基于FC-1394的空间载荷试验信息系统设计

IEEEl394是一种具有支持等时传输和异步传输的特点的高速串行数据总线,目前已在航天器载荷试验数据传输中得到良好应用,但在未来大型空间飞行器载荷试验信息传输的应用中仍存在重量功耗开销大、传输距离和速率有限等问题.光纤通道作为一种具有良好兼容性、可靠性高、低时延、传输距离远和传输速率高等优点的先进总线技术,可为上层协议提供通用的高速率数据传输通道.基于IEEEl394和光纤通道的基本特性,给出了一种适用于空间载荷试验信息系统的FC-1394桥接方案,并为基于IEEE1394和光纤通道协议映射的空间信息系统数据网络互连提供了一种解决方案.     

天地一体化飞行器测控通信网络体系构建

空间信息综合应用是未来航天的发展趋势,引进网络化技术,打造天地一体化测控通信网是实现信息综合应用的必由之路.一体化测控通信网作为空间信息传输、分发的公共基础设施,将各类飞行器、地/海/空/天基测控站（接收站）及指控中心、测控中心、用户等都作为网中的标准节点,以实现测控通信任务统一指挥控制、飞行器态势综合显示、测控通信资源综合利用和可持续发展.从新时期航天科技的发展特点得出,空间网络化是必然发展趋势.总结了国内外航天网络化发展的研究成果,提出测控通信网络化的定义、未来体系结构以及实施步骤,设计了空间网络化飞行验证试验的基本方案,剖析了空间网络化体系构建的关键技术.     

基于无迹卡尔曼滤波法的串联型电池系统 荷电状态估计研究

以锂离子电池为载体的电源系统为航天器稳定可靠运行提供了一种有效的方式.多个电池单体经串联可扩大电池系统容量,即串联型电池系统.为准确估计串联型锂离子电池系统的荷电状态(State of Charge,SOC),针对扩展卡尔曼滤波(Extended Kalman Filter,EKF)计算复杂、精度不高等问题,结合串联型电池系统空间状态方程,提出基于无迹卡尔曼滤波法(Unscented Kalman Filter,UKF)的串联型电池系统荷电状态估计算法.在恒流和脉冲两种工况下,通过对比分析UKF与EKF算法的仿真结果与实验数据的匹配情况,证明了提出算法的准确性和高鲁棒性.     

Gaussian pigeon-inspired optimization approach to orbital spacecraft formation reconfiguration

With the rapid development of space technology, orbital spacecraft formation has received great attention from international and domestic academics and industry. Compared with a single monolithic, the orbital spacecraft formation system has many advantages. This paper presents an improved pigeon-inspired optimization(PIO) algorithm for solving the optimal formation reconfiguration problems of multiple orbital spacecraft. Considering that the uniform distribution random searching system in PIO has its own weakness, a modified PIO model adopting Gaussian strategy is presented and the detailed process is also given. Comparative experiments with basic PIO and particle swarm optimization(PSO) are conducted, and the results have verified the feasibility and effectiveness of the proposed Gaussian PIO(GPIO) in solving orbital spacecraft formation reconfiguration problems.     

中国航天器新型热控系统构建进展评述

热控是由工程热物理与航天技术相互促进发展而形成的一门交叉学科，直接影响着航天器的总体设计水平。随着中国航天事业的飞速发展，对热控设计提出了越来越高的要求，并已成为制约中国航天器设计水平的关键瓶颈技术之一。本文综合评述了中国航天器新型热控系统构建的最新研究成果和进展，具体包括：针对载人航天、探月工程等不同任务需求，构建出了相应的新型热控系统，开发出了以泵驱单相流体回路、重力驱动两相流体回路、环路热管与水升华器等为代表的一批新型热控产品。在此基础上，结合中国航天工程实际需求，指出了今后的主要研究方向。     

Minus 35kV Space-Borne Instrument Power Supply

A -35kV power supply has been developed for a plasma experiment on the out-of-ecliptic mission. In addition, an isolation transformer has been developed to provide low voltage power at the -35kV potential. The design features incorporated to produce a spaceflight power supply housed within a 4 × 4 × 2.5 in package are discussed. The supply is powered from an unregulated spacecraft bus and provides a regulated output of -35kV ± 5 percent with less than 0.5 percent ripple over a temperature range -20°C + 60°C. The unit serves as a bias supply with an output current less than 0.5 , ?A. With the supply essentially operating unloaded, 5 percent regulation is achieved by sensing and regulating the first stage of a 12-stage Cockcroft/Walton multiplier. Control of the ac voltage input to the multiplier stack provides the regulation. The isolation transformer utilizes a ferrite u-core with the primary and secondary windings placed on opposite legs for separation. The transformer is encapsulated with the power supply.     

