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In Memory of James R. Wright

By: Jim Woodburn

A note from AGI's CEO, Paul Graziani :

We recently heard the tragic news that our friend, and former colleague, Jim Wright passed away. Jim’s passing is a tremendous loss for his family and friends. And, as an industry, we lost a giant -- a man of great intellect and determination. Jim’s award-winning contributions are well documented in countless reports and ground-breaking technical papers.

We will be forever indebted to Jim for his tenacity, intellect and fighting spirit. This is a great loss, especially for those of us that had the privilege of knowing Jim personally.

Please take a moment and read more about Jim and his extraordinary contributions in a tribute from his trusted friend and AGI colleague, Jim Woodburn.

On behalf of AGI and the aerospace community, we extend our deepest sympathy to Jim’s family.

In Memory of James R. Wright

On August 2, 2018, the field of spacecraft orbit determination lost one of its true pioneers, Jim Wright.

Those of us fortunate enough to have known Jim recognize him as a perpetual student, tireless theoretician and successful practitioner in the fields of astrodynamics and estimation theory. His contributions have been recorded in a myriad of technical papers, four patents in the areas of GPS data processing and estimation theory, and the success of numerous operational satellite programs. Jim’s pioneering work on the implementation of physically connected process noise in sequential estimators fundamentally changed the realm of the possible in operational orbit determination.

Amazingly, Jim’s career did not start in mathematics or engineering, but as a machinist making custom tools and as a musician, playing bass in the Army Band and trombone in the San Bernardino and Redlands Symphonies as well as the Bob Mannis Orchestra. His interest in astrodynamics and estimation began after he started working for Lockheed Space & Missiles Company at the Air Force Satellite Control Facility in Sunnyvale, CA. Following his new interest, Jim studied astrodynamics under Sam Herrick at UCLA. While Dr. Herrick died before Jim finished his doctoral program, the broad collection of graduate courses that he took provided the background  for his incredible career.

Jim’s time in southern California included positions at the Systems Development Corporation and working on several programs with The Aerospace Corporation where he first developed his approach to physically connected process noise. The role of process noise in orbit determination is to account for unknown deficiencies in the mathematical model of how the forces on a spacecraft affect its motion. Jim believed that orbit determination algorithms could be made more robust by using the proper physics to account for modeling limitations and identified the Kalman filter as the appropriate framework to accommodate the additive nature of force model uncertainties. Jim’s approach was groundbreaking because he pursued this line of reasoning in the face of the conventional wisdom of the early 1970s which held that orbit determination was not possible using sequential estimation algorithms.

Jim’s work in orbit determination rapidly expanded in significance after he joined the General Electric’s Military and Data Systems Organization in 1976. It was here, in his role as manager of the astrodynamics group, that Jim’s developments in sequential orbit determination were applied to operational military programs. Jim’s special ability to not only develop new estimation algorithms, but to bring them into operations provided immediate benefits to programs of national importance.  While working at GE, Jim received the prestigious “One in a Thousand” award, acknowledging his work and recognizing his team as “a national resource.”  

After GE, Jim worked for Applied Technology Associates (ATA) where he developed the next generation of his estimation technology in the Real-Time Orbit Determination (RTOD) program and served as the Vice President of Independent Research and Development. RTOD was an incredibly successful program, being used operationally on military programs and for the NASA Tracking and Data Relay Satellite System. During his years at GE and ATA, Jim was a pioneer in both the application of GPS observations to orbit determination and to the simultaneous orbit determination of multiple satellites in a relay based system.

Then in 1998, we were incredibly fortunate to have Jim join our team as a senior engineer. His talents and intellect were obvious early in his distinguished career at AGI. He quickly proceeded to build the latest version of his optimal estimation technology which became known as the Orbit Determination Tool Kit (ODTK). Especially impressive was that Jim taught himself C++ and object-oriented programming in order to personally build the first prototype. For the first time in his career as an astrodynamicist, Jim’s work was completely in the open. His approach to orbit determination was greeted with cautious optimism by the aerospace community. Early demonstrations and results, however, quickly converted the doubters into broad adopters and true believers. Before Jim’s ground-breaking discoveries, the notion of realistic error covariance in orbit determination seemed unachievable. But Jim accomplished something that few ever will showing the impossible to possible and making it commonplace and expected. Today, ODTK is used for numerous operational and proposed satellite missions covering all Earth-centered orbit regimes, libration orbits, lunar, and deep space applications.

Jim’s achievements are a testament to the rigor with which he attacked problems, always beginning with the fundamental principles and often involving the development of personal relationships with leading researchers in related fields along the way. It was not unusual for Jim to write and present papers in adjoining fields while working on an orbit determination problem. Those of us lucky enough to know Jim and have the privilege of working with him went along happily for the ride.

This paradigm held true for his personal interests as well. Whether it was learning to play new musical instruments, perfecting the cold storage of apples for consumption over the long Pennsylvania winter or advancing the art and science of sourdough bread making, Jim went to the ends of the Earth and beyond to find the “optimal” solution. Of course, those of us close to Jim know that he would have objected to the use of the term “optimal” without a clear definition of optimality being stated.

Beyond Jim’s incredibly stellar career, he was also a devoted husband, loving father, immensely proud grandfather and a loyal friend. Our hearts ache along with his family and friends.

Ad astra, Jim.

 

 

 

 

Posted: 8/16/2018 8:36:56 PM


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