Pub Date : 2002-09-01DOI: 10.1109/AERO.2001.931275
K. Bhasin, J. Hayden
NASA's future communications services will be supplied through a space communications network that mirrors the terrestrial Internet in its capabilities and flexibility. The notional requirements for future data gathering and distribution by this Space Internet have been gathered from NASA's Earth Science Enterprise (ESE), the Human Exploration and Development in Space (HEDS), and the Space Science Enterprise (SSE). This paper describes a communications infrastructure for the Space Internet, the architectures within the infrastructure, and the elements that make up the architectures. The architectures meet the requirements of the enterprises beyond 2010 with Internet compatible technologies and functionality. The elements of an architecture include the backbone, access, inter-spacecraft, and proximity communication parts. From the architectures, technologies have been identified which have the most impact and are critical for the implementation of the architectures.
{"title":"Space Internet architectures and technologies for NASA enterprises","authors":"K. Bhasin, J. Hayden","doi":"10.1109/AERO.2001.931275","DOIUrl":"https://doi.org/10.1109/AERO.2001.931275","url":null,"abstract":"NASA's future communications services will be supplied through a space communications network that mirrors the terrestrial Internet in its capabilities and flexibility. The notional requirements for future data gathering and distribution by this Space Internet have been gathered from NASA's Earth Science Enterprise (ESE), the Human Exploration and Development in Space (HEDS), and the Space Science Enterprise (SSE). This paper describes a communications infrastructure for the Space Internet, the architectures within the infrastructure, and the elements that make up the architectures. The architectures meet the requirements of the enterprises beyond 2010 with Internet compatible technologies and functionality. The elements of an architecture include the backbone, access, inter-spacecraft, and proximity communication parts. From the architectures, technologies have been identified which have the most impact and are critical for the implementation of the architectures.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130585574","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}
Pub Date : 2001-10-29DOI: 10.1109/AERO.2001.931345
J. Berner, K. Andrews
A new decoder is being developed by the Jet Propulsion Laboratory for NASA's Deep Space Network. This unit will decode the new turbo codes, which have recently been approved by the Consultative Committee for Space Data Systems (CCSDS). Turbo codes provide up to 0.8 dB improvement in E/sub b//N/sub 0/ over the current best codes used by deep space missions. The new decoder is being implemented in software running on commercial DSP chips, removing the need to design complicated and expensive hardware as was the case with the previous generation of codes. The decoder will time-tag the data frames, perform frame synchronization in the symbol domain (as opposed to the current bit domain synchronization), decode the turbo coded frames, and output the decoded bits in the CCSDS Standard Formatted Data Units format. The decoder is initially designed to operate up to 365 kbps, but will increase in rate as DSP clock rates increase. The implementation will go operational in October, 2003.
{"title":"Deep Space Network turbo decoder implementation","authors":"J. Berner, K. Andrews","doi":"10.1109/AERO.2001.931345","DOIUrl":"https://doi.org/10.1109/AERO.2001.931345","url":null,"abstract":"A new decoder is being developed by the Jet Propulsion Laboratory for NASA's Deep Space Network. This unit will decode the new turbo codes, which have recently been approved by the Consultative Committee for Space Data Systems (CCSDS). Turbo codes provide up to 0.8 dB improvement in E/sub b//N/sub 0/ over the current best codes used by deep space missions. The new decoder is being implemented in software running on commercial DSP chips, removing the need to design complicated and expensive hardware as was the case with the previous generation of codes. The decoder will time-tag the data frames, perform frame synchronization in the symbol domain (as opposed to the current bit domain synchronization), decode the turbo coded frames, and output the decoded bits in the CCSDS Standard Formatted Data Units format. The decoder is initially designed to operate up to 365 kbps, but will increase in rate as DSP clock rates increase. The implementation will go operational in October, 2003.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125303632","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}
Pub Date : 2001-10-13DOI: 10.1109/AERO.2001.931467
J. Wright
The Tropospheric Emission Spectrometer (TES) instrument seeks to analyze the chemical composition of the atmosphere based on the emission, absorption, and transmission of infrared radiation. Meeting the scientific objectives requires demanding analysis of the data being collected and processed. Visualization tools will assist in the understanding of the data and of the effects of the various types of processing being performed. The TES visualization tools are designed to verify correct functioning; of the instrument, provide early detection of potential problems, and report on the quality and validity of the science data for drawing scientific conclusions. Visualization displays include the Level III tools for displaying the end result of all the processing, merged and georeferenced for display relative to maps or global images, and displays for characterizing the behavior of the science processing algorithms and exploring the effects of implementation decisions. Displays of interest include plots of spectra and profiles, animations showing variations in the data along spatial or temporal axes, and results of various operations on the data. Together, these tools provide a visualization suite for more rapidly analyzing the science results of the TES instrument and detecting and identifying problems in the instrument or processing system.
