AAE 53200: Orbit Mechanics

Description:

Orbit determination of near-earth satellites and various perturbations; libration and attitude control; orbit transfer and interception; lunar theory and interplanetary orbits; ascending mechanics and reentry.

Format: 3 hrs lecture per week

Credit hours: 3

Status: Elective, Dynamics and Controls, Astronautics

Offered: Fall

Pre-requisite: AAE 340 or equivalent

Co-requisite: None

Course Instructor: Professor Howell

Text: None

Assessment Method: Homework and Projects 55%, Two Exams 30%, Final Exam 15% Grading Policy is Instructor option and may vary from year-to-year

Course Objective:

Introduce students to spacecraft orbital dynamics and the issues associated with orbital control and station keeping. Primary focus in regimes where two-body analysis and conics are a valid model. Computation and implementation of impulsive maneuvers in three dimensions; transfer orbits and Lambert's theorem to support discussions of mission trajectory design. Impact of the trajectory on other subsystems.

Necessary Background:

1. Calculus and differential equations through ODEs

2. Vector mechanics; particle/rigid body kinematics and dynamics; three-dimensional coordinate systems and transformations

3. Some introduction to perturbations and linear algebra

4. Numerical methods and tools such as MATLAB

Topics:

1. Introduction to the laws of Kepler and Newton; universal gravitation and integrals of motion.

2. Fundamental concepts associated with the two-body problem and conics; orbital elements.

3. Orbital maneuvers: (1) orbit establishment; (2) single impulse adjustments; (3) multiple impulse transfers including Hohmann transfers, local gravity fields and flybys, Hoelker and Silber transfers, Lambert time-of-flight theorem, three-dimensional transfers; (4) mission design issues.

4. Orbital perturbations including Euler-Hill equations for two-close orbiters and some navigational issues.

Relationship of course to program objectives:

This dual level course in spacecraft dynamics is based on the fundamentals from previous courses in particle and rigid body dynamics. Here, the focus is the translational motion of the spacecraft through an introductory study of the orbit characteristics. Maneuver analysis and design is a large component of the course as the students acquire the necessary technical competence in natural spacecraft motion (1) and an introduction to on-orbit operations.. An ability to formulate these engineering problems and the skills to analyze (as well as solve) them (2a) is addressed through homework exercises; this includes extensive graphical design and interpretation. The ability to communicate their analysis techniques and orally interpret their results (2c) is practiced in the homework as well as structured class discussions. Depending on the NASA launch schedules during the current semester, the homework and class examples are correlated to actual spacecraft/missions (4). Previous missions are used as examples as well.

Prepared by: Kathleen Howell

Date: January 17, 2001