Multiple Model-Based Synchronization Approaches for Time Delayed Slaving Data in a Space Launch Vehicle Tracking System

Due to the inherent characteristics of the flight mission of a space launch vehicle (SLV), which is required to fly over very large distances and have very high fault tolerances, in general, SLV tracking systems (TSs) comprise multiple heterogeneous sensors such as radars, GPS, INS, and electrooptical targeting systems installed over widespread areas. To track an SLV without interruption and to hand over the measurement coverage between TSs properly, the mission control system (MCS) transfers slaving data to each TS through mission networks. When serious network delays occur, however, the slaving data from the MCS can lead to the failure of the TS. To address this problem, in this paper, we propose multiple model-based synchronization (MMS) approaches, which take advantage of the multiple motion models of an SLV. Cubic spline extrapolation, prediction through an α-β-γ filter, and a single model Kalman filter are presented as benchmark approaches. We demonstrate the synchronization accuracy and effectiveness of the proposed MMS approaches using the Monte Carlo simulation with the nominal trajectory data of Korea Space Launch Vehicle-I

Space Station Planetology Experiments (SSPEX)

A meeting of 50 planetary scientists considered the uses of the Space Station to support experiments in their various disciplines. Abstracts (28) present concepts for impact and aeolian processes, particle formation and interaction, and other planetary science experiments. Summaries of the rationale, hardware concepts, accomodations, and recommendations are included

Aeronautical Engineering: A continuing bibliography with indexes

This bibliography lists 512 reports, articles and other documents introduced into the NASA scientific and technical information system in April 1982

The Biomechanics of Spear Throwing: An Analysis of the Effects of Anatomical Variation on Throwing Performance, with Implications for the Fossil Record

Accurate, high velocity throwing is a skill unique to humans among living species. It likely provided an adaptive advantage for our hominin ancestors, either in the context of hunting, or protection from predators. Thus, understanding how variation in body form and anatomy influences throwing ability may provide insight into the evolution of human morphology. Research has been done on various forms of ball and javelin throwing, yet the biomechanics of spear throwing were completely unknown. Moreover, it has been suggested that early modern humans had lesser effective mechanical advantage: EMA, the ratio of moment arm to load arm) than Neandertals, as a result of selection for throwing, as this could provide increased joint angular velocity at the cost of strength. However the biomechanical principles underpinning this assertion had not been tested empirically. Thus, the purpose of this dissertation is to establish the patterns of kinetics and kinematics used during spear throwing, to examine the morphological correlates of throwing performance and strength in living humans, and to consider the implications of the patterns observed for Paleolithic fossil hominins. Throwing performance, measured as the energy imparted to a thrown object: kinetic energy, Ke), was assessed in 41 experienced throwers throwing balls and spear-like objects. Joint linear and angular velocities, torques, and kinetic energies were calculated using high-speed infrared cameras. Subject anthropometrics, including body mass, height, and segment lengths, were measured externally, and arm muscle cross-sectional areas and EMA of the elbow and wrist were measured from magnetic resonance images. The maximum isometric strength of the elbow and wrist were measured using a load cell. Additionally, EMA of the elbow and wrist were estimated skeletally for available early Homo, Neandertal, Middle Paleolithic, Upper Paleolithic, and recent human specimens. It was demonstrated that the shoulder experiences very low angular velocities and torques, and the elbow is relatively less mobile during spear as compared with ball throwing. Thus, the literature on the arm in ball throwing will be of less relevance to the evolution of throwing. Furthermore, there is no direct correlation between spear Ke and any morphological or anatomical variable of the arm: including EMA). Instead, spear Ke is primarily produced by the legs and torso, where musculature, leg length, and shoulder breadth are correlated with greater Ke. This implies that research on throwing should focus on the legs and torso, and variation in the morphology of the arm should not be used to infer differential selection for throwing in Paleolithic hominins. No correlation was found between the EMA of the elbow or wrist and joint strength independent of muscle cross-sectional area. This is likely due to variation in muscle recruitment and activation, and because r is correlated with muscle size independent of body size. Furthemore, it was demonstrated that EMA cannot be measured reliably in the fossil record, as load arms are highly variable within and between individuals, even performing a highly trained activity like throwing. Consequently, they cannot be predicted from skeletal dimensions available in the fossil record. Furthermore, although there is a trend towards greater EMA of the elbow in Neandertals as compared with other fossil hominin samples, this variation is not functionally or adaptively relevant. No significant differences exist for moment arms between groups; rather, the difference in EMA is due to variation in load arms: ulna length). However, load arms measured skeletally are not relevant to living behaviors, and variation in load arms between these groups is due to known differences in brachial indices, which reflect climatic adaptations. Thus, EMA of the arm is not a useful measure of performance in Paleolithic fossil hominins

