Pub Date : 2005-03-05DOI: 10.1109/AERO.2005.1559471
M.E. Miller, S. Dougherty, J. Stella, P. Reddy
The capacity of the United States' National Airspace System (NAS) must double to handle the passenger demands that are projected over the next 25 years. NASA initiated the Virtual Airspace Modeling and Simulation (VAMS) Project in 2002 with participants, including members from industry, government, and academia to develop and share ideas on revolutionary concepts to meet the future demand. The constraints in the terminal area domain are the focus of Raytheon's VAMS concept, terminal area capacity enhancement concept (TACEC). TACEC envisions a high level of automation and synchronization, generating optimized 4D flight profiles to land/depart multiple aircraft "simultaneously" on closely spaced parallel runways. Implementation requires infrastructure improvements such as highly automated guidance and scheduling systems, timely data link, improved surveillance, and improved onboard navigation systems. This paper discusses the guidance and scheduling systems required to pair the aircraft for simultaneous landing. Performance required by the autopilot/navigation system to maintain control necessary for formation flight onto closely spaced parallel runways, data link and surveillance requirements are also addressed
{"title":"CNS requirements for precision flight in advanced terminal airspace","authors":"M.E. Miller, S. Dougherty, J. Stella, P. Reddy","doi":"10.1109/AERO.2005.1559471","DOIUrl":"https://doi.org/10.1109/AERO.2005.1559471","url":null,"abstract":"The capacity of the United States' National Airspace System (NAS) must double to handle the passenger demands that are projected over the next 25 years. NASA initiated the Virtual Airspace Modeling and Simulation (VAMS) Project in 2002 with participants, including members from industry, government, and academia to develop and share ideas on revolutionary concepts to meet the future demand. The constraints in the terminal area domain are the focus of Raytheon's VAMS concept, terminal area capacity enhancement concept (TACEC). TACEC envisions a high level of automation and synchronization, generating optimized 4D flight profiles to land/depart multiple aircraft \"simultaneously\" on closely spaced parallel runways. Implementation requires infrastructure improvements such as highly automated guidance and scheduling systems, timely data link, improved surveillance, and improved onboard navigation systems. This paper discusses the guidance and scheduling systems required to pair the aircraft for simultaneous landing. Performance required by the autopilot/navigation system to maintain control necessary for formation flight onto closely spaced parallel runways, data link and surveillance requirements are also addressed","PeriodicalId":117223,"journal":{"name":"2005 IEEE Aerospace Conference","volume":"90 7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129818345","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 : 2005-03-05DOI: 10.1109/AERO.2005.1559311
R. Gladden, P. Hwang, B. Waggoner, B. Mclaughlin, P. Fieseler, R. Thomas, M. Bigwood, P. Herrera
The Mission Management Office at the Jet Propulsion Laboratory was tasked with coordinating the relay of data between multiple spacecraft at Mars in support of the Mars exploration rover missions in early 2004. The confluence of three orbiters (Mars Global Surveyor, Mars Odyssey, and Mars Express), two rovers (Spirit and Opportunity), and one lander (Beagle 2) has provided a challenging operational scenario that required careful coordination between missions to provide the necessary support and to avoid potential interference during simultaneous relay sessions. As these coordination efforts progressed, several important lessons were learned that should be applied to future Mars relay activities.