International Space Station power storage upgrade planned

As the Earth-orbit International Space Station (ISS) grows, it needs more power which is generated by solar panels. For periods in which the planet Earth occults sunlight, energy is stored in the biggest set of batteries ever flown in space. Reliability of power is important in a space station because a failure requires costly launch of replacement components. Even greater importance results when astronauts work in the station. A power failure that causes the astronauts to perish would be a very serious event. The first battery-containing "integrated equipment module" was launched November 30, 2000 and installed on port 6 of the International Space Station. Two more modules will be launched by the United States; to be launched in 2004 is the European Space Agency's "attached COLUMBUS APM laboratory," which will have its own power system. Unexpected battery-related events occurred in the integrated equipment module during its first year-and-a-half in orbit. The problems and their solutions were described in papers presented at the 37/sup th/ Intersociety Energy Conversion Engineering Conference. Since the International Space Station carries more battery cells than any other spacecraft, the in-flight performance data from its battery assembly can be useful to engineers who design power supplies for other spacecraft. We, therefore, summarize the battery development process, the adopted design, and an unexpected in-flight battery degradation and its correction.     

Aerospace High Voltage Development

High voltage has been used for electrical power system generation, transmission, and distribution for over 75 years and manufacturers have been designing x-rays, radios/television transmitters and receivers for many years with excellent success. High voltage usage in aerospace equipment initiated during World War II with the advent of high power communications and radar for airplanes. About 20 years ago the first high voltage components were built for spacecraft systems. This article is to provide some insight into the status of high voltage for aerospace equipment and the differences between terrestial and aerospace system functions and the attendant problems. What are the basic differences between terrestial/commercial and aerospace equipment? The aerospace environment is defined as that significantly above the Earth's surface: From 5000 feet altitude to deep space. The basic differences are the constraints placed on the user vehicle (airplane, missile, or spacecraft). Constraints include: Atmospheric pressure, temperature, lifting capability, electronic requirements, and volume. Early airplanes needed only radios and mechanical pressurization instruments. Today's sophisticted airplanes require transmitters, receivers, controls, displays, and in the military case, special electronics. The addition of electronic devices has increased the electrical power demand from a few watts (for early aircraft) to well over one megawatt for special applications. There is the need for compact packaging to reduce weight and volume. Spacecraft with booster limitations are ever more restrictive of weight and volume then airplanes while they must maintain complete electrical system integrity for mission durations of several months to years.     

Parametric cost model for solar space power and DIPS systems

A detailed cost model has been developed to parametrically determine the program development and production cost of photovoltaic, solar dynamic, and dynamic isotope (DIPS) space power systems. The model is applicable in the net electrical power range of 3 to 300 kWe for solar power and 0.5 to 10 kWe for DIPS. Application of the cost model allows spacecraft or space-based power system architecture and design trade studies or budgetary forecasting and cost benefit analyses. The cost model considers all major power subsystems (i.e., power generation, power conversion, energy storage, thermal management, and power management/distribution/control). It also considers system cost effects such as integration, testing, and management. The cost breakdown structure, model assumptions, ground rules, bases, cost estimation relationship format, and rationale are presented, and the application of the cost model to 100-kWe solar space power plants and to a 1.0-kWe DIPS is demonstrated     

航天器进入制导方法综述

航天器制导系统的设计至关重要,直接关乎航天器能否安全返回地球或着陆行星表面指定区域。在给出航天器进入动力学模型的基础上,首先分析了进入制导问题建立及难点,然后综述了航天器进入制导方法的研究现状,分析了各类进入制导方法的优缺点。作为统一或通用方法,介绍了实际应用于中国航天工程再入返回的自适应预测校正制导方法。面向未来发展亟待解决的问题,在线快速规划可行轨迹的重要性凸显,分析了在线轨迹规划方法所需要解决的问题以及今后进入制导方法的发展方向。     

