2016 IEEE Aerospace Conference最新文献

{"title":"Operational impacts of the U.S. Federal Aviation Administration and the U.S. Laser Clearinghouse on an optical communications Earth relay","authors":"B. Edwards, R. Lafon, Edward Luzhansky","doi":"10.1109/AERO.2016.7500534","DOIUrl":"https://doi.org/10.1109/AERO.2016.7500534","url":null,"abstract":"NASA is planning to launch the next generation of a space-based Earth relay satellite sometime in the middle of the next decade to join the current Space Network, consisting of Tracking and Data Relay Satellites in space and the corresponding infrastructure on Earth. While the requirements and architecture for that relay satellite are unknown at this time, NASA is investing in communications technologies that could be deployed to provide new communications services. One of those new technologies is optical communications. The Laser Communications Relay Demonstration (LCRD) project, scheduled for launch in 2019 as a hosted payload, is a critical pathfinder towards NASA providing optical communications services on the next generation space-based relay. This paper will describe the concept of operations and the impacts of the U.S. Federal Aviation Administration and the U.S. Laser Clearinghouse on the Laser Communications Relay Demonstration. It will provide a high level overview of the link budgets and discuss the analysis done on both space to ground links and geostationary (GEO) to low Earth orbit (LEO) links. The U.S. Laser Clearinghouse is a United States Air Force Strategic Command organization that provides predictive avoidance analysis and deconfliction with U.S. and allies satellites and operations. NASA's policy is to be in compliant with the U.S. Laser Clearinghouse. Having a valid concept of operations that is compliant with the U.S. Federal Aviation Administration and the U.S. Laser Clearinghouse is critical to making optical communications a reality on future NASA science and exploration missions.","PeriodicalId":150162,"journal":{"name":"2016 IEEE Aerospace Conference","volume":"131 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116265162","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":"IPPW: A yearly forum for presentation of planetary entry missions","authors":"B. Bienstock, P. Beauchamp, E. Venkatapathy, M. Munk","doi":"10.1109/AERO.2016.7500759","DOIUrl":"https://doi.org/10.1109/AERO.2016.7500759","url":null,"abstract":"For the past 13 years, we have conducted the International Planetary Probe Workshop (IPPW) at venues in the United States and Europe. Our yearly meetings are attended by engineers, technologists, scientists, mission designers, space agency leaders, and students from around the world. We review the state-of-the-art in science, mission design, engineering implementation and technologies for the in situ robotic exploration of Solar System bodies. We feature discussions on innovative methodologies and techniques for upcoming probe and surface science missions. Student participation in our workshops is emphasized by the scholarships we offer to attract early career scientists and engineers to the field of entry, descent and flight in planetary atmospheres, as well as surface science exploration of other worlds. Through their interaction with professionals, we enable students to learn from experienced researchers and practitioners. During the weekend preceding the week-long workshop, we conduct a Short Course taught by community leaders, on topics pertinent to planetary probes. Examples of past courses include Extreme Environments Technologies, Probe Science Instrument Technologies, and Planetary Protection. Beginning with our 11th workshop in 2014, we have published a summary of the findings during the various sessions. The reports, as well as the materials from all workshops, are available on our public archive, and distributed to the world's national space agencies to serve as a basis for future international collaborations. Our presentation will review the history of the yearly IPPWs as well as the findings of IPPW-11 and IPPW-12, as documented in their Science and Technology Progress Reports on Planetary Probes.","PeriodicalId":150162,"journal":{"name":"2016 IEEE Aerospace Conference","volume":"24 7","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114035327","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":"Accelerator-based measurements relevant for shielding design in space","authors":"N. McGirl, L. Castellanos, Ashwin P. Srikrishna, L. Heilbronn, C. La Tessa, A. Rusek, M. Sivertz, S. Blattnig, M. Clowdsley, T. Slaba, C. Zeitlin","doi":"10.1109/AERO.2016.7500858","DOIUrl":"https://doi.org/10.1109/AERO.2016.7500858","url":null,"abstract":"Experimental work on light charged ion production from thick target shielding began this past May at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL). This paper presents the measured secondary light charged ion and neutron yields produced by 0.4- and 2.5-GeV protons and 0.4- and 1.0-AGeV iron ions striking a 30 g/cm2 aluminum target. Neutron and light charged ion (protons, deuterons, and tritons) measurements were taken with liquid scintillators and sodium iodide (NaI) detectors positioned at seven locations between 10 and 135 degrees off the beam axis to best cover the angular distributions of secondary particles, as determined by MCNPX simulations. In the liquid scintillators, neutron-gamma separation was achieved with pulse shape discrimination, and particle species were identified and isolated by analyzing the total charge deposited in the detector versus particle time of flight (TOF). After