STENGEL_fw.JPG Robert Stengel, a professor of mechanical and aerospace engineering at Princeton, was interviewed for the June 2009 issue IEEE Control Systems Magazine about his work developing aerospace and biomedical technologies.

The magazine asked Stengel about the changes he designed the manual control logic for the Apollo Lunar Module in the 1960s. He noted that early in his career "aerospace engineers used slide rules, hand-drawn graphs, mechanical calculators, blueprints, rules of thumb, precedent, and intuition to design and build airplanes."

"Today’s aerospace engineer has a wealth of computational tools to employ," he said. "Digital computers have replaced most of the earlier engineering tools, and user interfaces are interactive. Computer memory and speed have increased by orders of magnitude, turn-around time between program runs may be a few seconds, the cost of computing has plummeted, and new applications software has revolutionized the nature of engineering analysis and design."

The interview also discusses Stengel’s new textbook, Flight Dynamics, which took him 25 years to complete. Princeton engineers have written several text books on flight dynamics, and Stengel said he felt a responsibility to continue that tradition.

"Flight dynamics is the first ‘airplane course’ that most Princeton mechanical and aerospace engineering students take, building on the dynamics, aerodynamics, and math of earlier courses," Stengel said. "We cover fundamentals of aircraft, including historical material that motivates the evolution of aviation, as well as configuration aerodynamics, nonlinear flight dynamics, aircraft performance, stability, and control."

Stengel said his interest in biomedical applications of engineering began in 1970 after the Apollo program wrapped up. He said a number of aerospace engineers at the time were asking: “Now that we have gone to the moon, what shall we do next?”

He said his current areas of interest in the biomedical field – using computer networks based on the brain to classify data on DNA and optimal therapy for treating diseases – came from homework assignments he gave students in his Robotics and Intelligent Systems class.

"The objectives of my work are to identify those genes that are over or underexpressed in primary tumors, normal tissue, and lung and liver metastases and to correlate gene expression with various patient outcomes."