Quality management for space systems in ISRO

In a little over four decades, the Indian Space Program has carved a niche for itself with the unique application driven program oriented towards National development. The end-to-end capability approach of the space projects in the country call for innovative practices and procedures in assuring the quality and reliability of space systems. The System Reliability (SR) efforts initiated at the start of the projects continue during the entire life cycle of the project encompassing design, development, realisation, assembly, testing and integration and during launch. Even after the launch, SR groups participate in the on-orbit evaluation of transponders in communication satellites and camera systems in remote sensing satellites. SR groups play a major role in identification, evaluation and inculcating quality practices in work centres involved in the fabrication of mechanical, electronics and propulsion systems required for Indian Space Research Organization's (ISRO's) launch vehicle and spacecraft projects. Also the reliability analysis activities like prediction, assessment and demonstration as well as de-rating analysis, Failure Mode Effects and Criticality Analysis (FMECA) and worst-case analysis are carried out by SR groups during various stages of project realisation. These activities provide the basis for project management to take appropriate techno-managerial decisions to ensure that the required reliability goals are met. Extensive test facilities catering to the needs of the space program has been set up. A system for consolidating the experience and expertise gained for issue of standards called product assurance specifications to be used in all ISRO centres has also been established.     

Goals and preparation method for ground operations for the manned space flight Altair

The mission's success fully depends on the Payload Operations conducted during the space flight. The Ground Team has to be trained to assist the Space Crew, to replan the cosmonaut's activities when contingengies occurr onboard and to change or cancel Payload activities when required. In order to act efficiently during the mission, the Ground Team must be prepared in advance of the flight and able to operate special tools for tracking the mission's progress, anticipating problems and taking decisions in realtime.

This document sets out the approach for conducting such a preparation for Ground Operation. It will be focused on the Altaïr mission performed in July 1993 onboard the Russian Mir space station.     

Cross-cultural issues in space operations: A survey study among ground personnel of the European Space Agency

Today's space operations involve co-working of people with different ethnical, professional and organisational backgrounds. The aim of this study was to examine the implications of cultural diversity for efficient collaboration within the European Space Agency (ESA), and between ESA employees and representatives from other agencies. ESA employees from European countries (N=576) answered to the CULT Ground Survey. The results showed that differences in relation to leadership and decision making were the most important issues thought to interfere with efficient co-working within ESA, and between ESA employees and colleagues from other agencies. Employees who collaborated with more than three nationalities within ESA indicated most challenges in co-working due to differences in compliance, behavioural norms and competitiveness. Challenges in co-working differed between agencies, and these differences were consistent with value differences in the national populations. The results may have applied value for training of European employees working in international space program teams.     

Cross-cultural issues in space operations: A survey study among ground personnel of the European Space Agency

Today's space operations involve co-working of people with different ethnical, professional and organisational backgrounds. The aim of this study was to examine the implications of cultural diversity for efficient collaboration within the European Space Agency (ESA), and between ESA employees and representatives from other agencies. ESA employees from European countries (N=576) answered to the CULT Ground Survey. The results showed that differences in relation to leadership and decision making were the most important issues thought to interfere with efficient co-working within ESA, and between ESA employees and colleagues from other agencies. Employees who collaborated with more than three nationalities within ESA indicated most challenges in co-working due to differences in compliance, behavioural norms and competitiveness. Challenges in co-working differed between agencies, and these differences were consistent with value differences in the national populations. The results may have applied value for training of European employees working in international space program teams.     

对信息作战中赛博空间作战的理解

针对信息作战中赛博空间作战的理解问题,分析和总结了赛博空间的发展、概念、组成、特征、武器、作战过程以及信息作战同赛博空间作战的关系,得到了赛博空间作战对军事发展的启示。结果表明,信息作战同赛博空间作战具有较强的交叉性,而且信息作战涵盖了赛博空间作战。     

地-地战术导弹全程惯性制导弹道技术

利用比例导引弹道原理及弹道仿真,分析了150~250 km射程范围地-地战术导弹全程惯性制导弹道的设计原理。其弹道特征一般由熄火点、转弯点、俯冲点和目标点4个特征点组成,射程的改变通过改变转弯点、俯冲点和目标点3点的参数实现。通过弹道仿真研究,给出了各特征点的功能和选取原则,分析了全程制定控制弹道方案的优缺点。     

在课堂教学中提高学生英语学习的自主性

自主性学习在语言学习过程中发挥着不可估量的作用。论文阐释了学习自主性的涵义，探讨了课堂教学与英语自主学习之间的关系，从四个方面论述了课堂教学应如何帮助学生提高英语学习的自主性，并提出了实践过程中所应注意的问题。     

电磁频谱战作战样式初探

针对目前热议的电磁频谱战概念能力开发问题,在分析对比国内外电磁频谱战概念内涵基础上,给出了电磁频谱战定义.研究了电磁频谱战主要活动,给出了电磁频谱战作战样式,为电磁频谱战能力开发提供指导.     

The multicriteria approach for cost and specification optimization in space operations

The multicriteria approach, by its formalised and operational character, is a methodology well adapted to take into account simultaneously costs and other criteria (time scales, political criteria) from the beginning of the design phase.     

