Astrodynamics Commons^™

Data-Driven Learning Algorithms To Predict Spacecraft Trajectories In The Dro Family, Sarath Murarisetty, Hansaka Aluvihare Aluvihare, Oshani Jayawardane, Annika Anderson

Discovery Day - Daytona Beach

Generating precise, accurate, and efficient trajectories in the Earth-Moon circular restricted three-body problem (CR3BP) is crucial for long-term lunar missions, yet it remains challenging. A primary reason for this is that the CR3BP is an extremely nonlinear and chaotic system. Fortunately, neural networks present a promising approach for addressing such complex nonlinear challenges. In “Data-driven Learning Algorithms to Predict Spacecraft Trajectories in the DRO Family,” this work addresses the challenge of solving a nonlinear system within the CR3BP framework to determine the trajectories of spacecraft within the Distant Retrograde Orbit (DRO) family using neural networks (NNs). For a comprehensive comparison …

N31 Multi-Sensor Data Fusion For Enhanced Cislunar Space Domain Awareness Using Radar And Optical Observations, Lucas Bottero

Discovery Day - Daytona Beach

MULTI-SENSOR DATA FUSION FOR ENHANCED CISLUNAR SPACE DOMAIN AWARENESS USING RADAR AND OPTICAL OBSERVATIONS   As operations extend into cislunar space, maintaining Space Domain Awareness (SDA) becomes increasingly challenging due to the vast distances, sparse infrastructure, and complex gravitational dynamics between Earth and the Moon. Radar and optical sensors are the primary modalities used for space surveillance, each with its strengths and limitations. Radar offers continuous observation capabilities regardless of lighting conditions but is limited by power and range at cislunar distances. Optical sensors provide high angular precision but depend on favorable illumination and line-of-sight geometry. However, there has been limited …

Modeling A Spaceborne Passive Radar Architecture For Tracking Resident Space Objects Using Ground-Based Signals Of Opportunity, Chinmay Gaikwad

Discovery Day - Daytona Beach

Modeling a Spaceborne Passive Radar Architecture for Tracking Resident Space Objects Using Ground-Based Signals of Opportunity Due to an increase in manned and unmanned space activities, there is an increase in demand for resilient space operations. This project investigates passive-radar architecture for space domain awareness in which satellites in a low-Earth-orbit mega-constellation are adapted as distributed sensing platforms for tracking debris and other non-cooperative resident space objects. The motivation is to overcome the coverage, cost, and scalability limits of conventional active or ground-based systems by using lightweight passive receivers that exploit ground-based illuminators of opportunity. In this concept, the receivers …

Sun-Synchronous Low Earth Orbit Missions For Imaging Applications, Isaac Rosenthal

Discovery Day - Daytona Beach

Orbit and mission design are crucial elements that must be considered to achieve Earth observation data for land monitoring. This project examines the sun-synchronous low Earth orbit (LEO) implementations of missions with similar objectives: NASA’s Landsat 8 and ESA’s Sentinel-2 constellation. The purpose of this study is to evaluate how differing mission designs, impact imaging and coverage capabilities. Key design trade offs between the two missions include altitude effects on atmospheric drag and station-keeping, swath width versus field-of-view choices, and a single, centralized spacecraft architecture versus a multi-satellite distributed system. This is accomplished by analyzing different orbital parameters, ground track …

Evaluation Of Orbit And Mission Design Parameters Considered In Real Space Missions, Enrique Alejandro Amaya Villegas

Discovery Day - Daytona Beach

Orbit and mission design constitute a fundamental spacecraft subsystem, as the selected orbital regime and mission profile strongly influence power availability, communications geometry, propulsion requirements, and overall mission performance. This project investigates how key quantitative and qualitative parameters guide orbit and mission design decisions in real space missions, with particular emphasis on orbital altitude and inclination, ground coverage and revisit time, mission lifetime, launch vehicle performance constraints, and propulsion budgets. The primary objective is to develop a structured understanding of how high-level scientific or commercial objectives, together with cost, risk, and operational constraints, are translated into specific orbital architectures and …

Interplanetary Trajectory Optimization With Reinforcement Learning, Shiloh Cuffe

Discovery Day - Daytona Beach

This project investigates the application of reinforcement learning (RL) to optimize low-thrust interplanetary trajectory design, focusing on the Earth-Venus transfer leg of the BepiColombo mission. Traditional trajectory optimization methods, such as patched conics and genetic algorithms, often require simplifying assumptions or complex optimization schemes. This work formulates the trajectory design problem as an optimal control problem (OCP) within a Markov Decision Process (MDP) framework, enabling an RL agent to learn efficient transfer strategies under realistic spacecraft constraints. The objective is to develop an autonomous guidance approach capable of replicating or improving upon established mission designs. The spacecraft is modeled as …

