as well as the density and temperature of the local ionospheric plasma environment. The purpose of the FPMU is to provide direct measurements of ISS spacecraft charging as continuing construction leads to dramatic changes in ISS size and configuration. FPMU data are used for refinement and validation of the ISS spacecraft charging models used to evaluate the severity and frequency of occurrence of ISS charging hazards. The FPMU data and the models are also used to evaluate the effectiveness of proposed hazard controls. The FPMU consists of four probes: a floating potential probe, two Langmuir probes, and a plasma impedance probe. These probes measure the floating potential of the ISS, plasma density, and electron temperature. Redundant measurements using different probes support data validation by interprobe comparisons. The FPMU was installed by ISS crew members during an extra-vehicular activity on the starboard (S1) truss of the ISS in early August 2006 when the ISS configuration included only one 160-V U.S. photovoltaic (PV) array module. The first data campaign began a few hours after installation and continued for over five days. Additional data campaigns were completed in 2007 after a second 160-V U.S. PV array module was added to the ISS. This paper discusses the general operational characteristics of the FPMU as integrated on ISS, the functional performance of each probe, the charging behavior of the ISS before and after the addition of a second 160-V U.S. PV array module, and initial results from model comparisons. [ABSTRACT FROM AUTHOR]

In recent years, formation flying has been recognized as an enabling technology for a variety of mission concepts in both the scientific and defense arenas. Examples of developing missions at NASA include magnetospheric multiscale (MMS), solar imaging radio array (SIRA), and terrestrial planet finder (TPF). For each of these missions, a multiple satellite approach is required in order to accomplish the large-scale geometries imposed by the science objectives. In addition, the paradigm shift of using a multiple satellite cluster rather than a large, monolithic spacecraft has also been motivated by the expected benefits of increased robustness, greater flexibility, and reduced cost. However, the operational costs of monitoring and commanding a fleet of close-orbiting satellites is likely to be unreasonable unless the onboard software is sufficiently autonomous, robust, and scalable to large clusters. This paper presents the prototype of a system that addresses these objectives—a decentralized guidance and control system that is distributed across spacecraft using a multiple team framework. The objective is to divide large clusters into teams of "manageable" size, so that the communication and computation demands driven by N decentralized units are related to the number of satellites in a team rather than the entire cluster. The system is designed to provide a high level of autonomy, to support clusters with large numbers of satellites, to enable the number of spacecraft in the cluster to change post-launch, and to provide for on-orbit software modification. The distributed guidance and control system will be implemented in an object-oriented style using a messaging architecture for networking and threaded applications (MANTA). In this architecture, tasks may be remotely added, removed, or replaced post launch to increase mission flexibility and robustness. This built-in adaptability will allow software modifications to be made on-orbit in a robust manner. The prototype system, which is implemented in Matlab, emulates the object-oriented and message-passing features of the MANTA software. In this paper, the multiple team organization of the cluster is described, and the modular software architecture is presented. The relative dynamics in eccentric reference orbits is reviewed, and families of periodic, relative trajectories are identified, expressed as sets of static geometric parameters. The guidance law design is presented, and an example reconfiguration scenario is used to illustrate the distributed process of assigning geometric goals to the cluster. Next, a decentralized maneuver planning approach is presented that utilizes linearprogramming methods to enact reconfiguration and coarse formation keeping maneuvers. Finally, a method for performing online collision avoidance is discussed, and an example is provided to gauge its performance. [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]

The safety of on-orbit satellites is threatened by space debris with large residual angular velocity and the space debris removal is becoming more challenging than before. This paper explores the non-contact despinning and traction problem of high-speed rotating targets and proposes an eddy current brake and traction technology for space targets without any propellant consumption. The principle of the conventional eddy current brake is analyzed in this article and the concept of eddy current brake and traction without propellant is put forward for the first time. Secondly, according to the key technical requirements, a brand-new structure of a satellite generating artificial magnetic field is designed accordingly. Then the control mechanism of eddy current brake and traction without propellant is analyzed qualitatively by simplifying the model and conditions. Then, the magnetic pulse control method is proposed and analyzed quantitatively. Finally, the feasibility of the technology is verified by the numerical simulation method. According to the simulation results, the eddy current brake and traction technology based on magnetic pulses can make the angular speed of target decrease linearly without propellant during the process. This technology has huge advantages compared with conventional eddy current brake technology in terms of efficiency and reduced propellant consumption. [ABSTRACT FROM AUTHOR]