Recent advances in precision measurement & pointing control of spacecraft

There exists an increasing need for precision measurement & pointing control and extreme motion stability for current and future space systems, e.g., Ultra-Performance Spacecraft (UPS). Some notable technologies of realizing Ultra-Pointing (UP) ability have been developed particularly for Ultra-accuracy Ultra-stability Ultra-agility (3U) spacecraft over recent decades. Usually, Multilevel Compound Pointing Control Techniques (MCPCTs) are deployed in aerospace engineering, especially in astronomical observation satellites and Earth observation satellites. Modern controllers and/or algorithms, which are a key factor of MCPCTs for 3U spacecraft, especially the jitter phenomena that commonly exist in a UPS Pointing Control System (PCS), have also been effectively used in some UP spacecraft for a number of years. Micro-vibration suppression approaches, however, are often proposed to deal with low-level mechanical vibration or disturbance in the microgravity environment that is common for UPS. This latter approach potentially is one of the most practical UP techniques for 3U tasks. Some emerging advanced Disturbance-Free Payload (DFP) satellites that exploit the benefits of non-contact actuators have also been reported in the literature. This represents an interesting and highly promising approach for solving some challenging problems in the area. This paper serves as a state-of-the-art review of UP technologies and/or methods which have been developed, mainly over the last decade, specifically for or potentially could be used for 3U spacecraft pointing control. The problems discussed in this paper are of reference significance to UPS and millisecond optical sensors, which are involved in Gaofeng Project, deep space exploration, manned space flight, and gravitational wave detection.     

Energy and power

Energy sources for aerospace systems include electrochemicals, mechanical rotation, solar illumination, radioisotopes, and nuclear reactors. Energy is converted to power with engines, turbines, photovoltaics, thermoelectric and thermionic devices, and electrochemical processes. Although some early spacecraft flew with battery power, for longer flights the choice has been either solar or nuclear. Manned spacecraft must have power for the total mission duration including boost into orbit, on-orbit, and subsequent re-entry. Batteries are too heavy for extended manned space missions; tradeoff study alternatives range from radioisotope heated thermionic converters to hyperbolic-fueled engines. Arrays of solar cells are the obvious choice for powering space stations and for other extended-duration missions. This article emphasizes developments for space and airplane power systems. Enabling technologies are described along with significant spin-offs and future systems     

航天器空间辐射防护材料与防护结构

电子、质子、重离子、光子等空间辐射环境可在航天器材料或元器件中产生单粒子效应、总剂量效应、表面充放电效应、位移损伤效应、内带电效应等,因此,需要对航天器进行空间辐射防护。本文首先介绍空间辐射防护原理和防护有效性,进而从材料、分系统(或部组件)、航天器3个不同维度,对质量屏蔽防护材料、静电防护材料、抗辐射功能材料、航天器局部辐射防护结构和整星辐射防护结构进行了探讨,最后对未来发展的方向进行了讨论。     

POWOW: power without wires: a SEP concept for space exploration

Electric propulsion has emerged as a cost-effective solution to a wide range of satellite applications. Deep Space 1 successfully demonstrated electric propulsion as the primary propulsion source for a satellite. The POWOW concept is a solar-electric propelled spacecraft capable of significant cargo and short trip times for traveling to Mars. It would enter aerosynchronous orbit and from there, beam power to surface installations via lasers. The concept has been developed with industrial partner expertise in high efficiency solar cells, advanced concentrator modules, innovative arrays, and high power electric propulsion systems. The latest version of the spacecraft, the technologies used, and trip times to Mars are presented. The POWOW spacecraft is a general purpose solar electric propulsion system that uses new technologies that are directly applicable to commercial and government spacecraft with power levels ranging from a LEO power level of 4 kW up to GEO spacecraft about 1 MW. The system is modular, expandable, and amenable to learning curve cost projection methods     