{"title":"science data visualization tools for the Tropospheric Emission Spectrometer ground data system","authors":"J. Wright","doi":"10.1109/AERO.2001.931467","DOIUrl":"https://doi.org/10.1109/AERO.2001.931467","url":null,"abstract":"The Tropospheric Emission Spectrometer (TES) instrument seeks to analyze the chemical composition of the atmosphere based on the emission, absorption, and transmission of infrared radiation. Meeting the scientific objectives requires demanding analysis of the data being collected and processed. Visualization tools will assist in the understanding of the data and of the effects of the various types of processing being performed. The TES visualization tools are designed to verify correct functioning; of the instrument, provide early detection of potential problems, and report on the quality and validity of the science data for drawing scientific conclusions. Visualization displays include the Level III tools for displaying the end result of all the processing, merged and georeferenced for display relative to maps or global images, and displays for characterizing the behavior of the science processing algorithms and exploring the effects of implementation decisions. Displays of interest include plots of spectra and profiles, animations showing variations in the data along spatial or temporal axes, and results of various operations on the data. Together, these tools provide a visualization suite for more rapidly analyzing the science results of the TES instrument and detecting and identifying problems in the instrument or processing system.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126289562","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}
Pub Date : 2001-07-08DOI: 10.1109/AERO.2001.931269
M. Potter, M. Stuchly, M. Okoniewski
A method is outlined to represent near-field sources in the FDTD method by way of spherical wave expansions. Spherical wave modal amplitude functions are time-stepped on alternate 1-dimensional grids (in radius and time) analogous to plane waves in the total/scattered field formulation, with angular functions interpolated later. Initial validation is presented by comparing to the analytic solutions for a spherical resonator, and for an infinitesimal dipole, both showing excellent agreement. A brief discussion on the stability criterion is also presented. This method will allow the modeling of source (e.g. antenna) and scatterer interactions in the near-field without explicitly modeling the source. As a result, the computational resources necessary will be greatly reduced, allowing for faster runtimes and more complicated geometries.
{"title":"Modeling of near-field sources in the finite-difference time-domain (FDTD)","authors":"M. Potter, M. Stuchly, M. Okoniewski","doi":"10.1109/AERO.2001.931269","DOIUrl":"https://doi.org/10.1109/AERO.2001.931269","url":null,"abstract":"A method is outlined to represent near-field sources in the FDTD method by way of spherical wave expansions. Spherical wave modal amplitude functions are time-stepped on alternate 1-dimensional grids (in radius and time) analogous to plane waves in the total/scattered field formulation, with angular functions interpolated later. Initial validation is presented by comparing to the analytic solutions for a spherical resonator, and for an infinitesimal dipole, both showing excellent agreement. A brief discussion on the stability criterion is also presented. This method will allow the modeling of source (e.g. antenna) and scatterer interactions in the near-field without explicitly modeling the source. As a result, the computational resources necessary will be greatly reduced, allowing for faster runtimes and more complicated geometries.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124814931","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}
Pub Date : 2001-06-01DOI: 10.1109/AERO.2001.931237
S. Hughes, L. Mailhe
Leonardo-BRDF is a new NASA mission concept proposed to allow the investigation of radiative transfer and its effect on the Earth's climate and atmospheric phenomenon. Enabled by the recent developments in small-satellite and formation flying technology, the mission is envisioned to be composed of an array of spacecraft in carefully designed orbits. The different perspectives provided by a distributed array of spacecraft offer a unique advantage to study the Earth's albedo. This paper presents the flight dynamics analysis performed in the context of the Leonardo-BRDF science requirements. First, the albedo integral is investigated and the effect of viewing geometry on science return is studied. The method used in this paper, based on Gauss quadrature, provides the optimal formation geometry to ensure that the value of the integral is accurately approximated. An orbit design approach is presented to achieve specific relative orbit geometries while simultaneously satisfying orbit dynamics constraints to reduce formation-keeping fuel expenditure. The relative geometry afforded by the design is discussed in terms of mission requirements. An optimal Lambert initialization scheme is presented with the required /spl Delta/V to distribute all spacecraft from a common parking orbit into their appropriate orbits in the formation. Finally, formation-keeping strategies are developed and the associated /spl Delta/V's are calculated to maintain the formation in the presence of perturbations.