Abstract: Countries on every continent are making new or renewed commitments to domestic satellite programs. These programs have the potential to address national needs by enhancing access to information, improving infrastructure and providing inspiration to the public. How do countries without local expertise in space technology begin a new satellite program? What is the role of international collaboration in supporting the efforts of a new space fairing country? This paper explores such questions by highlighting outputs from intensive field work in Africa and Asia. Specifically, the study explores case studies of early space activity in these countries to search for lessons about the management of a young space program. The observations from field work are compared to ideas from scholarly literature on technological learning. The findings are organized using principles from systems architecture. The paper presents a model that captures many of the influences and strategic decision areas for a collaborative satellite development project. The paper also highlights the growth of capability among African countries in the area of satellite technology. [Copyright &y& Elsevier]

Abstract: Science and technology satellite-3 (STSAT-3) is being developed and is scheduled for launch in 2011. One of the primary objectives of its mission is to verify the performance of a hall thruster propulsion system (HPS) that uses xenon gas. According to its major functions, the HPS can be divided into several sub-modules. This paper presents the development and qualification of the hall effect thruster propulsion subsystem that includes a xenon feed system (XFS). The xenon feed system regulates the pressure down from the xenon propellant tank and supplies the xenon flows to the anode and cathode. The technology and xenon feed system developed for the STSAT-3 spacecraft will also be applicable to a variety of future electronic propulsion systems and micro-satellites. Details related to the overall development and performance results of the HPS are presented in this paper. [Copyright &y& Elsevier]

Abstract: This paper explores the process of building technological capability in government-led satellite programs within developing countries. The key message is that these satellite programs can learn useful lessons from literature in the international development community. These lessons are relevant to emerging satellite programs that leverage international partnerships in order to establish local capability to design, build and operate satellites. Countries with such programs include Algeria, Nigeria, Turkey, Malaysia and the United Arab Emirates. The paper first provides background knowledge about space activity in developing countries, and then explores the nuances of the lessons coming from the international development literature. Developing countries are concerned with satellite technology because satellites provide useful services in the areas of earth observation, communication, navigation and science. Most developing countries access satellite services through indirect means such as sharing data with foreign organizations. More countries, however, are seeking opportunities to develop satellite technology locally. There are objective, technically driven motivations for developing countries to invest in satellite technology, despite rich debate on this topic. The paper provides a framework to understand technical motivations for investment in satellite services, hardware, expertise and infrastructure in both short and long term. If a country decides to pursue such investments they face a common set of strategic decisions at the levels of their satellite program, their national context and their international relationships. Analysis of past projects shows that countries have chosen diverse strategies to address these strategic decisions and grow in technological capability. What is similar about the historical examples is that many countries choose to leverage international partnerships as part of their growth process. There are also historical examples from outside the space arena in which organizations have pursued technological capability. Scholars have analyzed these examples and developed insightful frameworks. The paper draws key concepts from this literature about the nature of development, technology, knowledge and organizational learning. These concepts are relevant to learning in new satellite programs, but the ideas must be applied cautiously because of the nature of satellite technology. The paper draws three major lessons from the international development literature regarding absorptive capacity, tacit knowledge and organizational learning; it synthesizes these lessons into a cohesive, original framework. The closing section proposes future work on a detailed study of technological learning in specific government satellite programs. [Copyright &y& Elsevier]