Development and verification of ground-based tele-robotics operations concept for Dextre

The Special Purpose Dextreous Manipulator (Dextre) is the latest addition to the on-orbit segment of the Mobile Servicing System (MSS); Canada's contribution to the International Space Station (ISS). Launched in March 2008, the advanced two-armed robot is designed to perform various ISS maintenance tasks on robotically compatible elements and on-orbit replaceable units using a wide variety of tools and interfaces. The addition of Dextre has increased the capabilities of the MSS, and has introduced significant complexity to ISS robotics operations. While the initial operations concept for Dextre was based on human-in-the-loop control by the on-orbit astronauts, the complexities of robotic maintenance and the associated costs of training and maintaining the operator skills required for Dextre operations demanded a reexamination of the old concepts. A new approach to ISS robotic maintenance was developed in order to utilize the capabilities of Dextre safely and efficiently, while at the same time reducing the costs of on-orbit operations. This paper will describe the development, validation, and on-orbit demonstration of the operations concept for ground-based tele-robotics control of Dextre. It will describe the evolution of the new concepts from the experience gained from the development and implementation of the ground control capability for the Space Station Remote Manipulator System; Canadarm 2. It will discuss the various technical challenges faced during the development effort, such as requirements for high positioning accuracy, force/moment sensing and accommodation, failure tolerance, complex tool operations, and the novel operational tools and techniques developed to overcome them. The paper will also describe the work performed to validate the new concepts on orbit and will discuss the results and lessons learned from the on-orbit checkout and commissioning of Dextre using the newly developed tele-robotics techniques and capabilities.     

Structured methods for identifying and correcting potential human errors in space operations

Human performance plays a significant role in the development and operation of any complex system, and human errors are significant contributors to degraded performance, incidents, and accidents for technologies as diverse as medical systems, commercial aircraft, offshore oil platforms, nuclear power plants, and space systems. To date, serious accidents attributed to human error have fortunately been rare in space operations. However, as flight rates go up and the duration of space missions increases, the accident rate could increase unless proactive action is taken to identity and correct potential human errors in space operations. The Idaho National Engineering and Environmental Laboratory (INEEL) has developed and applied structured methods of human error analysis to identify potential human errors, assess their effects on system performance, and develop strategies to prevent the errors or mitigate their consequences. These methods are being applied in NASA-sponsored programs to the domain of commercial aviation, focusing on airplane maintenance and air traffic management. The application of human error analysis to space operations could contribute to minimize the risks associated with human error in the design and operation of future space systems.     

测控中的近地轨道卫星SEL事件分析及操控

针对空间辐射环境影响下近地卫星某器件单粒子锁定（SEL）事件频发现象,在分析卫星轨道根数演变的基础上,详细讨论SEL事件时空分布特征。结果表明,SEL事件的星下点分布具有明显地域特征,其在南大西洋区域、南北两极区域、其他区域的比例接近于3∶2∶1;器件SEL事件平均发生率略高于0.134 d-1,太阳活动较强时的发生率不足0.103 d-1,而太阳活动较弱时则接近0.165 d-1;近日点附近时的发生率达到0.200 d-1,远日点附近时约为0.072 d-1。在测控中,针对SEL事件进行遥控作业自动识别与处理,操控时长平均为130 s。     

对地面军事电磁信息的天际防护系统

针对当前空间电子侦察、空间对抗的严峻形势,提出对地面军事电磁信息的天际防护系统。即针对有大量侦察卫星对地面防御系统所有电磁辐射信号进行侦收的现实,采取有效的反侦察措施,以适应太空作战制信息权任务的需求。明确了天际防护系统的作战使命以及应具备的主要功能,给出了系统的简要组成框图,具体分析了对地面电磁辐射信息的天际防护的相关问题,也提出了防护星组的布局问题等。最后,归纳了天际防护系统所应该专门研究的几个主要问题。     

Portable end-to-end ground system for low-cost mission support

This paper presents a revolutionary architecture of the end-to-end ground system to reduce overall mission support costs. The present ground system of the Jet Propulsion Laboratory (JPL) is costly to operate, maintain, deploy, reproduce, and document. In the present climate of shrinking NASA budgets, this proposed architecture takes on added importance as it should dramatically reduce all of the above costs. Currently, the ground support functions (i.e., receiver, tracking, ranging, telemetry, command, monitor and control) are distributed among several subsystems that are housed in individual rack-mounted chassis. These subsystems can be integrated into one portable laptop system using established Multi Chip Module (MCM) packaging technology and object-based software libraries. The large scale integration of subsystems into a small portable system connected to the World Wide Web (WWW) will greatly reduce operations, maintenance and reproduction costs. Several of the subsystems can be implemented using Commercial Off-The-Shelf (COTS) products further decreasing non-recurring engineering costs. The inherent portability of the system will open up new ways for using the ground system at the “point-of-use” site as opposed to maintaining several large centralized stations. This eliminates the propagation delay of the data to the Principal Investigator (PI), enabling the capture of data in real-time and performing multiple tasks concurrently from any location in the world. Sample applications are to use the portable ground system in remote areas or mobile vessels for real-time correlation of satellite data with earth-bound instruments; thus, allowing near real-time feedback and control of scientific instruments. This end-to-end portable ground system will undoubtedly create opportunities for better scientific observation and data acquisition.     

