Legacy Engineering, LLC
18662 MacArthur Blvd. Suite 457
Irvine, CA 92612-1426
Telephone: (949) 794-5860
Home Page: www. Legacyeng. com
TERRY R. ALT, Ph.D.
OBJECTIVE
I am interested in assignments where I can apply my extensive experience in the area
of control system development, design, analysis, and testing.
EXPERIENCE
12/2003 to Present: Legacy Engineering, LLC, Irvine, CA
 Consultant.
1998 to Present: Independent Contractor. Guidance, Navigation and Control
Engineer.
 2007 to Present: SpaceX. Developed flight control architecture and performed
stability analysis of first and second stage flight control system for the Falcon 1 and
Falcon 9 launch vehicles. Defined requirements, designed servo compensation,
performed stability analysis, and developed simulation models for hydraulic servo
actuators that control the vehicle. Developed slosh models and integrated finite
element models for stability and performance analysis. Designed filters and gains
for stabilizing these systems. Developed GPS/INS Kalman Filter for first and second
stages of a launch vehicle. Performed simulation and stability analysis of ACS for
Dragon spacecraft, including gain selection, filter design and performance
evaluation. Developed relative navigation Kalman filter using GPS for
Dragon/Space Station rendezvous operations. Developed attitude Kalman filter for
Dragon spacecraft.
 2005 to 2009: DRS Technologies. Developed gimbal control system for
stabilizing line-of-sight for GEO pointing imaging systems, ASTAMIDS and RAMICS.
Developed simulation of multi-body dynamics, sensors, servo motors, and control
software. Performed jitter and stability analysis. Developed GPS/INS system with
Kalman Filter estimating attitude, position, velocity, gyro and accelerometer biases,
scale factors and misalignments utilizing IMU’s and GPS. Coded and integrated
software into TI DSP. Performed version control of SW, developed test and
calibration procedures for components and for the integrated systems.
Compensated closed loop system, stabilizing flex body modes using spectrum
analyzers to obtain the frequency responses.
 2005 to 2008: General Dynamics. GeoEye1 Program. Developed and coded into
Simulink an attitude control system that performs time optimal slews and scans for
mapping areas on Earth, calibration maneuvers, Sun Pointing, Inertial Pointing and
LVLH Pointing. Performed jitter analysis and control system stability analysis using
finite element models of spacecraft and optics. Developed calibration procedures
TERRY R. ALT, Ph.D.
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EXPERIENCE (CONTINUED)
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and performed on orbit calibration for rate gyro, spacecraft inertia and RWA
alignment of spacecraft.
2004 to 2005: Jet Propulsion Lab. Developed, integrated and coded models in C
for simulating spacecraft rigid and flexible body dynamics, attitude control system,
fast mirror actuators, optical delay lines, camera sensors measuring centroids for
pointing and fringes for estimating optical path differences. Developed optical delay
line and angular pointing commanding and control algorithms and integrated into
simulation for performance evaluation.
1998 to 2003: Lockheed. SIRTF Program. Development of FSW and GSW for
pointing and attitude control system. Responsibilities include development, coding,
testing and requirement verification of attitude control system. Developed command
generation algorithm for remaining in the operational pointing zone. Developed
sensor/actuator fault detection algorithms for rate gyros, star trackers, sun sensors,
reaction wheels and thrusters. Developed fault responses and high-level fault
protection algorithms. Verified performance requirements using simulations and
analysis techniques.
2002: The Boeing Company, EL Segundo, CA. Coded attitude acquisition algorithms
and star tracker simulation models in C. Analyzed flight test data and developed
thermal snap torque models of a solar wing used for predicting attitude errors. Verified
attitude controller performance during reaction wheel momentum desaturation via
thrusters.
2002: Lockheed. SBIRS Program. Attitude determination analysis. Used
simulation to develop requirements for rate gyros and tune Kalman filter. Developed
procedure for early on-orbit calibration of IR sensors and rate gyros. Developed
S/W tools for extracting and displaying data from real-time and non-real-time
simulations.
1998: Lockheed. IMAGE Program. Developed simulations, algorithms and software
for the attitude determination and attitude control system of a spin stabilized spacecraft
utilizing sun sensors, star trackers, magnetometers and magnetic torque rods.
1984 to 1998: The Boeing Company
 Principal Engineer/Scientist. Space Station Division. Responsibilities included
leading the development, testing and integration of the Space Station Guidance,
Navigation and Control System which included: analytic design, analysis and
performance verification, software development, hardware/software integration,
system verification and unit testing of software. Technical lead for group of
engineers. Previous experience included being the principal investigator for internal
research and development project.
 Control system development, design, analysis and testing. Developed frequency
domain and time domain analysis techniques for multi-variable stability and robust
performance analysis of complex dynamic systems. Expert on classical control
theory, modern control theory and non-linear controls. Verified performance through
testing, analyzed and developed mathematical models, numerical simulations and
control algorithms for many different types of systems including spacecraft attitude
control systems, vibration control systems and electro-mechanical control systems.
TERRY R. ALT, Ph.D.
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EXPERIENCE (CONTINUED)
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Performed orbit and trajectory analysis for Earth-to-Moon and Earth-to-Mars vehicle
transfers. Designed and implemented analog circuitry and real-time embedded
code. Experience working with spectrum analyzers, microprocessors, logic
analyzers and emulators.
Software Experience. Developed real-time embedded flight code for Space Station
attitude control system, tested and integrated into Flight Equivalent Unit (FEU),
developed real-time MATE Simulation software simulating flight dynamics, effectors,
sensors and Russian software for software verification facility and integrated into
MATE processor. Utilized MATRIX-X auto code, developed templates and software
test drivers using C, C++ and Ada. Developed non-real-time code for high fidelity
non-linear simulation of multi-body flight dynamics and many frequency domain
analysis tools.
EDUCATION
Ph.D., Mechanical and Aerospace Engineering - University of California, Irvine, CA
M.S., Engineering - University of California, Irvine, CA
B.S., Aeronautical and Astronautical Engineering - Purdue University, IN
COMPUTER SKILLS
Experienced user of many software packages and computer languages including:
MATLAB/SIMULINK, Matrix-X, EASY5, ACSL, SD/FAST, AUTOSIM, ADAMS,
NASTRAN, FORTRAN, C & C++.
Experienced user with common operating systems including: UNIX, VMS, DOS,
Windows and Macintosh.
PUBLICATIONS
"Bounds on Parameter Uncertainty for Preserving a Minimum Damping Ratio of a
Vibration Suppression System," Proceedings AIAA GN&C Conference, 1990
"Robust Performance of an Active Damping System," Proceedings ASME-WAM, 1991
"Spacecraft Controls Analysis via Lyapunov Functions," Master's Thesis, UC Irvine,
1991
"Robustness Bounds for Linear Systems Under Uncertainty: Eigenvalues Inside a
Wedge," AIAA Journal of Guidance, Control, and Dynamics, July - August 1993
"Robust Performance Analysis of an Active Damping System," Proceedings 1993 ACC
"A Vibration Suppression System for the Space Station," Proceedings Fourth
International Conference on Adaptive Structures, 1993
"Demonstration of a Vibration Suppression System for the Space Station," Proceedings
of the 13th IFAC Symposium on Automatic Control in Aerospace, 1994
"A Reliable Control System Design for a Smart Structure," Proceedings IMECE, 1995
"A Reliable Control Design for Buildings Under Seismic Excitation," Proceedings
11WCEE, 1996
"Robust and Reliable Control via Quadratic Lyapunov Functions," PhD Dissertation, UC
Irvine, 1997