Pub Date : 2012-03-03DOI: 10.1109/AERO.2012.6187100
V. Vilnrotter
The potential development of large aperture ground-based “photon bucket” optical receivers for deep space communications has received considerable attention recently1. One approach currently under investigation proposes to polish the aluminum reflector panels of 34-meter microwave antennas to high reflectance, and accept the relatively large spotsize generated by even state-of-the-art polished aluminum panels. Here we describe the experimental effort currently underway at the Deep Space Network (DSN) Goldstone Communications Complex in California, to test and verify these concepts in a realistic operational environment. A custom designed aluminum panel has been mounted on the 34 meter research antenna at Deep-Space Station 13 (DSS-13), and a remotely controlled CCD camera with a large CCD sensor in a weather-proof container has been installed next to the subreflector, pointed directly at the custom polished panel. Using the planet Jupiter as the optical point-source, the point-spread function (PSF) generated by the polished panel has been characterized, the array data processed to determine the center of the intensity distribution, and expected communications performance of the proposed polished panel optical receiver has been evaluated.
{"title":"Experimental evaluation of the “polished panel optical receiver” concept on the Deep Space Network's 34 meter antenna","authors":"V. Vilnrotter","doi":"10.1109/AERO.2012.6187100","DOIUrl":"https://doi.org/10.1109/AERO.2012.6187100","url":null,"abstract":"The potential development of large aperture ground-based “photon bucket” optical receivers for deep space communications has received considerable attention recently1. One approach currently under investigation proposes to polish the aluminum reflector panels of 34-meter microwave antennas to high reflectance, and accept the relatively large spotsize generated by even state-of-the-art polished aluminum panels. Here we describe the experimental effort currently underway at the Deep Space Network (DSN) Goldstone Communications Complex in California, to test and verify these concepts in a realistic operational environment. A custom designed aluminum panel has been mounted on the 34 meter research antenna at Deep-Space Station 13 (DSS-13), and a remotely controlled CCD camera with a large CCD sensor in a weather-proof container has been installed next to the subreflector, pointed directly at the custom polished panel. Using the planet Jupiter as the optical point-source, the point-spread function (PSF) generated by the polished panel has been characterized, the array data processed to determine the center of the intensity distribution, and expected communications performance of the proposed polished panel optical receiver has been evaluated.","PeriodicalId":6421,"journal":{"name":"2012 IEEE Aerospace Conference","volume":"43 1","pages":"1-12"},"PeriodicalIF":0.0,"publicationDate":"2012-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80240465","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 : 2012-03-03DOI: 10.1109/AERO.2012.6187237
C. Kief, B. Zufelt, S. Cannon, J. Lyke, J. Mee
In terms of time and budget, integration is a significant time-consuming component of spacecraft development. While many useful COTS spacecraft components are available, interfacing and controlling these components in an integrated satellite system remains a complex engineering task. The Stanford/Cal Poly CubeSat and Poly-Picosatellite Orbital Dispenser (PPOD) standards have begun to standardize small satellite mechanical systems and revolutionize the way small satellites are deployed. NASA has recognized this as evident by their Educational Launch of Nanosatellites (ELaNa) program which recently selected 17 CubeSats for the ELaNa-4 launch in 2012 (including one high school). To capitalize on this momentum, the Air Force Research Lab (AFRL) has organized and supported a team of commercial and academic laboratories to develop and test an over-arching Space Plug-and-play Architecture (SPA) set of standards to support the rapid integration of independently developed satellite modular systems. SPA represents not only an electrical inter-connection and communication scheme, but a complete model for a self-organizing and self-configuring system to support the rapid assembly of mission-specific small satellites. Rather than forcing existing modules to be re-developed to a common messaging standard, SPA utilizes an XTEDS (eXtended Transducer Electronic Data Sheet) model. Each satellite module contains an electronic document describing its interface, capabilities, messages, data formats, etc. By reading a components XTEDS, other systems can quickly integrate and utilize a new module. While designed to initially take advantage of nanosatellites, everything developed can easily scale to larger spacecraft, UAVs or other aerospace and defense systems. This paper discusses our experience in developing the CubeSat Trailblazer, a 1U SPA-only spacecraft - launching in 2012 as a testbed for SPA technology. The mechanisms of self-organization for independent modules as a cooperating communications system are discussed. The simplifications associated with software development of a Command and Data Handler (CDH) is also presented.