Abstract: Korea has a short history in space development compared to neighboring countries like Japan, China, India and Russia. During the past 20 years, Korea has focused on developing satellite and rocket space technology under the national space development plan. KOMPSAT-1 and 2, and KSLV-1 are the results of the selection and concentration policy of the Korean government. Due to the arduous mission of developing hardware oriented space technology, the topic of space education and outreach for the general public has not received much in the national space program. But recently, the Korean government has begun planning a space science outreach program in the detailed action plan of the mid-long term national space development plan. This paper introduces and analyzes the organizations performing space education and outreach programs for primary and secondary schools in the Republic of Korea. “Young Astronaut Korea (YAK)” is one such program. This is a non-profit organization established to provide space education for students in 1989 when Korea just started its space development program. “YAK” is a unique group in Korea for space education and outreach activities because it is organized by branches at each school in the nation and it is much like the Boy Scout and Girl Scout programs. Space Science Museum and National Youth Space Center (NYSC), which are located near NARO space center in the southernmost part of the Korean peninsula are other examples of space education and outreach programs. NARO space center, which is the only launch site in Korea became the center of public interest by showing the KSLV-1 launch in 2009 and will be expected to play a key role for the space education of students in the Republic of Korea. The NYSC will perform many mission oriented space education programs for students as Space Camp in the USA does. This paper introduces the status of the space education and outreach programs of each organization and presents the future direction of space education and outreach for the Korean public and students. If these three organizations cooperate with each other and develop systematic programs of space education and outreach for the people, they will prepare a base for growth and progress in future space science and technology in Korea. [Copyright &y& Elsevier]

Abstract In this paper I revisit proposed definitions of the boundary between the Earth's atmosphere and outer space, considering orbital and suborbital trajectories used by space vehicles. In particular, I investigate the inner edge of outer space from historical, physical and technological viewpoints and propose 80 km as a more appropriate boundary than the currently popular 100 km Von Kármán line. Highlights • Historically, the lowest satellite orbits have had perigees as low as 80-90 km. • The Karman Line as originally defined lies between 70 and 90 km, not at 100 km. • This result is not sensitive to solar activity or other atmospheric variations. [ABSTRACT FROM AUTHOR]

Abstract: The alternative to using propellant for actuation of formation flying satellites is for each spacecraft to produce their own electromagnetic field that others in the formation can react against. This technique can be achieved by creating a steerable magnetic dipole and is called Electromagnetic Formation Flight (EMFF). EMFF can be implemented on a spacecraft by driving current through three orthogonal electromagnetic coils to create a steerable magnetic dipole in three dimensions. This paper investigates the applicability of EMFF as a means for attitude and translation control of multiple spacecraft maneuvering in close proximity. One example scenario is using two EMFF satellites as an inspector system to examine a non-EMFF satellite that is nearby. The results of the analysis show the design of the proximity guidance, navigation, and control laws that allow for rapid inspection scenarios. The primary role of EMFF is to impart forces and torques to maintain a satellite array. In addition, potential secondary roles of EMFF were investigated using EMFF in a multi-role sense. These included power transmission, passive, offensive capabilities, and use of the HTS coils as torque coils for geostationary satellites. The results of this paper show that EMFF is a promising propellantless formation flight technology. [ABSTRACT FROM AUTHOR]

The new millennium brought an asymptotic interest in space technology. Besides existing operational global positioning systems i.e. GPS and GLONASS, another two have already emerged: GALILEO and Compass/Beidou. Alternatives to GPS imposed the GNSS concept, which has crystallized in a short time. The true reasoning of this excessive need for positioning information is beyond the scope of this paper; instead, an analysis of orbital behaviour of GPS, GLONASS and GALILEO is conducted. GNSS orbits have similar characteristics permitting us to encompass them under the term Medium Earth Orbits (MEO). However, small differences between mean orbital elements of the three systems produce a significantly different reaction of their satellites' orbits to the natural perturbing factors. This study analyzes the three space segment characteristics, introduces the analytical method used to evaluate variations of orbital elements under the most significant perturbing influences and offers a broad comparative image of the dynamic behaviour of the three GNSS constellations. [ABSTRACT FROM AUTHOR]