Constraining the Evolutionary History of the Moon and the Inner Solar System: A Case for New Returned Lunar Samples

The Moon is the only planetary body other than the Earth for which samples have been collected in situ by humans and robotic missions and returned to Earth. Scientific investigations of the first lunar samples returned by the Apollo 11 astronauts 50 years ago transformed the way we think most planetary bodies form and evolve. Identification of anorthositic clasts in Apollo 11 samples led to the formulation of the magma ocean concept, and by extension the idea that the Moon experienced large-scale melting and differentiation. This concept of magma oceans would soon be applied to other terrestrial planets and large asteroidal bodies. Dating of basaltic fragments returned from the Moon also showed that a relatively small planetary body could sustain volcanic activity for more than a billion years after its formation. Finally, studies of the lunar regolith showed that in addition to containing a treasure trove of the Moon’s history, it also provided us with a rich archive of the past 4.5 billion years of evolution of the inner Solar System. Further investigations of samples returned from the Moon over the past five decades led to many additional discoveries, but also raised new and fundamental questions that are difficult to address with currently available samples, such as those related to the age of the Moon, duration of lunar volcanism, the lunar paleomagnetic field and its intensity, and the record on the Moon of the bombardment history during the first billion years of evolution of the Solar System. In this contribution, we review the information we currently have on some of the key science questions related to the Moon and discuss how future sample-return missions could help address important knowledge gaps