{"title":"The advent of the PnP Cube satellite","authors":"C. Kief, B. Zufelt, S. Cannon, J. Lyke, J. Mee","doi":"10.1109/AERO.2012.6187237","DOIUrl":"https://doi.org/10.1109/AERO.2012.6187237","url":null,"abstract":"In terms of time and budget, integration is a significant time-consuming component of spacecraft development. While many useful COTS spacecraft components are available, interfacing and controlling these components in an integrated satellite system remains a complex engineering task. The Stanford/Cal Poly CubeSat and Poly-Picosatellite Orbital Dispenser (PPOD) standards have begun to standardize small satellite mechanical systems and revolutionize the way small satellites are deployed. NASA has recognized this as evident by their Educational Launch of Nanosatellites (ELaNa) program which recently selected 17 CubeSats for the ELaNa-4 launch in 2012 (including one high school). To capitalize on this momentum, the Air Force Research Lab (AFRL) has organized and supported a team of commercial and academic laboratories to develop and test an over-arching Space Plug-and-play Architecture (SPA) set of standards to support the rapid integration of independently developed satellite modular systems. SPA represents not only an electrical inter-connection and communication scheme, but a complete model for a self-organizing and self-configuring system to support the rapid assembly of mission-specific small satellites. Rather than forcing existing modules to be re-developed to a common messaging standard, SPA utilizes an XTEDS (eXtended Transducer Electronic Data Sheet) model. Each satellite module contains an electronic document describing its interface, capabilities, messages, data formats, etc. By reading a components XTEDS, other systems can quickly integrate and utilize a new module. While designed to initially take advantage of nanosatellites, everything developed can easily scale to larger spacecraft, UAVs or other aerospace and defense systems. This paper discusses our experience in developing the CubeSat Trailblazer, a 1U SPA-only spacecraft - launching in 2012 as a testbed for SPA technology. The mechanisms of self-organization for independent modules as a cooperating communications system are discussed. The simplifications associated with software development of a Command and Data Handler (CDH) is also presented.","PeriodicalId":6421,"journal":{"name":"2012 IEEE Aerospace Conference","volume":"110 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2012-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80321293","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 : 2012-03-03DOI: 10.1109/AERO.2012.6187028
M. Swartwout, S. Jayaram, R. Reed, R. Weller
The effects of radiation on modern electronics are not well understood; devices with length scales below 60 nm are sensitive across a wider range of input energies and respond differently to different species than larger devices. This is not a trivial issue: existing predictive failure models are off by as much as three orders of magnitude. Complicating the problem is that modern devices have dozens of operating modes, requiring orders of magnitude more testing time. This increase in the required time (and cost) for ground testing, coupled with the greatly reduced cost (and development time) for space experimentation via CubeSats, has made spaceflight a sensible complement to ground testing. The Institute for Space and Defense Electronics (ISDE) at Vanderbilt University has partnered with the Space Systems Research Laboratory at Saint Louis University to develop Argus, a proposed flight campaign of perhaps a dozen CubeSat-class spacecraft spanning years. Argus will fly an array of radiation-effects modeling experiments; on-orbit event rates will be compared against ground predictions to help calibrate new predictive models developed at ISDE. Argus leverages COTS CubeSat systems and the extremely simple payload requirements to field a set of very low-cost, very automated passive platforms developed by students at both institutions. This paper will describe the challenges in modeling radiation effects on modern electronics as well as the new models developed at ISDE. The Argus campaign concept and drivers will be discussed, and the first two missions will be presented: COPPER, which flies in late 2012, and Argus-High, proposed for a 2013 launch.