The SMART-i mission was successfully completed on September 3, 2006, with a controlled crash on the visible side of the Moon. The primary electric-propulsion (EP) system included a nonredundant SNECMA PPS-i350-G Hall effect thruster. The thruster discharge was electrically floating with respect to the spacecraft ground. The cathode floating potential (UCRP) is an important thruster parameter, giving information on cathode performance and life expectancy. During ground testing and steady-state operation, UCRP was approximately constant and negative. However, in space, it was observed that the UCRP was slightly positive and was periodically varying in time by a few volts. The capability to compare to ground-test data and check the cathode good health and life potential was largely impaired. Fortunately, SMART-i included a plasma diagnostic package (electric-propulsion diagnostic package) with a Langmuir probe and a retarding-potential analyzer, both positioned on the same plane as the plasma thruster and provided data on the plasma potential as well as the energy of the charge-exchange ions. The short- and long-term correlations of these data with the cathode reference potential (CRP) were performed. It was concluded that the UCRP is evolving with respect to the plume potential near the cathode, and this potential difference is shown to be constant over the mission. Plume-potential distribution is adapting itself relative to the local plasma potential. The spacecraft potential with respect to the plasma potential is defined in steady state when the electron and ion currents entering and leaving the spacecraft are balanced. This balance depends primarily on the solar-array electrical configuration and orientation and thruster operating conditions. When the local plasma is chosen as a reference, the absolute cathode potential is found to be the same as the one on the ground. This paper confirms the good health of the cathodes. Contrary to a spacecraft without EP, the SMART-i spacecraft potential varies within a limited range and is comparatively close to zero during electric-thruster operation. In addition, UCRP can be used to derive the spacecraft potential throughout the mission. All the various cyclic and long-term effects influencing the spacecraft potential on SMART-i have been identified and characterized across the mission lifetime. In particular, a strong correlation between the solar-array rotation and the variation of the spacecraft potential has been established. [ABSTRACT FROM AUTHOR]

This paper concentrates upon the capability of India's satellite programme. india's satellite programme, which started its journey in 1975 with the launch of first expenmental satellite Aryabhatta, is now a well developed satellite manufacturer and launcher country. India is now able to manufacture more powerful INSAT class and remote sensing class satellites. These satellites have immense socio-economic benefits. Thes can be utilized for telecommunication, meteorology, broadcasting, weather forecasting. search and rescue services, urban planning, crop estimation, environment survey etc. All these are addressed in this paper. The paper also attempts to establish a relationship between space technology and nation-building. For nation-building, socio-economic, infrastructural developments are very necessary and space technology with its vanous applications can help India in its mission to become a developed country by 2020. Towards the end of the paper, it highlights the power of the India's space programmes; Which India can provide to other South-Asian countries for their socio-economic development . The rest of South-Asian countries regard India as a hegemonic power in the South Asia, because of its size, population, economy and military power. India by providing its useful space applications to these countries can improve its relations with them. [ABSTRACT FROM AUTHOR]

The paper concerns radio amateur satellites that are built by international student teams. For contacting a satellite, a single ground station is usually used. In this configuration and with the satellite on the low Earth orbit (LEO), teams have contact only for about 40 minutes per day. If the satellite has service for radio amateurs, they use it for 20 hours per day. A lot of them have connection to Internet. This is a big difference. In this paper, is shown how they can use the radio amateur transceivers and antenna systems in order to build ground stations network named distributed ground station system (DGSS). Frequencies, types of modulations, calculation of power budge, and the ways to control amateur stations by the Internet are also shown. These are essential procedures, because radio amateurs have their standards and habits. Finally a proposal of implementation dedicated DGSS system for radio amateurs with and without use of APRS network is put forward. Distributed ground station is one of the experiments on PW-Sat satellite, which is being build on the Warsaw University of Technology. [ABSTRACT FROM AUTHOR]

Abstract: The purpose of this paper is to present a design procedure for a phased array antenna. Phased array antennas are becoming very popular because of their capability for electronic beam forming. In this paper two phased array antennas will be presented, one for a geostationary satellite and other for a polar orbit satellite. A computer program specially written for this purpose phased array antenna design (PAAD) will also be demonstrated. This design method has the particularity of being able to create nulls of field in any direction of space, and that can be used for beam changing in real time applications. This is achieved by implementing an extended version of the Schelkunoff polynomial method applicable to planar arrays. In this paper, a description of two possible tracking systems (for both geostationary and polar orbits) will also be shown. These systems have many applications for industry and space technology and some of them will be presented as well. And finally, these phased array antennas will be designed considering microstrip patches as element sources. [Copyright &y& Elsevier]

