Professor Emeritus Richard E. Mortensen passed away at his home in Topanga in October 2004, at the age of 69 from natural causes.

By Professors N. Levan, D. Wiberg and P.K.C. Wang

Professor Emeritus Richard E. Mortensen passed away at his home in Topanga in October 2004, at the age of 69 from natural causes. He enjoyed a long and productive career in the UCLA Henry Samueli School of Engineering and Applied Science from 1965 to 1991.

Mortensen received his BS and MS in electrical engineering simultaneously from MIT in 1958. After graduation, he went to work for Space Technology Laboratories (later TRW Systems), where he applied mathematical and engineering skills in control theory to the control of rockets and spacecraft for NASA’s early space program. He was the first to propose the use of quaternion feedback for attitude control of rigid spacecraft.

He returned to graduate school and received his PhD in 1966 from UC Berkeley. His dissertation, “Optimal Control of Continuous-time Stochastic Systems,” was recognized by the control systems community as one of the pioneering works on stochastic control theory.

In 1965, he joined the faculty of the College of Engineering at UCLA as a member of the Department of System Science. His affiliation later changed when System Science merged with the Electrical Engineering Department in 1984.

Mortensen was well known for his keen intellect and his contributions to stochastic, nonlinear control systems, and was knowledgeable on a broad range of subjects. He authored many published technical papers, letters and book reviews, as well as university, government, and industry technical reports. His book, Random Signals and Systems was published in 1987. His most recent work focused on the development of load models for electric power systems.

Mortensen served as a consultant to several major engineering firms in Los Angeles, and was a guest lecturer at the Indian Institute of Science in Bangalore, India in 1991.

While at UCLA, he taught a wide variety of undergraduate and graduate courses in the area of system theory and control. He took his teaching responsibilities seriously, and was known for his carefully prepared lectures and effective teaching style that emphasized understanding of the basic principles and ideas.

Dick was a brilliant researcher and deeper thinker. He described himself as having a dichotomy of interests, one in the mathematical theory of control, and the other in seeking spiritual meaning of life. He expressed disappointment that so much work on control theory was used in advancing military objectives. He was a fervent advocate of peace, and protection of wildlife throughout the world. In 1991, he retired as Professor Emeritus to further his latter interest.

He will be greatly missed by his friends and colleagues. He is survived by several cousins, including David Wallace of Colorado Springs and Joanne Montgomery of Denver, Colorado.