{"title":"Mars relay coordination lessons learned","authors":"R. Gladden, P. Hwang, B. Waggoner, B. Mclaughlin, P. Fieseler, R. Thomas, M. Bigwood, P. Herrera","doi":"10.1109/AERO.2005.1559311","DOIUrl":"https://doi.org/10.1109/AERO.2005.1559311","url":null,"abstract":"The Mission Management Office at the Jet Propulsion Laboratory was tasked with coordinating the relay of data between multiple spacecraft at Mars in support of the Mars exploration rover missions in early 2004. The confluence of three orbiters (Mars Global Surveyor, Mars Odyssey, and Mars Express), two rovers (Spirit and Opportunity), and one lander (Beagle 2) has provided a challenging operational scenario that required careful coordination between missions to provide the necessary support and to avoid potential interference during simultaneous relay sessions. As these coordination efforts progressed, several important lessons were learned that should be applied to future Mars relay activities.","PeriodicalId":117223,"journal":{"name":"2005 IEEE Aerospace Conference","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127056230","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 : 2005-03-05DOI: 10.1109/AERO.2005.1559745
R. Oberto, E. Nilsen, R. Cohen, R. Wheeler, P. DeFlono, C. Borden
To meet the nation's goal of a new direction in human and robotic space exploration, the National Aeronautics and Space Administration (NASA) must rapidly develop concepts, architectures, and requirements for the next generation of space exploration systems. This requires a rapid architectural design capability, quick access to the vast expertise distributed throughout NASA centers and external partners, and impartial analysis of options. To accomplish these goals, the NASA Exploration Design Team (NEDT) has been established to provide the infrastructure, tools and processes to evaluate exploration program, mission and technology trade studies in a collaborative, distributed, real-time environment. Experience with JPL's Team X studies of robotic space missions (there have been over 650 designs to date) demonstrates that significant efficiencies can be captured in performing these complex studies in a collaborative environment with common tools and processes. Team X has reduced per-study costs by a factor of 5 and per-study duration by a factor of 10 compared to conventional design processes. The Team X concept has spread to other NASA centers, industry, academia, and international partners. The goal for NEDT at project completion is to achieve a study turn-around time of as low as 2 weeks. In this paper, we present an extension of the JPL Team X process to the NASA-wide collaborative design team. We describe the architecture and approach for such a process and elaborate on the implementation challenges of this process. We further discuss current ideas on how to address these challenges
{"title":"The NASA Exploration Design Team: blueprint for a new design paradigm","authors":"R. Oberto, E. Nilsen, R. Cohen, R. Wheeler, P. DeFlono, C. Borden","doi":"10.1109/AERO.2005.1559745","DOIUrl":"https://doi.org/10.1109/AERO.2005.1559745","url":null,"abstract":"To meet the nation's goal of a new direction in human and robotic space exploration, the National Aeronautics and Space Administration (NASA) must rapidly develop concepts, architectures, and requirements for the next generation of space exploration systems. This requires a rapid architectural design capability, quick access to the vast expertise distributed throughout NASA centers and external partners, and impartial analysis of options. To accomplish these goals, the NASA Exploration Design Team (NEDT) has been established to provide the infrastructure, tools and processes to evaluate exploration program, mission and technology trade studies in a collaborative, distributed, real-time environment. Experience with JPL's Team X studies of robotic space missions (there have been over 650 designs to date) demonstrates that significant efficiencies can be captured in performing these complex studies in a collaborative environment with common tools and processes. Team X has reduced per-study costs by a factor of 5 and per-study duration by a factor of 10 compared to conventional design processes. The Team X concept has spread to other NASA centers, industry, academia, and international partners. The goal for NEDT at project completion is to achieve a study turn-around time of as low as 2 weeks. In this paper, we present an extension of the JPL Team X process to the NASA-wide collaborative design team. We describe the architecture and approach for such a process and elaborate on the implementation challenges of this process. We further discuss current ideas on how to address these challenges","PeriodicalId":117223,"journal":{"name":"2005 IEEE Aerospace Conference","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127079308","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 : 2005-03-05DOI: 10.1109/AERO.2005.1559640
D. Bodden, W. Hadden, B. E. Grube, N. S. Clements
Flight critical systems in air vehicles achieve required reliability through different redundancy design techniques including physical system redundancy. Prognostics and health management technology provides the opportunity to eliminate some of the physical redundancy (and associated weight) through implementation of accurate remaining useful life (RUL) algorithms. Consideration of this subsystem design approach upfront during the conceptual design process rather than downstream during the detailed design phase of the air vehicle system may produce a more optimal air vehicle configuration with regard to reliability and weight. Results are presented for an unmanned air vehicle design optimization which included RUL algorithm confidence, control surface actuator redundancy and control surface configuration as optimization variables. Optimization constraints included landing dispersion, mission reliability and mission availability. Reductions in air vehicle weight were achieved with reasonable RUL accuracy requirements