While changing the handling characteristics of a conventional vehicle normally requires physical modification, a vehicle equipped with steer-by-wire can accomplish the same effect through active steering intervention. This paper presents an intuitive method for altering a vehicle's handling characteristics by augmenting the driver's steering command with full vehicle state feedback. The vehicle can be made more or less responsive depending on the driver's preference and particular operating conditions. Achieving a smooth, continuous change in handling quality requires both accurate state estimation and well-controlled steering inputs from the steer-by-wire system. Accurate estimates of vehicle states are available from a combination of global positioning system (GPS) and inertial navigation system (INS) sensor measurements. By canceling the effects of steering system dynamics and tire disturbance forces, the steer-by-wire system is able to track commanded steer angle with minimal error. Experimental results verify that with precise steering control and accurate state information, the handling modification is exactly equivalent to changing the front tire cornering stiffness. [ABSTRACT FROM AUTHOR]

The primary objective of the International Space Station (ISS) is to provide a long-term quiescent environment for the conduct of scientific research for a variety of microgravity science disciplines.This paper reports to the microgravity scientific community the results of an initial characterization of the microgravity environment on the International Space Station for increments 2 through 4. During that period almost 70,000 hours of station operations and scientific experiments were conducted. 720 hours of crew research time were logged aboard the orbiting laboratory and over half a terabyte of acceleration data were recorded and much of that was analyzed. The results discussed in this paper cover both the quasi-steady and vibratory acceleration environment of the station during its first year of scientific operation.For the quasi-steady environment, results are presented and discussed for the following: the space station attitudes Torque Equilibrium Attitude and the X-Axis Perpendicular to the Orbital Plane; station docking attitude maneuvers; Space Shuttle joint operation with the station; cabin de-pressurizations and the station water dumps.For the vibratory environment, results are presented for the following: crew exercise, docking events, and the activation/de-activation of both station life support system hardware and experiment hardware. Finally, a grand summary of all the data collected aboard the station during the 1-year period is presented showing where the overall quasi-steady and vibratory acceleration magnitude levels fall over that period of time using a 95th percentile benchmark. [Copyright &y& Elsevier]

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]

The recent developments in space technology demand various services to uncontrollable satellites, such as refueling and repairing, in order to extend their lifespans. However; there has so far been no research on such practical applications with flexible manipulators. In this paper; we address automated object capture with a two-arm flexible manipulator; which is a basic technology for such services in space. This object capturing strategy includes symmetric cooperative control, visual servoing, the resolution of the inverse kinematics problem and the optimization of the configuration of a two-arm redundant flexible manipulator For the performance improvement on the rise time of the internal forces at the instant of making contact, a transition control strategy is also proposed considering the resultant mechanical compliance associated with the internal forces. Moreover; we present the control system configuration for this task. This control system is based on IBM-compatible personal computers (PCs), and the computational loads for the task execution are distributed to several PCs connected to each other through the Ethernet. The effectiveness of the proposed control system and task sequence is validated with the experiments. [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]

Spacecraft formation flying is a key technology for future astronautics. The relative dynamics of formation flying in eccentric orbits is studied, and the relative motion between spacecrafts is analyzed in this paper. Based on the two-body problem, the extension of Hill equations is achieved and used in relative dynamics of eccentric orbits. Moreover, the transformation of differential variables is applied, and the algebraic solution of the relative motion is obtained, which can be generally used for spacecraft formation flying in eccentric orbits. In addition, the analysis and numerical simulations are given for the relative motion of spacecraft formation flying. The results demonstrate that each spacecraft in eccentric orbits can run in a periodic motion surrounding the master spacecraft under some conditions. And multiple spacecraft can also set up some special formations according to missions. [ABSTRACT FROM AUTHOR]

This paper presents the network architecture, engineering tests and their results for the Trans-Pacific Demonstrations (TPD). The experimental network was configured using an Intelsat satellite, N-STAR, and terrestrial networks in Japan, Canada and the United States. The TransPAC, submarine fiber-optic link was also used as a backup for the Intelsat link. We began to establish the full-scale experimental network in May 2000, and performed the engineering tests during about a two-month period of the TPD. We verified the connectivity of the satellite links, ATM connections, IP and higher layers, and then measured satellite link performance, ATM transmission performance, TCP/XTP performances and so on. As the result of the engineering test, we found that networks that include one or two satellite links can be used as network infrastructure for high data rate applications. [ABSTRACT FROM AUTHOR]

