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Full-Text Articles in Engineering
Optimal Relative Path Planning For Constrained Stochastic Space Systems, Nathan Bohus Stastny
Optimal Relative Path Planning For Constrained Stochastic Space Systems, Nathan Bohus Stastny
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Rendezvous and proximity operations for automated spacecraft systems requires advanced path planning techniques that are capable of generating optimal paths. Real-world constraints, such as sensor noise and actuator errors, complicate the planning process. Operations also require flight safety considerations in order to prevent the spacecraft from potentially colliding with the associated companion spacecraft. This work proposes a new, ground-based trajectory planning approach that seeks an optimal trajectory while meeting all mission constraints and accounting for vehicle performance and safety requirements. This approach uses a closed-loop linear covariance simulation of the relative trajectory coupled with a genetic algorithm to determine fuel …
Linear Covariance Analysis For Gimbaled Pointing Systems, Randall S. Christensen
Linear Covariance Analysis For Gimbaled Pointing Systems, Randall S. Christensen
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Linear covariance analysis has been utilized in a wide variety of applications. Historically, the theory has made significant contributions to navigation system design and analysis. More recently, the theory has been extended to capture the combined effect of navigation errors and closed-loop control on the performance of the system. These advancements have made possible rapid analysis and comprehensive trade studies of complicated systems ranging from autonomous rendezvous to vehicle ascent trajectory analysis. Comprehensive trade studies are also needed in the area of gimbaled pointing systems where the information needs are different from previous applications. It is therefore the objective of …
Statistical Methods For Launch Vehicle Guidance, Navigation, And Control (Gn&C) System Design And Analysis, Michael Benjamin Rose
Statistical Methods For Launch Vehicle Guidance, Navigation, And Control (Gn&C) System Design And Analysis, Michael Benjamin Rose
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A new tool for launch vehicle design and analysis is developed. The tool is capable of rapid analysis of requirements tradeoffs affecting system design and developed to reduce turnaround time for launch vehicle design and mission planning. It is streamlined to quickly determine trajectory and attitude control dispersions which represent how far the actual trajectory is expected to deviate from the nominal flight path, propellant dispersions which represent how much propellant is required to meet mission requirements, and navigation errors which represent how far the navigation filter’s estimate of the actual trajectory is expected to deviate from the actual trajectory. …
Terrain-Relative And Beacon-Relative Navigation For Lunar Powered Descent And Landing, Daniel Porter Christensen
Terrain-Relative And Beacon-Relative Navigation For Lunar Powered Descent And Landing, Daniel Porter Christensen
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
As NASA prepares to return humans to the moon and establish a long-term presence on the surface, technologies must be developed to access previously unvisited terrain regardless of the condition. Among these technologies is a guidance, navigation and control (GNC) system capable of safely and precisely delivering a spacecraft, whether manned or robotic, to a predetermined landing area. This thesis presents detailed research of both terrain-relative navigation using a terrain-scanning instrument and beacon-relative radiometric navigation using beacons in lunar orbit or on the surface of the moon. The models for these sensors are developed along with a baseline sensor suite …
Design Of The Guidance, Navigation, And Control Subsystem For The Proposed Firebird Spacecraft, Erin Robinson
Design Of The Guidance, Navigation, And Control Subsystem For The Proposed Firebird Spacecraft, Erin Robinson
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The Firebird spacecraft is a space mission to gather scientific and physical data on the effects of atmospheric deceleration, commonly called aerobraking. The objective of the Firebird mission is to measure specified aerobraking parameters over a range of reentry velocities to provide a database sufficient to construct and validate mathematical models of such aerobraking mission maneuvers. The Firebird senior design team designed the first spacecraft in the mission series to look at aerobraking at an altitude of 160 kilometers above the surface of the Earth. This paper looks specifically at the design of the subsystem that provides the guidance, navigation, …