Aerospace Engineering Commons^™

Survivability Analysis In The Shadow Of Apollo: Part I - Cislunar Debris Propagation And Spacecraft Vulnerability, Nathan R. Boone, Robert A. Bettinger

Faculty Publications

Although the reality of routine travel and sustained operations and habitation in space likely remains several decades away, the building blocks of space exploration and space system development necessary to realize this reality are currently being laid by peer, near-peer, and emerging space-faring nations. Traditionally, global space operations were notionally limited to near-Earth space, with mission altitudes extending to geosynchronous or even highly elliptical orbits. During the 2010s, however, space operations began moving beyond this paradigm to encompass cislunar space with reinvigorated U.S. initiatives to return to the Moon via the Artemis program, planned commercial space projects, and an accelerated …

Assessment Of Conventional And Air-Jet Wheel Deflectors For Drag Reduction Of The Drivaer Model, Sandra K. S. Boetcher, Kaloki L. Nabutola

Publications

Aerodynamic drag is a large resistance force to vehicle motion, particularly at highway speeds. Conventional wheel deflectors were designed to reduce the wheel drag and, consequently, the overall vehicle drag; however, they may actually be detrimental to vehicle aerodynamics in modern designs. In the present study, computational fluid dynamics simulations were conducted on the notchback DrivAer model—a simplified, yet realistic, open-source vehicle model that incorporates features of a modern passenger vehicle. Conventional and air-jet wheel deflectors upstream of the front wheels were introduced to assess the effect of underbody-flow deflection on the vehicle drag. Conventional wheel-deflector designs with varying heights …

Viability And Application Of Mounting Personal Pid Voc Sensors To Small Unmanned Aircraft Systems, Cheri Marcham

Publications

Small Unmanned Aerial Systems in Emergency Response

Current sUAS Uses

• Search and rescue
• Thermal imaging
• Evaluating structural stability
• Spread of wildfires
• Storm damage

Relative Pose Uncertainty Quantification Using Lie Group Variational Filtering, Christopher W. Hays

Doctoral Dissertations and Master's Theses

The applications of visual sensing techniques have revolutionized the way autonomous systems perceive their environment on Earth. In space, the challenge of accurate perception has proven to be a difficult task. Due to adverse lighting conditions, high-noise images are common and degrade the performance of traditional feature-based estimation and perception algorithms. This work explores the applications of a variational filtering scheme founded in Lie Group theory to an autonomous rendezvous, proximity operations and docking problem. Two methodologies, a Monte Carlo approach and an Unscented Transform, for propagating uncertainty using a Lie Group Variational Filter are introduced and developed.

Rf Fingerprinting Unmanned Aerial Vehicles, Norah Ondus

Doctoral Dissertations and Master's Theses

As unmanned aerial vehicles (UAVs) continue to become more readily available, their use in civil, military, and commercial applications is growing significantly. From aerial surveillance to search-and-rescue to package delivery the use cases of UAVs are accelerating. This accelerating popularity gives rise to numerous attack possibilities for example impersonation attacks in drone-based delivery, in a UAV swarm, etc. In order to ensure drone security, in this project we propose an authentication system based on RF fingerprinting. Specifically, we extract and use the device-specific hardware impairments embedded in the transmitted RF signal to separate the identity of each UAV. To achieve …

Integration Of Process Planning Into The Automated Fiber Placement Design For Manufacturing Cycle, Alex Brasington

Theses and Dissertations

Automated Fiber Placement (AFP) is a composite manufacturing technique utilizing a robotic or gantry-based system and an attached fiber placement head to lay a prescribed number of strips of composite material, additively forming large composite structures. This technique has enabled increased throughput with increased accuracy and reliability when compared with prior composite manufacturing methods. However, even with the current state-of-the-art AFP process which employs advanced computer simulations and complex robotic operations, the data from various levels of the manufacturing lifecycle is isolated. This results in an incoherent system between the initial design phase and final part completion with limited ability …

Development Of A Converging-Channel Drop Tower For Sphere Symmetric Isolated Single Droplet Combustion, Nicholas Alexander Demaio

Theses and Dissertations

The dawn of a new Space Age is upon us; Microgravity combustion of hydrocarbon fuels is a popular method of research and characterization. This allows for a one-dimensional analysis by suppressing the buoyancy forces produced by gravity and the large temperature differential between the flame boundary and the surrounding air. The current testing methods are expensive and require extensive preparation on the researchers behalf. There is a need to investigate an alternative method that is inexpensive, repeatable, and comparable to the other approaches that coincides with the literature.

