Aerospace Engineering Commons^™

A Critical Perspective On The Indian Experience, K. P. Madhu

Online Journal of Space Communication

Growth in the use of satellites for education has been phenomenal in India. Beginning in the 1970s with the SITE project (Satellite Instructional Television Experiment) using a borrowed US satellite, then in the 1980s having its own indigenous INSAT satellite for educational TV, to having a full fledged educational channel on national TV in the 1990s, to the potential of 72 educational channels on EDUSAT at the beginning of the 21st century, shows long-term interest and commitment to this sector.

Distance Education Projects In Kyrgyzstan, Aida Aidakyeva

Online Journal of Space Communication

Kyrgyzstan is a landlocked country in Central Asia, one of the former Soviet Union republics, endowed with few natural resources, but it has a tremendously advantageous location on the major crossroads between Asia and Europe. Under the Soviet system the educational level of the population used to be very high in Kyrgyzstan. Recently the quality of education has started to worsen due to the continuous migration of the nation's specialists to more economically developed countries.

Distance Education Via Satellite: An Early Case Study Of The Indonesian Distance Education Satellite System, Willard D. Shaw

Online Journal of Space Communication

In 1980, the U.S. Agency for International Development initiated the AID Rural Satellite Program (RSP) to explore the potential of telecommunications as a means of extending scarce expert resources and expanding educational opportunities to remote and rural areas. Building on simple, interactive, and inexpensive telephone-based technologies, the Program developed teleconferencing systems for use as a development tool. Three pilot projects-in Indonesia, the West Indies, and Peru-were implemented to test and demonstrate that audioteleconferencing could reliably and affordably support development activities in education, health and agriculture.

The abstract of this paper is available in Bahasa Indonesia. See supplemental files below.

Telesecundaria Of Mexico, Jose Calderoni

Online Journal of Space Communication

A perspective by one who has spent many years working in a distance education program that is successful…

Mexico's Educational Satellite Program

Satellite Technology Applications In Education: Examples From Greece, Yioryos Nardis

Online Journal of Space Communication

In ancient Greece, there was a mechanism for processing space information from the earth. The Antikythera has since been referred to as the world's first (mechanical) computer. In Greece, the Antikythera mechanism was used to fabricate calendars and schedules for seasons of harvesting and for organizing religious festivals. More than two millennia later, the descendants of these early scholars and technicians are still using outer space to educate themselves, but now the mechanism is electronic and digital using software and spaced-based satellites.

Worldspace Satellite Radio, S. Rangarajan

Online Journal of Space Communication

There are significant challenges to the delivery of quality education to less-developed nations. The primary obstacle is the lack of available and affordable connectivity solutions. Broadcast satellites can play an important role to fill this void. Particularly, digital broadcast satellites can provide audio and multimedia contents to multiple locations simultaneously. WorldSpace, with its extensive reach and low-cost terminals, offers a viable solution to increase the access to global educational resources. This solution includes audio formats, asynchronous multimedia delivery and creation of virtual classrooms with instructor-led, synchronous delivery of audio-visual presentations. These help enhance the quality of education delivery across Africa …

The Broadband Satellite System "Ipstar": Applications In Asia-Pacific Region, Masudul Biswas

Online Journal of Space Communication

The increasing trend of data traffic has turned the world into an information society. Even so, a significant portion of the areas and populations of the world have remained outside the flow of data traffic keeping them information-poor. That is why the issue of "digital divide" has popped up. But it is the cost-effectiveness factor of delivering systems that has guided the changes taking place in information and communication technologies that will ultimately benefit the end users.

Satellite-Based Distance Education In India, Sanjay Jasola, Ramesh Sharma

Online Journal of Space Communication

EduSat is the first satellite of India designed specifically to serve the educational sector. It was put into geo-stationary orbit by the GSLV-3 launch vehicle (on September 20, 2004) by the Indian Space Research Organization (ISRO).

Ipstar And Education In Thailand, Taksin Uppalakom

Online Journal of Space Communication

The satellite communication project called IPSTAR was first developed in 1997 by Shin Satellite of Thailand. The project's aim was to deliver an inexpensive broadband satellite better suited to consumer markets. This project included a broadband satellite with more advanced ground system capabilities. The model for the IPSTAR ground system was first field deployed in the year 2000 using IPSTAR first generation services on conventional satellites. These first generation services are still available in various countries on Thaicom, INSAT, APSTAR and ST-1 satellites.