According to the pictures of a sub-meter resolution optical satellite which were acquired on orbit, there is a phenomenon of jitter in the process of taking pictures. As the main attitude control component of the satellite, the flywheel will produce the disturbance in its normal work, which has great influence on the high resolution optical satellite. This paper has respectively researched the flywheel components' disturbance mechanism from four parts, including uneven rotator, rotator friction, bearing disturbance, foundation loose, and builds the mathematical model of disturbance to analyze the characteristics of disturbance. We have simulated and tested the flywheel components' disturbance. The disturbance force of flywheel components is 2 N magnitude and the torque of disturbance is 1.5 N·m magnitude in time domain. The flywheel's infrastructure should be more inflexible especially around 90-100 Hz. For this target high resolution optical satellite, there should be effective damping measures around 48.6 Hz, 190.4 Hz and 285.4 Hz to decrease the flywheel disturbance to guarantee the high precision of the satellite. The result would offer guidance for system optimization design and vibration isolation compensation of the later type of improved satellite or other same type of satellites. [ABSTRACT FROM AUTHOR]

Copyright of Yearbook of European Integration / Rocznik Integracji Europejskiej is the property of Faculty of Political Science & Journalism, Adam Mickiewicz University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: This paper presents the development of solar arrays for Argentine satellite missions performed within the frame of cooperation agreements between the Argentine National Atomic Energy Commission (CNEA) and the Argentine National Commission for Space Activities (CONAE). Relevant issues such as simulation and design, solar cells characterisation, set up of soldering and bonding processes, radiation damage and development of testing techniques, are reviewed. A chamber for testing solar cells and other devices in a simulated space environment, and the integration and tests of two engineering models for qualification of space technology processes are described. The requirements and solar array design for 3 missions, Aquarius/SAC-D and SAOCOM 1A and 1B, are presented. Finally, the flight model for the SAC-D mission, which was launched on 10 June 2011, is outlined, and telemetry data analysis from the first stages of the mission is presented. [Copyright &y& Elsevier]

Abstract: In recent years, there has been continuing interest in the participation of university research groups in space technology studies by means of their own microsatellites. The involvement in such projects has some inherent challenges, such as limited budget and facilities. Also, due to the fact that the main objective of these projects is for educational purposes, usually there are uncertainties regarding their in orbit mission and scientific payloads at the early phases of the project. On the other hand, there are predetermined limitations for their mass and volume budgets owing to the fact that most of them are launched as an auxiliary payload in which the launch cost is reduced considerably. The satellite structure subsystem is the one which is most affected by the launcher constraints. This can affect different aspects, including dimensions, strength and frequency requirements. In this paper, the main focus is on developing a structural design sizing tool containing not only the primary structures properties as variables but also the system level variables such as payload mass budget and satellite total mass and dimensions. This approach enables the design team to obtain better insight into the design in an extended design envelope. The structural design sizing tool is based on analytical structural design formulas and appropriate assumptions including both static and dynamic models of the satellite. Finally, a Genetic Algorithm (GA) multiobjective optimization is applied to the design space. The result is a Pareto-optimal based on two objectives, minimum satellite total mass and maximum payload mass budget, which gives a useful insight to the design team at the early phases of the design. [Copyright &y& Elsevier]

Abstract: Space technology and resources are used around the world to address societal challenges. Space provides valuable satellite services, unique scientific discoveries, surprising technology applications and new economic opportunities. Many developing countries formally recognize the advantages of space resources and pursue national level activity to harness them. There is limited data or documentation on the space activities of developing countries. Meanwhile, traditional approaches to summarize national space activity do not necessarily capture the types of activity that developing countries pursue in space. This is especially true if they do not have a formal national space program or office. Developing countries pursue national space activity through activities of many types—from national satellite programs to commercial use of satellite services to involvement with international space institutions. This research aims to understand and analyze these trends. This paper introduces two analytical frameworks for evaluating space activity at the national level. The frameworks are specifically designed to capture the activity of countries that have traditionally been less involved in space. They take a broad view of space related activity across multiple societal sectors and disciplines. The discussion explains the approach for using the frameworks as well as illustrative examples of how they can be applied as part of a research process. The first framework is called the Mission and Management Ladders. This framework considers specific space projects within countries and ranks them on “Ladders” that measure technical challenge and managerial autonomy. This first method is at a micro level of analysis. The second framework is called the Space Participation Metric (SPM). The SPM can be used to assign a Space Participation score to countries based on their involvement in various space related activities. This second method uses a macro level of analysis. The authors developed both frameworks as part of a long term research program about the space activities of developing countries. This aspect of the research focuses on harnessing multiple techniques to summarize complex, multi-disciplinary information about global space activity. [Copyright &y& Elsevier]