{"title":"A preliminary formation flying orbit dynamics analysis for Leonardo-BRDF","authors":"S. Hughes, L. Mailhe","doi":"10.1109/AERO.2001.931237","DOIUrl":"https://doi.org/10.1109/AERO.2001.931237","url":null,"abstract":"Leonardo-BRDF is a new NASA mission concept proposed to allow the investigation of radiative transfer and its effect on the Earth's climate and atmospheric phenomenon. Enabled by the recent developments in small-satellite and formation flying technology, the mission is envisioned to be composed of an array of spacecraft in carefully designed orbits. The different perspectives provided by a distributed array of spacecraft offer a unique advantage to study the Earth's albedo. This paper presents the flight dynamics analysis performed in the context of the Leonardo-BRDF science requirements. First, the albedo integral is investigated and the effect of viewing geometry on science return is studied. The method used in this paper, based on Gauss quadrature, provides the optimal formation geometry to ensure that the value of the integral is accurately approximated. An orbit design approach is presented to achieve specific relative orbit geometries while simultaneously satisfying orbit dynamics constraints to reduce formation-keeping fuel expenditure. The relative geometry afforded by the design is discussed in terms of mission requirements. An optimal Lambert initialization scheme is presented with the required /spl Delta/V to distribute all spacecraft from a common parking orbit into their appropriate orbits in the formation. Finally, formation-keeping strategies are developed and the associated /spl Delta/V's are calculated to maintain the formation in the presence of perturbations.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126458109","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}
Pub Date : 2001-03-17DOI: 10.1109/AERO.2001.931170
K. Price, V. Urbancek
Air Force/Raytheon 95K High Efficiency Cryocooler (95 K HEC) Program is developing a new two-stage hybrid Stirling-pulse tube space qualified refrigerator with high heat lift capacity, high efficiency, low weight and size, and low production costs relative to the current state-of-the-art. The basic program will deliver a protoflight Stirling-class Thermo Mechanical Unit (TMU) with protoflight radiation hard electronics. The cooler is designed to support 10 W heat lift from a 95 K source to a 300 K sink. Motor power consumption is to be less than 100 W and system power (including electronics) is to be less than 137 W. The cooler is to weigh no more than 6 Kg. The TMU cold head and compressor designs are highly versatile to enable low cost tailoring to meet the needs of a wide variety of applications. The first demonstration of this versatility is a program option to deliver a companion high-capacity 35 K cryocooler. This cooler will also have an aggressive efficiency requirement. The 95K and 35 K TMU will share over 95% of components, resulting in significant production efficiencies. Another result of this high degree of commonality is that each cooler can be powered and controlled by standardized command and control electronics.
{"title":"Raytheon 95 K high efficiency cryocooler program","authors":"K. Price, V. Urbancek","doi":"10.1109/AERO.2001.931170","DOIUrl":"https://doi.org/10.1109/AERO.2001.931170","url":null,"abstract":"Air Force/Raytheon 95K High Efficiency Cryocooler (95 K HEC) Program is developing a new two-stage hybrid Stirling-pulse tube space qualified refrigerator with high heat lift capacity, high efficiency, low weight and size, and low production costs relative to the current state-of-the-art. The basic program will deliver a protoflight Stirling-class Thermo Mechanical Unit (TMU) with protoflight radiation hard electronics. The cooler is designed to support 10 W heat lift from a 95 K source to a 300 K sink. Motor power consumption is to be less than 100 W and system power (including electronics) is to be less than 137 W. The cooler is to weigh no more than 6 Kg. The TMU cold head and compressor designs are highly versatile to enable low cost tailoring to meet the needs of a wide variety of applications. The first demonstration of this versatility is a program option to deliver a companion high-capacity 35 K cryocooler. This cooler will also have an aggressive efficiency requirement. The 95K and 35 K TMU will share over 95% of components, resulting in significant production efficiencies. Another result of this high degree of commonality is that each cooler can be powered and controlled by standardized command and control electronics.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132164971","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}
Pub Date : 2001-03-12DOI: 10.1109/AERO.2001.931192
R. Zebulum, A. Stoica, D. Keymeulen
Evolvable Hardware (EHW) applications have, so far, encompassed the synthesis of standard analog and digital circuits' building blocks through Genetic Algorithms (GAs). Currently, the research effort in EHW is being driven towards twofold purposes: the synthesis of circuits of medium to high complexity; and the design of reconfigurable architectures that facilitate the system evolvability and on-chip implementation of the evolved circuits. This work addresses these issues by describing the evolution of Digital to Analog Converters (DACs). We investigate the efficiency of the evolutionary system when using different representations and when evolving current and voltage mode circuits. A new technique based on hierarchical evolution is devised to enhance the evolutionary speed and the design scalability. New methods to increase the competitiveness of the evolved designs are also discussed.
