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Satellite Conjunction Assessment Risk Analysis For “Dilution Region” Events: Issues And Operational Approaches, Matthew D. Hejduk 2019 Astrorum Consulting LLC

Satellite Conjunction Assessment Risk Analysis For “Dilution Region” Events: Issues And Operational Approaches, Matthew D. Hejduk

Space Traffic Management Conference

An important activity within Space Traffic Management is the detection and prevention of possible on-orbit collisions between space objects. The principal parameter for assessing collision likelihood is the probability of collision, which is widely accepted among conjunction assessment practitioners; but it possesses a known deficiency in that it can produce a false sense of safety when the orbital position uncertainties for the conjuncting objects are high. The probability of collision is said to be “diluted” in such a situation and to understate the possible risk; certain approaches have been recommended by researchers to provide (largely conservative) risk estimates and remediation ...


Near Real Time Satellite Event Detection And Characterization With Remote Photoacoustic Signatures, Justin Spurbeck, Moriba K. Jah 2019 University of Texas at Austin

Near Real Time Satellite Event Detection And Characterization With Remote Photoacoustic Signatures, Justin Spurbeck, Moriba K. Jah

Space Traffic Management Conference

Active satellites frequently maneuver to mitigate conjunctions and maintain nominal mission orbits. With an ever-growing Resident Space Object (RSO) population, the need to detect and predict any changes in active RSO trajectories has become increasingly important. There is typically a lag on the order of hours to days from time of maneuver to unmodeled dynamic event detection depending on the magnitude of the delta-v. For uncooperative objects, this detection lag poses a threat to other satellites. Implementing an active photoacoustic signature change detection methodology to detect and predict unmodeled dynamic events would reduce the overall conjunction risk and provide a ...


Space Objects Classification And Characterization Via Deep Learning And Light Curves: Applications To Space Traffic Management, Roberto Furfaro, Richard Linares, Vishnu Reddy 2019 University of Arizona

Space Objects Classification And Characterization Via Deep Learning And Light Curves: Applications To Space Traffic Management, Roberto Furfaro, Richard Linares, Vishnu Reddy

Space Traffic Management Conference

Recent advancements in deep learning (e.g. Convolutional Neural Networks (CNN), Recurrent Neural networks (RNN)) have demonstrated impressive results in many practical and theoretical fields (e.g. speech recognition, computer vision, robotics). Whereas deep learning methods are becoming ubiquitous, they have been barely explored in SSA applications, in particular with regard to object characterization for Space Traffic Management (STM).

In this paper, we report the results obtained in designing and training a set of CNNs and RNNs for Space Object (SO) classification and characterization using light-curve measurements. More specifically, we provide a comparison between deep networks trained on both physically-based ...


Educating The Space Scientists At Embry-Riddle Through Design, Build And Fly Rocketry Experience, Pedro Llanos, Robert E. Haley, Sathya Gangadharan 2019 Embry-Riddle Aeronautical University - Daytona Beach

Educating The Space Scientists At Embry-Riddle Through Design, Build And Fly Rocketry Experience, Pedro Llanos, Robert E. Haley, Sathya Gangadharan

Pedro J. Llanos (www.AstronauticsLlanos.com)

Practical experience for students in rockets and payloads is very valuable in the space industry, and it is something that would give them an advantage over other applicants. Students in Embry-Riddle Aeronautical University’s Payload and Integration class were given the opportunity to build a level 1 rocket and gain experience developing, testing, and integrating payloads into a rocket. The students were given the tasks to come up with an idea for a payload, design the payload to fit within the rocket for flight, and assemble and launch the rocket with the payload in the payload bay. The tasks required ...


Design Of An Attitude Control System For A Spacecraft With Propellant Slosh Dynamics, Nolan Coulter 2018 Embry-Riddle Aeronautical University

Design Of An Attitude Control System For A Spacecraft With Propellant Slosh Dynamics, Nolan Coulter

Dissertations and Theses

The presence of propellant slosh dynamics in a spacecraft system during a maneuver leads to attitude control system (ACS) performance degradation resulting in attitude tracking errors and instability. As spacecraft missions become more complex and involve longer durations, a substantial propellant mass is required to achieve the mission objectives and perform orbital maneuvers. When the propellant tanks are only partially filled, the liquid fuel moves inside the tanks with translational and rotational accelerations generating the slosh dynamics. This research effort performs a comparative study with different optimal control techniques and a novel application of a model reference artificial immune system ...


