Electrical Ground Support Equipment Research Articles

Life test result on 4 channel VCELs chip used in 28Gb/s data transfer in space application

For aeronautic applications, in-service Structural Health Monitoring (SHM) is a now established as a key technique to assess the performance and the integrity of composite aircraft structures for real-time in situ monitoring. For space industry, the Assembly Integration and Test including Electrical Ground Support Equipment is an essential tool enabling a satellite or space launcher developer to integrate and validate the electrical functions of its spacecraft before the launching process. In addition, satellite operators and worldwide SatCom manufacturers are willing to improve the on-board processing capacity, functionality and flexibility. In this context, opto-transceiver technology becomes a major building block regarding the highlighted aeronautic, space and ground telecommunication needs.In this context, the paper deals with the robustness evaluation of 850 nm GaAs VCSEL chip on Submount (CoS) used to 4 channel transceivers at 28 Gbit/s. The reliability investigation has been evaluated for two different manufacturers of VCELs and we perform the robustness of the technology regarding the final environment to define the limit usable for space applications. In this paper, we present the first technology of VCSELs. The main failure mechanisms have been defined to establish degradation laws associated. This last action is useful to define the ad equation between technology chosen and mission profile. These results are using for RYTHMS (ReliabilitY of opto-Transceivers for Health Monitoring Systems) Clean sky 2 project.

SpaceART SpaceWire Sniffer for Link Monitoring: A Complete Communication Analysis in a Time-Constrained Test Scenario.

The on-board communication standard adopted in current generation space missions of the European Space Agency, and many other agencies as well, is SpaceWire (SpW). In a SpW network, data are exchanged as well-formed packets, whose structure offers low packet overhead and allows developers to tailor their implementation for SpW applications. The development of SpW-compliant devices requires a specific set of test instruments, namely Electrical Ground Support Equipment (EGSE), to verify the correct functionality of SpW units under test. An example of a SpW EGSE is the SpaceART EGSE Emulator, an EGSE for generation and processing of SpW packets for a time-constrained use-case scenario. This EGSE has been developed to address a mission-related SpW communication between a device and an Instrument Control Unit (ICU). It has allowed the generation and processing of specific SpW packets, which cannot be provided by the mostly used general-purpose SpW EGSEs. In this scope, the SpaceART SpW Sniffer, a SpW link analyser for unobtrusive monitoring of SpW link, has been employed to run a comprehensive set of tests and provide further information on the considered scenario. The SpaceART EGSE Emulator-ICU communication has been thoroughly tested through the SpaceART SpW Sniffer, unobtrusively analysing the exchanged data and allowing to assess the compliance with the defined time constraints from an external point of view. The use of the Sniffer has been crucial for testing the on-board communication, providing important support for the success of the mission employing the tested ICU.

Demonstration of One Hundred Kilogram Xenon Throughput by a Low-Power Hall Thruster

The Hall thruster component of the Ascendant Sub-Kilowatt Transcelestial Electric Propulsion System (known ASTRAEUS) successfully demonstrated a propellant throughput of over 100 kg of xenon and demonstrated a total of of impulse in a long-duration wear test. The thruster was operated for a total of 7205 h, with the test broken into five segments each with a different discharge power between 200 and 1350 W: 3291 h at 300 V/1000 W, 1739 h at 500 V/1000 W, 416 h at 400 V/600 W, 388 h at 200 V/200 W, and 1371 h at 300 V/1350 W. Telemetry and temperature measurements periodically recorded throughout the test revealed constant performance across each test segment and over the full test duration. Each segment was sufficiently long to obtain erosion rate data on the thruster by an optical profilometer. Subnominal magnetic field strengths were inadvertently applied to the thruster during the first 5 khr of the test due to an electrical ground-support equipment issue, which caused a downstream shift of the discharge plasma and higher erosion of the thruster’s pole covers than originally expected. This issue was corrected for the latter three test segments; however, the thruster performance and operational behavior at all reference operating conditions remained unaffected. The long-duration wear test was voluntarily terminated after the thruster processed 100.3 kg of xenon (Xe). This marks the world’s first long-duration wear test of a low-power magnetically shielded Hall thruster with a center-mounted hollow cathode wherein over 100 kg Xe throughput was demonstrated.

