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Articles 3181 - 3210 of 11097

Full-Text Articles in Aerospace Engineering

Current Development: How One Faith-Based Organization Uses Satellite Technology To Bridge The Digital Divide, Jeffrey B. Roberts Jun 2021

Current Development: How One Faith-Based Organization Uses Satellite Technology To Bridge The Digital Divide, Jeffrey B. Roberts

Online Journal of Space Communication

From its founding in 1830, the Church of Jesus Christ of Latter-day Saints has endeavored to fulfill the divine command to "Go ye into all the world, and preach the gospel to every creature." Proclaiming the gospel of Jesus Christ throughout the world remains a daunting challenge even in modern times. How does a religious organization preach its doctrine to people of all nations, race, cultures, etc? How does it support its growing membership and provide the necessary training for new members and new leaders? How does it assure that its teachings remain consistent around the world? How does it …


Current Development: The Digital Divide - An Appalachian Ohio Perspective, John C. Hoag Jun 2021

Current Development: The Digital Divide - An Appalachian Ohio Perspective, John C. Hoag

Online Journal of Space Communication

The objective of this paper is to assess the role of satellite communication with respect to the Digital Divide in the United States. A secondary objective is to review the capabilities, capacity, and availability of current solutions in light of potential applications in other markets and situations.

This paper contains a review of the Digital Divide in general with additional attention to local Ohio developments and the use of satellite broadband Internet service. We then discuss different satellite-based solutions for residential and commercial Internet access.


Current Development: Satellite Newsgathering Crosses The Digital Divide, Eli Flournoy Jun 2021

Current Development: Satellite Newsgathering Crosses The Digital Divide, Eli Flournoy

Online Journal of Space Communication

Current developments in news gathering.


Current Development: Learning Without Boundary: Application Of Satellite Communication System On Distance Education, Hsin-Ho Tsao Jun 2021

Current Development: Learning Without Boundary: Application Of Satellite Communication System On Distance Education, Hsin-Ho Tsao

Online Journal of Space Communication

Nowadays, the concept of global village has been developed over the world due to the development of communication technology. The information boundaries between areas and regions are gradually eliminated. People are able to have long-distance communication and information exchange, such as searching information via the Internet and making long distance calls that include images. The convenience of communication brought by the technology is applied to education as well.


Issue 5: From The Guest Editor, Bruce Elbert Jun 2021

Issue 5: From The Guest Editor, Bruce Elbert

Online Journal of Space Communication

This issue of the Online Journal of Space Communication focuses on a matter of social concern for which satellite technology is well-positioned to help overcome traditional communication limitations of terrain and distance. Literally the entire globe is within the reach of one satellite system or another, making it possible to extend telephone, television, radio, data and Internet communications to every corner and everybody.


Bibliometric Analysis On Artificial Compressibility Method Based Cfd Simulations, Bhavna Hemraj Joshi Miss, Chandrakant R. Sonawane Dr, Priyambada Bada Praharaj Mrs, Anand Kumar Pandey Dr Jun 2021

Bibliometric Analysis On Artificial Compressibility Method Based Cfd Simulations, Bhavna Hemraj Joshi Miss, Chandrakant R. Sonawane Dr, Priyambada Bada Praharaj Mrs, Anand Kumar Pandey Dr

Library Philosophy and Practice (e-journal)

This bibliometric analysis in this paper aims to study the quantitative progress done in the artificial compressibility (AC) method-based CFD simulation and analyze its potential in solving incompressible flow simulations in computational fluid dynamics smoothly. The sector of CFD is enhancing more and more maturely due to advancements in computing architecture, numerical methods, and simulation tools. There have been various attempts to solve the pressure-velocity coupling issue in the Navier-Stokes equation. The artificial compressibility method (ACM), as opposed to pressure-correction methods, solves the incompressible equation in a non-segregated manner. With the introduction of the ACM, the system of the equation …


Nasa Micro-G Next Challenge: Sample Container Dispensing Device, Kristin G. Kraybill-Voth, Kelsey L. Mickelson, Oscar D. Popravka Jun 2021

Nasa Micro-G Next Challenge: Sample Container Dispensing Device, Kristin G. Kraybill-Voth, Kelsey L. Mickelson, Oscar D. Popravka

