{"title":"Mars Science Laboratory Entry, Descent, and Landing Triggers","authors":"D. Kipp, M. San Martín, J. Essmiller, D. Way","doi":"10.1109/AERO.2007.352825","DOIUrl":"https://doi.org/10.1109/AERO.2007.352825","url":null,"abstract":"In 2010, plans call for the Mars Science Laboratory (MSL) mission to pioneer the next generation of robotic entry, descent, and landing (EDL) systems by delivering the largest and most capable rover to date to the surface of Mars. Improved altitude performance, coupled with latitude limits as large as 45 degrees off the equator and a precise delivery to within 10 km of a surface target, will allow the science community to select the MSL landing site from thousands of scientifically interesting and previously inaccessible locations. Realizing these impressive performance metrics requires proper execution of a complex sequence of time-critical flight system reconfiguration events. This sequence, which begins approximately 15 minutes prior to touchdown, includes cruise stage separation, cruise balance mass jettison, entry balance mass jettison, parachute deployment, heatshield separation, backshell separation, rover separation, and flyaway start. Each of these events must occur within a narrow operational envelope and must be triggered autonomously based on estimates of the spacecraft state. Triggers are either 'timed', whereby the spacecraft state estimate is reliant upon pre-flight predictions, or 'sensed', whereby the spacecraft state estimates are constructed in real-time using data from the on-board sensor suite. Regardless of method, all triggers must execute properly in the presence of potentially significant variability in Martian winds, atmospheric properties, and surface topography. Careful budgeting is necessary to manage uncertainties and impacts on EDL performance. This paper discusses the design of trigger algorithms that control event execution during the EDL sequence and highlights some of the related challenges faced by the MSL design team.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"103 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79151292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An Objectively Optimized Earth Observing System","authors":"David John Lary","doi":"10.1109/AERO.2007.353089","DOIUrl":"https://doi.org/10.1109/AERO.2007.353089","url":null,"abstract":"This paper describes one vision for future Earth observing systems. New in this vision is the desire for symbiotic communication to dynamically guide an observation system. An earth observation system which is not just a single satellite acting on its own but a constellation of satellites, and sub-orbital platforms such as unmanned aerial vehicles, and ground observations interacting with computer systems used for modeling, data analysis and dynamic observation guidance. An autonomous objectively optimized observation direction system (OOODS) is of great utility for earth observation. In particular, to have a fleet of smart assets that can be reconfigured based on the changing needs of science and technology. The OOODS integrates a modeling and assimilation system within the sensor web allowing the autonomous scheduling of the chosen assets and the autonomous provision of analyses to users. The OOODS operates on generic principles that could easily be used in configurations other than the specific examples described here. Metrics of what we do not know (state vector uncertainty) are used to define what we need to measure and the required mode, time and location of the observations, i.e. to define in real time the observing system targets. Metrics of how important it is to know this information (information content) are used to assign a priority to each observation. The metrics are passed in real time to the sensor web observation scheduler to implement the observation plan for the next observing cycle. The same system could also be used to reduce the cost and development time in an observation sensitivity simulation experiment (OSSE) mode for the optimum development of the next generation of space and ground-based observing systems.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"4 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79224237","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Performance Evaluation of Video Codecs in the Space Environment","authors":"P. Tsao, C. Okino, L. Clare","doi":"10.1109/AERO.2007.352901","DOIUrl":"https://doi.org/10.1109/AERO.2007.352901","url":null,"abstract":"In human missions to other planets and natural satellites (e.g., return to the Moon and future missions to Mars), there will be a need to provide video services for such functions as monitoring analysis, personal private video conversations and general public outreach. There is a desire to provide these services by leveraging terrestrial Internet concepts and technology. In this work we focus on the video performance mechanisms as they are impacted in a space environment where long range latencies and bit errors arise in the wireless/RF links. We provide results from experiments using open source implementations of commercial video standards. Both Peak Signal-to-Noise Ratio (PSNR) and Structural Similarity (SSIM) are used as a performance metrics.