Access To Education In Africa Via Satellite, Hala Ibrahim

Online Journal of Space Communication

The potential of satellite technologies to improve access to education in Africa is discussed in this paper. Education contributes to sustainable development in Africa. However, accessibility to quality education has been stalled by many barriers, including lack of infrastructure, lack of trained teachers, high teacher/student ratios and shortage of educational materials. Satellites are among the information and communication technologies (ICTs) with the potential to by-pass terrestrial barriers to deliver educational services to scattered users.

The Challenges Of Distance Education, Abdul Waheed Khan

Online Journal of Space Communication

Education is of extreme importance as it is key to equipping the workforce with the skills needed to develop national economies. The importance is exemplified by the "Education for All" movement, a global commitment to provide quality basic education for all children, youth and adults, which links directly to the UN Millennium Development Goals (MDGs). Sustainable development of quality primary education is dependent on complementary development in the secondary and tertiary education sectors. With economies relying more and more on the generation and application of knowledge, productivity is increasingly dependent on the development and spread of technological innovation. Higher education …

Satellite Distance Education In China, Tom Wang

Online Journal of Space Communication

The establishment of the China Education Television (CETV) station in July 1986, the broadcast of the first special TV channel for satellite education and the opening of the second special channel are widely regarded as three milestones in the early stage of satellite distance education in China.

Cape 4 Stem Outreach, Hayden Hulin, Nick Pugh

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Hayden Hulin and Nick Pugh titled "CAPE4 STEM Outreach" from September 15, 2021.

Marketing Collateral And Social Media, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Marketing Collateral and Social Media" from September 14, 2021.

Thermal Barrier Coating For Carbon Fiber-Reinforced Composite Materials, Heejin Kim, Jungwon Kim, Juhyeong Lee, Min Wook Lee

Mechanical and Aerospace Engineering Faculty Publications

Carbon fiber-reinforced plastic (CFRP) composites are widely employed in lightweight and high performance applications including supercars, aero-vehicles, and space components. However, although carbon fibers are thermally stable, the low thermal endurance of the matrix materials remains a critical problem in terms of the performance of the material. In this study, we proposed a new, Al₂O₃-based thermal barrier coating (TBC) for the CFRP composites. The TBC comprised α-phase Al₂O₃ particles with a mean diameter of 9.27 μm. The strong adhesion between the TBC and the CFRP substrate was evaluated using a three point bending …

Submicron Metal 3d Printing By Ultrafast Laser Heating And Induced Ligand Transformation Of Nanocrystals, Chinmoy Podder, Xiangtao Gong, Xiaowei Yu, Wan Shou, Heng Pan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Currently, light-based three-dimensional (3D) printing with submicron features is mainly developed based on photosensitive polymers or inorganic-polymer composite materials. To eliminate polymer/organic additives, a strategy for direct 3D assembly and printing of metallic nanocrystals without additives is presented. Ultrafast laser with intensity in the range of 1 x 1010 to 1 x 1012 W/cm2 is used to nonequilibrium heat nanocrystals and induce ligand transformation, which triggers the spontaneous fusion and localized assembly of nanocrystals. The process is due to the operation of hot electrons as confirmed by a strong dependence of the printing rate on laser pulse duration varied in …

Issue 11: Contributors, Don Flournoy

Online Journal of Space Communication

Biographical information for the Issue 11 contributors:

Daniel Butler

Don Flournoy

Scott Madry

Joseph Pelton

Comparison Of Theoretical And Multi-Fidelity Optimum Aerostructural Solutions For Wing Design, Jeffrey D. Taylor, Douglas F. Hunsaker

Mechanical and Aerospace Engineering Student Publications and Presentations

As contemporary aerostructural research for aircraft design trends toward high-fidelity computational methods, aerostructural solutions based on theory are often neglected or forgotten. In fact, in many modern aerostructural wing optimization studies, the elliptic lift distribution is used as a benchmark in place of theoretical aerostructural solutions with more appropriate constraints. In this paper, we review several theoretical aerostructural solutions that could be used as benchmark cases for wing design studies, and we compare them to high-fidelity solutions with similar constraints. Solutions are presented for studies with 1) constraints related to the wing integrated bending moment, 2) constraints related to the …