Gravity Gradient Exploration Satellite, Luke Ritchie, Isaac Rosenthal, Benjamin Mason, Nathaniel O’Hara

Discovery Day - Daytona Beach

The Gravity Gradient Exploration Satellite (GGEOS) is a single-unit CubeSat technology demonstration being developed by a group of four undergraduate aerospace engineering students at Embry-Riddle Aeronautical University. The mission is designed to validate a controlled, motor-driven, semi-rigid space-tether and deployment system. Space tethers offer significant potential for gravity gradient stabilization and propellant-less electrodynamic propulsion, however past missions have frequently failed due to rebound and tangling from their spring-based deployment systems and elastic tethers. GGEOS mitigates these challenges using a semi-rigid, tape-measure-like tether, deployed with a stepper-motor-driven extrusion system enabling slow, controlled deployment and reduced post-deployment problems. The spacecraft architecture utilizes …

Engineering Path Trajectories With Gravitational Fields, Eliane Dean, Aidan Hart, Isabel Noot, Nathan Browning, Valeria Villazon Fito

Discovery Day - Daytona Beach

This project explores how vector calculus concepts play a role in aerospace engineering though spacecraft trajectory design. In particular, the notion of vector fields is used to model the gravitational force, whose work done is expressed through line integrals. By taking the curl of the gravitational field and showing it is zero, the field is recognised as conservative, implying that the work done by gravity is path independent. This property is conceptually linked to gravitational potential energy and the principle of energy conservation. The results are then applied to spacecraft motion, where engineers use energy-base methods to determine efficient trajectories …

Feasibility And Performance Of Aerogravity Assists For Ceres Missions, Divinaa E. Burder

International Journal of Aviation, Aeronautics, and Aerospace

This work investigates the feasibility and performance of aerogravity assist (AGA) maneuvers for missions to Ceres, with emphasis on both interplanetary trajectory design and atmospheric flight dynamics. AGAs provide substantially greater turning capability than pure gravity assists by exploiting aerodynamic lift during atmospheric passes, thereby enabling greater heliocentric energy changes than pure gravity assists. To quantify these benefits, this study integrates a broad interplanetary trajectory search with high-fidelity atmospheric performance modeling. Candidate trajectories for launch years 2030–2050 are generated for multiple inner-planet encounter sequences using vehicles with lift-to-drag ratios (L/D) between 1 and 7. Atmospheric flight segments are simulated using …

Compact Cislunar Orbital Representation For Efficient Tracking In Cislunar Space, Mauro Palomo

Doctoral Dissertations and Master's Theses

Expanding lunar missions require efficient, interoperable orbital tracking where existing methods fail to scale. Two-Line Elements (TLEs) lack applicability beyond geocentric regimes, while high-accuracy Orbit Ephemeris Messages (OEMs) require excessive data volumes and bandwidth to communicate. To support increased lunar traffic, this paper proposes the Compact Cislunar Orbital Representation (CCOR), providing a novel framework that strikes a balance between TLE level efficiency and OEM-level fidelity, ensuring multi-actor communication for missions in the cislunar region. By evaluating the framework across six diverse cislunar trajectories, this study demonstrates the CCOR’s robustness and ability to compress thousands of OEM state vectors into a …

Adaptive Control Combined With Integral Concurrent Learning For Trajectory Tracking Near Asteroids, Alvaro Diaz Rodrigo

Doctoral Dissertations and Master's Theses

Close-proximity operations in the vicinity of Near-Earth Asteroids (NEAs) are essential for scientific studies and possible future planetary-defense missions. Unlike motion around large celestial bodies, spacecraft dynamics near small, rotating asteroids are dominated by weak, highly irregular gravity fields. While full characterization of an asteroid’s shape enables high-fidelity gravitational modeling, such information is typically unavailable in realistic mission scenarios, and in-situ exploration is often required. As a result, the forces acting on the spacecraft cannot be modeled accurately in advance, leading to significant uncertainty in the equations of motion and challenging guidance and control strategies. To address these challenges, the …

Adaptive Methods Of Resident Space Object Identification For Space Situational Awareness, Evan Pavetto-Stewart