Toward Building Resilient, Sustainable, And Smart Infrastructure In The 21st Century, Aly Mousaad Aly 2018 Louisiana State University

Toward Building Resilient, Sustainable, And Smart Infrastructure In The 21st Century, Aly Mousaad Aly

Faculty Publications

In recent years, as a result of significant climate change, stringent windstorms are becoming more frequent than before. Given the threat that windstorms bring to people and property, wind/structural engineering research is imperative to improve the resilience of existing and new infrastructure, for community safety and assets protection. The Windstorm Impact, Science and Engineering (WISE) research program at Louisiana State University (LSU) focuses on creating new knowledge applicable to the mitigation of existing and new infrastructure, to survive and perform optimally under natural hazards. To achieve our research goals, we address two imperious challenges: (i) characterization of realistic wind ...


Julia Language Ephemeris And Physical Constants Reader For Solar System Bodies, Julia Mihaylov, Renee Spear 2018 Embry-Riddle Aeronautical University

Julia Language Ephemeris And Physical Constants Reader For Solar System Bodies, Julia Mihaylov, Renee Spear

Undergraduate Research Symposium - Prescott

This presentation was the forerunner a second paper by the authors for the AAS/AIAA conference in January 2019, and is not available for download. For a description of the first presentation, see the authors' Discovery Day 2018 - Presentation.

Publicly released in 2012, the Julia language is a relatively new, open source dynamic language. One major benefit of Julia is its combined capabilities of both dynamic and static coding languages. It nearly matches the computational efficiency of static languages, such as FORTRAN or C, and exceeds that of dynamic languages, such as MATLAB or Python. Additionally, unlike Python, Julia was ...


Orbital Constellation Design And Analysis Using Spherical Trigonometry And Genetic Algorithms: A Mission Level Design Tool For Single Point Coverage On Any Planet, Joseph R. Gagliano 2018 Cal Poly, SLO

Orbital Constellation Design And Analysis Using Spherical Trigonometry And Genetic Algorithms: A Mission Level Design Tool For Single Point Coverage On Any Planet, Joseph R. Gagliano

Master's Theses and Project Reports

Recent interest surrounding large scale satellite constellations has increased analysis efforts to create the most efficient designs. Multiple studies have successfully optimized constellation patterns using equations of motion propagation methods and genetic algorithms to arrive at optimal solutions. However, these approaches are computationally expensive for large scale constellations, making them impractical for quick iterative design analysis. Therefore, a minimalist algorithm and efficient computational method could be used to improve solution times. This thesis will provide a tool for single target constellation optimization using spherical trigonometry propagation, and an evolutionary genetic algorithm based on a multi-objective optimization function. Each constellation will ...


Exploring The Concept Of A Deep Space Solar-Powered Small Spacecraft, Kian Guillaume Crowley 2018 California Polytechnic State University, San Luis Obispo

Exploring The Concept Of A Deep Space Solar-Powered Small Spacecraft, Kian Guillaume Crowley

Master's Theses and Project Reports

New Horizons, Voyager 1 & 2, and Pioneer 10 & 11 are the only spacecraft to ever venture past Pluto and provide information about space at those large distances. These spacecraft were very expensive and primarily designed to study planets during gravitational assist maneuvers. They were not designed to explore space past Pluto and their study of this environment is at best a secondary mission. These spacecraft rely on radioisotope thermoelectric generators (RTGs) to provide power, an expensive yet necessary approach to generating sufficient power. With Cubesats graduating to interplanetary capabilities, such as the Mars-bound MarCO spacecraft, matching the modest payload requirements ...


Use Of Manifolds In The Insertion Of Ballistic Cycler Trajectories, Oliver K. Morrison 2018 California Polytechnic State University, San Luis Obispo

Use Of Manifolds In The Insertion Of Ballistic Cycler Trajectories, Oliver K. Morrison

Master's Theses and Project Reports

Today, Mars is one of the most interesting and important destinations for humankind and copious methods have been proposed to accomplish these future missions. One of the more fascinating methods is the Earth-Mars cycler trajectory which is a trajectory that accomplishes repeat access to Earth and Mars with little to no fuel-burning maneuvers. This would allow fast travel to and from Mars, as well as grant the possibility of multiple missions using the same main vehicle.

