Module code: EEEM009

## Module Overview

Expected prior learning: EEE3039 SPACE DYNAMICS AND MISSIONS and EEE3040 SPACE SYSTEM DESIGN, or equivalent learning. General prior knowledge of basic control theory is recommended.

Module purpose: This module provides advanced understanding of the dynamics of satellites and of methods for controlling satellite motion.

### Module provider

Computer Science and Electronic Eng

LUCCA FABRIS Andrea (Maths & Phys)

### Module cap (Maximum number of students): N/A

Independent Learning Hours: 97

Lecture Hours: 13

Tutorial Hours: 10

Guided Learning: 10

Captured Content: 20

Semester 2

None.

## Module content

Indicative content includes the following.

• Essential elements of control theory.

• Review of Attitude dynamics and coordinates (e.g., quaternions). Euler and kinematic equations. Rotational motion of a spinning body. Gravity Gradient Stabilisation.

• Attitude determination and estimation: attitude sensors. Estimation methods: triad method, q-method Quest algorithm, the Extended Kalman Filter.

• Attitude control. Attitude actuators: momentum/reaction wheels, thrusters, magnetotorques. Design of control loops  Application examples.

• Overview of Satellite orbits. Review of Keplerian orbits and the most useful orbits for Earth orbiting satellites. Brief introduction to time and coordinate frames and the complexities of their definition.

• Perturbation effects in real orbits. Long and short periodic variations and secular evolution.

• Atmospheric drag modelling. Effects of Solar radiation pressure. Earth’s non-spherical mass distribution. Perturbations effects on key Earth orbits.

• Orbit determination and Estimation. Data for orbit estimation and determination, GPS, Radar tracking, Least Squares method, Weighted Least Squares Methods, Batch Least Squares method, The Conventional and Extended Kalman filters.

• Orbit control: Gauss Variational Equations; Impulsive vs Low-thrust manoeuvres; Principle of Lyapunov control theory and nonlinear control design;

• Rendezvous in space: Hill-Clohessy-Wiltshire equations and relative motion control via pole placement and linear quadratic regulators.

## Assessment pattern

Assessment type Unit of assessment Weighting
Coursework COURSEWORK (MATLAB) 20
Examination OPEN BOOK EXAM (2HR) 80

N/A

## Assessment Strategy

The assessment strategy for this module is designed to provide students with the opportunity to demonstrate the following. The written examination will assess the knowledge and assimilation of real satellite orbits and how to model them, evaluation of real-world algorithms used for attitude and orbit control, and the limitations of sensors and actuators used on modern satellites. The practical software-tool-based theoretical assignment will assess how the student can apply these models to representative cases.

Thus, the summative assessment for this module consists of the following.

• Software-tool-based theoretical assignment.

• Open-book written examination

Any deadline given here is indicative. For confirmation of exact date and time, please check the assessment calendar issued to you.

Formative assessment and feedback

For the module, students will receive formative assessment/feedback in the following ways.

• During lectures, by question-and-answer sessions.

• Via the marking of written reports.

## Module aims

• To develop an understanding of the complexities of real satellite missions, and of practical methods to determine and control the orbit and attitude of spacecraft.

## Learning outcomes

 Ref Attributes Developed 002 Understand and evaluate algorithms for attitude and orbit determination KCT M1, M2, M3 003 Apply spacecraft attitude and orbit models to representative cases KCT M3, M4, M6 004 Design algorithms for spacecraft attitude and orbit control and report them in written format CPT M3, M4, M17 005 Gain knowledge about the working principles and limitations of sensors and actuators used on modern satellites KC M13 001 Understand orbital and attitude dynamics KC M1, M2, M3

Attributes Developed

C - Cognitive/analytical

K - Subject knowledge

T - Transferable skills

P - Professional/Practical skills

## Methods of Teaching / Learning

The learning and teaching strategy is designed to achieve the aims that students should

• Develop an understanding of real satellite orbits and the factors that influence (perturb) these orbits.

• Develop an understanding of real satellite attitude dynamics.

• Apply and evaluate practical methods in order to control satellite orbits.

• Apply and evaluate practical methods in order to control satellite attitude dynamics.

Learning and teaching methods include the following.

•  Captured lectures

• Summary lectures

• Tutorials (guided study of example problems/past examinations)

• Practice lecture

• Guided learning

• Independent study (including practical problem-based assignment and preparation for final exam)

Indicated Lecture Hours (which may also include seminars, tutorials, workshops and other contact time) are approximate and may include in-class tests where one or more of these are an assessment on the module. In-class tests are scheduled/organised separately to taught content and will be published on to student personal timetables, where they apply to taken modules, as soon as they are finalised by central administration. This will usually be after the initial publication of the teaching timetable for the relevant semester.