{"title":"PHM as a Design Variable in Air Vehicle Conceptual Design","authors":"D. Bodden, W. Hadden, B. E. Grube, N. S. Clements","doi":"10.1109/AERO.2005.1559640","DOIUrl":"https://doi.org/10.1109/AERO.2005.1559640","url":null,"abstract":"Flight critical systems in air vehicles achieve required reliability through different redundancy design techniques including physical system redundancy. Prognostics and health management technology provides the opportunity to eliminate some of the physical redundancy (and associated weight) through implementation of accurate remaining useful life (RUL) algorithms. Consideration of this subsystem design approach upfront during the conceptual design process rather than downstream during the detailed design phase of the air vehicle system may produce a more optimal air vehicle configuration with regard to reliability and weight. Results are presented for an unmanned air vehicle design optimization which included RUL algorithm confidence, control surface actuator redundancy and control surface configuration as optimization variables. Optimization constraints included landing dispersion, mission reliability and mission availability. Reductions in air vehicle weight were achieved with reasonable RUL accuracy requirements","PeriodicalId":117223,"journal":{"name":"2005 IEEE Aerospace Conference","volume":"113 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127156386","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 : 2005-03-05DOI: 10.1109/AERO.2005.1559698
Abdel Bayoumi, W. Ranson, Les Eisner, L. Grant
The objectives of our program are to evaluate the cost and effectiveness of the AH-64 (Apache) and UH-60 (Blackhawk) helicopters' on-board vibration monitoring (VM) system, to provide an annual cost savings analysis of the vibration management enhancement program (VMEP) for the AH-64 and UH-60 aircraft fleets, and to initially correlate vibration signals with the ULLS-A (logistics) database to create a costs benefits analysis (CBA) model. Logistics (ULLS-A) and vibration (VMU) data were collected for Blackhawks and Apaches from different establishments (South Carolina Army National Guard, Alabama Army National Guard, deployed units in Kosovo, and Korea), warehoused in our database, and analyzed. In addition, all personnel from these bases were surveyed to examine other nontangible benefits of the program. In order to provide a timely and sufficient cost and economic analysis to support the effective allocation and management of resources for Army programs, a CBA model has been developed. Our goal was to develop and maintain cost and economic analyses as effective and efficient tools for decision-making while supporting management decisions by quantifying the resource impact of alternative options. The model utilizes test flight information from the ULLS-A database in order to estimate a cost savings and recovery of the initial cost of the VMU hardware installation and future cost savings for the Apache and Blackhawk helicopters. It includes cost variables such as: test flight hours, hours per flight, cost per flight hour, VMEP investment, number of VMEP helicopters, RT&B flights, and non-RT&B flights. It also includes nontangible variables such as: availability, morale, safety, operational flight hours gained, premature parts failure, mission aborts, and unscheduled maintenance occurrence. As of today, our activities have been highlighted by savings in parts cost, operational support, an increase in mission capability rates, a decrease in maintenance, and an increase in total flight time. Other highlights of nontangible benefits include an increase in confidence for early diagnosis, an increase in attention and performance, an increase in personnel morale, and an increase in safety and sense of safety
{"title":"Cost and effectiveness analysis of the AH-64 and UH-60 on-board vibrations monitoring system","authors":"Abdel Bayoumi, W. Ranson, Les Eisner, L. Grant","doi":"10.1109/AERO.2005.1559698","DOIUrl":"https://doi.org/10.1109/AERO.2005.1559698","url":null,"abstract":"The objectives of our program are to evaluate the cost and effectiveness of the AH-64 (Apache) and UH-60 (Blackhawk) helicopters' on-board vibration monitoring (VM) system, to provide an annual cost savings analysis of the vibration management enhancement program (VMEP) for the AH-64 and UH-60 aircraft fleets, and to initially correlate vibration signals with the ULLS-A (logistics) database to create a costs benefits analysis (CBA) model. Logistics (ULLS-A) and vibration (VMU) data were collected for Blackhawks and Apaches from different establishments (South Carolina Army National Guard, Alabama Army National Guard, deployed units in Kosovo, and Korea), warehoused in our database, and analyzed. In addition, all personnel from these bases were surveyed to examine other nontangible benefits of the program. In order to provide a timely and sufficient cost and economic analysis to support the effective allocation and management of resources for Army programs, a CBA model has been developed. Our goal was to develop and maintain cost and economic analyses as effective and efficient tools for decision-making while supporting management decisions by quantifying the resource impact of alternative options. The model utilizes test flight information from the ULLS-A database in order to estimate a cost savings and recovery of the initial cost of the VMU hardware installation and future cost savings for the Apache and Blackhawk helicopters. It includes cost variables such as: test flight hours, hours per flight, cost per flight hour, VMEP