위성탑재용 영상레이다의 운용성 검증을 위한 전기적 지상지원장비 설계방안

위성에 탑재되는 영상레이다 시스템은 위성 발사 전 수행되는 지상시험이 매우 중요하게 수행된다. 영상레이다의 운용성은 운용변수의 초기설계 이외에도 이를 운용하고 제어하는 제어장치의 역할이 중요하게 요구된다. 이러한 제어장치의 운용성 시험을 통해 영상레이다의 실제 운용성을 사전 검증할 수 있다. 이러한 시험은 고용량 영상데이터의 통신과 분석을 요구하며 이를 검증하기 위해서는 지상시험을 지원할 수 있는 구성품 모의와 데이터 분석을 위한 다양한 전기적 지상지원장비가 필요하다. 본 논문에서는 영상레이다 운용성 검증을 위한 전기적 지상지원장비의 설계방안을 제시하고, 시험의 자동화 및 분석을 위한 영상레이다 데이터 분석 장비에 대한 설계와 개발방안을 제시하며 실제 위성 영상레이다의 원시 데이터를 입력하여 분석하여 결과를 제시하였다.

On-line pattern discovery in telemetry sequence of micro-satellite

In micro-satellite engineering, telemetry data is the only basis for the ground staffs to judge the condition of spacecraft in-orbit, and is also a critical reference for testing, operation, and Prognostics and Health Management (PHM). In practice, the analysis and processing of raw telemetry data is very complicated and cumbersome. To maintain the micro-satellites' performance and ensure their reliability, it is important to implement on-line interesting pattern discovery in the ground station monitoring system or Electrical Ground Support Equipment (EGSE) system. The goal of this paper is to monitor evolving telemetry sequence of micro-satellite, and to discover subsequences that are similar to the given query sequence, under the Dynamic Time Warping (DTW) distance. However, in the processing of telemetry sequence, massive amounts of data arrive continuously and it is infeasible to directly use DTW distance. Therefore, this paper improves the DTW and proposes a novel method (eDTW) that can perform pattern discovery on telemetry sequence online. First, the sub-sequence time warping matrix is constructed by taking the telemetry sequence as the X-axis and the query sequence as the Y-axis; Second, calculate the DTW distance from each unit, and the initial position of each path; Finally, determine the current local optimal subsequence and determine the next starting point of the next discovery. Experiments with telemetry sequence of Tsinghua University's NS2 satellite show that eDTW can discover interesting pattern quickly, with no buffering of stream values and without comparing pairs of streams. Our experimental case studies show that eDTW can incrementally capture correlations and discover trends, efficiently and effectively.

MTF DETERMINATION OF SENTINEL-4 DETECTOR ARRAYS

Abstract. The Institute for Optical Sensor Systems was involved in many international space projects in recent years. These include, for example, the fokal plane array (FPA) of the hyperspectral sensors ENMAP or Sentinel-4, but also the FPA for the high resolution FPA for Kompsat-3. An important requirement of the customer is the measurement of the detector MTF for different wavelengths. A measuring station under clean room conditions and evaluation algorithms was developed for these measurements. The measurement setup consist of a collimator with slit target in focus for illumination at infinity, a gimbal mounted detector facing an auxiliary lens in front, a halogen lamp with monochromator or filter, as well as optical and electrical ground support equipment. Different targets and therefore also different measurement and data evaluation opportunities are possible with this setup. Examples are slit, edge, pin hole but also a Siemens star. The article describes the measurement setup, the different measuring and evaluation procedures and exemplary results for Sentinel-4 detector.

한국형발사체 발사대 고압가스 공급시스템 소개

한국형발사체 발사대시스템은 지상기계설비, 추진제공급설비, 발사관제설비 그리고 기반시설로 구성된다. 추진제공급설비의 구성품인 고압가스 공급시스템은 우주발사체 발사 운용에 필요한 고압가스를 저장하고 각 사용처에 공급하는 역할을 수행한다. 고압가스 공급시스템은 고압가스 저장부, 조정패널, 제어서브시스템 등으로 구성되며, 조정패널 중 자동패널은 제어기와 연동되어 원격으로 구동이 가능하도록 구축된다. 본 논문에서는 한국형발사체와 발사대시스템 지상설비의 특성을 고려하여 설계된 고압 가스 공급시스템에 대해 소개하고자 한다. The KSLV-II launch complex system consists of mechanical ground support equipment(MGSE), fuel ground support equipment(FGSE), electrical ground support equipment(EGSE) and infrastructures. Compressed gas supply system, as a part of FGSE, is responsible for launch operations such as gas intake, storage, supply to launch vehicle and ground support equipments. This system consists of three primary elements such as gas storage part, control panel and controller. Automatic panels, as a part of control panel, are manufactured to operate remotely by controller. This study presents compressed gas supply system which is designed for KSLV-II and ground support equipment characteristics.