{"title":"Experiments on the evolution of digital to analog converters","authors":"R. Zebulum, A. Stoica, D. Keymeulen","doi":"10.1109/AERO.2001.931192","DOIUrl":"https://doi.org/10.1109/AERO.2001.931192","url":null,"abstract":"Evolvable Hardware (EHW) applications have, so far, encompassed the synthesis of standard analog and digital circuits' building blocks through Genetic Algorithms (GAs). Currently, the research effort in EHW is being driven towards twofold purposes: the synthesis of circuits of medium to high complexity; and the design of reconfigurable architectures that facilitate the system evolvability and on-chip implementation of the evolved circuits. This work addresses these issues by describing the evolution of Digital to Analog Converters (DACs). We investigate the efficiency of the evolutionary system when using different representations and when evolving current and voltage mode circuits. A new technique based on hierarchical evolution is devised to enhance the evolutionary speed and the design scalability. New methods to increase the competitiveness of the evolved designs are also discussed.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116447203","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}
Pub Date : 2001-03-10DOI: 10.1109/AERO.2001.931398
A. Lees, G. D. Colman
Seeded fault testing is defined as the process of installing used parts with a quantified service created defect into an otherwise healthy piece of equipment for the purpose of developing diagnostic and prognostic techniques to identify impending failure in that piece of equipment. Having conducted seeded fault testing of an installed and fully functional but non-flying Bell 206 helicopter gearbox, it has been found that application of seeded fault techniques can produce significant benefits relative to the validation and subsequent use of prognostic and diagnostic algorithms. Having developed a level of expertise on the Bell 206, additional plans are being developed to conduct seeded fault testing of a T56 propeller reduction gearbox prior to moving to the complete installed engine assembly. The work completed so far has shown that in complex equipment, some prognostic and diagnostic techniques are valid and in other cases shown some techniques to be invalid even though they may have worked in less complex equipment. Development of a database of seeded fault data for general industry provides an essential tool for evaluation and refinement of future algorithms. Early application of seeded fault test data in a program using a condition based maintenance approach on complex mechanical equipment has in many industries produced significant benefits for the equipment operators in terms of higher equipment availability, lower operating costs and increased safety.
{"title":"Use and benefit of seeded fault testing in development of advanced diagnostic and prognostic algorithms","authors":"A. Lees, G. D. Colman","doi":"10.1109/AERO.2001.931398","DOIUrl":"https://doi.org/10.1109/AERO.2001.931398","url":null,"abstract":"Seeded fault testing is defined as the process of installing used parts with a quantified service created defect into an otherwise healthy piece of equipment for the purpose of developing diagnostic and prognostic techniques to identify impending failure in that piece of equipment. Having conducted seeded fault testing of an installed and fully functional but non-flying Bell 206 helicopter gearbox, it has been found that application of seeded fault techniques can produce significant benefits relative to the validation and subsequent use of prognostic and diagnostic algorithms. Having developed a level of expertise on the Bell 206, additional plans are being developed to conduct seeded fault testing of a T56 propeller reduction gearbox prior to moving to the complete installed engine assembly. The work completed so far has shown that in complex equipment, some prognostic and diagnostic techniques are valid and in other cases shown some techniques to be invalid even though they may have worked in less complex equipment. Development of a database of seeded fault data for general industry provides an essential tool for evaluation and refinement of future algorithms. Early application of seeded fault test data in a program using a condition based maintenance approach on complex mechanical equipment has in many industries produced significant benefits for the equipment operators in terms of higher equipment availability, lower operating costs and increased safety.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"131 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115142297","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}
Pub Date : 2001-03-10DOI: 10.1109/AERO.2001.931395
S. Dimaggio, Brian H. Sako
Condition monitoring of rotating machinery using vibration measurements has been improved due to advances in both data acquisition and digital signal processing techniques. For example, one method that has become popular is known as envelope detection, or demodulated resonance analysis. This method requires bandpass filtering of the vibration signal in the vicinity of a structural resonance that occurs in the transmission path between a potential defect and the transducer. This implies that a basic understanding of the structural dynamics associated with the system being monitored is required. It is the purpose of this paper to suggest a basic mathematical model that may aid the analyst in choosing the proper filter to use in the envelope detection technique. Additionally, the paper presents some simple experimental and analytical techniques that provide relevant system identification information for the model. In the course of the paper, the general method of envelope detection is reviewed as it applies to the condition assessment of turbopumps using gearbox vibration measurements. The effectiveness of the method is assessed using data acquired during a ground test of an actual rocket engine that experienced a gear failure. Potential use of the demodulated resonance technique as an effective method in aerospace telemetry applications is suggested.