investment, number of VMEP helicopters, RT&B flights, and non-RT&B flights. It also includes nontangible variables such as: availability, morale, safety, operational flight hours gained, premature parts failure, mission aborts, and unscheduled maintenance occurrence. As of today, our activities have been highlighted by savings in parts cost, operational support, an increase in mission capability rates, a decrease in maintenance, and an increase in total flight time. Other highlights of nontangible benefits include an increase in confidence for early diagnosis, an increase in attention and performance, an increase in personnel morale, and an increase in safety and sense of safety","PeriodicalId":117223,"journal":{"name":"2005 IEEE Aerospace Conference","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127522252","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 : 2005-03-05DOI: 10.1109/AERO.2005.1559422
O. Gnawali, M. Polyakovt, P. Bose, R. Govindan
Envisioned space exploration systems and planned space science missions involve increasingly large number of satellites and surface rovers/sensors communicating for coordinated science operations or for on-demand commanding and/or transfer of data. Current approaches that use static routing cannot scale to large numbers of satellites and spacecrafts of future missions. This requires a dynamic approach that can discover networks and links as they become available and intelligently use them for routing. Furthermore, most of the science missions will be geared towards collecting data using various sensors. Adoption of a data-centric communication mechanism can enable in-network aggregation and processing which help make data forwarding more efficient. In this paper, we briefly describe ASCoT, a routing system for science missions of tomorrow, which a) leverages the predictability of satellite trajectories to effect position-based routing in the space backbone, and b) departs from traditional address-centric communication and uses a data-centric architecture to enable energy efficient and low latency operation in proximity networks. Our simulation study using STK/OPNET shows that ASCoT architecture is viable
{"title":"Data centric, position-based routing in space networks","authors":"O. Gnawali, M. Polyakovt, P. Bose, R. Govindan","doi":"10.1109/AERO.2005.1559422","DOIUrl":"https://doi.org/10.1109/AERO.2005.1559422","url":null,"abstract":"Envisioned space exploration systems and planned space science missions involve increasingly large number of satellites and surface rovers/sensors communicating for coordinated science operations or for on-demand commanding and/or transfer of data. Current approaches that use static routing cannot scale to large numbers of satellites and spacecrafts of future missions. This requires a dynamic approach that can discover networks and links as they become available and intelligently use them for routing. Furthermore, most of the science missions will be geared towards collecting data using various sensors. Adoption of a data-centric communication mechanism can enable in-network aggregation and processing which help make data forwarding more efficient. In this paper, we briefly describe ASCoT, a routing system for science missions of tomorrow, which a) leverages the predictability of satellite trajectories to effect position-based routing in the space backbone, and b) departs from traditional address-centric communication and uses a data-centric architecture to enable energy efficient and low latency operation in proximity networks. Our simulation study using STK/OPNET shows that ASCoT architecture is viable","PeriodicalId":117223,"journal":{"name":"2005 IEEE Aerospace Conference","volume":"29 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128983763","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 : 2005-03-05DOI: 10.1109/AERO.2005.1559484
M. Shamma
This paper looks at the general packet radio system (GPRS) technology as an alternative communications technology for the air traffic users within a managed air space. This technology can compliment, or back up the more conventional links such as VHF digital link modes VDL 2,3,4. Theoretical maximum speeds of up to 171 kilobits per second (kbps) are achievable with GPRS. In addition, it is a widely accepted migration step toward Third generation universal mobile telecommunication system (3G UMTS) which will provide even more capabilities through the use of wideband code division multiple access (W-CDMA). This study involved the computation of availability/blockage of voice and controller pilot data link communications (CPDLC) data over GSM/GPRS. The Erlang B was used for the voice, while the Erlang C was used for the data services to compute the availability of each. Traffic loads are obtained for the airport, terminal, and enroute airspace domains. Several parameters that effect the availability results were studied including the outage definition time, range of service data, number of available TDMA logical channels, and buffer size. The results show very good availability for busiest airspace demand rates for year 2015. Overall, the voice communications will reduce the system availability the most, followed by the data applications. The most significant reduction of ideal maximum capacity is probably the limitation of the controller's human capability to handle a large group of aircraft within a sector. Nonetheless, automation advancements may improve that limitation in the future