Doctoral Dissertations and Master's Theses

One of the fundamental tenets of Space Situational Awareness (SSA) is the detection and sub sequent identification of Resident Space Objects (RSOs) within unresolved optical space imagery. This function is vital to the documentation and tracking of RSOs in their respective operational orbits, knowledge that is necessary for collision avoidance efforts and Space Domain Awareness (SDA) applications. In previous work, development was begun on a MATLAB program called RSOID to fulfill this purpose by accepting a collection (or ’collect’) of unresolved imagery and outputting a sequence of RSO locations (called a ’tracklet’) that can be used to determine the RSO’s …

Simulation Results Of Spaceborne Ssa Using A Comprehensive Passive Radar Model, Chinmay Gaikwad, Filipe Senra, Thomas Alan Lovell, Hao Peng, Berker Pekoz, Tianyu Yang

Publications

In this paper, a high-fidelity simulation framework is developed to assess the feasibility of tracking space debris using a large low-Earth orbit (LEO) satellite constellation equipped with onboard passive radar sensors. By exploiting illumination from a distributed network of ground-based transmitters, the constellation provides consistent line-of-sight access to debris objects at higher altitudes, enabling angles-only detection and tracking. This approach yields a scalable, automated, and cost-effective architecture for next-generation space surveillance and contributes to more resilient space traffic management. A complete angles-only passive-radar orbit-determination pipeline is introduced and demonstrated. Initial orbital states are generated using a rate-aware constrained admissible-region multiple-hypothesis …

Orbital Maneuvers And Interplanetary Trajectory Design Via Reinforcement Learning, Roberto Cuéllar Rangel

Doctoral Dissertations and Master's Theses

This dissertation investigates the application of reinforcement learning (RL) to the design and optimization of low-thrust spacecraft trajectories, with an emphasis on autonomy, adaptability, and robustness in the presence of system uncertainties and unmodeled perturbations. Classical approaches to low-thrust trajectory design are predominantly grounded in optimal control theory, which relies on the availability of precise dynamical models and often requires problem-specific reformulation and solver tuning. While optimal control methods offer high accuracy under deterministic conditions, their sensitivity to stochastic disturbances and computational limitations in highly nonlinear or uncertain environments pose significant challenges for future autonomous space missions.

To address these …

Robust Adaptive Rigid Body State And Mass Property Estimation Via Unscented Kalman Filter On Tse(3) With Process Noise Estimation, Herman Gunter

Doctoral Dissertations and Master's Theses

Mass property estimation, including mass, center of mass, and moment of inertia, is a crucial yet challenging problem in spacecraft autonomy and astrodynamics. Knowledge of mass properties of a spacecraft is essential for future astronautical missions, as changes in the mass properties of a spacecraft due to a shift in cargo distribution often require a careful and costly recalculation to ensure applied control inputs produce the desired results. As spacecraft missions grow in both duration and number, meeting the need for precise and accurate measurements becomes increasingly complex. Stochastic effects, such as angle and velocity random walks, along with persistent …

Solar Sailing Adaptive Control Around The Earth-Moon Lagrange Point L4 For Stellar Observations, Luis Mendoza Zambrano

Doctoral Dissertations and Master's Theses

To expand our knowledge about the influence of the Sun in the cislunar region, as well as our understanding of shocks due to Coronal Mass Ejections and large coronal magnetic reconnection, a solar sailing approach is proposed to separately capture lunar occultations and observe the solar corona from L₄ of the Earth-Moon system. Single and multiple shooting techniques are described along with a pseudo arc-length continuation method for preliminary orbit design. Periodic orbits in the vicinity of L₄ are obtained in the context of the Earth-Moon circular restricted three-body problem (CR3BP) and the Sun-Earth-Moon bi-circular restricted four-body problem …

Satellite Reorientation Using Reinforcement Learning Under Unknown Attitude Failure, Matthew Willoughby

Doctoral Dissertations and Master's Theses

This study presents a reinforcement learning (RL) approach for reestablishing communication with deep-space satellites under unknown attitude determination and control system (ADCS) failures. When traditional fault-tolerant control methods cannot restore signal, the proposed RL controller acts as a last-resort measure by autonomously reorienting the satellite’s antenna toward Earth while charging the battery via solar panels. A generic reward function, designed for the RL-based method, enables the controller to adapt to diverse failure scenarios, including severe actuator noise, misalignment, and complete actuator failure. Simulations are conducted in the Basilisk environment and trained with the tonic framework and demonstrate ranging capabilities of …

