Astrodynamics Commons^™

Computation Of Hypersonic Flows With Lateral Jets Using K-Ω Turbulence Model, Spatika Dasharati Iyengar

Doctoral Dissertations and Master's Theses

Thermal Protection systems (TPS) are used as shields in space vehicles which encounter high heat and temperatures at the reentry altitudes. Among them, the cooling techniques and the ablative coatings are most popular. However, they have their own weight limitations. In the recent decade, another classification of TPS called the Non-Ablative Thermal Protection systems (NaTPS) have gained significance. The spike-lateral jet method is an NaTPS concept proposed for drag and heat flux reduction in hypersonic nose cones. Numerical simulations are conducted to analyze the effectiveness of spike-lateral jet concept at re-entry altitudes. The spike attached to the hemispherical nose has …

Spacecraft Trajectory Optimization Suite (Stops): Optimization Of Multiple Gravity Assist Spacecraft Trajectories Using Modern Optimization Techniques, Timothy J. Fitzgerald

Master's Theses

In trajectory optimization, a common objective is to minimize propellant mass via multiple gravity assist maneuvers (MGAs). Some computer programs have been developed to analyze MGA trajectories. One of these programs, Parallel Global Multiobjective Optimization (PaGMO), uses an interesting technique known as the Island Model Paradigm. This work provides the community with a MATLAB optimizer, STOpS, that utilizes this same Island Model Paradigm with five different optimization algorithms. STOpS allows optimization of a weighted combination of many parameters. This work contains a study on optimization algorithm performance and how each algorithm is affected by its available settings.

STOpS successfully found …

Leveraging External Sensor Data For Enhanced Space Situational Awareness, Charlie T. Bellows

Theses and Dissertations

Reliable Space Situational Awareness (SSA) is a recognized requirement in the current congested, contested, and competitive environment of space operations. A shortage of available sensors and reliable data sources are some current limiting factors for maintaining SSA. Unfortunately, cost constraints prohibit drastically increasing the sensor inventory. Alternative methods are sought to enhance current SSA, including utilizing non-traditional data sources (external sensors) to perform basic SSA catalog maintenance functions. Astronomical data, for example, routinely collects serendipitous satellite streaks in the course of observing deep space; but tactics, techniques, and procedures designed to glean useful information from those collects have yet to …

Earth Magnetosphere Model Investigations For Coupled Orbit-Attitude Space Debris Perturbations, Eiji Shibata, Carolin Frueh Dr.

The Summer Undergraduate Research Fellowship (SURF) Symposium

As more objects are placed into orbit, collisions become increasingly more likely, leading to a so-called Kessler Syndrome: collisions between existing debris creates more debris, causing a cascading effect of larger amounts of debris being put into orbit, even in the absence of launches, making future space fairing difficult or impossible. Natural forces influence the orbit and attitude of uncontrolled debris objects. The natural plasma environment can lead to space object charging. The subsequent orbital movement in the geomagnetosphere induces Lorentz forces that act both on the orbit and attitude of the space object. Those forces have not been investigated …

Orbit Estimation Of Non-Cooperative Maneuvering Spacecraft, Gary M. Goff

Theses and Dissertations

Due to the ever increasing congestion of the space environment, there is an increased demand for real-time situation awareness of all objects in space. An unknown spacecraft maneuver changes the predicted orbit, complicates tracking, and degrades estimate accuracies. Traditional orbit estimation routines are implemented, tested, and compared to a multiple model format that adaptively handles unknown maneuvers. Multiple Model Adaptive Estimation is implemented in an original way to track a non-cooperative satellite by covariance inflation and filtering-through a maneuver. Parameters for successful instantaneous maneuver reconstruction are analyzed. Variable State Dimension estimation of a continuously maneuvering spacecraft is investigated. A requirements …

Suborbital Spaceflight: A Student Team’S Plan To Send A Rocket To Space, Bryce Chanes, William Carpenter, Julio Benavides, Matthew Haslam, Brenda Haven

Aviation / Aeronautics / Aerospace International Research Conference

The Eagle Space Flight Team was created with the goal of becoming the first undergraduate team to design, build, and launch a rocket capable of suborbital spaceflight. In order to achieve this goal, the team will have to design a rocket capable of atmospheric flight at speeds over Mach 5 and launch it on one of the largest amateur rocket motors ever made. Over the next three years, the team will progress towards accomplishing this feat through a series of incremental test flights. Before the space flight, the team will build three sub-scale rockets designed to reach altitudes of 30,000’, …