{"title":"GSM/GPRS Erlang capacity analyses and simulations under air traffic loading conditions","authors":"M. Shamma","doi":"10.1109/AERO.2005.1559484","DOIUrl":"https://doi.org/10.1109/AERO.2005.1559484","url":null,"abstract":"This paper looks at the general packet radio system (GPRS) technology as an alternative communications technology for the air traffic users within a managed air space. This technology can compliment, or back up the more conventional links such as VHF digital link modes VDL 2,3,4. Theoretical maximum speeds of up to 171 kilobits per second (kbps) are achievable with GPRS. In addition, it is a widely accepted migration step toward Third generation universal mobile telecommunication system (3G UMTS) which will provide even more capabilities through the use of wideband code division multiple access (W-CDMA). This study involved the computation of availability/blockage of voice and controller pilot data link communications (CPDLC) data over GSM/GPRS. The Erlang B was used for the voice, while the Erlang C was used for the data services to compute the availability of each. Traffic loads are obtained for the airport, terminal, and enroute airspace domains. Several parameters that effect the availability results were studied including the outage definition time, range of service data, number of available TDMA logical channels, and buffer size. The results show very good availability for busiest airspace demand rates for year 2015. Overall, the voice communications will reduce the system availability the most, followed by the data applications. The most significant reduction of ideal maximum capacity is probably the limitation of the controller's human capability to handle a large group of aircraft within a sector. Nonetheless, automation advancements may improve that limitation in the future","PeriodicalId":117223,"journal":{"name":"2005 IEEE Aerospace Conference","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132413945","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 : 2005-03-05DOI: 10.1109/AERO.2005.1559314
R. Thompson, S. Francis, R. Olsen, M. Parsons, R. Coffman, R. Braun
The Cadmus mission responds to the need for a Europa surface exploration mission in the 2021 time frame that complements and extends the science performed by the Jupiter icy moons orbiter (JIMO) and Galileo spacecraft. Cadmus will help prepare for future subsurface and sample return missions. Europa is one of the most intriguing outer solar system planetary bodies due to the compelling evidence that an ocean of salty water exists approximately 20 km beneath the surface. This liquid water could make Europa a haven for life. The NASA Office of Space Science (OSS) has identified the search for life in the solar system and the resources necessary to support extraterrestrial life as an important area of study. The Cadmus mission investigates the habitability of Europa from the surface to determine the likelihood that life exists on the moon. By studying the crustal dynamics of the moon, the Cadmus mission assesses the extent to which a flux of water and ice exists between the possible subsurface ocean and the surface. Cadmus investigates the presence of nutrients and signs of energy resources in the crustal ice and also assesses the environmental suitability of the Europa environment to the evolution and sustainability of life. To reduce mission operations cost and complexity the mission architecture includes two landers that will land on the surface independently and utilize a high degree of autonomy.
{"title":"Cadmus: a Europa lander concept","authors":"R. Thompson, S. Francis, R. Olsen, M. Parsons, R. Coffman, R. Braun","doi":"10.1109/AERO.2005.1559314","DOIUrl":"https://doi.org/10.1109/AERO.2005.1559314","url":null,"abstract":"The Cadmus mission responds to the need for a Europa surface exploration mission in the 2021 time frame that complements and extends the science performed by the Jupiter icy moons orbiter (JIMO) and Galileo spacecraft. Cadmus will help prepare for future subsurface and sample return missions. Europa is one of the most intriguing outer solar system planetary bodies due to the compelling evidence that an ocean of salty water exists approximately 20 km beneath the surface. This liquid water could make Europa a haven for life. The NASA Office of Space Science (OSS) has identified the search for life in the solar system and the resources necessary to support extraterrestrial life as an important area of study. The Cadmus mission investigates the habitability of Europa from the surface to determine the likelihood that life exists on the moon. By studying the crustal dynamics of the moon, the Cadmus mission assesses the extent to which a flux of water and ice exists between the possible subsurface ocean and the surface. Cadmus investigates the presence of nutrients and signs of energy resources in the crustal ice and also assesses the environmental suitability of the Europa environment to the evolution and sustainability of life. To reduce mission operations cost and complexity the mission architecture includes two landers that will land on the surface independently and utilize a high degree of autonomy.","PeriodicalId":117223,"journal":{"name":"2005 IEEE Aerospace Conference","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132971911","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 : 2005-03-05DOI: 10.1109/AERO.2005.1559341
A. Goldberg, K. Havelund, Conor McGann
Autonomous systems are systems that can operate without human interference for extended periods of time in changing environments, likely in remote locations. Software is usually an essential part of such systems. However, adaptation of autonomy software is limited by its complexity and the difficulty of verifying and validating it. We describe an approach named runtime verification for testing autonomy software. Runtime verification is a technique for generating test oracles from abstract specifications of expected behavior. We describe its application to the PLASMA planning system, used in the recent Mars exploration rover missions. We furthermore discuss alternative autonomy V&V approaches.