Utilizing Augmented Reality For Immersive Space Mission Design, Joseph Anderson

Doctoral Dissertations and Master's Theses

Designing spacecraft mission trajectories is a complex, tedious, and stringent process that requires a strong background in astrodynamics and programming due to the complex dynamical environment of space. The current 2D visualization methods for displaying these geometrically abstract trajectories make it difficult to understand the true nature of more complex orbits. Advancements in immersive headsets and their intuitive interaction capabilities make them ideal for solving and understanding 3D problems that require complex spatial representations, revealing an innovative and unique opportunity for the astrodynamics and space mission planning field. This effort covers the development of an immersive space mission design tool …

Coupled Dynamics In The Cislunar Region And Spacecraft Attitude Prediction In A Higher-Fidelity Model​, Annika Anderson

Doctoral Dissertations and Master's Theses

The cislunar region of space is a complex, multi-body dynamical environment that cannot be modeled trivially. Traditional point-mass assumptions made to simplify the mission design process may be insufficient for accurately predicting spacecraft motion in environments where orbit-attitude coupling is non-negligible. One of the most famous of such models is the circular restricted three-body problem. This thesis advances the state of the art in astrodynamics by modeling all bodies in the problem as rigid bodies, allowing for spacecraft orientation to be propagated and considered. Two models are under consideration—the circular restricted full three-body problem (CRF3BP) and a full higher-fidelity ephemeris …

Robust Spacecraft Autonomy For Deep Space Exploration In Special Euclidean Group Se(3), Matthew Wittal

Doctoral Dissertations and Master's Theses

Over the past half-century, humanity has gained extensive experience conducting manned spaceflight near Earth. Arguably, "near Earth" could even include the Moon — the most distant destination humans have reached. However, "near" in this work primarily refers low Earth orbit (LEO). One could argue that we have not truly left Earth since the Apollo, as spacecraft in some LEOs remain subject to atmospheric drag thus emphasizing their continued connection to Earth's immediate environment. Reflecting on this, it becomes clear that humanity has largely remained bound to Earth’s immediate vicinity since the Apollo missions reached the Moon. However, that is set …

A Low-Complexity Algorithm For Trajectory Generation In The Three-Body Problem, Brian P. Baker-Mcevilly

Doctoral Dissertations and Master's Theses

The Cislunar realm holds intrinsic value for scientific, commercial, and military applications as numerous entities have begun to invest resources into the expansion and utilization of the region. As the Cislunar region continues to grow, there is an escalating need for efficient methods of trajectory generation in this multi-body dynamical system for computationally limited systems. Thus, a low-complexity classical algorithm is proposed to achieve accurate orbital trajectories in the three-body problem. The proposed algorithm solves a polynomial interpolation problem, formulated using state measurements, through the unique decomposition of a dense system into sparse matrices. Several relevant Cislunar trajectories are simulated …

Assessing General Propulsion Architectures For Fast Transit Times To Mars For Crewed Missions, Vivek Bhatt

Doctoral Dissertations and Master's Theses

As NASA and commercial contractors, such as SpaceX, continue to develop their programs with Artemis and Starship, respectively, it is becoming more and more apparent that the program developments are ultimately for finding a way to put humans onto Mars. However, when we approach the current timeline of going to Mars, it usually involves a 6-9 month one way trip. Due to this, human spaceflight to Mars becomes more dangerous as exposure to affects such as solar radiation, long exposure to low gravity fields, and isolation. These are some of the many hazards that come with interplanetary space travel for …

Sliding Mode Control With Chattering Reduction, Suryamshu Ramesh

Doctoral Dissertations and Master's Theses

Sliding Mode Control is a powerful nonlinear control methodology that can handle parametric uncertainties and external disturbances. However, the discontinuous and high-frequency switching nature of the control law introduces the chattering phenomenon, which leads to potential actuator degradation, alterations to the desired response characteristics and, sometimes, instability during control implementation. The main objective of this thesis is to study Sliding Mode Control with chattering reduction. The Sliding Mode Control law involves an equivalent control component and a discontinuous control component. A disturbance estimation is performed based on Lyapunov analysis and adaptive control techniques and then included in the control law …

Initial Orbit Determination Of Uncooperative Satellites Using Particle Swarm Optimization From The Point Of View Of A Novel Observer Orbit, Taylor Yow

Doctoral Dissertations and Master's Theses

Initial orbit determination is an incredibly valuable tool in the field of space situational awareness (SSA). As the number of launches increases every year, more objects are being put into space around the Earth and with political tensions mounting between certain space-accessing countries such as the United States of America (USA), Russia, and China, the number of satellites whose orbits are unknown to a political rival are increasing as well. In this research, orbit estimation of uncooperative target satellites from the point of view of novel orbits using particle swarm optimization (PSO) algorithm is explored. Two cost functions for the …

