Determination of attitude motion of the Foton M-2 satellite using the data of onboard measurements of its angular velocity

We present the resutls of a prompt determination of the uncontrolled attitude motion of the Foton M-2 satellite, which was in orbit from May 31 to June 16, 2005. The data of onboard measurements of the angular velocity vector were used for this determination. The measurement sessions were carried out once a day, each lasting 83 min. Upon terminating a session, the data were transmitted to the ground to be processed using the least squares method and integrating the equations of motion of the satellite with respect to its center of mass. As a result of processing, the initial conditions of motion during a session were estimated, as well as parameters of the mathematical model used. The satellite’s actual motion is determined for 12 such sessions. The results obtained in flight completely described the satellite’s motion. This motion, having begun with a small angular velocity, gradually became faster, and in two days became close to the regular Euler precession of an axisymmetric solid body. On June 14, 2005 the angular velocity of the satellite with respect to its longitudinal axis was approximately 1.3 degrees per second, and the angular velocity projection onto a plane perpendicular to this axis had a magnitude of about 0.11 degrees per second. The results obtained are consistent with more precise results obtained later by processing the data on the Earth’s magnetic field measured on the same satellite, and they complement the latter in determination of the motion in the concluding segment of the flight, when no magnetic measurements were performed.     

Uncontrolled motion of the <Emphasis Type="Italic">Foton M-2</Emphasis> satellite and quasistatic microaccelerations on its board

The results of determining the uncontrolled rotational motion of the Foton M-2 satellite (in orbit from May 31 to June 16, 2005) are presented. The determination was made using the data of onboard measurements of the Earth’s magnetic field strength. Segments 270 min long (three orbits) were selected from these data covering the first two thirds of the flight. On each such segment the data were processed jointly by the least squares method using integration of the equations of attitude motion of the satellite. In processing, the initial conditions of motion and parameters of the used mathematical model were estimated. The thus obtained results gave a complete overview of the satellite motion. This motion, having started with a small angular velocity, gradually accelerated, and in two days became close to the regular Euler precession of an axisymmetric solid body. On June 09, 2005 (the last day of measurements) the angular velocity of the satellite relative to its lengthwise axis was about 1.1 deg/s, while the projection of the angular velocity onto a plane perpendicular to this axis had an absolute value of about 0.11 deg/s. Deviations of the lengthwise axis from a normal to the orbit plane did not exceed 60°. Based on the results of determination of the rotational motion of the satellite, calculations of quasi-static microaccelerations on its board are performed.     

奥林普斯(Olympus)卫星的起死回生

1989年7月12日Olympus—1卫星用Ariane—3发射成功。1991年5月29日的事故导致Olympus试验通信卫星失控,结果使卫星漂离定点位置。Olympus调查委员会详细地研究了这些事件。本文综述了由欧洲空间局(ESA)局长主管的Olympus飞行任务营救小组所作的一系列工作。     

鹊桥中继通信卫星在轨运行一年（英文）

Queqiao relay communications satellite was developed to provide relay communications services for the lander and the rover on the far side of the moon. From entering into its halo mission orbit around the Earth-moon libration point 2 on June 14, 2018, it has operated on orbit more than fifteen months. It worked very well and provided reliable, continuous relay communications services for the lander and the rover to accomplish the goals of Chang'e 4 lunar far side soft landing and patrol exploration mission. The on-orbit operation status of Queqiao relay communications satellite is summarized in this paper.     

The use of refined model of aerodynamic moment in the problem of reconstruction of the <Emphasis Type="Italic">Foton</Emphasis> satellite rotational motion

A new mathematical model of the uncontrolled rotational motion of the Foton satellite is presented. The model is based on the Euler dynamic equations of rigid body motion and takes into account the action upon the satellite of four external mechanical moments: gravitational, restoring aerodynamic, moment with constant components in the satellite-fixed coordinate system, and moment arising due to interaction of the Earth’s magnetic field with the satellite’s proper magnetic moment. To calculate the aerodynamic moment a special geometrical model of the outer satellite shell is used. Detailed form of the formulas giving above-mentioned moments in the equations of satellite motion is agreed with the form of the considered motion. Model testing is performed by determining with its help the rotational motion of the Foton M-2 satellite (it was in orbit from May 31, 2005 to June 16, 2005) using the data of the onboard measurements of the Earth’s magnetic field strength. The use of the new model has led to a relatively small improvement in the accuracy of the motion determination, but allowed us to obtain physically real estimates of some parameters.     