Abstract: This paper analyzes the historical paths of eight countries – from Africa, Asia and Latin America – as they have pursued technological capability in the area of space technology. The analysis is unfolded in three stages. The first stage introduces a framework called the Space Technology Ladder. This Ladder framework posits a path through four major technology categories, as follows: 1) establishing a national space agency; 2) owning and operating a satellite in low Earth orbit; 3) owning and operating a satellite in geostationary orbit; and 4) launching satellites. The second stage of the analysis uses data to create a graphical timeline, by mapping the historical achievements of the eight countries onto the Ladder framework. The results provide information about the similarities and differences in the technology strategies of the various countries. The third stage is a discussion of the strategic decisions faced by the countries under study. Exploring their diverse strategies is an initial step toward developing prescriptive theory to inform developing country space programs. [Copyright &y& Elsevier]

This paper deals with the controller design of the attitude control system of spacecraft. The sliding mode controller was proposed to avoid the influence of parameters' uncertainty and the external disturbance. The delay factor was introduced in the reaching-law to reduce the control torque required by the system, which could save on the payload of the spacecraft. The simulation results are illustrated to verify the designed controller. The effect of improving the stability of the controller is also verified by using the sign function. [ABSTRACT FROM AUTHOR]

Abstract: Since 1971 the UN Programme on Space Applications, implemented by the Office for Outer Space Affairs, has been organizing workshops, symposiums and expert meetings and providing training opportunities in the practical applications of space technology. In 2009 the Office launched the Basic Space Technology Initiative (BSTI). The BSTI encompasses a range of activities in support of capacity building in space technology development in response to the growing interest of academic and governmental organizations in many countries to establish basic, indigenous capabilities to develop nano- and small satellites. Considerations such as the education and training of experts, the creation of required testing and building infrastructure, opportunities for international cooperation and the applicable legal and regulatory frameworks are therefore of particular interest to these organizations. The BSTI aims to assist them with their efforts. This paper describes the origins of the initiative, the activities that have been conducted to date and the work planned for 2011 and beyond. [Copyright &y& Elsevier]

The present paper aims at presenting the state of the art in terms of operational applications of space techniques in Africa, particularly in the fields of Geographic Information Systems, Remote Sensing, and Global Navigation Satellite Systems. The methodology adopted is subdivided into three steps: 1) Assessment of Spatial Data Infrastructure, 2) Analysis of Space Technique Applications, and 3) Education and training of Qualified Human Resources. The assessment of Spatial Data Infrastructure allowed highlighting the African reference frames namely African Doppler Survey, and African Geodetic Reference Frame. This assessment also includes earth observation satellite systems developed by the following countries: Algeria, Egypt, Morocco, Nigeria and South Africa. There are a number of regional organizations, along with a number of Symposia and fora being held at regular basis. Space techniques were used in operational ways to conduct development projects in collaboration with other organizations at national, regional or continental levels: examples of ARTEMIS project for rainfall forecasting, AFRICOVER project for land cover mapping, supported by United Nations Food and Agriculture Organization. CAMELEO and WATERMED projects were conducted respectively for desertification monitoring and water use efficiency in collaboration with the countries of North Africa, which were supported by the European Commission. ROSELT project has been conducted by Sahara and Sahel Observatory. GRID Database and Global Environmental Outlook Reports were established by UNEP. World Bank has also established a series of Environmental Information Systems. The review of space education and training of qualified human resources showed that there are two United Nations Regional Centers for Space Sciences and Technology Education in Nigeria for English speaking countries and in Morocco for French speaking countries. The review also showed that 13 African countries out of 69 countries are member states of the United Nations Committee on Peaceful Uses of Outer Space. In summary, space techniques/applications along with conventional methods are being used in Africa depending on the needs of countries, regions and sub-regions to find out appropriate solutions for natural resources management, environmental monitoring, urban and regional planning, costal and marine ecosystems, environmental impact assessment, hazards and crisis management, health care and socio-economical conditions monitoring. [ABSTRACT FROM AUTHOR]