A low-cost converging-channel drop tower was designed and fabricated for sphero-symmetric single …

Nonlinear Intelligent Model Predictive Control Of Mobile Robots, Benjamin Albia

Theses and Dissertations

This thesis presents a framework for an artificial neural network (ANN) model-based nonlinear model predictive control of mobile ground robots. A computer vision analysis module was first developed to extract quantitative position information from onboard camera feed with respect to a prescribed path. Various strategies were developed to construct nonlinear physical plant models for model predictive control (MPC), including the physics-based model (PBM), the ANN trained on PBM-generated data, the ANN trained on test-captured data, and the ANN initially trained on PBM-generated data and then retrained with captured data. All the models predict physical states and positions of the robot …

Empirical Modeling Of Tilt-Rotor Aerodynamic Performance, Michael C. Stratton

Mechanical & Aerospace Engineering Theses & Dissertations

There has been increasing interest into the performance of electric vertical takeoff and landing (eVTOL) aircraft. The propellers used for the eVTOL propulsion systems experience a broad range of aerodynamic conditions, not typically experienced by propellers in forward flight, that includes large incidence angles relative to the oncoming airflow. Formal experiment design and analysis techniques featuring response surface methods were applied to a subscale, tilt-rotor wind tunnel test for three, four, five, and six blade, 16-inch diameter, propeller configurations in support of development of the NASA LA-8 aircraft. Investigation of low-speed performance included a maximum speed of 12 m/s and …

Aerospace Mechanics And Controls, Carlos Montalvo

Textbooks

This report represents aerospace mechanics and controls for CubeSats, quadcopters and aircraft. A CubeSAT is a small satellite on the order of 10 centimeters along each axis. A 1U satellite is a small cube with 10 cm sides. These satellites are used for a variety of missions and created by a variety of different organizations. When deployed from a rocket, a CubeSAT may obtain a large angular velocity which must be reduced before most science missions or communications can take place. Maximizing solar energy charging also involves better pointing accuracy. To control the attitude of these small satellites, reaction wheels, …

Combined Devices Of Facts Technology, Bahrom Ravshanovich Normuratov Associate Lecturer, Misrikhan Misrikhanov, Shukhrat Khamidov

Technical science and innovation

FACTS - Flexible Alternative Current Transmission System technology is a family of devices, each of which can be used individually and in concert with other devices to control the interrelated parameters of the electrical power system. The mission of FACTS technology is to improve the control of power flows in both steady-state and transient modes of EPS. Flexibility of Electric Power Transmission, applied as "The ability to adapt to changes in transmission system or operating conditions while maintaining sufficient operating limits in steady-state and transient modes". Controlled Flexible AC Transmission Lines - Flexibility from Electric Power Transmission means "AC Power …

The Return To Anisotropy Across A Jet In Crossflow, Gregory P. Sakradse

Dissertations and Theses

With data from experiments on a jet of air emitting from an orifice flush with the floor of a wind tunnel providing a transverse flow, analysis is conducted to extract information about the state of anisotropy in the Reynolds stress tensor. Inflow velocities are modulated across two distinct turbulence intensity regimes while holding jet exit conditions constant, providing an opportunity to isolate effects of both jet to crossflow velocity ratio, r and the effects of the turbulence carried by the crossflow. Anisotropy in the Reynolds stress tensor is examined through anisotropy invariant maps and evolution of the function F, …

Start With Simple Spacecraft: Cansat & Cricketsat, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Start with Simple Spacecraft: CanSat & CricketSat" from September 22, 2021.

Flexible Mold For Microstructures Replication, Zefu Ren, Dae Won Kim

Student Works

Space debris has been a growing concern in space exploration sector. To combat this issue, biomimicry is utilized to create a gecko’s feet microstructure that will be attached to a gripper or robotic arm. This will enable capture of debris through the use of dry adhesive microstructure. However, the production of such microstructures is expensive which hinders their implementation. The objective of this research is to develop an advanced fabrication process to mass produce gecko’s feet microstructure with soft polymer mold. The possibility of using different coating methods with coating materials will be justified. The process of fabricating mold and …

Issue 12: Contributors, Don Flournoy

Online Journal of Space Communication

Biographical information on the Issue 12 contributors.

Usdla: An Instructional Media Selection Guide For Distance Learning, Jolly T. Holden, Philip Westfall

Online Journal of Space Communication

Purpose and Use of the Media Selection Guide

Increasingly, educators and trainers are challenged within their respective
organizations to provide for the efficient distribution of instructional con-
tent using instructional media. The appropriate selection of instructional
media to support distance learning is not intuitive and does not occur as a
matter of personal preference. On the contrary, instructional media selec-
tion is a systematic sequence of qualitative processes based on sound in-
structional design principles. Although media selection is often mentioned
when studying the discipline of instructional technology or Instructional
Systems Design (ISD), it is sometimes overlooked when applying the …

U.S. Government Education And Training Network, Philip Westfall

Online Journal of Space Communication

The U.S. Government Education and Training Network is a network of networks operated by a consortium of 17 federal agencies. With over 10,000 scheduled hours of broadcasting each year (4,500 from ATN alone), from 15 uplinks reaching out to over 1,500 receive sites, GETN offers high-quality, low-cost ITV with virtually limitless distribution capability within the US today and overseas.

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.