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Algorithms For Small Satellite Formation Flying, Robert B. Larue
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 …
Leveraging External Sensor Data For Enhanced Space Situational Awareness, Charlie T. Bellows
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 …
Solar Radiation Pressure Modeling Issues For High Altitude Satellites, Dayne G. Cook
Solar Radiation Pressure Modeling Issues For High Altitude Satellites, Dayne G. Cook
Theses and Dissertations
Current satellite orbit propagation techniques employ a solar radiation pressure model that makes simplifying assumptions concerning the satellite and its orbital geometry. Solar radiation pressure, a non-gravitational perturbation, significantly affects satellite motion at high altitudes. The model currently in use by the Air Force for orbit determination includes the following assumptions: a constant cross-sectional area projected to the Sun, cylindrical Earth shadow for eclipse, and specular reflection. In reality, the satellite's cross-sectional area with respect to the Sun constantly changes, the Earth's shadow is conical, and reflection is both specular and diffuse. Additionally, the solar flux received at the Earth …