{"title":"Basic system identification for condition monitoring of turbopumps [rocket engines]","authors":"S. Dimaggio, Brian H. Sako","doi":"10.1109/AERO.2001.931395","DOIUrl":"https://doi.org/10.1109/AERO.2001.931395","url":null,"abstract":"Condition monitoring of rotating machinery using vibration measurements has been improved due to advances in both data acquisition and digital signal processing techniques. For example, one method that has become popular is known as envelope detection, or demodulated resonance analysis. This method requires bandpass filtering of the vibration signal in the vicinity of a structural resonance that occurs in the transmission path between a potential defect and the transducer. This implies that a basic understanding of the structural dynamics associated with the system being monitored is required. It is the purpose of this paper to suggest a basic mathematical model that may aid the analyst in choosing the proper filter to use in the envelope detection technique. Additionally, the paper presents some simple experimental and analytical techniques that provide relevant system identification information for the model. In the course of the paper, the general method of envelope detection is reviewed as it applies to the condition assessment of turbopumps using gearbox vibration measurements. The effectiveness of the method is assessed using data acquired during a ground test of an actual rocket engine that experienced a gear failure. Potential use of the demodulated resonance technique as an effective method in aerospace telemetry applications is suggested.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116713148","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}
Pub Date : 2001-03-10DOI: 10.1109/AERO.2001.931741
R. Boyd
The X2000 Program is a technology development program that will provide next generation avionics for missions to deep space. The goal of the X2000 Program is to develop revolutionary flight and ground systems which can be replicated by missions at a low cost, affording timely new science and mission opportunities to investigators and institutions. With the implementation of shorter development phases for projects, the need for better metrics to track a project's status became necessary. This paper describes different methods for tracking such performance. Schedule performance is discussed using event-driven performance assessment metrics, receivables/deliverables, slack tables, etc. Financial performance is addressed by discussion of earned value (cost variance/schedule variance), cash flow, reserves management, risk reduction funds, etc. Although X2000 IFDP is not a flight project, it is delivering hardware to other projects and is being managed as if it were a flight project.
{"title":"Managing schedule and financial risk: lessons learned on X2000","authors":"R. Boyd","doi":"10.1109/AERO.2001.931741","DOIUrl":"https://doi.org/10.1109/AERO.2001.931741","url":null,"abstract":"The X2000 Program is a technology development program that will provide next generation avionics for missions to deep space. The goal of the X2000 Program is to develop revolutionary flight and ground systems which can be replicated by missions at a low cost, affording timely new science and mission opportunities to investigators and institutions. With the implementation of shorter development phases for projects, the need for better metrics to track a project's status became necessary. This paper describes different methods for tracking such performance. Schedule performance is discussed using event-driven performance assessment metrics, receivables/deliverables, slack tables, etc. Financial performance is addressed by discussion of earned value (cost variance/schedule variance), cash flow, reserves management, risk reduction funds, etc. Although X2000 IFDP is not a flight project, it is delivering hardware to other projects and is being managed as if it were a flight project.","PeriodicalId":329225,"journal":{"name":"2001 IEEE Aerospace Conference Proceedings (Cat. No.01TH8542)","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116776294","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}
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