Optimization Of Interplanetary Transfer Trajectories Using The Invariant Manifolds Of Halo Orbits, Ryan Yedinak

Master's Theses

Traditionally, two-body dynamics have been used to design orbital trajectories for interplanetary missions using a series of Lambert’s transfers and gravity assists. Although these are reliable methods, they have extremely high fuel requirements, especially for missions to outer planets. From an orbital mechanics perspective, three ways of reducing fuel requirements for these types of missions are utilizing low energy transfer trajectories, applying low thrust engine parameters, and implementing orbit optimization techniques.

The goal of this thesis is to combine low energy transfers created from the dynamics of the Circular Restricted Three-Body Problem (CRTBP) with low-thrust orbit optimization techniques to develop …

Visual Navigation And Control For Spacecraft Proximity Operations With Unknown Targets, Wyatt J. Harris

Theses and Dissertations

Many current and future spacecraft missions must conduct rendezvous and proximity operations (RPO) with resident space objects (RSOs). An important subset of spacecraft RPO that is yet to be demonstrated on-orbit involves final approach maneuvers with respect to RSOs where no information (such as geometry, inertia, relative velocity, etc.) is known about the target a priori, and no information is actively provided by the target during maneuvering. Such operation with respect to ‘unknown’ targets represents an important possible mission set for Department of Defense spacecraft and is the subject of this research. Two visual servoing frameworks capable of autonomously controlling …

Stochastic Satellite Air Drag With The Ballistic Coefficient As A Random Variable, Everett B. Palmer Iv

Theses and Dissertations

The drag acceleration caused by the Earth's atmosphere is a significant cause of prediction uncertainty for low Earth orbit satellites. Most existing research has focused on improving deterministic atmospheric density predictions or on density as a random variable. This research investigates a new paradigm and focuses on modeling the uncertainty caused by air drag using the ballistic coefficient, a component of air drag that is independent of the model used to predict atmospheric density. Time series of ballistic coefficient values were calculated and analyzed as random processes. These random processes were then used as the foundation of a stochastic satellite …

A Real-Time Algorithm To Achieve Precise Coordinated Arrival Times In A Time-Variant Environment, Shawn S. Stephens

Theses and Dissertations

The coordinated arrival time problem seeks to control a vehicle's trajectory to achieve some pre-defined final state at a desired arrival time. The persistent monitoring problem is a type of coordinated arrival problem where a stationary or moving ground target must be constantly observed by a group of aircraft. This research simplifies the problem to overfly the target at specific time intervals relative to the other aircraft in the group while increasing the difficulty of the problem by considering aircraft traveling at vastly different airspeeds. The result of this research is a real time guidance algorithm which accurately guides a …

Optimal Incorporation Of Non-Traditional Sensors Into The Space Domain Awareness Architecture, Albert R. Vasso

Theses and Dissertations

The United States Government is the world’s de facto provider of space object cataloging data, but is challenged to maintain pace in an increasingly complex space environment. This work advances a multi-disciplinary approach to better understand and evaluate an underexplored solution recommended by national policy, in which current collection capabilities are augmented with non-traditional sensors. System architecting and literature identify likely needs, performance measures, and contributors to a conceptualized Augmented Network. Multiple hypothetical telescope architectures are modeled and simulated on four separate days throughout the year, then evaluated against performance measures and constraints using optimization. Decision analysis and Pareto optimality …

Evaluation Of Additively Manufactured Lattices Under High Strain Rate Impact, Derek G. Spear

Theses and Dissertations

Several additively manufactured lattice designs and configurations were evaluated under compression loads under various strain rates from quasi-static to highly dynamic. These experiments examined how the mechanical behavior of the lattice changed based on the lattice design properties and the applied strain rates. The modulus of elasticity, yield strength, plateau stress, and toughness were observed to decrease with an increase in strain rate, revealing that the lattice designs exhibit a negative strain rate sensitivity. A new lattice flow stress model was developed to account for the mechanical response of the lattice and was incorporated into a computational model for simulation. …