isolation, the TOF technique was utilized to produce energy spectra for protons, deuterons, tritons, and neutrons at various locations. Additionally, the stopping powers of light charged ions were compared in NaI detector pairs to generate energy spectra for protons, deuterons, and tritons. Preliminary results demonstrated promising agreement with MCNPX Monte Carlo transport code simulations for protons, deuterons, tritons, and neutrons, despite the lack of a full background characterization and optimization of detector settings. Results are expected to improve over the next three years with an increase in beam time, inclusion of specific liquid scintillator detection efficiencies, and an investigation of the physics model parameters in MCNPX. Future experiments will include the use of both forward and back targets composed of high-density polyethylene or aluminum with thicknesses of 20, 40, and 60 g/cm2. Furthermore, proton, helium, carbon, silicon, and iron projectiles will be utilized at energies of 0.4, 0.75, 1.5, and 2.5 AGeV. Ultimately, these measurements will be incorporated in the uncertainty analysis for the engineering codes that NASA uses to develop optimal shielding thicknesses for spacecraft and space habitat design.","PeriodicalId":150162,"journal":{"name":"2016 IEEE Aerospace Conference","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125320581","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":"NDE of bridging delamination using guided waves: Simulated and experimental results","authors":"I. Saxena, Narciso Guzman, V. Dayal","doi":"10.1109/AERO.2016.7500769","DOIUrl":"https://doi.org/10.1109/AERO.2016.7500769","url":null,"abstract":"Bridging delamination detection in rotor blade edges is difficult with NDE methods such as radiography and thermography. By bridging delamination we mean that the delaminated surfaces are in full or partial contact with each other along a curved geometry. An array of ultrasound sensors along a line can track guided Lamb wave propagation for NDE of composites, and are particularly useful for larger structures. Guided ultrasound waves, such as Lamb waves, when scattered from such defects, are shown to be detected along a line of Bragg grating fiber optic transducers. Simulation results from ANSYS models of curved composite samples with bridging defects that correlate well with our Lamb wave measurements have also been obtained. The models confirm what is observed in our experimental studies on laboratory specimens, that reflections of guided waves occur from delamination/bridging defects in the bends of rotor blades and aircraft leading edge type curved composite structures, and can be used to locate and identify these defects. Potential applications of these NDE techniques, and industrial components to which they are relevant, are discussed. A description of the sensor design and detection system is also outlined.","PeriodicalId":150162,"journal":{"name":"2016 IEEE Aerospace Conference","volume":"133 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131444181","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":"Costas loop and FFT based BPSK demodulation for pulsed radar receivers","authors":"Dylon Mutz, K. George","doi":"10.1109/AERO.2016.7500658","DOIUrl":"https://doi.org/10.1109/AERO.2016.7500658","url":null,"abstract":"This study presents an algorithm to demodulate Binary Phase-Shift Keying (BPSK) signal of unknown frequency and phase contained in wideband radar pulse signal. The algorithm utilizes Fast Fourier Transform (FFT) and Costas Loop in order to lock onto the frequency and phase of the BPSK carrier wave. It was found that the FFT can produce a peak frequency within 25MHz of the actual carrier frequency for BPSK signals. This was using random signal characteristics in the 125MHz to 1375MHz range and from 4-128 bits per 4k samples. The FFT is used to identify the initial peak frequency with which to work with. It was found that an accurate frequency within approximately +165kHz was needed for good demodulation within a Costas Loop. An innovative algorithm was designed to improve the accuracy. This algorithm involves running parallel Costas Loops in 200kHz increments at all frequencies within +25MHz of the obtained frequency. The output phase is then analyzed for a locked state using several derivatives and FIR filters. The algorithm then produces a scalar value for each loop which represents the phase stability. The loop with the lowest scalar value, which corresponds to higher stability, is then chosen for its frequency and final phase value. The carrier wave is then reconstructed and multiplied into the received BPSK signal to recover the modulated data wave. Extensive simulations were performed to ascertain the performance of the algorithm; 10,000 trials were performed with randomized signal values of 125-1375MHz, 0-20dB SNR, and 8-128 bits per 4k samples. The algorithm can demodulate a BPSK signal successfully for 82% of the total 10,000 random trials. While this algorithm is expected to require a large amount of resources, either software or hardware related, it only needs to run once to obtain an accurate frequency. After this initial run, only one Costas Loop needs to run for the rest of the demodulation process, unless the carrier frequency is altered or if frequency-hopping is being used.","PeriodicalId":150162,"journal":{"name":"2016 IEEE Aerospace Conference","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131500885","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":"Space rendezvous and capture testbed","authors":"Russell Smith, David