{"title":"Argus: A flight campaign for modeling the effects of space radiation on modern electronics","authors":"M. Swartwout, S. Jayaram, R. Reed, R. Weller","doi":"10.1109/AERO.2012.6187028","DOIUrl":"https://doi.org/10.1109/AERO.2012.6187028","url":null,"abstract":"The effects of radiation on modern electronics are not well understood; devices with length scales below 60 nm are sensitive across a wider range of input energies and respond differently to different species than larger devices. This is not a trivial issue: existing predictive failure models are off by as much as three orders of magnitude. Complicating the problem is that modern devices have dozens of operating modes, requiring orders of magnitude more testing time. This increase in the required time (and cost) for ground testing, coupled with the greatly reduced cost (and development time) for space experimentation via CubeSats, has made spaceflight a sensible complement to ground testing. The Institute for Space and Defense Electronics (ISDE) at Vanderbilt University has partnered with the Space Systems Research Laboratory at Saint Louis University to develop Argus, a proposed flight campaign of perhaps a dozen CubeSat-class spacecraft spanning years. Argus will fly an array of radiation-effects modeling experiments; on-orbit event rates will be compared against ground predictions to help calibrate new predictive models developed at ISDE. Argus leverages COTS CubeSat systems and the extremely simple payload requirements to field a set of very low-cost, very automated passive platforms developed by students at both institutions. This paper will describe the challenges in modeling radiation effects on modern electronics as well as the new models developed at ISDE. The Argus campaign concept and drivers will be discussed, and the first two missions will be presented: COPPER, which flies in late 2012, and Argus-High, proposed for a 2013 launch.","PeriodicalId":6421,"journal":{"name":"2012 IEEE Aerospace Conference","volume":"11 1","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2012-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80984857","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 : 2012-03-03DOI: 10.1109/AERO.2012.6187265
B. Drake
The current United States Space Policy [1] as articulated by the White House and later confirmed by the Congress [2] affirms that “[t]he extension of the human presence from low-Earth orbit to other regions of space beyond low-Earth orbit will enable missions to the surface of the Moon and missions to deep space destinations such as near-Earth asteroids and Mars.” Human exploration of the Moon and Mars has been the focus of numerous exhaustive studies and planning, but missions to Near-Earth Asteroids (NEAs) has, by comparison, garnered relatively little attention in terms of mission and systems planning. This paper examines the strategic implications of human exploration of NEAs and how they can fit into the overall exploration strategy. This paper specifically addresses how accessible currently known NEAs are in terms of mission duration, technologies required, and overall architecture construct. Example mission architectures utilizing different propulsion technologies such as chemical, nuclear thermal, and solar electric propulsion were formulated to determine resulting figures of merit including number of NEAs accessible, time of flight, mission mass, number of departure windows, and length of the launch windows. These data, in conjunction with what we currently know about these potential exploration targets (or need to know in the future), provide key insights necessary for future mission and strategic planning. The analysis suggests that a human mission to a NEA is more representative of a human mission to Mars, and thus would more suitably serve as a final demonstration test of the Mars systems rather than the first human mission beyond low-Earth orbit1, 2.