Mechanical Engineering

This Final Design Review (FDR) report outlines a Cal Poly San Luis Obispo senior design project developing a sample container dispensing device for NASA Johnson Space Center’s Micro-g NExT design challenge, a competition for university students. NASA aims to bring the first woman and next man to the moon through the Artemis missions beginning in 2024. The Micro-g NExT 2021 challenges focus on developing equipment which will support the Artemis mission, where Astronauts will conduct extensive geological sampling to further the scientific understanding of the moon. Our team designed, built, and tested a device that holds sample bags as they …


Autonomous Mission Planning For Spacecraft Rendezvous And Proximity Operations, Julia C. Bell Jun 2021

Autonomous Mission Planning For Spacecraft Rendezvous And Proximity Operations, Julia C. Bell

Theses and Dissertations

The evolving space environment has created a demand for autonomous spacecraft that can maneuver in complex and sometimes contentious environments. Constraint enforcement, such as an avoidance zone to prevent collision with a target, is a key component of autonomous control to ensure safety and performance requirements are met. Finite-horizon Model Predictive Control (MPC) is a popular control method due to its improved computation time while optimizing performance. Two areas of MPC in need of expansion are time-varying constraints and phase transitions in multi-phase applications. In this work, MPC is employed to track the reference trajectory of a multi-phase satellite inspection …


A Flat Plate Skin Friction Correlation Including Transition, Jaret M. Wedow Jun 2021

A Flat Plate Skin Friction Correlation Including Transition, Jaret M. Wedow

Master's Theses

Many existing boundary layer models treat transition as a rapid switch from laminar to turbulent flow, with correlations defining properties in each respective region. Natural transition, however, is not always a very spanwise uniform process, with the onset of transition varying somewhat between different streamwise paths of fluid flow. Thus, a spanwise average of natural transition can result in a more gradual, extended transition region than many existing models predict. Modern applications, such as aircraft wings and fuselages, are extremely streamlined and smooth, allowing for natural transition to occur rather than flow tripping to turbulent near the leading edge. Under …


Development Of A Cubesat Conceptual Design Tool And Implementation Of The Eps Design Module, Sean K. Nogrady Jun 2021

Development Of A Cubesat Conceptual Design Tool And Implementation Of The Eps Design Module, Sean K. Nogrady

Master's Theses

This thesis is the product of an effort to develop a CubeSat Conceptual Design Tool for the California Polytechnic State University CubeSat Laboratory. Such a tool is necessary due to inefficiencies with the current conceptual design process. It is being developed to increase accessibility, reduce design time, and promote good systems engineering within CubeSat development.

The development of the architecture of a conceptual design tool, the core user-interface element, and the completion of a module for the electrical power subsystem is the focus of this thesis. The architecture is built around different modules to design different subsystems that work in …


Prediction Of In-Plane Stiffnesses And Thermomechanical Stresses In Cylindrical Composite Cross-Sections, Bryson M. Chan Jun 2021

Prediction Of In-Plane Stiffnesses And Thermomechanical Stresses In Cylindrical Composite Cross-Sections, Bryson M. Chan

Master's Theses

Accurate mechanical analysis of composite structures is necessary for the prediction of laminate behavior. Cylindrical composite tubes are a mainstay in many structural applications. The fundamental design of circular composite cross-sections necessitates the development of a comprehensive composite lamination theory. A new analytical method is developed to characterize the behavior of thin-walled composite cylindrical tubes using a modified plate theory. A generated numerical solver can predict properties such as axial stiffness, bending stiffness, layer stresses, and layer strains in composite tubes subjected to combined mechanical loading and thermal effects. The model accounts for the curvature by transforming and translating the …


Analytical, Numerical, And Computational Methods To Analyze The Time To Empty Open, Closed, And Variable-Topped Inverted Bottles, Callen Schwefler Jun 2021

Analytical, Numerical, And Computational Methods To Analyze The Time To Empty Open, Closed, And Variable-Topped Inverted Bottles, Callen Schwefler

Master's Theses

Recent unexpected experimental observations of the emptying of inverted bottles with perforations has generated interest in modeling and simulation of this phenomenon. It was observed that as a perforation, i.e., a small hole at the "top" of the inverted bottle, is added and enlarged, the overall emptying time first increases to a maximum value and then decreases until it reaches a lower limit. The change in emptying time is associated with a transition from jetting, where only water exits the neck, to glugging, a competition between air and water flows at the neck of the bottle.