Newill-Smith, G. Udomkesmalee, Brian Lee, E. Eberly, Sam Ortega, M. Roman","doi":"10.1109/AERO.2016.7500902","DOIUrl":"https://doi.org/10.1109/AERO.2016.7500902","url":null,"abstract":"This paper presents a testbed for autonomous rendezvous and capture of small, high-speed, passive objects. While there have been several successful autonomous rendezvous and docking flight systems, a compact and standardized solution for the retrieval of very small passive objects has yet to be demonstrated. Development of a notional standard, on-orbit sample capture/return architecture would not only enable NASA missions such as potential Mars Sample Return and lunar sample return, but it could also minimize the cost and risks associated with those future missions. The testbed presented in this paper was designed for the Space Rendezvous And Capture Competition (Space RACE), a candidate competition being developed for NASA Centennial Challenges. The competition, in which competitors would build mobile robotic platforms to autonomously chase and capture a mock Orbital Sample (OS), emulates major aspects of proposed on-orbit sample capture: locating and tracking a passive target using limited fiducials, developing an approach algorithm, grappling the target, and manipulating the target for insertion into a notional Sample Return Capsule. These elements would also be pertinent to orbital debris cleanup and terrestrial applications such as warehouse packaging and autonomous harvesting. A prototype was built and successfully used to test the Space RACE concept. The prototype consists of a flat, circular track 17m in diameter, four PulsON 410 Ultra Wideband ranging radios, and a four-wheeled robotic platform called the OS-Bot. An on-board autonomous controller uses the ranging radios in the prototype to calculate the position of the OS-Bot in real-time and follow a predefined, arbitrary path. This method of navigation avoids the use of track-fixed fiducials and allows the simulation of any orbital scenario. The system also supports mounting of additional radios on competitor platforms, allowing for minimally invasive monitoring of competitor position and velocity. These aspects both prevent competitors from merely “line-following” to the OS and allow the simulation of numerous mission scenarios which approximate orbital dynamics. Results are presented in this paper for the successful testing of this platform using low resolution sensors in an environment subject to frequent multi-path ranging errors. In addition, a filter is presented which could improve the response of the controller and deliver more robust operation.","PeriodicalId":150162,"journal":{"name":"2016 IEEE Aerospace Conference","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133447154","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":"Application of asteroid redirection methods to orbital debris removal","authors":"Michael C. F. Bazzocchi, M. Emami","doi":"10.1109/AERO.2016.7500750","DOIUrl":"https://doi.org/10.1109/AERO.2016.7500750","url":null,"abstract":"This paper discusses the applicability of some of the asteroid redirection methods, prominently studied in the literature, to orbital debris removal. The tasks of asteroid redirection and orbital debris removal share the common goal of controlled redirection of an uncooperative target. Three asteroid redirection methods are systematically compared and analyzed to assess their viability for an orbital debris reentry mission, i.e., ion beam shepherd, laser sublimation, and tugboat. These methods are investigated in terms of the characteristics of the orbital debris population and based on the major criteria for mission design of controlled reentry of uncooperative objects. In addition, the uncertainty intrinsic to the orbital debris population is quantified through the use of a Monte Carlo simulation, which provides insight into the robustness of the methods for various ranges of orbital debris. The Analytical Hierarchy Process will be employed to assess the viability of each method in a logically consistent fashion, namely, through aggregation of the relative preference (of each method) and relative importance (of each criterion). The advantages and drawbacks of each redirection method are discussed in light of the assessment results for orbital debris reentry.","PeriodicalId":150162,"journal":{"name":"2016 IEEE Aerospace Conference","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133588576","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":"Architecting the ground segment of an optical space communication network","authors":"Iñigo Del Portillo, M. Sánchez, B. Cameron, E. Crawley","doi":"10.1109/AERO.2016.7500803","DOIUrl":"https://doi.org/10.1109/AERO.2016.7500803","url":null,"abstract":"Optical communications are envisioned as a key technology for space communication in the near future. This transition to optical terminals is being pushed by the higher data volume demand of certain missions (i.e.: missions DESDyNI (now cancelled) and NISAR had together a requirement of 60 Tb/day, whereas the data-volume transmitted daily by the Space Network nowadays is roughly 40 Tb) and by the spectrum encroachment in current RF bands. In addition, recent missions like LLCD and OPALS have demonstrated that optical systems present multiple advantages with respect to RF terminals, such as their lower mass, size and power and the higher data-rate they offer (up to 10 Gbps). However, one of the main issues of using optical systems is the space-to-ground link, due to the difficulty of penetrating through atmospheric clouds. Geographic diversity