{"title":"Strategic considerations of human exploration of Near-Earth asteroids","authors":"B. Drake","doi":"10.1109/AERO.2012.6187265","DOIUrl":"https://doi.org/10.1109/AERO.2012.6187265","url":null,"abstract":"The current United States Space Policy [1] as articulated by the White House and later confirmed by the Congress [2] affirms that “[t]he extension of the human presence from low-Earth orbit to other regions of space beyond low-Earth orbit will enable missions to the surface of the Moon and missions to deep space destinations such as near-Earth asteroids and Mars.” Human exploration of the Moon and Mars has been the focus of numerous exhaustive studies and planning, but missions to Near-Earth Asteroids (NEAs) has, by comparison, garnered relatively little attention in terms of mission and systems planning. This paper examines the strategic implications of human exploration of NEAs and how they can fit into the overall exploration strategy. This paper specifically addresses how accessible currently known NEAs are in terms of mission duration, technologies required, and overall architecture construct. Example mission architectures utilizing different propulsion technologies such as chemical, nuclear thermal, and solar electric propulsion were formulated to determine resulting figures of merit including number of NEAs accessible, time of flight, mission mass, number of departure windows, and length of the launch windows. These data, in conjunction with what we currently know about these potential exploration targets (or need to know in the future), provide key insights necessary for future mission and strategic planning. The analysis suggests that a human mission to a NEA is more representative of a human mission to Mars, and thus would more suitably serve as a final demonstration test of the Mars systems rather than the first human mission beyond low-Earth orbit1, 2.","PeriodicalId":6421,"journal":{"name":"2012 IEEE Aerospace Conference","volume":"1 1","pages":"1-18"},"PeriodicalIF":0.0,"publicationDate":"2012-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91259693","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 : 2012-03-03DOI: 10.1109/AERO.2012.6187076
D. Mehoke, P. K. Swaminathan, C. Carrasco, Robert C. Brown, G. Kerley, K. Iyer
The Solar Probe Plus (SPP) spacecraft will go closer to the Sun than any manmade object has gone before, which has required the development of new thermal and micrometeoroid protection technologies. During the 24 solar orbits of the mission, the spacecraft will encounter a thermal environment that is 50 times more severe than any previous spacecraft. It will also travel through a dust environment previously unexplored, and be subject to particle hypervelocity impacts (HVI) at velocities much larger than anything previously encountered. New analytical methodologies and designs have been developed to meet this environment's extreme micrometeoroid protection challenge while also fulfilling the mission's low mass requirement. These new analytical capabilities and protection system concepts could produce similar benefits if applied to Earth orbiting and deep space missions. The SPP dust study was developed to overcome the velocity limitations in the existing micrometeoroid and orbital debris (MMOD) analysis capability. In this study, we developed the hydrocode modeling techniques needed to characterize the material behaviors for a high-shock particle impact event. An additional novel development was an algorithm to calculate the particle flux on specific spacecraft surfaces. Our approach predicts particle impacts for a given spacecraft geometry, including the aforementioned effects. In addition, our approach introduces a size-velocity particle correlation, which lowers the shielding needed for a given protection level. This paper covers the new analytical capabilities developed for the SPP dust environment and how they dramatically lower the mass of the protective systems. The paper also discusses the application of these new analytical capabilities to spacecraft protection in the LEO debris field.
{"title":"A review of the Solar Probe Plus dust protection approach","authors":"D. Mehoke, P. K. Swaminathan, C. Carrasco, Robert C. Brown, G. Kerley, K. Iyer","doi":"10.1109/AERO.2012.6187076","DOIUrl":"https://doi.org/10.1109/AERO.2012.6187076","url":null,"abstract":"The Solar Probe Plus (SPP) spacecraft will go closer to the Sun than any manmade object has gone before, which has required the development of new thermal and micrometeoroid protection technologies. During the 24 solar orbits of the mission, the spacecraft will encounter a thermal environment that is 50 times more severe than any previous spacecraft. It will also travel through a dust environment previously unexplored, and be subject to particle hypervelocity impacts (HVI) at velocities much larger than anything previously encountered. New analytical methodologies and designs have been developed to meet this environment's extreme micrometeoroid protection challenge while also fulfilling the mission's low mass requirement. These new analytical capabilities and protection system concepts could produce similar benefits if applied to Earth orbiting and deep space missions. The SPP dust study was developed to overcome the velocity limitations in the existing micrometeoroid and orbital debris (MMOD) analysis capability. In this study, we developed the hydrocode modeling techniques needed to characterize the material behaviors for a high-shock particle impact event. An additional novel development was an algorithm to calculate the particle flux on specific spacecraft surfaces. Our approach predicts particle impacts for a given spacecraft geometry, including the aforementioned effects. In addition, our approach introduces a size-velocity particle correlation, which lowers the shielding needed for a given protection level. This paper covers the new analytical capabilities developed for the SPP dust environment and how they dramatically lower the mass of the protective systems. The paper also discusses the application of these new analytical capabilities to spacecraft protection in the LEO debris field.","PeriodicalId":6421,"journal":{"name":"2012 IEEE Aerospace Conference","volume":"40 1","pages":"1-13"},"PeriodicalIF":0.0,"publicationDate":"2012-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90529946","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 : 2012-03-03DOI: 10.1109/AERO.2012.6187332
Irene Skupniewicz Smith, Nija Shi, Christopher Webster
Flight controllers in NASA's mission control centers work day and night to ensure that missions succeed and crews are safe. The IT goals of NASA mission control centers are similar to those of most businesses: to evolve IT infrastructure from basic to dynamic. This paper describes Mission Control Technologies (MCT), an application platform that is powering mission control today and is designed to meet the needs of future NASA control centers. MCT is an extensible platform that provides GUI components and a runtime environment. The platform enables NASA's IT goals through its use of lightweight interfaces and configurable components, which promote standardization and incorporate useful solution patterns. The MCT architecture positions mission control centers to reach the goal of dynamic IT, leading to lower cost of ownership, and treating software as a strategic investment.