Exploring the Function and Adaptive Context of Paleo-Arctic Projectile Points

This dissertation presents new data on projectile point variability, technological organization, and site distribution in Upper Paleolithic Siberia and late Pleistocene/early Holocene Beringia, relating projectile point morphology, weapon systems, use wear data, and site assemblage variability to functional and cultural application spaces of prehistoric technologies. This research is divided into three related articles, first focusing on experimental investigations of the relationships between Beringian projectile point forms and prehistoric weapon systems. Lithic bifacial, simple osseous, and composite projectile point forms observed in the Beringian record are tested as arming elements of three weapon-delivery systems allowing for quantitative comparing of efficiency and lethality performances for each individual combination of weapon system and projectile-point morphology. Results indicate lithic bifacial and composite projectile points are most effective hafted as spear thrower points and hand-thrust spear tips, respectively. Better defined functional characterizations of prehistoric hunting toolkits furthers understandings of adaptive responses to resource fluctuation, landscape use, and technological organization. Next, this dissertation updates the geochronology and occupation record of the Blair Lakes Archaeological District, specifically the north shore of Blair Lake south, to contribute to our understanding of understudied landscapes in interior Alaska. Testing and excavation results confirm regional occupations that began nearly 11,000 calendar years ago and continued through the historic period. Together these results demonstrate the significance of the Blair Lakes Archaeological District and enhance our understanding of Holocene technological variability, site distribution, mobility, and landscape use in interior Alaska. This research concludes with a comparative morphological and use wear analysis of 11 osseous artifact assemblages from Upper Paleolithic and Mesolithic sites across Siberia and Beringia, focusing on the relationships between raw material, point morphology, and function. Results show that raw material significantly influences point morphology, morphological variability increases during the late Upper Paleolithic, and osseous artifacts offer an avenue for exploring prehistoric cultural application spaces. Ultimately, this dissertation provides insight into functional and cultural application spaces of Beringian projectile points, providing a better understanding of prehistoric hunting tool kits and technological organization of Beringian foragers and the relation of these adaptations to changing ecological conditions. This dissertation presents new data on projectile-point variability, technological organization, and site distribution in Upper Paleolithic Siberia and late Pleistocene/early Holocene Beringia, relating projectile-point morphology, weapon systems, use-wear data, and site-assemblage variability to functional and cultural application spaces of prehistoric technologies. This research is divided into three related articles, first focusing on experimental investigations of the relationships between Beringian projectile point forms and prehistoric weapon systems. Lithic bifacial, simple osseous, and composite projectile point forms observed in the Beringian record are tested as arming elements of three weapon-delivery systems allowing for quantitative comparison of efficiency and lethality performances for each individual combination of weapon system and projectile-point morphology. Results indicate lithic bifacial and composite projectile points are most effective hafted as spear-thrower points and hand-thrust spear tips, respectively. Better defined functional characterizations of prehistoric hunting toolkits furthers understandings of adaptive responses to resource fluctuation, landscape use, and technological organization. Next, this dissertation updates the geochronology and occupation record of the Blair Lakes Archaeological District, specifically the north shore of Blair Lake south, to contribute to our understanding of understudied landscapes in interior Alaska. The field project was designed in part to provide the author with an important experience directing a project in which new archaeological materials relevant to other facets of the dissertation were obtained. Testing and excavation results confirm regional occupations that began nearly 11,000 calendar years ago and continued through the historic period. Together these results demonstrate the significance of the Blair Lakes Archaeological District and enhance our understanding of Holocene technological variability, site distribution, mobility, and landscape use in interior Alaska. This research concludes with a comparative morphological and use wear analysis of 11 osseous artifact assemblages from Upper Paleolithic and Mesolithic sites across Siberia and Beringia, focusing on the relationships between raw material, point morphology, and function. Results show that raw material significantly influenced point morphology, significant morphological variability existed during the late Upper Paleolithic, and osseous artifacts offer an avenue for exploring prehistoric cultural application spaces. Specifically, this stud shows that osseous projectile points inset with microblades were an extremely lethal weapon tip, as also indicated in the experimental work presented earlier in the dissertation. Ultimately, this dissertation provides insight into functional and cultural application spaces of Beringian projectile points, providing a better understanding of prehistoric hunting tool kits and technological organization of Beringian foragers and the relation of these adaptations to changing ecological conditions

Sonic Boom: Six Decades of Research

Sonic booms generated by aircraft traveling at supersonic speeds have been the subject of extensive aeronautics research for over 60 years. Hundreds of papers have been published that document the experimental and analytical research conducted during this time period. The purpose of this publication is to assess and summarize this work and establish the state-of-the-art for researchers just entering the field, or for those interested in a particular aspect of the subject. This publication consists of ten chapters that cover the experimental and analytical aspects of sonic boom generation, propagation and prediction with summary remarks provided at the end of each chapter. Aircraft maneuvers, sonic boom minimization, simulation techniques and devices as well as human, structural, and other responses to sonic booms are also discussed. The geometry and boom characteristics of various low-boom concepts, both large civil transports and smaller business-jet concepts, are included. The final chapter presents an assessment of civilian supersonic overland flight and highlights the need for continued research and a low-boom demonstrator vehicle. Summary remarks are provided at the end of each chapter. The studies referenced in this publication have been drawn from over 500 references

AFIT School of Engineering Contributions to Air Force Research and Technology. Calendar Year 1971

This report contains abstracts of Master of Science theses and Doctoral Dissertations completed during the 1971 calendar year at the School of Engineering, Air Force Institute of Technology

The Shock and Vibration Bulletin. Part 1: Invited Papers, Vibrations and Acoustics, Blast and Shock

Development in the modeling and simulation of shock and vibration phenomena are considered. Predicting the noise exposure of payloads in the space shuttle, prediction for step-stress fatigue, pyrotechnique shock simulation using metal-to-metal impact, and prediction of fragment velocities and trajectories are among the topics covered