of ground stations has been proposed as an alternative to mitigate these effects. The goal of this paper is to analyze different architectures for the ground segment of a fully optical space relay-communications network to serve LEO missions. In particular, we analyze the tradespace characterized by the decisions 1) number and location of optical ground stations, 2) use of GEO relay satellites vs. direct to Earth (DTE) approach and 3) presence of crosslinks among relay satellites. To that end, we use historical NOAA's weather data and the cloud fraction dataset from Aqua's and Terra's MODIS instruments to characterize weather conditions across the globe. We later use these models to determine the best locations to place ground stations that support optical terminals. Next, we present ONGSA, a network simulator that incorporates the cloud models in order to simulate end-to-end operations of the optical network. Finally we exercise ONGSA to explore the aforementioned tradespace and analyze both cost and performance (in terms of availability) for each architecture.","PeriodicalId":150162,"journal":{"name":"2016 IEEE Aerospace Conference","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133605110","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":"Implementation of non-intrusive jet exhaust species distribution measurements within a test facility","authors":"P. Wright, D. Mccormick, J. Kliment, K. Ozanyan, Mark P. Johnson, J. Black, S. Tsekenis, E. Fisher, H. McCann, M. Lengden, David Wilson, W. Johnstone, V. Archilla, Alvaro Gonzalez-Nunez, Yutong Feng, J. Nilsson","doi":"10.1109/AERO.2016.7500731","DOIUrl":"https://doi.org/10.1109/AERO.2016.7500731","url":null,"abstract":"We report on the installation and commissioning of two systems for the measurement of cross-sectional distributions of pollutant species in jet exhaust, within the engine ground test facility at INTA, Madrid. These systems use optical tomography techniques to estimate the cross-sectional distributions of CO2 and soot immediately behind the engine. The systems are designed to accommodate the largest civil aviation engines currently in service, without obstruction of the exhaust or bypass flows and with negligible effect upon the entrained flow behavior. We describe the physical construction and installation status of each system. In the case of the CO2 system, we examine the challenges of achieving the structural rigidity necessary for adequate suppression of pointing error within 126 laser-based transmittance measurements, each utilizing a 7 m overall path length. We describe methods developed for efficient implementation of co-planarity and 4-degree-of-freedom alignment of individual paths within this beam array. We also present laboratory performance data for three alternative optical designs that differ in their approach to the management of pointing error and turbulence-induced beam wander and spread. The FLITES soot monitoring capability is based on laser induced incandescence (LII) and uses a short-pulse fiber laser and two CCD cameras, in an autoprojection arrangement. We describe the measurement geometry currently being implemented in the test cell and discuss optical design issues, including once again the effect of the plume itself.","PeriodicalId":150162,"journal":{"name":"2016 IEEE Aerospace Conference","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133775137","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":"Optimal space suit mass for Mars extravehicular activity","authors":"C. Carr","doi":"10.1109/AERO.2016.7500869","DOIUrl":"https://doi.org/10.1109/AERO.2016.7500869","url":null,"abstract":"Enabling efficient extravehicular activity (EVA) is a key requirement for future human planetary exploration. Relative to unsuited human movement, space suits can impose substantial bioenergetic costs through their direct impact on load carried, as well as joint torques and inertial effects. This work focuses on the former, as represented by the weight of the space suit, taken to include suit, life support system, and other gear carried, which must be borne by astronauts during EVA. Gas pressure space suit legs can be treated as human-stabilized columns supported by air pressure, constraining the available forces for suit self-support. Here I model how suit pressure, gravitational acceleration, and gait characteristics interact to determine whether pressure suits are self-supporting or whether part of their weight must be carried by a suited astronaut. For the purposes of this model, optimal suit mass is defined as the maximum allowable mass at which the space suit is self-supporting across the range of human gait. The model suggests that complete suit self-support was achieved during Apollo lunar surface exploration despite 81 kg to 96 kg EVA system mass. However, on Mars, such a suit would not achieve self-support. Achieving Moon-like levels of self-support is estimated to require a 45 kg Mars suit. NASA EVA prototype suits for planetary exploration significantly exceed this mass but can compensate by operating at higher suit pressures. However, if low pressure (3.8 to 4.3 psi) operation is required to enable astronaut mobility, significant suit mass reductions will be required for astronaut explorers of Mars to avoid direct load carrying bioenergetics penalties and their associated impact on portable life support system sizing or performance margins.","PeriodicalId":150162,"journal":{"name":"2016 IEEE Aerospace Conference","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131886868","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}