Frank E. Marble, a
Marble's Aug. 11 death at a Pasadena nursing facility was caused by illnesses related to old age, said his son, Steve, an editor at the Los Angeles Times.
Frank Marble helped develop innovations that made rockets more efficient and dampened the noise generated by the turbines in jet engines. He also trained generations of scientists at JPL and Caltech, where he continued working well after his 1989 retirement as a professor of mechanical engineering and jet propulsion.
At Caltech in the late 1940s, Marble forged a close friendship with a young aeronautics genius from China named Qian Xuesen, or in the Chinese notation of the day, Tsien Hsue-shen.
Qian, who died in 2009, later was revered as the father as the father of China's space and missile programs.
When U.S. officials in 1950 accused Qian of being a Communist, Marble became one of his most active defenders. After the accusations came into play at immigration hearings, Qian was forbidden to travel more than 25 miles from the Caltech campus until his deportation.
"He was essentially under house arrest for a period of five years," Marble said in a 1994 Caltech oral history. "The feeling was that in five years what he knew would be sufficiently out of date so that they could get rid of him."
In the meantime, Marble and his wife, Ora Lee, found a rental house for the beleaguered scientist and his young family, who had been evicted when his case hit the headlines. At a restaurant in Delaware, Marble confronted the government's only witness, a former Caltech colleague who told him the FBI was pressuring him to testify. Marble later accompanied Qian to hearings that stretched over six weeks.
Ultimately, Qian returned to China and didn't come back.
"It was one of the greatest tactical errors the United States has ever made," Marble told the Orlando Sentinel in 2001.
Born in Cleveland on July 21, 1918, Marble received his bachelor's and master's degrees from the Case Institute of Technology. During World War II, he worked in a government lab and, in 1948, he received his doctorate in aeronautics and mathematics from Caltech.
He served on committees advising NATO, NASA and the Air Force, and was a visiting professor at Cornell, MIT and elsewhere.
Fascinated with airplanes as a boy, he flew his own until he was 70.
Ora Lee, Marble's wife of 70 years, died several months ago. He is survived by his son.