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"22 1 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77485945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A Low Cost Rendezvous Mission to 99942 Apophis","authors":"R. Howard, R. Gillett","doi":"10.1109/AERO.2007.352749","DOIUrl":"https://doi.org/10.1109/AERO.2007.352749","url":null,"abstract":"In recent years the public has become more aware of the potentially catastrophic consequences of an asteroid collision with Earth. Congress has taken note of this and instructed NASA to develop a program to determine the resources required to detect, track, characterize, and, if necessary, mitigate potentially hazardous objects. Characterization of an asteroid deemed sufficiently dangerous requires a space mission to determine its key attributes with sufficient accuracy to implement a mitigation scheme. Characterization mission designs to date have been based on the NASA Discovery mission model. This paper presents an approach for reducing the cost of NEO characterization missions by adapting low cost spacecraft and launch vehicle designs now in production by Orbital Sciences. Specifically, we show how the configuration of one of Orbital's small spacecraft designs coupled with a liquid propulsion system from an Orbital GEO communications spacecraft design is adapted to support delivery of a small science payload to the potentially hazardous near Earth asteroid 99942 Apophis. Using a C3 of less than 10 km2/s2, the Minotaur V low cost launch vehicle will place the spacecraft at Apophis in 321 days from a 2 May 2012 launch.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"20 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83497686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of Tracking Errors on Performance of Telescope Arrays Receiver for Deep Space Optical Communication","authors":"A. Hashmi, A. Eftekhar, A. Adibi, F. Amoozegar","doi":"10.1109/AERO.2007.352930","DOIUrl":"https://doi.org/10.1109/AERO.2007.352930","url":null,"abstract":"On Earth, a large aperture telescope is required to achieve the substantial data rates needed for a deep space optical communication link. However, not only are large telescopes very costly but, it is also very difficult to attain near diffraction limited performance with large apertures. An array of relatively smaller sized telescopes combined to form a larger synthesized aperture is a viable and efficient alternative to a large monolithic telescope. However, the performance of telescope arrays needs to be investigated under certain limiting factors such as turbulence, tracking errors etc. In this paper, we analyze the impact of tracking errors on the performance of telescope arrays. A deep space optical communication link between Mars and a telescope array receiver on earth is simulated. A closed loop tracking system is employed at the receiver end to cater for the random tracking errors. Monte Carlo Simulation results show that, under tracking errors the performance of telescope arrays can reach very close to that of a large monolithic telescope with the same total photon collecting area. Hence, telescope arrays are a cost-effective alternative for deep space optical communication.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"60 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83510586","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}
L. Rockett, D. Patel, S. Danziger, B. Cronquist, J.J. Wang
{"title":"Radiation Hardened FPGA Technology for Space Applications","authors":"L. Rockett, D. Patel, S. Danziger, B. Cronquist, J.J. Wang","doi":"10.1109/AERO.2007.353098","DOIUrl":"https://doi.org/10.1109/AERO.2007.353098","url":null,"abstract":"High performance, high density, radiation hardened Field Programmable Gate Arrays (FPGAs) are in great demand for military and space applications to reduce design cost and cycle time. BAE Systems has implemented radiation hardened 150nm bulk CMOS process technology in its foundry located in Manassas, VA to support such advanced product needs. BAE Systems and Actel Corporation are collaborating to bring the next-generation radiation hardened FPGA product for space applications to market. This paper will describe the rad hard AX-250 FPGA and the electrical and radiation test data on rad hard 150nm product hardware, FPGA device structures and anti-fuse arrays, as part of the overall FPGA product installation and qualification effort.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"587 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77216365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Prospecting Rovers for Lunar Exploration","authors":"J. B. Graham","doi":"10.1109/AERO.2007.352706","DOIUrl":"https://doi.org/10.1109/AERO.2007.352706","url":null,"abstract":"A study of rover options for exploring the permanently shadowed regions of the lunar environment is presented. The potential for nearly continuous solar illumination and the possible existence of substantial water ice deposits focus the exploration planner's attention on the polar regions of the Moon. These regions feature permanently shadowed craters that, remote sensing data suggest, may contain water ice. This water ice, if present, can be converted to fuel cell reactants, breathing oxygen, potable water, and rocket propellant, all vital resources for the ultimate exploration of the moon and the solar system. To provide early ground truth on the existence and abundance of this water ice for subsequent mission planning purposes, the NASA lunar precursor robotics program (LPRP) sponsored a study of potential prospecting rover concepts as one part of the LPRP-2 pre-phase A studies. Numerous vehicle configurations were conceptualized to support a suite of prospecting and scientific measurement equipment for sustained operations in a permanently shadowed crater. Trades and analyses were performed for key functions including mobility, power, and thermal management. Rover options in the 400 to 530 kg class are developed which are capable of either confirming the presence of water ice at the poles or conclusively demonstrating its absence.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"4 2","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91492402","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}
K. Keller, A. Baldwin, S. Ofsthun, K. Swearingen, J. Vian, T. Wilmering, Z. Williams