SATSIM—A real-time multi-satellite simulator for test and validation in formation flying projects

The satellite simulator SATSIM was developed during the experimental PRISMA multi-satellite formation flying project and was primarily aimed to validate the Guidance, Navigation and Control system (GNC) and the on-board software in a simulated real-time environment. The SATSIM system has as a main feature the ability to simulate sensors and actuators, spacecraft dynamics, intra-satellite communication protocols, environmental disturbances, solar illumination conditions as well as solar and lunar blinding. The core of the simulator consists of MATLAB/Simulink models of the spacecraft hardware and the space environment. The models run on a standard personal computer that in the simplest scenario may be connected to satellite controller boards through a CAN (Controller Area Network) data bus. SATSIM is, in conjunction with the RAMSES Test and Verification system, able to perform open-loop, hardware-in-the-loop as well as full-fledged closed-loop tests through the utilisation of peripheral sensor unit simulators. The PRISMA satellites were launched in June 2010 and the project is presently in its operational phase. This paper describes how a low cost but yet reliable simulator such as the SATSIM platform in different configurations has been used through the different phases of a multi-satellite project, from early test of onboard software running on satellite controller boards in a lab environment, to full-fledged closed-loop tests of satellite flight models.     

Insight-HXMT:China's First X-Ray Astronomical Satellite

The Hard X-ray Modulation Telescope(HXMT) satellite is the first X-ray astronomical satellite in China. Utilizing the "direct demodulation image reconstruction method", HXMT will perform broad band(1-250 keV) survey of large sky areas in scanning mode, which can result in source detection characterized with high sensitivity and spatial resolution. Point observation is another key working mode of HXMT, and is specified for observations of galactic bright sources like X-Ray Binary(XRB) and others. Additionally, HXMT also has a powerful capability developed for monitoring gamma-ray bursts, which is quite unique in the world due to its energy coverage of 200 keV-3 MeV and largest detection area. The HXMT satellite was launched by a Long March 4 B(LM-4 B) rocket from the Jiuquan Satellite Launch Center on June 15, 2017. The payloads onboard HXMT are a High Energy X-ray Telescope(HE), a Medium Energy X-ray Telescope(ME), a Low Energy X-ray Telescope(LE), and a Space Environment Monitor(SEM).This paper introduces the main technical aspects of the satellite, including scientific objectives, technical features, mission design, and system design.     

Determination of <Emphasis Type="Italic">Foton M-2</Emphasis> satellite attitude motion by the data of microacceleration measurements

The results of reconstruction of uncontrolled attitude motion of the Foton M-2 satellite using measurements with the accelerometer TAS-3 are presented. The attitude motion of this satellite has been previously determined by the measurement data of the Earth’s magnetic field and the angular velocity. The TAS-3 data for this purpose are used for the first time. These data contain a well-pronounced additional component which made impossible their direct employment for the reconstruction of the attitude motion and whose origin was unknown several years ago. Later it has become known that the additional component is caused by the influence of the Earth’s magnetic field. The disclosure of this fact allowed us to take into account a necessary correction in processing of TAS-3 data and to use them for the reconstruction of the attitude motion of Foton M-2. Here, a modified method of processing TAS-3 data is described, as well as results of its testing and employing. The testing consisted in the direct comparison of the motion reconstructed by the new method with the motion constructed by the magnetic measurements. The new method allowed us to find the actual motion of Foton M-2 in the period June 9, 2005–June 14, 2005, when no magnetic measurements were carried out.     