Abstract: Upcoming space missions utilizing hyperspectral or other high-resolution sensors will generate a vast amount of data in orbit. The average communication duration between a spacecraft in low Earth orbit (LEO) to a dedicated ground station is short and in addition, due to the high amount of data to be transferred at link times, a high-performance communication system on board of the satellite is indispensable. A solution that provides longer acquisition times with the ground station is to employ a high data-rate inter-satellite link to a geostationary relay satellite, which requires a flat, compact, steerable, light-weight yet robust antenna. Such an antenna system (antenna module plus pointing module) was developed for S-Band at the Institute of Astronautics (Technische Universität München), in cooperation with German space companies, research institutes and the German Aerospace Center (DLR). Its successful operation via the geostationary relay satellite Artemis was demonstrated in cooperation with ESA in 2007. This paper describes the evaluation of an antenna system in the Ka-Band, as a successor to be developed in the next two years for high data rates and the various applications of such an antenna system. [Copyright &y& Elsevier]

Abstract: Space technology has the vast potential for addressing a variety of societal problems of the developing countries, particularly in the areas of communication, education and health sectors, land and water resources management, disaster management and weather forecasting. Both remote sensing and communication technologies can be used to achieve this goal. With its primary emphasis on application of space technology, on an end-to-end basis, towards national development, the Indian Space Programme has distinguished itself as one of the most cost-effective and development-oriented space programmes in the world. Developing nations are faced with the enormous task of carrying development-oriented education to the masses at the lower strata of their societies. One important feature of these populations is their large number and the spread over vast and remote areas of these nations, making the reaching out to them a difficult task. Satellite communication (Satcom) technology offers the unique capability of simultaneously reaching out to very large numbers, spread over vast areas, including the remote corners of the country. It is a strong tool to support development education. India has been amongst the first few nations to explore and put to use the Satcom technology for education and development-oriented services to the rural masses. Most of the developing countries have inadequate infrastructure to provide proper medical care to the rural population. Availability of specialist doctors in rural areas is a major bottleneck. Use of Satcom and information technology to connect rural clinics to urban hospitals through telemedicine systems is one of the solutions; and India has embarked upon an effective satellite-based telemedicine programme. Space technology is also useful in disaster warning and management related applications. Use of satellite systems and beacons for locating the distressed units on land, sea or air is well known to us. Indian Space Research Organisation (ISRO) is already a part of the International initiative called Satellite Aided Search and Rescue System. The programme to set up satellite-based Village Resource Centres (VRCs) across India, for providing a variety of services relevant to the rural communities, is also a unique societal application of space technology. The VRCs are envisaged as single window delivery mechanism for a variety of space-based products and services, such as tele-education; telemedicine; information on natural resources for planning and development at local level; interactive advisories on agriculture, fisheries, land and water resources management, livestock management, etc.; interactive vocational training towards alternative livelihood; e-governance; weather information; etc. This paper describes the various possibilities and potentials of Satcom and Remote Sensing technologies for societal applications. The initiatives taken by Indian Space Research Organisation in this direction are highlighted. [Copyright &y& Elsevier]

Abstract: On-board software is a critical element in the operation and functionality of a space system. The functional requirements of space systems can change over time, and unforeseen failures can affect systems performance, thereby necessitating modifications and upgrades to the on-board software. Remote software upgrades as an option, can help space systems in operation to maintain their functionality in an uncertain environment, or even take advantage of uncertainty by adding novel applications or improving functionality while in space. In this paper, the concept of increasing flexibility of space systems through software is defined and some examples are discussed. The author presents a quantitative framework for measuring the value of flexibility in space systems. A case study on a direct broadcast satellite (DBS) is presented and the value of flexibility introduced to the satellite by software upgrade is measured using the flexibility framework. The quantitative flexibility framework allows decision-makers to assess the extent of software flexibility their space systems can exhibit in the face of uncertainty. [Copyright &y& Elsevier]