{"title":"Optimizing flight control software with an application platform","authors":"Irene Skupniewicz Smith, Nija Shi, Christopher Webster","doi":"10.1109/AERO.2012.6187332","DOIUrl":"https://doi.org/10.1109/AERO.2012.6187332","url":null,"abstract":"Flight controllers in NASA's mission control centers work day and night to ensure that missions succeed and crews are safe. The IT goals of NASA mission control centers are similar to those of most businesses: to evolve IT infrastructure from basic to dynamic. This paper describes Mission Control Technologies (MCT), an application platform that is powering mission control today and is designed to meet the needs of future NASA control centers. MCT is an extensible platform that provides GUI components and a runtime environment. The platform enables NASA's IT goals through its use of lightweight interfaces and configurable components, which promote standardization and incorporate useful solution patterns. The MCT architecture positions mission control centers to reach the goal of dynamic IT, leading to lower cost of ownership, and treating software as a strategic investment.","PeriodicalId":6421,"journal":{"name":"2012 IEEE Aerospace Conference","volume":"128 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2012-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89597821","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 : 2012-03-03DOI: 10.1109/AERO.2012.6187108
P. Shannon, D. Kwon, D. Eastin
Traditional military procurement of communication satellites is a long-duration high-cost process. Growing demand for these assets and increased budget constraints are driving the investigation and development of alternative acquisition methods. Leasing of communication bandwidth or transponders is an established alternative to procurement in the commercial satellite industry and for some wideband military communication missions. In general, leasing has not existed for specialized military communication missions or for complete satellite systems. Current specialized military satellite communication technology, such as those systems used for communication with airborne intelligence surveillance and reconnaissance (AISR) assets, is not flexible enough to lease to customers beyond the United States Government (USG). This inability to lease to a larger market results in sole customer business models, which historically require long duration guaranteed contracts to manage the financial risks of the investment by contractors. Appropriation laws and established procurement cycles prevent the USG from signing lease contracts for durations greater than a few years, which under current arrangements, lead to prohibitively high financial risks for the satellite owners. Therefore, there is a need to identify plausible new leasing arrangements that decrease the acquisition schedule and minimize cost to the USG while simultaneously managing the financial risk to the satellite owner. Three primary leasing arrangements are explored in this paper - a full satellite service lease from a commercial operator, a service lease from a satellite manufacturer, and a lease-to-buy arrangement. To identify and evaluate these arrangements, a discounted cash flow (DCF) model was developed to price each of the architectures and to evaluate the business cases from the perspective of the satellite owner. An internal rate of return (IRR) threshold was set based on assumed risk and alternative investment opportunities for the various arrangements. The price of the leases were then set to meet the IRR threshold, and lifecycle costs of the systems were calculated based on the price. Sensitivity analyses were then performed to identify lease arrangements that allow the business model to close for the satellite owner while minimizing lifecycle cost for the USG. Overall, this paper demonstrates the viability of leasing specialized military communication satellites to the government as an alternative to traditional procurement.
