2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)最新文献

{"title":"Design of hybrid mobile communication networks for planetary exploration","authors":"R. Alena, J. Ossenfort, C. Lee, E. Walker, T. Stone","doi":"10.1109/aero.2004.1367716","DOIUrl":"https://doi.org/10.1109/aero.2004.1367716","url":null,"abstract":"The mobile exploration system project (MEX) at NASA Ames Research Center has been conducting studies into hybrid communication networks for future planetary missions. These networks consist of space-based communication assets connected to ground-based Internets and planetary surface-based mobile wireless networks. These hybrid mobile networks have been deployed in rugged field locations in the American desert and the Canadian arctic for support of science and simulation activities on at least six occasions. This work has been conducted over the past five years resulting in evolving architectural complexity, improved component characteristics and better analysis and test methods. A rich set of data and techniques have resulted from the development and field testing of the communication network during field expeditions such as the Haughton Mars project and NASA mobile agents project. This paper defines design, analysis and test methods for hybrid mobile communication networks, identifying the key issues and constraints that affect performance in both the radio frequency (RF) and network engineering disciplines. Previous work by the MEX team has addressed the architecture and detailed analysis of wireless networks including the results of field tests. We continue the analysis using a new 802.11b backbone utilizing two repeaters that significantly increase range and coverage but greatly increase latency, which reduces overall network throughput. The addition of a satellite link can result in significant additional throughput loss due to light-speed delays in the space segment interacting with variable latencies in the multi-hop wireless network. The paper analyzes and presents RF domain field test results combined with network performance metrics which describe a comprehensive approach for designing and optimizing future hybrid mobile networks.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125588237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Demonstration of single axis combined attitude control and energy storage using two flywheels","authors":"Barbara H. Kenny, Ralph H. Jansen, P. Kascak, T. Dever, Walter Santiago","doi":"10.1109/aero.2004.1368077","DOIUrl":"https://doi.org/10.1109/aero.2004.1368077","url":null,"abstract":"The energy storage and attitude control subsystems of the typical satellite are presently distinct and separate. Energy storage is conventionally provided by batteries, either NiCd or NiH, and active attitude control is accomplished with control moment gyros (CMGs) or reaction wheels. An overall system mass savings can be realized if these two subsystems are combined using multiple flywheels for simultaneous kinetic energy storage and momentum transfer. Several authors have studied the control of the flywheels to accomplish this and have published simulation results showing the feasibility and performance. This paper presents the first experimental results showing combined energy storage and momentum control about a single axis using two flywheels.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133053040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Got software? What managers and engineers need to know","authors":"P. Jansma","doi":"10.1109/MAES.2009.4839274","DOIUrl":"https://doi.org/10.1109/MAES.2009.4839274","url":null,"abstract":"As part of a JPL-wide software quality initiative aimed at addressing the challenges of developing, managing and acquiring software, a team at JPL generated a detailed software training plan for training both managers and engineers. The team took the approach of treating the software training program as though it were a system development task, and went through all the typical phases of system development including requirements, design, implementation, etc. During the requirements collection phase, the team conducted dozens of interviews and identified the specific skills needed. The skills fell into categories such as software management, software engineering, systems engineering and other technical areas. However, an equally important finding was that several \"soft\" skills were deemed critical for the successful and timely management and implementation of software-intensive systems. This paper discusses JPL's approach and \"lessons learned\" from planning and delivering a software training program in an engineering and scientific environment.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116585029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A fuel-optimal trajectory for a constrained hypersonic vehicle using a direct transcription method","authors":"A. Ngo","doi":"10.1109/AERO.2004.1368066","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368066","url":null,"abstract":"It is well-known that the takeoff weight of a space operation vehicle is composed mainly of fuel. Payload and vehicle hardware make up only a small percentage of the total weight. As a consequence, an important component of mission design for a space operation vehicle is trajectory planning since mission designers can increase the amount of payload or time-in-orbit by reducing the fuel required to accomplish the mission. In this paper, a method to calculate a fuel-optimal cruise trajectory for a hypersonic space vehicle is presented. The method of direct transcription is used to discretize the state and control variables along the vehicle's flight path to transform the optimization problem into a nonlinear programming problem to find the most fuel-efficient trajectory. Structural constraint in terms of normal loading on the vehicle is imposed along the trajectory. Comparisons are made between the fuel-optimal trajectory and static cruise trajectory.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"239 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132904184","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated battery module based on Li-ion cells and COTS ICs for advanced microsatellites","authors":"C. Del Vecchio Blanco, M. D'Errico","doi":"10.1109/AERO.2004.1368074","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368074","url":null,"abstract":"A six Li-ion cell string is used as the core of a modular battery for a total 100 Wh@C/2 capacity and a Wh efficiency of about 90%. Integrated charge/discharge prototype electronics is based on COTS components which allows us to obtain an efficiency greater than 90% and negligible mass and volume. Electronics can be managed by an integrated microcontroller which can by reprogrammed by the on-board computer. Battery management is foreseen at three levels: local battery module, power conditioning unit and on-board computer.