Using Machine Learning To Predict Hypervelocity Fragment Propagation Of Space Debris Collisions, Katharine Larsen, Riccardo Bevilacqua

Student Works

The future of spaceflight is threatened by the increasing amount of space debris, especially in the near-Earth environment. To continue operations, accurate characterization of hypervelocity fragment propagation following collisions and explosions is imperative. While large debris particles can be tracked by current methods, small particles are often missed. This paper presents a method to estimate fragment fly-out properties, such as fragment, velocity, and mass distributions, using machine learning. Previous work was performed on terrestrial data and associated simulations representing space debris collisions. The fragmentation of high-velocity fragmentation can be modeled by terrestrial fragmentation tests, such as static detonations. Recently, stereoscopic …

Rigid Body Constrained Motion Optimization And Control On Lie Groups And Their Tangent Bundles, Brennan S. Mccann

Doctoral Dissertations and Master's Theses

Rigid body motion requires formulations where rotational and translational motion are accounted for appropriately. Two Lie groups, the special orthogonal group SO(3) and the space of quaternions H, are commonly used to represent attitude. When considering rigid body pose, that is spacecraft position and attitude, the special Euclidean group SE(3) and the space of dual quaternions DH are frequently utilized. All these groups are Lie groups and Riemannian manifolds, and these identifications have profound implications for dynamics and controls. The trajectory optimization and optimal control problem on Riemannian manifolds presents significant opportunities for theoretical development. Riemannian optimization is an attractive …

Predicting Dynamic Fragmentation Characteristics From High-Impact Energy Events Utilizing Terrestrial Static Arena Test Data And Machine Learning, Katharine Larsen, Riccardo Bevilacqua, Omkar S. Mulekar, Elisabetta L. Jerome, Thomas J. Hatch-Aguilar

Student Works

To continue space operations with the increasing space debris, accurate characterization of fragment fly-out properties from hypervelocity impacts is essential. However, with limited realistic experimentation and the need for data, available static arena test data, collected utilizing a novel stereoscopic imaging technique, is the primary dataset for this paper. This research leverages machine learning methodologies to predict fragmentation characteristics using combined data from this imaging technique and simulations, produced considering dynamic impact conditions. Gaussian mixture models (GMMs), fit via expectation maximization (EM), are used to model fragment track intersections on a defined surface of intersection. After modeling the fragment distributions, …

Autonomous Space Surveillance For Arbitrary Domains, David Zuehlke

Doctoral Dissertations and Master's Theses

Space is becoming increasingly congested every day and the task of accurately tracking satellites is paramount for the continued safe operation of both manned and unmanned space missions. In addition to new spacecraft launches, satellite break-up events and collisions generate large amounts of orbital debris dramatically increasing the number of orbiting objects with each such event. In order to prevent collisions and protect both life and property in orbit, accurate knowledge of the position of orbiting objects is necessary. Space Domain Awareness (SDA) used interchangeably with Space Situational Awareness (SSA), are the names given to the daunting task of tracking …

Experimental Validation Of Inertia Parameters And Attitude Estimation Of Uncooperative Space Targets Using Solid State Lidar, Alessia Nocerino, Roberto Opromolla, Giancarmine Fasano, Michele Grassi, Spencer John, Hancheol Cho, Riccardo Bevilacqua

Student Works

This paper presents an experimental activity aimed at assessing performance of techniques for inertia and attitude parameters estimation of an uncooperative but known space target. The adopted experimental set-up includes a scaled-down 3D printed satellite mock-up, a spherical air bearing and a low-cost solid-state LIDAR. The experimental facility also comprises a motion capture system to obtain a benchmark of the pose (position and attitude) parameters and an ad-hoc designed passive balancing system to keep the centre of mass as close as possible to the centre of rotation. The LIDAR-based 3D point clouds, collected while the target rotates on the spherical …

Incorporation Of Trajectory Behaviors In The Vicinities Of Different Planetary Moons Using Finite-Time Lyapunov Exponent Maps, David Canales Garcia, Kathleen C. Howell, Elena Fantino

PanaSoMM

There is an increasing interest in future space missions devoted to the exploration of key moons in the Solar system. These many different missions may involve libration point orbits as well as trajectories that satisfy different endgames in the vicinities of the moons. To this end, an efficient design strategy to produce low-energy transfers between the vicinities of adjacent moons of a planetary system is introduced that leverages the dynamics in these multi-body systems. Such a design strategy is denoted as the moon-to-moon analytical transfer (MMAT) method. It consists of a general methodology for transfer design between the vicinities of …