{"title":"Leasing of specialized military communication satellites","authors":"P. Shannon, D. Kwon, D. Eastin","doi":"10.1109/AERO.2012.6187108","DOIUrl":"https://doi.org/10.1109/AERO.2012.6187108","url":null,"abstract":"Traditional military procurement of communication satellites is a long-duration high-cost process. Growing demand for these assets and increased budget constraints are driving the investigation and development of alternative acquisition methods. Leasing of communication bandwidth or transponders is an established alternative to procurement in the commercial satellite industry and for some wideband military communication missions. In general, leasing has not existed for specialized military communication missions or for complete satellite systems. Current specialized military satellite communication technology, such as those systems used for communication with airborne intelligence surveillance and reconnaissance (AISR) assets, is not flexible enough to lease to customers beyond the United States Government (USG). This inability to lease to a larger market results in sole customer business models, which historically require long duration guaranteed contracts to manage the financial risks of the investment by contractors. Appropriation laws and established procurement cycles prevent the USG from signing lease contracts for durations greater than a few years, which under current arrangements, lead to prohibitively high financial risks for the satellite owners. Therefore, there is a need to identify plausible new leasing arrangements that decrease the acquisition schedule and minimize cost to the USG while simultaneously managing the financial risk to the satellite owner. Three primary leasing arrangements are explored in this paper - a full satellite service lease from a commercial operator, a service lease from a satellite manufacturer, and a lease-to-buy arrangement. To identify and evaluate these arrangements, a discounted cash flow (DCF) model was developed to price each of the architectures and to evaluate the business cases from the perspective of the satellite owner. An internal rate of return (IRR) threshold was set based on assumed risk and alternative investment opportunities for the various arrangements. The price of the leases were then set to meet the IRR threshold, and lifecycle costs of the systems were calculated based on the price. Sensitivity analyses were then performed to identify lease arrangements that allow the business model to close for the satellite owner while minimizing lifecycle cost for the USG. Overall, this paper demonstrates the viability of leasing specialized military communication satellites to the government as an alternative to traditional procurement.","PeriodicalId":6421,"journal":{"name":"2012 IEEE Aerospace Conference","volume":"9 1","pages":"1-13"},"PeriodicalIF":0.0,"publicationDate":"2012-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89990050","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 : 2012-03-03DOI: 10.1109/AERO.2012.6187015
L. Heilbronn
Comparisons are shown between transport model calculations and secondary-neutron cross sections from 400 MeV/nucleon Kr + Pb interactions. Variations are made in the input files used for the calculations in order to take into account corrections applied to the data for background, flux attenuation, and other effects inherent with neutron measurements at accelerator facilities. Results show that the calculations are very sensitive to a number of input parameters that have an effect on the overall shape and magnitude of the calculated spectra, which in turn have a significant effect on the degree of agreement between data and code. Recommendations are made regarding what input data to select for model calculations, based on these results1 2.
{"title":"Modeling accelerator-based neutron measurements","authors":"L. Heilbronn","doi":"10.1109/AERO.2012.6187015","DOIUrl":"https://doi.org/10.1109/AERO.2012.6187015","url":null,"abstract":"Comparisons are shown between transport model calculations and secondary-neutron cross sections from 400 MeV/nucleon Kr + Pb interactions. Variations are made in the input files used for the calculations in order to take into account corrections applied to the data for background, flux attenuation, and other effects inherent with neutron measurements at accelerator facilities. Results show that the calculations are very sensitive to a number of input parameters that have an effect on the overall shape and magnitude of the calculated spectra, which in turn have a significant effect on the degree of agreement between data and code. Recommendations are made regarding what input data to select for model calculations, based on these results1 2.","PeriodicalId":6421,"journal":{"name":"2012 IEEE Aerospace Conference","volume":"2772 1","pages":"1-6"},"PeriodicalIF":0.0,"publicationDate":"2012-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86490531","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 : 2012-03-03DOI: 10.1109/AERO.2012.6187286
J. Christensen, D. B. Anderson, M. Greenman, B. Hansen
The Air Force Research Laboratory (AFRL) is sponsoring an effort to develop Plug-and-Play (PnP) technology for spacecraft systems. The Space PnP Architecture (SPA) supports a method of constructing arbitrarily complex arrangements of components. SPA is a networked data exchange model. This paper presents the SPA network architecture in relation to the standard five layers of the Open System Interconnect (OSI) model. The responsibilities and functionality of each layer are described. The SPA networking provides a unified methodology for self-discovery and self-configuration of heterogeneous PnP networks. The SPA networking approach is shown to be elegant, robust, and scalable.