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133063734","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A ground docking test facility for docking mechanism","authors":"C. Zhigang, Zhang Guangyu, Zhao Xuezeng","doi":"10.1109/AERO.2004.1368073","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368073","url":null,"abstract":"Chinese space program require extensive testing to verify design and performance and to qualify hardware. For this purpose a docking test facility (DTF) is being designed. It allows reproduction on the ground of the same relative motion and contact forces and torque of two docking mechanisms that would occur in space docking to verify capturing and buffering capabilities of docking mechanism. The DTF can realize five-degree-of-freedom motion with a three-degree-of-freedom turntable and a two-degree-of-freedom carriage. The technique involves gravity balance equipment to eliminate gravitation on the active docking ring, special mass and inertia simulator to simulate spacecraft's mass and inertia properties, friction compensation using DC servomotor, and momentum compensation using flywheel. This paper describes DTF with emphasis on the configuration, features and functions.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132179317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of fastener failure in a thermal protection system panel","authors":"J. Rosenstengel, I. Miller, M. DeSimio, M. Derriso, K. Brown, W. Braisted, S. Olson","doi":"10.1109/AERO.2004.1368041","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368041","url":null,"abstract":"This paper presents development methods and application results for a structural health monitoring (SHM) system for assessing the condition of mechanical fasteners in a test article representing a realistic portion of a thermal protection system. The test article is a carbon-carbon panel bolted through 15 brackets to a backing structure. Mechanical states considered include all bolts fastened to a nominal torque value, or one of the 15 bolts loosened. Four transducers on the backing structure provide actuation and sensing signals. Spectral functions are computed from all single and pair-wise signal combinations: (cross) power spectral densities, transfer functions, and coherence functions. Automated analysis of the spectral functions shows frequency intervals exist over which the function values are indicative of the mechanical state of the test article. These frequency intervals are used to provide features for the SHM classifier. Statistical pattern recognition methods select a subset of the features. The status of the test article is determined as \"undamaged\" or \"bolt j is loose.\" The overall localization accuracy of the SHM system on test data is 99.1% with 99.7% probability of detecting a damaged condition at a 0.2% probability of a false alarm.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"126 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128070367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Silicon carbide electronic devices and integrated circuits for extreme environments","authors":"J. Cooper","doi":"10.1109/AERO.2004.1368045","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368045","url":null,"abstract":"Silicon carbide (SiC) is a wide bandgap semiconductor that is highly suited for operation in extreme environments, including high temperatures and high levels of radiation. Electronic-grade wafers of SiC first became commercially available in the early 1990's, and since that time SiC electronic device technology has progressed rapidly. This work reviews the current status of electronic device technology in SiC and assess the prospects for applying this technology to operation in extreme environments.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115556097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High temperature experiments using programmable transistor array","authors":"R. Zebulum, Xin Guo, D. Keymeulen, M. I. Ferguson, V. Duong, A. Stoica","doi":"10.1109/AERO.2004.1368038","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368038","url":null,"abstract":"Temperature and radiation tolerant electronics, as well as long life survivability are the key capabilities required for future NASA missions. Current approaches to electronics for extreme environments focus on component level robustness and hardening. Compensation techniques such as bias cancellation circuitry have also been employed. However, current technology can only ensure very limited lifetime in extreme environments. This paper presents a novel approach, based on evolvable hardware technology, which allows adaptive in-situ circuit redesign/reconfiguration during operation in extreme environments. This technology complements material/device advancements and increases the mission capability to survive harsh environments. The approach is demonstrated on a mixed-signal programmable chip, which recovers functionality until 280/spl deg/C. We show in this paper the functionality recovery at high temperatures for a variety of circuits, including rectifiers, amplifiers and filters.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123707293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An overview of formation flying technology development for the Terrestrial Planet Finder mission","authors":"M. Aung, A. Ahmed, M. Wette, D. Scharf, J. Tien, G. Purcell, M. Regehr, B. Landin","doi":"10.1109/AERO.2004.1368062","DOIUrl":"https://doi.org/10.1109/AERO.2004.1368062","url":null,"abstract":"The objective of the Terrestrial Planet Finder (TPF) mission is to find and characterize earth-like planets orbiting other stars. Three architectural options are under consideration for this mission: a formation-flying interferometer (FFI), a structurally-connected interferometer, and a coronagraph. One of these options can be selected as the TPF baseline design in 2006. This paper describes the technology tasks underway to establish the viability of precision formation flying for the FFI option. In particular, interferometric science observations require autonomous precise control and maneuvering of five spacecraft to an accuracy of 2 cm in range and 1 arc-minute in bearing. This precision must be maintained over interspacecraft ranges varying from a few meters to hundreds of meters. Autonomous operations, ranging from formation acquisition and formation maneuvering to high precision formation flying during science observations, are required. Challenges lie in meeting the demanding performance requirements as well as in demonstrating the long-term robustness of the autonomous formation flying system. These challenges are unprecedented for deep space missions. To address them, research is under way in the areas of formation control algorithms, relative sensor technologies, system design, end-to-end real-time system simulation, and ground-based and micro-g end-to-end system demonstrations. Four interrelated testbeds are under development concurrently with the FFI system design. The testbeds include the formation algorithms & simulation testbed (FAST), the formation sensor testbed (FST), the formation control testbed (FCT) and the synchronized position hold engage re-orient experimental satellites (SPHERES) experiment. Formation flying technologies developed under the StarLight project and the NASA Distributed Spacecraft Technology (DST) program are being leveraged and expanded to meet the TPF requirements. This paper provides an overview of the ongoing precision formation flying technology development activities.","PeriodicalId":208052,"journal":{"name":"2004 IEEE Aerospace Conference Proceedings (IEEE Cat. No.04TH8720)","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129770615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}