Insertion from Earth-orbit onto the cycler trajectory has not been thoroughly ex- plored and the only existing method so far is a Hohmann-esque transfer ...


Interplanetary Transfer Trajectories Using The Invariant Manifolds Of Halo Orbits, Megan S. Rund 2018 California Polytechnic State University, San Luis Obispo

Interplanetary Transfer Trajectories Using The Invariant Manifolds Of Halo Orbits, Megan S. Rund

Master's Theses and Project Reports

Throughout the history of interplanetary space travel, the Newtonian dynamics of the two-body problem have been used to design orbital trajectories to traverse the solar system. That is, that a spacecraft orbits only one large celestial body at a time. These dynamics have produced impressive interplanetary trajectories utilizing numerous gravity assists, such as those of Voyager, Cassini, Rosetta and countless others. But these missions required large amounts of delta-v for their maneuvers and therefore large amounts of fuel mass. As we desire to travel farther and more extensively in space, these two-body dynamics lead to impossibly high delta-v values, and ...


Thermal Vacuum Chamber Refurbishment And Analysis, Adrian Michael Williams 2018 California Polytechnic State University, San Luis Obispo

Thermal Vacuum Chamber Refurbishment And Analysis, Adrian Michael Williams

Master's Theses and Project Reports

Spacecraft are subject to different environments while on orbit around the Earth and beyond. One of the most critical of these environments that must be counteracted is the thermal environment. Each spacecraft has an operating temperature that is specified in the mission requirements. The requirement stems from internal component operating temperatures that are critical to mission success. Prior to placing the spacecraft in orbit, engineers must be sure that the spacecraft will survive or risk losing the mission entirely.

The primary way to mitigate this risk is to use a thermal vacuum chamber (TVAC). The chamber is designed to resemble ...


Parameter Study Of An Orbital Debris Defender Using Two Team, Three Player Differential Game Theory, David F. Spendel 2018 Air Force Institute of Technology

Parameter Study Of An Orbital Debris Defender Using Two Team, Three Player Differential Game Theory, David F. Spendel

Theses and Dissertations

The United States Air Force and other national agencies rely on numerous space assets to project their doctrine. However, space is becoming an increasingly congested, contested, and competitive environment. A common risk mitigation strategy for the orbit debris problem is either performing evasive maneuvers, or placing additional shielding on the satellite before launch. Current risk mitigation strategies have significant consequences to satellite operators and may not produce sufficient risk mitigation. This research poses that an orbital debris defender, which would defend the primary satellite from orbital debris, may be a more effective risk mitigation strategy. By assuming the worst case ...


Human Optimization And Performance Enhancement In Flight Via Real-Time Biofeedback (Project Have Hope), Michael S. Fritts 2018 Air Force Institute of Technology

Human Optimization And Performance Enhancement In Flight Via Real-Time Biofeedback (Project Have Hope), Michael S. Fritts

Theses and Dissertations

A four-phase, chronological, and build-up approach was implemented that commenced with basic hardware testing in a centrifuge and culminated in flights augmented by real-time biofeedback displays. A prototype Portable Electrocardiogram Unit (PECGU) was designed and proven to accurately measure heart rate (HR) and display percent heart rate reserve (%HRR). Results showed that %HRR was not a sole predictor of cognitive state. Cognitive responses indicated some correlation with %HRR, but were influenced by environment (centrifuge vs. flight). Subjective perceived exertion levels did not show statistically significant changes during test with biofeedback. A G-tracking task was evaluated during centrifuge and flight tests ...


Optimal Trajectory Generation In A Dynamic Multi-Body Environment Using A Pseudospectral Method, Jacob A. Dahlke 2018 Air Force Institute of Technology

Optimal Trajectory Generation In A Dynamic Multi-Body Environment Using A Pseudospectral Method, Jacob A. Dahlke

Theses and Dissertations

High-altitude parking orbits could provide resiliency to the military space infrastructure by providing redundancy in key assets, allowing for rapid reconstitution of underperforming satellites. When analyzing trajectories in a high-altitude regime, two-body models of Keplerian motion become less accurate since the gravitational effects of other bodies are no longer negligible. To provide a higher fidelity model of the dynamics in a high-altitude regime, a multiple-body model can be used. In the Earth-Moon system, a spacecraft operating in the high-altitude regime can be modeled with three-body dynamics. With certain simplifying assumptions, the model is called the circular-restricted three-body problem (CR3BP). The ...


