Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
-
- De-orbit (2)
- Matlab (2)
- Simulator (2)
- Attitude Control (1)
- Barycentric (1)
-
- C++ (1)
- Cuda (1)
- Drag (1)
- Drag sail (1)
- Electric (1)
- Free Return Trajectory (1)
- Galaxy (1)
- Gpu (1)
- Gravity (1)
- Hubble (1)
- Integrator (1)
- Lagrange Points (1)
- Lambert (1)
- Launch Window (1)
- Low (1)
- MEX (1)
- Matlab GUI (1)
- Mechanics (1)
- N-body (1)
- NASA Procedural Requirements for Limiting Orbital Debris (1)
- Orbit (1)
- Orbit Propagation (1)
- Orbital (1)
- Orbital debris (1)
- Pork Chop Plot (1)
Articles 1 - 8 of 8
Full-Text Articles in Astrodynamics
Three-Axis Stabilized Earth Orbiting Spacecraft Simulator, Alan F. Ma, Nikola N. Dominikovic
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 …
High-Fidelity Low-Thrust Trajectory Determination Research And Analysis, Tyler Hill
High-Fidelity Low-Thrust Trajectory Determination Research And Analysis, Tyler Hill
Aerospace Engineering
This document discusses a numerical analysis method for low thrust trajectory propagation known as the proximity quotient or Q-Law. The process uses a Lyapunov feedback control law developed by Petropoulos[1] to propagate trajectories of spacecraft by minimizing the user defined function at the target orbit. A simplified propagator is created from the core mechanics of this method in MATLAB and tested in several user defined cases to demonstrate its capabilities. Several anomalies arose in test cases where variations in eccentricity, inclination, right ascension of the ascending node, and argument of perigee were specified. Solutions to these anomalies are discussed …
Computation Time Comparison Between Matlab And C++ Using Launch Windows, Tyler Andrews
Computation Time Comparison Between Matlab And C++ Using Launch Windows, Tyler Andrews
Aerospace Engineering
Processing speed between Matlab and C++ was compared by examining launch windows and handling large amounts of data found in pork chop plots. A compilation of code was generated in Matlab to produce the plots and an identical file was created in C++ that was then compiled and run in Matlab to plot the data. This file is known as a MEX-file. This report outlines some of the basics when working with MEX-files and the problems that face users. For Lambert’s solver, multi revolution cases were considered and some pork chop plots of single revolution trajectories were plotted. Three different …
Accelerating Lambert's Problem On The Gpu In Matlab, Nathan Parrish
Accelerating Lambert's Problem On The Gpu In Matlab, Nathan Parrish
Aerospace Engineering
The challenges and benefits of using the GPU to compute solutions to Lambert’s Problem are discussed. Three algorithms (Universal Variables, Gooding’s algorithm, and Izzo’s algorithm) were adapted for GPU computation directly within MATLAB. The robustness of each algorithm was considered, along with the speed at which it could be computed on each of three computers. All algorithms used were found to be completely robust. Computation time was measured for computation within a for-loop, a parfor-loop, and a call to the MATLAB command ‘arrayfun’ with gpuArray-type inputs. Then, a Universal Variables Lambert’s solver was written in CUDA and compiled for use …
The Numerical Open-Source Many-Body Simulator (Noms), Jason Lloyd Daniel, Javen Kyle Foster-O'Neal
The Numerical Open-Source Many-Body Simulator (Noms), Jason Lloyd Daniel, Javen Kyle Foster-O'Neal
Aerospace Engineering
This paper outlines the setup and creation of an object-oriented N-body simulator as part of a continued project to explore physical phenomenon and human-computer natural interaction technologies. The tools and processes required to build an N-body simulator are also included. Several integrators were evaluated based on their ability to maintain system energy The 2nd order integrator Verlet and 3rd order integrator Hermite algorithms had the greatest accuracy to model large-scale N-body dynamics for their given computation time. Other algorithms required significantly shorter time steps to achieve similar short-term accuracy. At present, NOMS can reasonably simulate 10,000 particles at less than …
Comprehensive Matlab Gui For Determining Barycentric Orbital Trajectories, Steve Katzman
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 …
De-Orbiting Upper Stage Rocket Bodies Using A Deployable High Altitude Drag Sail, Robert A. Hawkins Jr., Joseph A. Palomares
De-Orbiting Upper Stage Rocket Bodies Using A Deployable High Altitude Drag Sail, Robert A. Hawkins Jr., Joseph A. Palomares
Aerospace Engineering
This report examines the effectiveness of a drag sail to de-orbit upper stage rocket bodies. Many other perturbations contribute to the de-orbiting of these rocket bodies, and these perturbations will also be discussed briefly. This paper will show the length of time needed to force the altitudes of various launch vehicle stages with varying drag area sizes to less than 100 km. The upper stage of the Delta IV launch vehicle in an orbit with an altitude of 500 km will naturally de-orbit in 720 days but when equipped with a 20 m2 drag sail, it will de-orbit in …
Investigating Various Propulsion Systems For An External Attachment For A Controlled-Manual De-Orbit Of The Hubble Space Telescope, Nelson De Guia
Investigating Various Propulsion Systems For An External Attachment For A Controlled-Manual De-Orbit Of The Hubble Space Telescope, Nelson De Guia
Aerospace Engineering
This reports explains the results for a proposed senior project. This project concerns the Hubble Space Telescope, and exploring the possibility of having an external propulsion attachment for a manual de-orbit. The Hubble Space Telescope was proposed to return to Earth via the Space Shuttle. Although, through the current U.S. Space Administration, the Space Shuttle has been retired before the Hubble Space Telescope was retrieved. By completing this project, the results could provide insight to what type of propulsion would best de-orbit the Hubble upon its retirement. Different propulsion systems were considered to attempt to determine an optimal attachment, varying …