Functional verification and performance tests of an ultra-low shock non-explosive actuator for hold-down and release mechanisms for space applications

This paper addresses the functional verification and performance assessment of an ultra-low shock non-explosive actuator appropriate to space applications of hold-down and release mechanisms. To demonstrate that the design implementation and manufacturing methods have resulted in an engineering model conforming to the set of functional, performance and environmental requirements specified, a space qualification test campaign is typically required. To ensure the readiness of the engineering model and the adequacy of the mechanical and electrical ground support equipment required for the entire qualification test campaign, a set of functional verification procedures and performance characterization tests were systematized and undertaken before the mechanism qualification. A preload monitoring system was developed and calibrated, and the performance of the mechanism was evaluated through the estimation of the release time and the measurement of the self-generated shock. The main results and conclusions taken from these tests are presented and discussed here.

Cost impact of automated acceptance testing of electrical ground support equipment for spacecraft testing

In today's environment, building a reliable and cost effective spacecraft is perhaps emphasized more than ever before. Sponsors are looking for the same high quality products but at lower costs and with shorter schedules. Whether it is a spacecraft for the Department of Defense (DoD), a research observatory for the National Aeronautics and Space Administration (NASA), or a commercial communications satellite, total cost is a significant factor.

Design and performance test of spacecraft test and operation software

Main test processor (MTP) software is the key element of Electrical Ground Support Equipment (EGSE) for spacecraft test and operation used in the Chinese Academy of Space Technology (CAST) for years without innovation. With the increasing demand for a more efficient and agile MTP software, the new MTP software was developed. It adopts layered and plug-in based software architecture, whose core runtime server provides message queue management, share memory management and process management services and forms the framework for a configurable and open architecture system. To investigate the MTP software's performance, the test case of network response time, test sequence management capability and data-processing capability was introduced in detail. Test results show that the MTP software is common and has higher performance than the legacy one.

AN AI ELECTRICAL GROUND SUPPORT EQUIPMENT FOR CONTROLLING AND TESTING A SPACE INSTRUMENT

A versatile and modular electrical ground support equipment (EGSE) system has been developed using artificial intelligence (AI) techniques to control and test the PESCA instrument and the communication process of the satellite without any human supervision. The PESCA instrument has been designed and built with the purpose of studying solar energetic particles and the anomalous cosmic rays. It will be part of the Russian FOTON satellite payload that is scheduled to be launched in December 2007. The tool allows complete and autonomous control, verification, and validation of the PESCA instrument, although its modularity makes it extensible to other onboard instruments.