{"title":"Runtime verification for autonomous spacecraft software","authors":"A. Goldberg, K. Havelund, Conor McGann","doi":"10.1109/AERO.2005.1559341","DOIUrl":"https://doi.org/10.1109/AERO.2005.1559341","url":null,"abstract":"Autonomous systems are systems that can operate without human interference for extended periods of time in changing environments, likely in remote locations. Software is usually an essential part of such systems. However, adaptation of autonomy software is limited by its complexity and the difficulty of verifying and validating it. We describe an approach named runtime verification for testing autonomy software. Runtime verification is a technique for generating test oracles from abstract specifications of expected behavior. We describe its application to the PLASMA planning system, used in the recent Mars exploration rover missions. We furthermore discuss alternative autonomy V&V approaches.","PeriodicalId":117223,"journal":{"name":"2005 IEEE Aerospace Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130217073","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 : 2005-03-05DOI: 10.1109/AERO.2005.1559576
R. J. Quaale, B. Hindman, B. Engberg, P. Collier
Robust link margin stability is critical to maintaining successful laser communications at long range through the atmosphere. Laser power impinging on the receiver must sufficiently exceed all noise for adequate link closure and bit determination. Losses associated with statistical terms can heavily reduce received signal power, which will cause the bit error rate (BER) to rise. A high BER can lead to unacceptable data loss. Large statistical losses are manifested in platform jitter, and atmospheric scintillation. It is essential for system performance that these combined losses are represented as accurately as possible. A detailed picture of system dynamics is achieved through combining numerical simulation of these two terms and including the mitigating influence of forward error correction (FEC) and interleaving. Trade space analysis is performed that incorporates platform jitter, atmospheric fades and various FEC-interleaver combinations. A sensitivity analysis is shown that illustrates the affects of various signal to noise ratios (SNR) on BER and how link efficiency can be increased through these mitigating techniques. FEC-interleaver combinations show a two order of magnitude decrease in BER when implemented
{"title":"Mitigating Environmental Effects on Free-Space Laser Communications","authors":"R. J. Quaale, B. Hindman, B. Engberg, P. Collier","doi":"10.1109/AERO.2005.1559576","DOIUrl":"https://doi.org/10.1109/AERO.2005.1559576","url":null,"abstract":"Robust link margin stability is critical to maintaining successful laser communications at long range through the atmosphere. Laser power impinging on the receiver must sufficiently exceed all noise for adequate link closure and bit determination. Losses associated with statistical terms can heavily reduce received signal power, which will cause the bit error rate (BER) to rise. A high BER can lead to unacceptable data loss. Large statistical losses are manifested in platform jitter, and atmospheric scintillation. It is essential for system performance that these combined losses are represented as accurately as possible. A detailed picture of system dynamics is achieved through combining numerical simulation of these two terms and including the mitigating influence of forward error correction (FEC) and interleaving. Trade space analysis is performed that incorporates platform jitter, atmospheric fades and various FEC-interleaver combinations. A sensitivity analysis is shown that illustrates the affects of various signal to noise ratios (SNR) on BER and how link efficiency can be increased through these mitigating techniques. FEC-interleaver combinations show a two order of magnitude decrease in BER when implemented","PeriodicalId":117223,"journal":{"name":"2005 IEEE Aerospace Conference","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130268501","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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