Statistical method for ground and sky coverage calculation

A novel statistical method has been devised for evaluating the ground and the sky coverage of an observation experiment on board a satellite. Owing to its unrivalled rapidity compared with other conventional calculation techniques, the method can be applied to evaluate the coverage percentages for the whole globe or any area on it, to calculate the visibility percentages for one or more ground stations and to determine the percentages of observation time of any given celestial direction including Sun, Moon, Earth and Ground Stations constraints. The orbits considered can be elliptical and account is taken of the drift due to the Earth's oblateness.     

载人航天器地面试验验证体系研究

在载人航天器的研制过程中,地面试验验证是保证产品在实际应用环境中正常运行、满足任务要求的主要手段之一。文章在对载人航天器试验技术与方法调研的基础上,系统总结了载人航天器试验覆盖性分析和验证的成功经验,提出了载人航天器系统级试验规划设计方法,找出了系统试验验证技术的薄弱环节。结合载人航天后续任务的特点,从试验管理、试验覆盖性分析、仿真与试验的协调、新型试验技术、试验基础设施等5个方面提出了载人航天器试验技术发展方向和需重点解决的问题,可为后续载人航天器的研制和试验技术发展提供支持。     

The European Astronaut Centre prepares for International Space Station operations

The European Space Agency (ESA) contribution to the International Space Station (ISS) goes much beyond the delivery of hardware like the Columbus Laboratory, its payloads and the Automated Transfer Vehicles. ESA Astronauts will be members of the ISS crew. ESA, according to its commitments as ISS international partner, will be responsible to provide training on its elements and payloads to all ISS crewmembers and medical support for ESA astronauts. The European Astronaut Centre (EAC) in Cologne has developed over more than a decade into the centre of expertise for manned space activities within ESA by contributing to a number of important co-operative spaceflight missions. This role will be significantly extended for ISS manned operations. Apart from its support to ESA astronauts and their onboard operations, EAC will have a key role in training all ISS astronauts on ESA elements and payloads. The medical support of ISS crew, in particular of ESA astronauts has already started. This paper provides an overview on status and further plans in building up this homebase function for ESA astronauts and on the preparation towards Training Readiness for ISS crew training at EAC, Cologne. Copyright 2001 by the European Space Agency. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. Released to IAF/IAA/AIAA to publish in all forms.     

GPS based onboard and onground orbit operations for small satellites

In extension to common applications such as groundtrack displays and antenna steering, the SGP4 orbit model is proposed for operational orbit determination in small satellite missions. SGP4 is an analytical orbit model for Low-Earth orbiting satellites that is widely used for the propagation of NORAD twoline elements. Twoline elements may hence be generated completely independent of NORAD. Their use as exclusive source of orbital information simplifies the operations concept and reduces mission costs through the extensive use of existing low-cost mission support software. Due to small computer resource requirements of 8–10kByte, the SGP4 model may also be applied for onboard orbit computations making use of e.g. a 80186 processor, thus ensuring full compatibility of ground-based and onboard operations. The proposed approach is particularly suited in combination with a space-borne GPS receiver, were the C/A-code navigation solutions are treated as measurements that are adjusted in a least-squares sense using the SGP4 model. As consequence, inherent drawbacks of the pure navigation solutions such as data gaps and scatter as well as limited velocity accuracy are avoided, while the operational navigation activities are kept at a minimum. The feasibility of the concept is illustrated based on real GPS navigation data from the TOPEX/Poseidon and the MIR space station with an inherent data quality of 50–100 m. It is shown that 3 hours of data within a 4 day period are sufficient to keep the position error within 4 km, that is considered sufficient for most applications.     

Human roles in future space operations.

Mankind has evolved in the biosphere from essentially another animal to the level that his industries and societies are powerful components of the life-cycles of Earth. Terrestrial industrial experience can be extended to the use of matter from the Moon and other non-terrestrial sources to create permanent habitats and industry in space. Space stations in low Earth orbit and small bases on the Moon can be the foci of early space industries for learning how to grow in space with local resources. Several near term and long range research topics appropriate to permanent human occupancy of space are reviewed.     

浅谈如何提高大一新生公共外语自主学习的策略

随着改革开放进程的加快我国社会迅猛向前发展,与此同时推动我国与国际世界的交往日益频繁,因此培养大量的有专业知识和技能同时能够熟练掌握一门外语的高级专业人才成为我国社会的紧迫任务。对于在校非英语专业的大学生来说,他们把大量时问都花在了本专业知识的学习上,因此英语学习时间就变得捉襟现肘,所以培养他们英语自主学习能力进而提高其英语学习效率就变得尤为重要。本文将首先介绍自主学习定义,然后阐述提倡自主学习的必要性,最后研究总结出如何提高非专业大一新生大学英语自主学习能力的策略。