통신탑재체와 소프트웨어 위성버스체를 통합한 HITL 시뮬레이터의 설계 및 구현

국가우주개발 중장기 계획의 일환으로 "통신방송위성(CBS: Communications and Broadcasting Satellite) 탑재체 개발 사업"이 한국전자통신연구원을 중심으로 국내산업체와 공동으로 추진되었다. 통신탑재체는 Ku대역 및 Ka대역 통신중계기와 안테나로 구성되며, 2000년 5월부터 2003년 4월까지 3년 동안 기술검증모델 탑재체가 개발되었다. 본 사업에서 통신방송위성을 위한 위성버스체는 개발되지 않으므로 위성을 이루는 통신탑재체와 버스체의 구성이 완벽하지 않았다. 이러한 문제를 해결하기 위해 위성버스체를 대신할 소프트웨어 위성시뮬레이터의 개발이 요구되었다. 개발에 적용된 위성버스체는 무궁화위성 버스체를 그 대상 모델로 가정하였다. 독립적으로 존재하는 하드웨어 통신탑재체와 소프트웨어 위성시뮬레이터의 연동은 통신탑재체의 기능 시험 및 검증을 목적으로 개발된 전기적 지상시험장치(EGSE: Electrical Ground Support Equipment)의 전력, 원격명령 및 원격측정 시스템(PCTS: Power, Command and Telemetry System)을 통해 이루어지도록 설계되었다. 이러한 시스템 개발을 통해 하드웨어 통신탑재체와 실시간으로 연동되는 Hardware-in-the-loop(HITL) 통신방송위성 시뮬레이터(CBSSIM: CBS Simulator)를 구현하였다. CBSSIM의 위성버스체 모델은 모멘텀 바이어스 삼축 안정화 방식의 정지궤도 위성이고, CBSSIM은 PCTS와 TCP/IP로 연결되고, 통신탑재체는 DC하니스 및 MIL-STD-1553B로 PCTS와 연결된다. CBSSIM은 실시간 처리부을 통해 통신탑재체와 위성버스체 모델로 원격명령을 전송하며, 통신중계기로부터 실제 원격측정 자료와 위성버스체 모델로부터 생성된 원격측정 자료를 수집한다. CBSSIM은 다양한 그래픽 사용자 인터페이스(GUI: Graphic User Interface)를 통해 위성의 상태를 감시할 수 있으며, 통신위성의 발사 전후 및 궤도 운용시의 상태를 모사할 수 있다. 본 논문에서는 객체지향 기법에 의해 위성버스체를 모사한 CBSSIM과 통신탑재체 및 통신탑재체와 CBSSIM을 연동시키는 PCTS를 포함한 HITL시뮬레이터의 설계 및 구현 내용에 관해 기술한다.에 관해 기술한다. Engineering qualification model payload for a communications and broadcasting satellite(CBS) was developed by ETRI from May, 2000 to April, 2003. For. the purpose of functional test and verification of the payload, a real-time hardware-in-the-loop(HITL) CBS simulator(CBSSIM) was also developed. We assumed that the spacecraft platform for the CBSSIM is a geostationary communication satellite using momentum bias three-axis stabilization control technique based on Koreasat. The payload hardware is combined with CBSSIM via Power, Command and Telemetry System(PCTS) of Electrical Ground Support Equipment(EGSE). CBSSIM is connected with PCTS by TCP/IP and the payload is combined with PCTS by MIL-STD-1553B protocol and DC harness. This simulator runs under the PC-based simulation environment with Windows 2000 operating system. The satellite commands from the operators are transferred to the payload or bus subsystem models through the real-time process block in the simulator. Design requirements of the CBSSIM are to operate in real-time and generate telemetry. CBSSIM provides various graphic monitoring interfaces and control functions and supports both pre-launch and after-launch of a communication satellite system. In this paper, the HITL simulator system including CBSSIM, communications payload and PCTS as the medium of interface between CBSSIM and communications payload will be described in aspects of the system architecture, spacecraft models, and simulator operation environment.

The Rosetta plasma consortium: Technical realization and scientific aims

The Rosetta spacecraft will rendez-vous with comet Wirtanen round 2011 and will study it for a period of nearly two years, thus providing a unique opportunity to monitor its behaviour over a wide range of distances from the Sun. A plasma and wave package, the Rosetta Plasma Consortium, RPC, will be part of the Rosetta orbiter payload. RPC is a highly integrated package that consists of five sensors: the Langmuir Probe, LAP, the Ion and Electron Sensor, IES, the Ion Composition Analyzer, ICA, the Fluxgate Magnetometer, MAG, and the Mutual Impedance Probe, MIP. RPC also includes the common instrument control, spacecraft interface, and power management unit, PIU, plus the Electrical Ground Support Equipment, EGSE. The prime objectives of RPC are to investigate: (1) the physical properties of the cometary nucleus and its surface, (2) the inner coma structure, dynamics, and aeronomy, (3) the development of cometary activity, and the microscopic and macroscopic structure of the solar-wind interaction region as well as the formation and development of the cometary tail. In addition, the planned asteroid, possibly Otawara and Siwa, flybys will provide an excellent opportunity to study in detail the physics of the solar wind-asteroid interaction. The magnetic and electric conductivity properties of the asteroid will also be studied.

The Digital Wave-Processing Experiment on Cluster

The wide variety of geophysical plasmas that will be investigated by the Cluster mission contain waves with a frequency range from DC to over 100 kHz with both magnetic and electric components. The characteristic duration of these waves extends from a few milliseconds to minutes and a dynamic range of over 90 dB is desired. All of these factors make it essential that the on-board control system for the Wave-Experiment Consortium (WEC) instruments be flexible so as to make effective use of the limited spacecraft resources of power and telemetry-information bandwidth. The Digital Wave Processing Experiment, (DWP), will be flown on Cluster satellites as a component of the WEC. DWP will coordinate WEC measurements as well as perform particle correlations in order to permit the direct study of wave/particle interactions. The DWP instrument employs a novel architecture based on the use of transputers with parallel processing and re-allocatable tasks to provide a high-reliability system. Members of the DWP team are also providing sophisticated electrical ground support equipment, for use during development and testing by the WEC. This is described further in Pedersen et al. (this issue).