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Full-Text Articles in Engineering
Optimal Non-Coplanar Launch To Quick Rendezvous, Gregory B. Sears
Optimal Non-Coplanar Launch To Quick Rendezvous, Gregory B. Sears
Theses and Dissertations
The purpose of this study was to determine the feasibility of launching a Delta Clipper-like vehicle on an optimal, non-coplanar trajectory to rendezvous with an earth orbiting object in one orbit or less. The focus of the research was to determine what such a trajectory would look like, and to determine the cost, in payload mass, of flying such a trajectory. A model for the ascent trajectory was developed using the dynamics equations of motion, an atmosphere model, and an aerodynamic model for the DC-Y concept vehicle. A boundary value problem was posed and solved for a coplanar rendezvous. The …
Orbit Estimation Using Track Compression And Least Squares Differential Correction, Vincent J. Chioma
Orbit Estimation Using Track Compression And Least Squares Differential Correction, Vincent J. Chioma
Theses and Dissertations
This thesis develops two methods of compressing a track of radar observations of a satellite into a single state vector and associated covariance matrix, and a method of estimating orbits using results from multiple tracks. The track compression uses least squares differential correction to determine a state vector at the central observation time. The resulting state vectors and covariance matrices are then used to estimate the satellite's orbit, also using least squares differential correction. Numerical integration using two-body, J2 and an atmospheric drag model is used to represent the dynamics. This orbit estimation produces a state vector which includes …
Relative Equilibria Of A Rigid Satellite In A Central Gravitational Field, Jeffrey A. Beck
Relative Equilibria Of A Rigid Satellite In A Central Gravitational Field, Jeffrey A. Beck
Theses and Dissertations
We apply noncanonical Hamiltonian methods to examine relative equilibria of a rigid body in a central gravitational field. These equilibria correspond to fixed points of a reduced set of equations expressed in a rotating frame and are representative of an orbiting satellite with fixed attitude relative to an observer rotating at the orbital rate. Our objective is to clarify the relationship between the classical approximation and a recent noncanonical Hamiltonian treatment. In contrast to the classical approximation, the orbital and attitude equations of motion for the noncanonical system remain coupled and the general solution is a circular orbit for which …