This paper develops analytical …


Cultivating Creativity In Aerospace Systems Engineering To Manage Complexity, Kenneth Lucas Dodd Jun 2021

Cultivating Creativity In Aerospace Systems Engineering To Manage Complexity, Kenneth Lucas Dodd

Master's Theses

In recent decades, complexity in aerospace programs has been increasing, leading to large budget and schedule overruns. Many of the risks of complex system development can be attributed to the inadequacy of linear methods when applied to nonlinear domains, i.e., oversimplification in a program amplifies the amount of risk produced when a system behaves unexpectedly. Effectively managing complexity involves responding to the various sources of complexity, whether it appears in the objective behavior of the system itself or in the subjective behavior of the people developing it. Thus, the engineering of complex systems requires nonlinear modeling methods of the system …


Toward Cost-Effective Residential Energy Reduction And Community Impacts: A Data-Based Machine Learning Approach, Adel Naji, Badr Al Tarhuni, Jun-Ki Choi, Salahaldin Alshatshati, Seraj Ajena Jun 2021

Toward Cost-Effective Residential Energy Reduction And Community Impacts: A Data-Based Machine Learning Approach, Adel Naji, Badr Al Tarhuni, Jun-Ki Choi, Salahaldin Alshatshati, Seraj Ajena

Mechanical and Aerospace Engineering Faculty Publications

Many U.S. utilities incentivize residential energy reduction through rebates, often in response to state mandates for energy reduction or from a desire to reduce demand to mitigate the need to grow generating assets. The assumption built into incentive programs is that the least efficient residences will be more likely take advantage of the rebates. This, however, is not always the case. The main goal of this study was to determine the potential for prioritized incentivization, i.e., prioritizing incentives that deliver the greatest energy savings per investment through an entire community. It uses a data mining approach that leverages known building …


3-Axis Reaction Wheel System For Cubesats, Alexandra Mae Lee, Daniel Leon, Christopher Pablo Casillas, Rose Mccarver Jun 2021

3-Axis Reaction Wheel System For Cubesats, Alexandra Mae Lee, Daniel Leon, Christopher Pablo Casillas, Rose Mccarver

Mechanical Engineering

Reaction wheels are a common, but expensive, component used in CubeSats, that can accurately position a satellite using an imparted momentum (or impulse) from a rotating flywheel to adjust a satellite’s attitude. This document serves as the final design review and report for the 3-Axis Reaction Wheel Senior Design Project in the Mechanical Engineering Department of California Polytechnic State University, San Luis Obispo. The goal of this project is to produce a functional, low-cost 3-axis reaction wheel system based on previous research done by a master’s student at Cal Poly to be implemented in future CubeSats in the Cal Poly …


Simulation Of A Configurable Hybrid Aircraft, Brandon Bartlett Jun 2021

Simulation Of A Configurable Hybrid Aircraft, Brandon Bartlett

Master's Theses

As the demand for air transportation is projected to increase, the environmental impacts produced by air travel will also increase. In order to counter the environmental impacts while also meeting the demand for air travel, there are goals and research initiatives that aim to develop more efficient aircraft. An emerging technology that supports these goals is the application of hybrid propulsion to aircraft, but there is a challenge in effectively exploring the performance of hybrid aircraft due to the time and money required for safe flight testing and due to the diverse design space of hybrid architectures and components. Therefore, …


Soarnet, Deep Learning Thermal Detection For Free Flight, Jake T. Tallman Jun 2021

Soarnet, Deep Learning Thermal Detection For Free Flight, Jake T. Tallman

Master's Theses

Thermals are regions of rising hot air formed on the ground through the warming of the surface by the sun. Thermals are commonly used by birds and glider pilots to extend flight duration, increase cross-country distance, and conserve energy. This kind of powerless flight using natural sources of lift is called soaring. Once a thermal is encountered, the pilot flies in circles to keep within the thermal, so gaining altitude before flying off to the next thermal and towards the destination. A single thermal can net a pilot thousands of feet of elevation gain, however estimating thermal locations is not …


Metallurgical And Thermal Processing Investigation Of Additively Manufactured Superalloys Jbk-75 And Nasa-Hr-1, Allyse Birken, Derek Noel Jun 2021

Metallurgical And Thermal Processing Investigation Of Additively Manufactured Superalloys Jbk-75 And Nasa-Hr-1, Allyse Birken, Derek Noel

Materials Engineering

Aerojet Rocketdyne is investigating the use of directed energy deposition (DED), an additive manufacturing process, to reduce cost and lead time for manufacturing complex rocket engine components for their RS-25 engines. JBK-75 and NASA-HR-1, two Fe-Ni-base, age-hardenable (γ′) superalloys, are used for nozzle structural jackets and hot gas manifolds. Currently, these parts are produced using traditional forging or casting methods followed by intensive machining operations. Additionally, these alloys were designed for use in the wrought condition and require a different set of post-processing heat treatments when produced using DED due to their dendritic, segregated microstructure in the as-built condition. Homogenization …