ST-5微小卫星与星座及其空间飞行验证——为未来微小卫星的空间应用展现广阔前景

美国NASA于2006年3月22日成功发射三颗ST-5微小卫星,并组成星座,用于空间地磁观测。经过90天飞行演示,于6月20日顺利结束。演示验证很成功。卫星重25kg,功率24W具有通常卫星全部功能。卫星多项先进技术在演示中得到肯定,空间观测获得史无前例的数据。为此,文章介绍了ST-5微小卫星的先进技术和设计经验。ST-5将为今后微小卫星空间应用展现广阔前景。     

Operation and performance of a second generation, solid state, star tracker, the ASC

The Advanced Stellar Compass (ASC) is a second generation star tracker, consisting of a CCD camera and its associated microcomputer. The ASC operates by matching the star images acquired by the camera with its internal star catalogs. An initial attitude acquisition (solving the lost in space problem) is performed, and successively, the attitude of the camera is calculated in celestial coordinates by averaging the position of a large number of star observations for each image. Key parameters of the ASC for the Ørsted satellite and Astrid II satellite versions are: mass as low as 900 g, power consumption as low as 5.5W, relative attitude angle errors less than 1.4 arcseconds in declination, and 13 arcseconds in roll, RMS, as measured at the Mauna Kea, HI observatories of the University of Hawaii in June 1996.     

Design and implementation of the flight dynamics system for COMS satellite mission operations

The first Korean multi-mission geostationary Earth orbit satellite, Communications, Ocean, and Meteorological Satellite (COMS) was launched by an Ariane 5 launch vehicle in June 26, 2010. The COMS satellite has three payloads including Ka-band communications, Geostationary Ocean Color Imager, and Meteorological Imager. Although the COMS spacecraft bus is based on the Astrium Eurostar 3000 series, it has only one solar array to the south panel because all of the imaging sensors are located on the north panel. In order to maintain the spacecraft attitude with 5 wheels and 7 thrusters, COMS should perform twice a day wheel off-loading thruster firing operations, which affect on the satellite orbit. COMS flight dynamics system provides the general on-station functions such as orbit determination, orbit prediction, event prediction, station-keeping maneuver planning, station-relocation maneuver planning, and fuel accounting. All orbit related functions in flight dynamics system consider the orbital perturbations due to wheel off-loading operations. There are some specific flight dynamics functions to operate the spacecraft bus such as wheel off-loading management, oscillator updating management, and on-station attitude reacquisition management. In this paper, the design and implementation of the COMS flight dynamics system is presented. An object oriented analysis and design methodology is applied to the flight dynamics system design. Programming language C# within Microsoft .NET framework is used for the implementation of COMS flight dynamics system on Windows based personal computer.     

Dynamics of Planetary Waves in the Ionosphere as Observed from GPS Satellites

The GPS satellite data are used to study the dynamics of the ionospheric total electron content (TEC) over Central Europe in the summer season from June 23 to September 30, 1996. The TEC variations within the range of periods typical of the planetary waves were found to be nearly synchronous with the neutral wind variations in the mesosphere and with the variations in the occurrence of ionospheric sporadic layers. The observed TEC variations were interpreted as the result of penetration of energy carried by nonstationary Rossby waves to the upper atmospheric altitudes.     

Maiden Flight of Long March 7——The New Generation Medium Launch Vehicle in China

On June 25, 2016, the Long March 7(LM-7) launch vehicle completed its maiden flight successfully. LM-7, as a new generation of medium and basic launch vehicle based on the design concepts of non-toxic and nonpolluting, was developed for the purpose of launching a cargo spacecraft to the Chinese space station. Based on the experience on launching cargo spacecraft and satellites, LM-7 can be adapted for mainstream satellite launch missions in the future with its characteristics of serialization and continuous optimization. LM-7 is expected to be used to launch manned spacecraft in the future. This paper presents a general review of LM-7 with regard to the general scheme and provides references for the development prospects of a medium launch vehicle series in China.     

Effects of small-scale plasma disturbance on the IKB-1300 spacecraft potential

The potential of the Intercosmos-Bulgaria-1300 (IKB-1300) satellite launched to a circular orbit at an altitude ～900 km was measured with several instruments. Care was taken to equalize the potential along the satellite surface. The satellite was placed inside the conducting screen and the solar cells had a metal coating. The satellite potential slightly varied along the trajectory and in the typical case it was “?2”B that corresponds to 5 kTe/e. While the satellite crossed the auroral zone small-scale fluctuations of plasma and field parameters, known as shocks, were recorded. In this region a sharp decrease of the satellite negative potential is often observed. In this case the potential variations well correlate with the increasing flux of energetic electrons. The observed variations can be explained by secondary electron emission from the satellite surface.     

