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Aerospace Engineering

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Full-Text Articles in Navigation, Guidance, Control and Dynamics

Feasibility Of Cubesat Formation Flight Using Rotation To Achieve Differential Drag, Skyler M. Shuford Jun 2013

Feasibility Of Cubesat Formation Flight Using Rotation To Achieve Differential Drag, Skyler M. Shuford

Aerospace Engineering

This paper presents the results of a study conducted to understand the feasibility of CubeSat formation flight. The mechanism for separation and formation studied was differential drag, achieved by rotating the CubeSats to give them different cross-sectional areas. Intuitively, lower altitude orbits provide much higher separation effects. Although the most influential orbital effects occur with maximum and minimum cross-sectional areas, an attitude-controlled and a tumbling CubeSat may provide enough differential drag to meet separation requirements of a mission. Formation flight is possible, but due to the non-linearity of the system, gain scheduling may be the most effective method of long …

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Three-Axis Stabilized Earth Orbiting Spacecraft Simulator, Alan F. Ma, Nikola N. Dominikovic Oct 2012

Three-Axis Stabilized Earth Orbiting Spacecraft Simulator, Alan F. Ma, Nikola N. Dominikovic

Aerospace Engineering

This report details the method and results of the program created for simulating an Earth orbiting spacecraft with control actuators and orbital perturbations. The control actuators modeled are reaction thrusters, reaction/momentum wheels, and control moment gyros (CMG). The perturbations modeled were gravity gradient, electromagnetic torques, solar radiation pressure, gravity gradients, third-body effects, Earth oblateness and atmospheric drag. This simulation allows for satellite control in all 6 degrees of freedom for any Earth orbiting spacecraft. Assumptions include rigid body dynamics, no sensor noise, constant spacecraft cross-sectional area, constant coefficient of drag and reflectivity, ignoring the effects due to the moon, moment …

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Comprehensive Matlab Gui For Determining Barycentric Orbital Trajectories, Steve Katzman Jun 2012

Comprehensive Matlab Gui For Determining Barycentric Orbital Trajectories, Steve Katzman

Aerospace Engineering

When a 3-body gravitational system is modeled using a rotating coordinate frame, interesting applications become apparent. This frame, otherwise known as a barycentric coordinate system, rotates about the system’s center of mass. Five unique points known as Lagrange points rotate with the system and have numerous applications for spacecraft operations. The goal of the Matlab GUI was to allow easy manipulation of trajectories in a barycentric coordinate system to achieve one of two end goals: a free-return trajectory or a Lagrange point rendezvous. Through graphical user input and an iterative solver, the GUI is capable of calculating and optimizing both …

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An Analysis Of Stabilizing 3u Cubesats Using Gravity Gradient Techniques And A Low Power Reaction Wheel, Erich Bender Jun 2011

An Analysis Of Stabilizing 3u Cubesats Using Gravity Gradient Techniques And A Low Power Reaction Wheel, Erich Bender

Aerospace Engineering

The purpose of this paper is to determine the feasibility of gravity gradient stabilizing a 3U CubeSat and then using a miniature reaction wheel to further increase stability characteristics. This paper also serves as a guide to understanding and utilizing quaternions in attitude control analysis. The analytical results show that using 33 centimeter booms and 400 gram tip masses, a 3U CubeSat will experience a maximum of 6 degrees of angular displacement in yaw and pitch, and less than .5 degrees of angular displacement in the nadir axis. A .120 kilogram miniature reaction wheel developed by Sinclair Interplanetary was introduced …

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Interplanetary Gravity Assisted Trajectory Optimizer (Igato), Jason Bryan Jun 2010

Interplanetary Gravity Assisted Trajectory Optimizer (Igato), Jason Bryan

Aerospace Engineering

Interplanetary space travel is an extremely complicated endeavor that is severely limited by our current technological advancements. The amount of energy required to transport a spacecraft from one planet to the next, or even further, is extraordinary and in some cases is even impossible given our current propulsive capabilities. Due to these complications, the search for other means of exchanging energy became imperative to future space exploration missions. One particularly powerful method that was discovered, and the most commonly used one, is referred to as planetary gravity assist. In order to plan out multiple gravity assist trajectories, complex and robust …

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Senior Project: Global Position Determination From Observed Relative Position Of Celestial Bodies, Michael Holmes Jun 2010

Senior Project: Global Position Determination From Observed Relative Position Of Celestial Bodies, Michael Holmes

Aerospace Engineering

A method was developed to determine the latitude and longitude of an observer based on the observed position of the Moon and several other celestial bodies. The basic principal developed dealt with the proximity of the Moon. Its relative displacement from calculated values was measured using photography by comparison with stars near the Moon. Photographs were taken from a location in San Luis Obispo at Longitude 120°35.9' and Latitude 35°13.3'. The analysis method has determined the location of the observer to a Longitude of 117°43.8'. An additional method located the observer to 36°38.7'N Latitude and 114°47.6'W Longitude.

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