Space Suit Attachment Quick Release System, Elyse C. Gillis-Smith, Andres I. Elzaurdia, Cole H. Stanton, Michael T. Roth Jun 2021

Space Suit Attachment Quick Release System, Elyse C. Gillis-Smith, Andres I. Elzaurdia, Cole H. Stanton, Michael T. Roth

Mechanical Engineering

NASA plans to make it back to the Moon by 2024 with their Artemis Program, and stay there for a longer period of time to conduct research which will support the future of space exploration. While on the lunar surface, astronauts need to maximize their efficiency by carrying tools on their Exploration Extravehicular Mobility Unit (xEMU), and to accommodate this need, the Extravehicular Activity (EVA) Tools Team is pursuing a utility belt concept. The objective of this project is to develop a system capable of interfacing between the utility belt and any given tool, while also accommodating numerous restrictions and …


Uav For Medical Equipment Distribution, Richard Barakat, Logan Christensen, Brandon Halebsky, Justin Slavick Jun 2021

Uav For Medical Equipment Distribution, Richard Barakat, Logan Christensen, Brandon Halebsky, Justin Slavick

Mechanical Engineering

This Final Design Review report documents the senior project participating in the Vertical Flight Society’s 38th Annual Student Design Competition sponsored by The Boeing Company. The goal of this project and competition is to develop an unmanned vertical lift for medical equipment distribution capable of safely delivering a 50 kg payload over distances up to 200 km. This system must be autonomous and have a backup plan to land if any part of the system malfunctions. We discuss the research and justification that drove the selection of the aircraft configuration, a winged quadcopter with a rear propeller. Furthermore, we document …


Passive Disposal Of Launch Vehicle Stages In Geostationary Transfer Orbits Leveraging Small Satellite Technologies, Marc Alexander Galles Jun 2021

Passive Disposal Of Launch Vehicle Stages In Geostationary Transfer Orbits Leveraging Small Satellite Technologies, Marc Alexander Galles

Master's Theses

Once a satellite has completed its operational period, it must be removed responsibly in order to reduce the risk of impacting other missions. Geostationary Transfer Orbits (GTOs) offer unique challenges when considering disposal of spacecraft, as high eccentricity and orbital energy give rise to unique challenges for spacecraft designers. By leveraging small satellite research and integration techniques, a deployable drag sail module was analyzed that can shorten the expected orbit time of launch vehicle stages in GTO. A tool was developed to efficiently model spacecraft trajectories over long periods of time, which allowed for analysis of an object’s expected lifetime …


One Dimensional Study Of Magnetoplasmadynamic Thrusters For A Potential New Class Of Heavy Ion Drivers For Plasma Jet Driven Magnetoinertial Fusion, Patrick M. Brown Jun 2021

One Dimensional Study Of Magnetoplasmadynamic Thrusters For A Potential New Class Of Heavy Ion Drivers For Plasma Jet Driven Magnetoinertial Fusion, Patrick M. Brown

Theses and Dissertations

Plasma Jet Driven Magnetoinertial Fusion (PJMIF) requires high velocity heavy ion drivers in order to compress a magnetized target to fusion conditions. Previous work with heavy ion drivers has revealed sub-par accelerations due to plasma instabilities; thus, it is necessary to investigate new methods of heavy ion plasma acceleration. One such method is Magnetoplasmadynamic (MPD) thrusters. Past studies of these thrusters have been conducted at an initial temperature at or below the energy of full ionization. Here MPD thrusters are investigated using a Godunov type MHD solver with a Harten-Lax van Leer-D (HLLD) flux solving scheme assuming the plasma is …


Six Degree-Of-Freedom Mission Planning For Reentry Trajectories, Peter Davis Jun 2021

Six Degree-Of-Freedom Mission Planning For Reentry Trajectories, Peter Davis

Theses and Dissertations

Traditional reentry dynamics and planning has typically explored 3 Degrees-of- Freedom (3 DOF) or pseudo 6-DoF problem formulations. This research expands upon previous work and presents a path-constrained optimal control formulation of a fully 6 Degrees-of-Freedom (3 DOF) dynamic system for an unpowered Reentry Vehicle (RV). In a full 6-DoF dynamic system, the translation, rotation and rotational rates are continually tracked. A system of equations of motion are developed to express the dynamics of the RV in terms of defined states and the RV's physical control detections. A neural-network is used to approximate the aerodynamic database of an exemplary RV. …