{"title":"Health Management Engineering Environment and Open Integration Platform","authors":"K. Keller, A. Baldwin, S. Ofsthun, K. Swearingen, J. Vian, T. Wilmering, Z. Williams","doi":"10.1109/AERO.2007.352919","DOIUrl":"https://doi.org/10.1109/AERO.2007.352919","url":null,"abstract":"The Phantom Works' role at The Boeing Company is to facilitate the development and transition of emerging technologies into Boeing products to provide a competitive advantage. Phantom works is developing a health management engineering environment (HMEE) to foster and transition health management technology from industry, academia and government technology base to Boeing Products. The HMEE consists of a program analysis and modeling environment, a development environment and an operations environment. The Program Analysis and Modeling Environment provides the processes and tools to do performance/cost driver analysis, root cause analysis, solution formulation, and cost/benefit trade studies including fleet simulation modeling. The development environment provides the design processes and synthesis tools required to develop solutions. The operations environment provides the processes and tools to integrate, test and mature the hardware and software elements of the health management solution. Major elements of the HMEE are an open software reference architecture, access to hardware laboratories to characterize degraded components/ subsystems, a data repository to store and access laboratory and field data, and hardware and software to support end to end technology demonstrations. It will support progressive levels of integration and demonstration from a single technology on a PC to the integration of this technology into a complete IVHM system with hardware in the loop as needed to provide vehicle data and address integration into vehicle avionics or a ground support system. Significant elements of the HMEE are in place with additional expansion and integration ongoing. The Boeing Phantom Works IVHM team is acquiring hardware, tools and algorithms from a number of suppliers to create a pool of resources for system level, end to end demonstrations of IVHM applications and development tools.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"34 1","pages":"1-16"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86978313","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}
J. Kreng, M. Sue, S.K. Do, Y. Krikorian, S. Raghavan
{"title":"Telemetry, Tracking, and Command Link Performance Using the USB/STDN Waveform","authors":"J. Kreng, M. Sue, S.K. Do, Y. Krikorian, S. Raghavan","doi":"10.1109/AERO.2007.352931","DOIUrl":"https://doi.org/10.1109/AERO.2007.352931","url":null,"abstract":"The USB/STDN waveform (unified S-band/spaceflight tracking and data network) has been used to provide telemetry, tracking, and command (TT&C) services for many satellites in addition to NASA near-earth orbital missions. The tracking and command signals are used in the forward link, or the uplink (earth-to-space), while the spacecraft tracking and telemetry signals are used in the return link, or the downlink (space-to-earth). An uplink with a square-wave PRN ranging (pseudorandom noise) or tone-ranging signal is used to improve the carrier acquisition, and ranging performance. Typically the downlink signal is a heavily filtered signal that is needed to reject the side lobes or harmonics of the square waves to satisfy the NTIA (national telecommunications and information administration, a part of US department of commerce) emission spectrum requirements. This filtered downlink signal, sometimes called \"sine-wave,\" intentionally reduces adjacent channel interference (ACI) at earth station receivers. In these space links, it is very important to analyze the modulation losses that affect the TT&C link performance. Currently available analyses assume an unfiltered forward link signal (uplink or earth-to-space link), and a heavily filtered return link (downlink or space-to-earth link). In this paper the modulation losses applicable to the USB/ STDN signal with and without spectral filtering are derived for both the forward link (FWD) and the return link (RTN). As examples of the use of the derived modulation loss expressions, four sets of link analyses for the USB link are given in this paper: unfiltered FWD/unfiltered RTN, unfiltered FWD/filtered RTN, filtered FWD/unfiltered RTN, and filtered FWD/ filtered RTN links.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"7 1","pages":"1-15"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87319392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Reconfiguring Flower Constellations Using Continuous Firing","authors":"D. Mortari, V. Nicolai, M. Ruggieri, P. Salvini","doi":"10.1109/AERO.2007.352789","DOIUrl":"https://doi.org/10.1109/AERO.2007.352789","url":null,"abstract":"Flower constellation have been proposed as a new facility to manage multiple satellite deployment. The number of possible configurations is very wide, according to specific requirements, and has been presented in previous papers. The present paper addresses the concept of the reconfiguration of a satellite set from a flower constellation said A to a flower constellation said B. No initial assumptions are taken for the satellite number in the two configurations: case of a staged deployment (number increase), a satellite failure (number decrease), special needs due to changes in market demands (no changes in number). All cases are discussed in order to find an opportunity to manage important on-orbit decisions, for planning an \"economic risks free\" deployment or, differently, to design a mission with several reconfigurations over the time of life.","PeriodicalId":6295,"journal":{"name":"2007 IEEE Aerospace Conference","volume":"9 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2007-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87329401","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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