结合卫星遥感的 PM2.5 浓度估算与站点异常分析

针对大气污染难监测、异常数据难分析等问题，充分发挥气象卫星多时相观测优势，以N维代价函数算法为依托进行逐小时气溶胶光学厚度反演。进一步以随机森林回归算法为基础，结合气象参数、地面监测参数等辅助变量进行近地面PM2.5浓度估算，并据此开展时空分布与浓度异常分析。江苏省2021年1–6月PM2.5浓度遥感估算精度验证结果显示，其相关性精度达到94%，偏差为5.59μg/m³，证明以卫星遥感数据为基础进行PM2.5浓度估算具有高可靠性与可行性。通过其建立的全区域、多时相监测体系可有效进行PM2.5浓度的时空分布分析，明晰PM2.5分布状况，助力空气污染治理管控。通过卫星估算结果与地面站点监测结果的对比分析，准确识别大泉街道数据低报事件，验证人为干扰数据采集工作，实现星地数据双向监督。文章研究证明，卫星遥感技术可有效支撑近地面PM2.5浓度估算与数据异常分析，推动新时代生态文明建设。     

卫星双向时间传递中的卫星运动误差研究

对转发卫星运动引入误差进行了研究。推导了卫星双向时间传递中的卫星运动误差模型,用两行轨道根数（TLE）对目前在轨的多颗地球同步轨道卫星（GEO）的运动进行计算。仿真结果显示：GEO卫星的受摄运动导致的卫星运动误差迭数百皮秒,卫星运动规律呈现周日特性,导致1d中不同时刻进行的卫星双向时间传递操作产生不同大小的卫星运动误差。     

Ocean observation and international cooperation

This article reports on the types of effects changes in the oceans can have on the Earth’s atmosphere and climate and on progress in monitoring and understanding these effects with particular reference to the French–US Topex-Poseidon satellite. It discusses the types of results that are now becoming available and describes some of the future satellites that are set to continue Topex–Poseidon’s work. This article was first published in Elsevier’s Nouvelle Revue d’ Aeronautique et d’ Astronautique, No. 3, May–June 1998.     

基于热响应的卫星推进剂剩余量测量方法研究

介绍了基于热响应法的卫星推进剂剩余量在轨测量方法的原理,给出了国外在Telstar 11,LM 3000,BSS601平台日本通信卫星,Turksat 1C卫星的应用情况。给出了将该方法用于国内卫星的设想,并归纳了推进剂在轨空间分布高精度仿真、带液条件下贮箱内复杂传热过程高精度热仿真、贮箱与整星耦合热分析仿真等关键技术。     

伽利略导航试验卫星电子系统设计概述

从2005年12月发射首颗试验卫星以来,欧洲伽利略卫星导航系统建设进入了新的阶段。GIOVE-A卫星平台和有效载荷电子设备的设计体现了当前先进的综合电子系统设计思想,卫星电子系统在集成化、模块化和网络化等方面具备了较高的技术水平。文章调研并分析了伽利略系统首颗试验卫星GIOVE-A的电子系统设计研制和在轨运行情况,可为我国全球导航卫星系统研制提供参考。     

太阳,地球,卫星相关模拟源设计

“风云二号”自旋稳定地球同步气象卫星，以地球脉冲作为姿态控制基准，以太阳脉冲作为图像扫描基准，太阳、地球、卫星三者之间的相对关系在连续不断地运动变化。为了验证扫描成像原理和在地面测试卫星的成像质量，需对三者的相对关系进行研究。在此基础上，研制出太阳、地球、卫星相关模拟源，成功地用电子信号准确模拟“风云二号”卫星在静止轨道上感受到的不断变化的太阳、地球信号，使卫星的成像测试顺利进行，同时发现了卫星设计中存在的问题。