Improving The Stability And Operability Of A Small-Scale Rotating Detonation Engine, Nathan T. Fiorino Jun 2021

Improving The Stability And Operability Of A Small-Scale Rotating Detonation Engine, Nathan T. Fiorino

Theses and Dissertations

A small scale RDE was designed with a channel diameter of 28 mm and channel gap of 2 mm and operated on nitrous oxide (N2O) and ethylene (C2H4) as the oxidizer and fuel respectively. Changes to the original Jets in Crossflow (JIC) injection scheme and spark plug ignition method were implemented to counteract previously observed wave instabilities. Successful detonation was observed over a range of mass flows (0.035-0.068 kg/s) and equivalence ratios (ɸ = 0.6-1.4) and a stable single wave mode with frequency up to 16.8 kHz was observed for the first time. Injection …


Adaptive-Optimal Control Of Spacecraft Near Asteroids, Madhur Tiwari Jun 2021

Adaptive-Optimal Control Of Spacecraft Near Asteroids, Madhur Tiwari

Doctoral Dissertations and Master's Theses

Spacecraft dynamics and control in the vicinity of an asteroid is a challenging and exciting problem. Currently, trajectory tracking near asteroid requires extensive knowledge about the asteroid and constant human intervention to successfully plan and execute proximity operation. This work aims to reduce human dependency of these missions from a guidance and controls perspective. In this work, adaptive control and model predictive control are implemented to generating and tracking obstacle avoidance trajectories in asteroid’s vicinity.

Specifically, direct adaptive control derived from simple adaptive control is designed with e modification to track user-generated trajectories in the presence of unknown system and …


Electric Field Induced Self-Assembly Of Mesoscale Structured Materials And Smart Fluids, Suchandra Das May 2021

Electric Field Induced Self-Assembly Of Mesoscale Structured Materials And Smart Fluids, Suchandra Das

Dissertations

This dissertation aims to study the forces that drive self-assembly in binary mixtures of particles suspended in liquids and on fluid-liquid interfaces when they are subjected to a uniform electric or magnetic field. Three fluid-particle systems are investigated experimentally and theoretically : (i) Suspensions of dielectric particles in dielectric liquids; (ii) Suspensions of ferromagnetic and diamagnetic particles in ferrofluids; and (iii) Dielectric particles on dielectric fluid-liquid interfaces. The results of these studies are then used to estimate the parameter values needed to assemble materials with desired mesoscale microstructures.

The first fluid-particle system studied is an electrorheological (ER) fluid formed using …


Issue 4: Contributors, W.M. (Mac) Evans May 2021

Issue 4: Contributors, W.M. (Mac) Evans

Online Journal of Space Communication

The material in this issue has been developed and supplied by Telesat, the Communications Research Centre, and the Canadian Space Agency - the major players in Satellite Communications in Canada.


The Role Of Partnerships Government/Industry/International, W.M. (Mac) Evans May 2021

The Role Of Partnerships Government/Industry/International, W.M. (Mac) Evans

Online Journal of Space Communication

Much of Canada's involvement in space activities, particularly in the earlier years, related to its interest in satellite communications as a means to provide equitable access by all Canadians to telecommunications services. It also provided the impetus for Canada signing a cooperative agreement with ESA. There are a number of firsts in satellite communications to which Canada can lay claim. However the environment for space communications systems and services has changed dramatically and continues to change due to factors such as global deregulation, rapid advance of telecommunications technology, industrial consolidation and intense competition.


Market Analysis, W.M. (Mac) Evans May 2021

Market Analysis, W.M. (Mac) Evans

Online Journal of Space Communication

Canadian space companies have developed impressive and globally competitive competencies in some niche areas of satellite communications. This has allowed them to be very successful in domestic and export markets. In fact, 63% of total 2000 revenues of $1.4 billion were from Telecommunications. Satellite communications can be considered the cornerstone of the Canadian space industry at large.


Industry Capabilities And Services, W.M. (Mac) Evans May 2021

Industry Capabilities And Services, W.M. (Mac) Evans

Online Journal of Space Communication

Space Communication technologies have provided the world with satellite communications and global satellite navigation infrastructures that have become strategic assets for the economic, political, and military sectors of countries around the world. Their omnipresence in our everyday lives and their significant role in world commerce, security and humanitarian operations such as Search and Rescue have made telecommunications and global navigation satellites indispensable.