Coalescence Characteristics Of Bulk Nanobubbles In Water: A Molecular Dynamics Study Coupled With Theoretical Analysis, Eric Bird, Eric Smith, Zhi Liang

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The Coalescence of Two Nanobubbles (NBs) in Water is a Process of Great Importance to Many Industrial Applications. in This Work, We Study the Coalescence of Two Equal-Sized Nitrogen NBs in Water using Molecular Dynamics (MD) Simulations and Continuum-Based Theoretical Analysis. We Vary the NB Diameter from 30 to 50 Nm and Study the Coalescence Characteristics Including the Expansion Speed of the Capillary Bridge between Two Coalescing NBs, the Dynamic Regime of NB Coalescence, the Diameter of Fully Merged NBs, and the Temperature Variation of NBs during the Coalescence Process. for All Cases, We Show the MD Simulation Results Can …

Pseudospectral Methods Of Robust Optimal Motion Planning For Multi-Aperture Space Systems With Motion And Vibration Compensation, Brian W. Bishop

Theses and Dissertations

For multi-body, flexible systems, the ability to achieve rapid reorientation maneuvers can be impacted by nonlinear dynamics and uncertainty in the model parameters impacting the ability to achieve an optimal trajectory computed using nominal parameter values. Trajectory sensitivity to parameter variations increases final pointing error and residual vibrational energy in the system. This manuscript explores using pseudospectral methods to generate robust optimal control trajectories minimizing trajectory sensitivity to parameter variations and derives maneuvers minimizing residual energy and pointing error. The robustness of open-loop optimal control is compared to a standard maneuver derived using traditional methods demonstrating the ability to simultaneously …

Stabilization Of Energy Level Sets Of Underactuated Mechanical Systems Exploiting Impulsive Braking, Nilay Kant, Ranjan Mukherjee, Hassan Khalil

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Recent investigations of underactuated systems have demonstrated the benefits of control inputs that are impulsive in nature. Here we consider the problem of stabilization of energy level sets of underactuated systems exploiting impulsive braking. We consider systems with one passive degree-of-freedom (DOF) and the energy level set is a manifold where the active coordinates are fixed and the mechanical energy equals some desired value. A control strategy comprised of continuous inputs and intermittent impulsive braking inputs is presented. The generality of the approach is shown through simulation of a three-DOF Tiptoebot; the feasibility of implementation of impulsive control using standard …

Application Of Vortex Tubes To Gas Turbine Film Cooling, Matthew N. Fuqua

Theses and Dissertations

To improve thermal efficiency and reduce fuel consumption, gas turbine engines typically operate at increasingly higher turbine inlet temperatures--well in excess of turbine blade material limits--and film cooling schemes are normally employed to reduce metal temperatures within acceptable limits and prevent structural failure. Cooling requirements vary across a blade surface, but there currently exists no means by which coolant temperatures can be locally adjusted to facilitate optimized usage across a blade. Ranque-Hilsch vortex tubes were investigated as a means of adjusting coolant temperatures solely by fluidic means, induced by the phenomenon of temperature separation. Analytical frameworks were developed to determine …

Blade Optimization For Ground Level Low Speed Wind Turbines, Ryan Foster

Symposium of Student Scholars

Low speed wind turbines can provide inexpensive and clean energy in areas where large scale wind power generation is impractical. The purpose of this research is to explore factors that affect the efficiency of low speed wind turbine blades. The factors that were tested include angle of attack, angle of twist, chord length, average thickness, span, and taper ratio. The goal is to determine a combination of these variables to enable maximum power extraction from a low wind speed source. These blade parameters are optimized for the Southeastern region of the United States. NOAA weather data at ground level are …

Lifting Flow Over A Cylinder As A Lift System, Kyle Mello

Symposium of Student Scholars

The goal of this project is to conceptually design a lift system consisting of rotating cylinders that may improve certain flight characteristics when compared to conventional wings for a typical two passenger airplane. The functions of flaps, ailerons, lift to weight ratio and structural responses are considered. The cylindrical model is developed within CFD simulation software such that it generates the same lift produced by the wings of a Cessna 172 wings at cruising speed. Incompressible flow theoretical solutions are initially shown to compare favorably with the computational predictions for elementary cylindrical designs.

The rotating cylinder aircraft generates the same …