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Showing 1 to 20 of 135 for “"space vehicles"”.
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Nonlinear Dynamics Analysis and Control of Space Vehicles with Flexible Structures
<p>Space vehicles that implement hardware such as antennas, solar panels, and other extended appendages necessary for their respective missions must consider the nonlinear rotational and vibrational dynamics of these flexible structures. Formulation and analysis of these flexible structures must …
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A perturbation approach to control of rotational/translational maneuvers of flexible space vehicles
An open loop control law is applied to a flexible spacecraft that admits translational, as well as rotational and flexural motion. The translational degrees of freedom are coupled to the rotation and deformation through the active controls applied to the structure. The objective of any maneuver is …
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Atmospheric signal delay affecting GPS measurements made by space vehicles during launch, orbit and reentry
… delays experienced by GPS signals traveling to space vehicles during launch, orbit and reentry. I calculate these delays for receivers at 0 km to 1700 km altitude by ray-tracing through the Global Reference Atmosphere Model (1999) and the International Reference Ionosphere (2001). These delays …
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Linear covariance analysis trade study of autonomous navigation schemes for cislunar missions
Deep space missions to the Moon and Mars under NASA's Constellation Program are a tangible goal. However, the Deep Space Network (DSN) antennas which provided ground based navigation state updates to spacecraft of the Apollo era are aging and overtaxed. The over-reliance on this ground based system …
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Alternative Foam Treatments For The Space Shuttle's External Tank
The Space Shuttle Columbia accident and the recent excitement surrounding Discovery's return to space brought excessive media attention to the foam products used on the External Tank (ET). In both cases, videos showed chunks of foam or ablative material falling away from the ET during lift off. …
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Designing star trackers to meet micro-satellite requirements
… contradictory to the requirements of smaller space vehicles. Thus, it is of interest to design smaller, lower cost, albeit reduced capability star trackers that can provide adequate attitude and rate determination to small, highly maneuverable, low-cost spacecraft. This thesis discusses the …
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An Examination of Soviet and Russian Military Space Systems
The USSR, the world's largest spacefarer, launched the first object into space, the first man, the first woman and the first anti-satellite weapon. The USSR launched thousands of vehicles during its existence and maintained the longest orbiting space station. The Russian Federation, the largest …
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Optical Path Length Multiplexing of Optical Fiber Sensors
… mines, offshore platforms, air, sea, land, and space vehicles, energy distribution systems, medical patient surveillance systems, etc. Optical path length multiplexing (OPLM) is a modification to traditional white-light interferometry techniques to multiplex extrinsic Fabry-Perot interferometers …
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Neural Network Burst Pressure Prediction in Composite Overwrapped Pressure Vessels from Acoustic Emission Data
<p>Composites have grown in importance in the aerospace industry where high specific strength is a priority. Weight reduction in space vehicles is critical because of the exorbitant cost associated with placing objects into space. Major weight savings have been obtained by switching from all metal …
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Dynamics and Control of Higher-order Nonholonomic Systems
… stabilizable via smooth feedback, including space vehicles with multiple slosh modes and Prismatic-Prismatic-Revolute (PPR) robots moving open liquid containers, as well as an interesting class of systems that do not admit asymptotically stabilizing continuous static or dynamic state …
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Space Vehicle Testing
… a critical component of building and delivering space vehicles with testing as the preferred method. This Master’s Project presents the space vehicle test process from planning through test design and execution. It starts with an overview of the requirements, validation, and verification. The …
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A systems and cost analysis of human rated Mars entry, descent, and landing vehicles
… obstacles to sending humans to Mars. However, spacecraft costs are typically not taken into consideration until after the preliminary vehicle and mission concepts have been designed. Once costs have been estimated, managers and project teams often lack confidence that the final cost of the …
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Vertical Take-Off and Landing Control via Dual-Quaternions and Sliding Mode
<p>The landing and reusability of space vehicles is one of the driving forces into renewed interest in space utilization. For missions to planetary surfaces, this soft landing has been most commonly accomplished with parachutes. However, in spite of their simplicity, they are susceptible to …
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Validation of CFD Simulations for Hypersonic Flow Over a Yawed Cone
… accuracy to compute the hypersonic flows about space vehicles with fully turbulent flow.</p>
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The Effects of Rarefaction and Thermal Non-Equilibrium on a Blunt Body and a Bicone in Hypersonic Flow and Their Shape Optimization for Reducing Both Drag and Heat Transfer
<p>Design of space vehicles pose many challenging problems due to their hypersonic speeds since they need to travel through different flow regimes due to changes in the density of the atmosphere with altitude. Some of the key characteristics associated with hypersonic flow are extremely high …
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Dynamic Code Selection Method for Content Transfer in Deep Space Network
Space communications feature large round-trip time delays (for example, between 6.5 and 44 minutes for Mars to Earth and return, depending on the actual distance between the two planets) and highly variable data error rates, for example, bit error rate (BER) of 10−5 is very comand even higher BERs …
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Experimental Evaluation of the Rate of Rise Technique for Measuring Outgassing Rates in a Vacuum
With an increase of interest in space flight and vacuum research, there has been a corresponding increase in the need for values of outgassing rates of many materials. In space flight the knowledge of the outgassing rates of components and materials used in construction of space vehicles allow the …
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Characterization of functionally graded materials through fractal geometry
… for heat shielding tiles on the reentry space vehicles replacing the conventional ceramic tiles. This system while providing a structurally and thermally excellent heat shielding also reduces the weight penalty by introducing metal in the system without compromising on the strength. In …
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Computation of Hypersonic Flows with Lateral Jets Using k-ω Turbulence Model
… Protection systems (TPS) are used as shields in space vehicles which encounter high heat and temperatures at the reentry altitudes. Among them, the cooling techniques and the ablative coatings are most popular. However, they have their own weight limitations. In the recent decade, another …
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