New architectures for space power systems

Electric power generation and conditioning have experienced revolutionary development over the past two decades. Furthermore, new materials such as high energy magnets and high temperature superconductors are either available or on the horizon. Our work is based on the premise that new technologies are an important driver of new power system concepts and architectures. This observation is borne out by the historical evolution of power systems both in terrestrial and aerospace applications. This paper introduces new approaches to designing space power systems by using several new technologies. Two new architectures are introduced: the current source current intensive system and the articulate system. Basic characteristics of these systems have been investigated. Some aspects of the articulate system architecture, as discussed in this paper can be implemented in the short term. Flexible AC transmission systems which are now undergoing rapid development and implementation, can be regarded as a subset of the family of control methodologies which constitute the realm of articulate systems     

Thermodynamic cycles for spacecraft power plants

A problem of applying closed multiloop thermodynamic cycles with mixing of dissimilar working gases in spacecraft power plants has been considered. The advantage of these cycles that is due to reduction of a heat quantity being rejected into space has been shown for ecologically clean generation of electric energy in prolonged space flights.     

Comparison of Bit Synchronization Schemes Using AM and Summed Clocks

This paper considers bit synchronization through the use of a separate clock signal which is either amplitude modulated onto or summed with the data signal. For continuous data transmission, such schemes are known to be inferior, in the sense of efficient use of power, to schemes which derive synchronization directly from the data signal. However, these techniques have application in burst systems such as spacecraft command systems, and in systems where receiver simplicity is more important than power conservation. For systems in which the composite data-clock signal subsequently modulates an RF carrier, it is shown that the summed clock signal performs slightly better than the AM clock signal, and that for both signal types, the optimum allocation of power between data and clock is approximately 9:1.     

AMTEC cells challenge energy converters

Sodium-base alkali-metal-thermal-to-electric conversion (AMTEC) cells have been receiving attention. Recently they were selected for the next generation deep-space missions, which need a converter that makes electricity from radioisotope heat. The AMTEC cell, being an electrochemical converter of heat to electricity, has no moving parts and is not limited to Carnot-cycle efficiency. However, its heat source and sink have to be near each other, so the challenge in AMTEC design is to minimize thermal losses and maximize electricity production. This required clever thermal designs. By 1991, high-temperature materials and computer modeling became available. The important AMTEC application was generating power from radioisotope heat in deep space missions. These spacecraft power needs had previously been supplied by inefficient thermoelectric converters     

An equivalent ground thermal test method for single-phase fluid loop space radiator

Thermal vacuum test is widely used for the ground validation of spacecraft thermal control system. However, the conduction and convection can be simulated in normal ground pressure environment completely. By the employment of pumped fluid loops’ thermal control technology on spacecraft, conduction and convection become the main heat transfer behavior between radiator and inside cabin. As long as the heat transfer behavior between radiator and outer space can be equivalently simulated in normal pressure, the thermal vacuum test can be substituted by the normal ground pressure thermal test. In this paper, an equivalent normal pressure thermal test method for the spacecraft single-phase fluid loop radiator is proposed. The heat radiation between radiator and outer space has been equivalently simulated by combination of a group of refrigerators and thermal electrical cooler(TEC) array. By adjusting the heat rejection of each device, the relationship between heat flux and surface temperature of the radiator can be maintained. To verify this method,a validating system has been built up and the experiments have been carried out. The results indicate that the proposed equivalent ground thermal test method can simulate the heat rejection performance of radiator correctly and the temperature error between in-orbit theory value and experiment result of the radiator is less than 0.5 C, except for the equipment startup period. This provides a potential method for the thermal test of space systems especially for extra-large spacecraft which employs single-phase fluid loop radiator as thermal control approach.     

磁强计在航天器上的应用与前景

随着科学的进步,磁强计已被广泛地应用于航天器.本文首先根据磁强计测量原理的不同,对其进行分类.分别介绍各类磁强计的物理测量原理,描述其特性、精度、适用范围.同时概括目前在航天器得到较广泛应用的磁强计.在此基础上,进一步具体分析磁强计作为卫星载荷、姿态测量和控制以及自主导航轨道计算的方法、作用和特点.然后,针对这三个方面应用指出其在航天器上应用存在主要问题和关键技术.最后,对磁强计在航天器上的应用进行总结.同时对其未来的发展进行展望,磁强计在航天器上仍有着良好发展前景.