University of Southern California USC Department of Astronautical Engineering The USC Andrew and Erna Viterbi School of Engineering USC
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ASTE 331a Fall 2019:
Spacecraft Systems Engineering

3 units
Lecture Tuesdays and Thursdays 9:30-10:50 AM, KAP 147


Dan Erwin, RRB 222, (213) 740-5358,

Office Hours: Tuesdays 1-4 PM, Wednesdays 10-12 AM.

NOTE: ASTE 331a is the first semester of a two-semester course. The second semester will be about space systems engineering and about the design process; there will be a spacecraft design project done in teams.

Learning Objectives:

After completing this two-semester course, a student will be able to:

  • Understand the fundamental physics of spacecraft systems
  • Understand the relationship between mission requirements and system performance requirements
  • Design subsystems to meet performance requirements
  • Make design choices taking system tradeoffs into account
  • Understand the steps in performing a complete spacecraft system design


There are two required textbooks:

  1. Vincent L. Pisacane, Fundamentals of Space Systems, 2nd ed. Oxford, 2005. ISBN 978-0195162059.
  2. Space Mission Engineering: The New SMAD, James R. Wertz, David F. Everett and Jeffery J. Puschell, eds. Microcosm, 2011. ISBN 978-1881883159.
Pisacane is a true textbook and explains things starting from first principles. SMAD is more of a reference; its explanations are quite terse, but it is more up to date and has more information on actual missions.

Midterm Exam: Tuesday, October 29, in class.

Final Exam: Thursday, December 12, 11:00 AM-1:00 PM in the regular classroom.

Homework: Assigned weekly. Due on Thursdays in class.

Grading: Homework, 25%; midterm exam, 30%; final exam, 45%.

Software used:

Matlab: A general-purpose numeric computation environment, with some symbolic capability. An interpreted C-like language, extended with vector and matrix syntax, is coupled with mathematics and graphics libraries. The student who is comfortable with Matlab will be able to do numeric solution of any problem he or she is faced with, as well as provide graphical representation of the solutions.

NX (Siemens): A package for computer-aided design (CAD) and analysis. Used in AME coursework, so if you do not already have it installed, you will soon need to in any case. In this class, NX is used for structural analysis, particularly analysis of resonant vibration frequencies.

ANSYS Structures: A package for computer-aided mechanical and thermal analysis of structures. In this class, Ansys is used for thermal analysis of spacecraft.

STK (Systems Toolkit): A package for setting up, simulating, and visualizing the operation of space missions. Launch, orbits and stationkeeping, attitude dynamics and control, communications, and ground station operations can all be simulated. ASTE has a site license for STK through a donation from the company, Analytical Graphics Inc. (AGI). For installation and licensing of STK, see

Course Material:

The times and topics given below are approximate, and the list may change as the semester progresses. We will see how things go and take more or less time on each topic as seems appropriate.








08/27 & 08/29

Intro to spacecraft systems and the notion of tradeoffs. Intro to space environment: Solar cycle, atmospheric composition. Numerical solution of systems of ordinary differential equations. Orbit decay. Collisional mean free path. Continuum vs. free-molecular flow. Ionosphere and plasma frequency. Geomagnetic field. Van Allen belts. South Atlantic anomaly.

Ch. 2, secs. 1, 3, 4

Ch. 7, sec. 1


09/03 & 09/05

Magnetosphere. Motion of charged particles in magnetic field. Spacecraft charging in LEO and GEO. Microgravity, gravity gradients, tidal forces.

Ch. 2, secs. 2, 5-7

Ch. 7, sec. 2-5


09/10 & 09/12

Start on attitude and orbital control system (AOCS). Quaternions. Converting between attitude representations: Euler, RPY, transformation matrix, quaternion. Moment of inertia tensor and principal coordinates. Parallel axis theorem. Similarity transform. Transformation of time derivatives between inertial and rotating frames. Euler's equations for rigid body rotation. Stability of spin about principal axis.

Ch. 5

Ch. 19, sec. 1


09/17 & 09/19

Kinematic equation for quaternion. Full equations of rigid body rotation. Spacecraft attitude measurement. Gyroscopes. Triad method for determining attitude from axis measurements. External torques on spacecraft.

Ch. 5

Ch. 19, sec. 1


09/24 & 09/26

Moment of inertia of assembly of components. Gravity gradient torque. Intro to reaction wheels/momentum wheels. Attitude accuracy and jitter. Precession of spinning spacecraft. Attitude control using thrusters, reaction wheels, control-moment gyros, magnetic torque rods. Angular momentum dumping.

Ch. 6

Ch. 21, sec. 2


10/01 & 10/03

Start spacecraft power systems. Eclipse in LEO. Electric circuits: voltage, current, power, resistors, diodes, MOSFETs. Shunts. Photovoltaics: Basic performance, I-V characteristics, temperature variation, radiation degradation. Coverglass properties. Thermal cycling.

Ch. 6

Ch. 21, sec. 2


10/08 & 10/10

Solar array topology to mitigate shading and hot spots. Batteries. Power system sizing and design. Spacecraft thermal subsystem. Thermal sources.

Ch. 7

Ch. 22, sec. 2


10/15 & 10/17

Blackbody radiation. Absorptance and emittance of surfaces and coatings. Heat exchange mechanisms. Thermal control techniques: Heat pipes, MLI, heaters, louvers. Equilibrium temperature of simple object.

Ch. 7

Ch. 22, sec. 2


10/22 & 10/24

Radiative heat transfer. Lumped approximation for time-dependent heat transfer equations. Analysis of thermal performance. Start on spacecraft structures. Intro to structural analysis using NX. Review using last year's exams.

Ch. 8

Ch. 22, sec. 1


10/29 & 10/31

MIDTERM EXAM. Role and requirements of structure. Interface with launch vehicle. Launch loads. Stress analysis of common shapes. Thermal stresses.

Ch. 8

Ch. 22, sec. 1


11/05 & 11/07

Materials: Metals, composites, sandwich structures. Structural dynamics. Resonant frequencies. Lumped-mass approximation. Truss analysis.

Ch. 8

Ch. 22, sec. 1


11/12 & 11/14

Intro to S/C communications. Gain, loss in decibels. Electromagnetic propagation: Latency, polarization, refraction. Atmospheric refractive dip. Transmission of atmosphere. Rain attenuation. Diffraction. Reflective focusing of radiation. Sampling and Nyquist limit. Digitization of analog signals. Communications architectures. Communication link design. Noise temperature. Shannon channel capacity. Antenna gain.

Ch. 9

Ch. 16


11/19 & 11/21

Tradeoff: Antenna gain vs. power. Noise sources. Bit error probability. Modulation and coding. Types of antennas. Transmitter and antenna mass. Multiplexing. Optics and remote sensing. Optical systems. Diffraction and shot noise limits. Imaging of Earth from space.

Ch. 9

Ch. 16; Ch. 17, sec. 1


11/26 & 11/28

Intro to S/C command and telemetry.

Ch. 10

Ch. 21, sec. 1


12/03 & 12/05


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