{"title":"Scalable network approach for the Space Plug-and-Play architecture","authors":"J. Christensen, D. B. Anderson, M. Greenman, B. Hansen","doi":"10.1109/AERO.2012.6187286","DOIUrl":"https://doi.org/10.1109/AERO.2012.6187286","url":null,"abstract":"The Air Force Research Laboratory (AFRL) is sponsoring an effort to develop Plug-and-Play (PnP) technology for spacecraft systems. The Space PnP Architecture (SPA) supports a method of constructing arbitrarily complex arrangements of components. SPA is a networked data exchange model. This paper presents the SPA network architecture in relation to the standard five layers of the Open System Interconnect (OSI) model. The responsibilities and functionality of each layer are described. The SPA networking provides a unified methodology for self-discovery and self-configuration of heterogeneous PnP networks. The SPA networking approach is shown to be elegant, robust, and scalable.","PeriodicalId":6421,"journal":{"name":"2012 IEEE Aerospace Conference","volume":"140 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2012-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86598920","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 : 2012-03-03DOI: 10.1109/AERO.2012.6187008
M. Swartwout
In last year's conference, we presented a statistical look at the 316 rideshare missions launched from 1990-2010, examining issues of mass, nations of origin and launch and mission type. Examinations of the data indicated that the broad range of mission types, sizes and participating nations could be classified in several useful ways. For example, we were able to forecast a bifurcation of rideshares into the CubeSat-scale and ESPA-scale categories. In this paper, we will expand on last year's results in three meaningful ways. First, we will extend the analysis back to the first rideshare in 1960 and up through 2011. In doing so, we will be able to confirm what were anecdotal conjectures from the previous paper: that the changes in the numbers and demographics of rideshares can be tied to the availability of specific launch vehicles/systems (namely the Ariane, Dnepr, Shuttle and P-POD); and that the avalanche of CubeSat flights represents a significant change in the nature of rideshares. The second extension of previous work will be the further subclassification of rideshares into military, civil, commercial and educational categories. Identifying the nature of the rideshare operator will help us better correlate the launches available to different missions. For example, we will show that the large number of U.S. rideshare missions is actually a large number of DoD rideshare missions, with a handful of U.S. civil, commercial and educational flights (most of them in the last 5 years). With this new data, we will further refine our forecasts of the launches available for various mission categories in the next few years.
{"title":"A statistical survey of rideshares (and attack of the CubeSats, part deux)","authors":"M. Swartwout","doi":"10.1109/AERO.2012.6187008","DOIUrl":"https://doi.org/10.1109/AERO.2012.6187008","url":null,"abstract":"In last year's conference, we presented a statistical look at the 316 rideshare missions launched from 1990-2010, examining issues of mass, nations of origin and launch and mission type. Examinations of the data indicated that the broad range of mission types, sizes and participating nations could be classified in several useful ways. For example, we were able to forecast a bifurcation of rideshares into the CubeSat-scale and ESPA-scale categories. In this paper, we will expand on last year's results in three meaningful ways. First, we will extend the analysis back to the first rideshare in 1960 and up through 2011. In doing so, we will be able to confirm what were anecdotal conjectures from the previous paper: that the changes in the numbers and demographics of rideshares can be tied to the availability of specific launch vehicles/systems (namely the Ariane, Dnepr, Shuttle and P-POD); and that the avalanche of CubeSat flights represents a significant change in the nature of rideshares. The second extension of previous work will be the further subclassification of rideshares into military, civil, commercial and educational categories. Identifying the nature of the rideshare operator will help us better correlate the launches available to different missions. For example, we will show that the large number of U.S. rideshare missions is actually a large number of DoD rideshare missions, with a handful of U.S. civil, commercial and educational flights (most of them in the last 5 years). With this new data, we will further refine our forecasts of the launches available for various mission categories in the next few years.","PeriodicalId":6421,"journal":{"name":"2012 IEEE Aerospace Conference","volume":"41 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2012-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80022235","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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