The Study And Application Of Carbon Nanotube Film Heaters For Space Applications, Christopher C. Rocker 2018 Air Force Institute of Technology

The Study And Application Of Carbon Nanotube Film Heaters For Space Applications, Christopher C. Rocker

Theses and Dissertations

The purpose of this research was to examine the feasibility of using Carbon Nanotube (CNT) sheets as thin film heaters for space applications. The ability to maintain the temperature of space components has a direct impact on a space vehicle's operation and longevity. Currently etched foil heaters are used to heat satellite batteries. Battery heaters are the focus of this research. However, as this study will show, they have limitations and are susceptible to failure. CNT sheets have many beneficial properties and show potential in replacing the etched foil design. In this study test specimens were created by forming ...


Algorithms For Small Satellite Formation Flying, Robert B. LaRue 2018 Air Force Institute of Technology

Algorithms For Small Satellite Formation Flying, Robert B. Larue

Theses and Dissertations

This thesis presents algorithms for spacecraft formation flying using impulsive thrust and low-thrust methods. The general circular orbit formation initial conditions are derived in terms of equinoctial elements. Physical significance of the bounded relative motion parameters is presented for the case of general circular orbits. The developed algorithms are posed in terms of equinoctial elements for a singularity-free approach. The algorithms are assessed by numerical propagation of the inertial equations of motion with J2 and drag perturbations. Methods are presented for minimizing the ΔV required for formation initialization. An examination of the performance of open-loop and closed-loop control is provided ...


Space-Based Maneuver Detection And Characterization Using Multiple Model Adaptive Estimation, Justin D. Katzovitz 2018 Air Force Institute of Technology

Space-Based Maneuver Detection And Characterization Using Multiple Model Adaptive Estimation, Justin D. Katzovitz

Theses and Dissertations

An increasingly congested space environment requires real-time and dynamic space situational awareness (SSA) on both domestic and foreign space objects in Earth orbits. Current statistical orbit determination (SOD) techniques are able to estimate and track trajectories for cooperative spacecraft. However, a non-cooperative spacecraft performing unknown maneuvers at unknown times can lead to unexpected changes in the underlying dynamics of classical filtering techniques. Adaptive estimation techniques can be utilized to build a bank of recursive estimators with different hypotheses on a system's dynamics. The current study assesses the use of a multiple model adaptive estimation (MMAE) technique for detecting and ...


Responsible Behavior For Constellations And Clusters, Darren McKnight, Jonathan Rosenblatt, Darren Garber 2018 Integrity Applications, Inc.

Responsible Behavior For Constellations And Clusters, Darren Mcknight, Jonathan Rosenblatt, Darren Garber

Space Traffic Management Conference

Many large constellations are being considered for deployment over the next ten years into low earth orbit (LEO). This paper seeks to quantify the risks that these constellations pose to the debris environment, the risks that the debris environment poses to these constellations, and the risks that these constellations pose to themselves. The three representative constellations examined in detail in this paper are operated (or planned to be operated) by Spire Global, Iridium, and OneWeb. This paper provides a balanced risk analysis including collision risk, operational risk, and non-adherence risk. For perspective, the risk posed by these economically useful constellations ...


Space Operations In The Suborbital Space Flight Simulator And Mission Control Center: Lessons Learned With Xcor Lynx, Pedro Llanos, Christopher Nguyen, David Williams, Kim O. Chambers Ph.D., Erik Seedhouse, Robert Davidson 2018 Embry-Riddle Aeronautical University

Space Operations In The Suborbital Space Flight Simulator And Mission Control Center: Lessons Learned With Xcor Lynx, Pedro Llanos, Christopher Nguyen, David Williams, Kim O. Chambers Ph.D., Erik Seedhouse, Robert Davidson

Journal of Aviation/Aerospace Education & Research

This study was conducted to better understand the performance of the XCOR Lynx vehicle. Because the Lynx development was halted, the best knowledge of vehicle dynamics can only be found through simulator flights. X-Plane 10 was chosen for its robust applications and accurate portrayal of dynamics on a vehicle in flight. The Suborbital Space Flight Simulator (SSFS) and Mission Control Center (MCC) were brought to the Applied Aviation Sciences department in fall 2015 at Embry-Riddle Aeronautical University, Daytona Beach campus. This academic and research tool is a department asset capable of providing multiple fields of data about suborbital simulated flights ...


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