HONG KONG — In the winter of 1967, a group of Chinese space experts trudged across a desert in China’s western borderlands in search of a crashed test rocket.
The cold crept into their sheepskin coats, one of the experts, Ma Zuoxin, recalled in a 2014 documentary film. “It chilled us to the bone.”
But they kept walking for days, he said, trailing their leader, Ren Xinmin. And at dusk on the fifth night, Dr. Ren at last spotted the rocket’s blackened wreckage poking out of the ground.
For Dr. Ren, who died on Sunday at 101, the desert odyssey was just one gambit in a lifelong quest to develop China’s space program.
He is best known for designing the first Chinese satellite to be successfully launched into space. In the 2004 book “China’s Space Program: From Conception to Manned Spaceflight,” Brian Harvey wrote that the launch, in April 1970, prompted Mao Zedong, the founder of the People’s Republic of China and chairman of the Communist Party, to commend Dr. Ren in an address to the nation.
The launch was additionally significant because China’s top leaders saw the space program as a symbol of modernity and an effort to keep up with the space race between the United States and the Soviet Union.
One of Dr. Ren’s projects was a weather satellite. But Lawrence R. Sullivan, who has studied the history of science and technology in China and is a professor emeritus of political science at Adelphi University on Long Island, said in a telephone interview that Dr. Ren’s work had a clear military dimension.
“If you develop missiles that can hit cities or that can put satellites in orbit, they’re both missiles,” he said. “They’re not that much different.”
Dr. Ren’s death, in Beijing, was announced on Monday by the state-owned China Aerospace Science and Technology Corporation, which conducts research and development for the country’s space program.
Dr. Ren is survived by his wife, Yu Shuangqin; two daughters, Ren Zhixiang and Ren Zhige; and two sons, Ren Zhizhong and Ren Zhixing, according to a company representative who was reached by telephone but who declined to be identified.
Dr. Ren was born on Dec. 5, 1915, in the eastern province of Anhui, reports in the Chinese news media said. After graduating from a military university in the southwestern city of Chongqing, he moved to the United States and earned a doctorate in applied mechanics from the University of Michigan.
He returned to China in 1949, the year the People’s Republic was founded, and later worked at a military research academy. Professor Sullivan said that Dr. Ren, a specialist in liquid rocket fuels, most likely worked under Qian Xuesen, a rocket scientist known as the founder of China’s space program.
Over the years Dr. Ren worked on several variations of the rocket that sent China’s first satellite into space. Chinese state media said he had been the chief designer for six major space projects.
His former colleagues have described him in interviews with Chinese newspapers as restlessly ambitious and energetic. One colleague, Wang Hang, said that Dr. Ren rarely took long lunch breaks and often worked deep into the night.
But he was also humble and accessible, his colleagues said.
Zhang Enzhao, a former official at the Academy of Aerospace Propulsion Technology in the central city of Xi’an, said that on a summer day in the 1960s, he saw Dr. Ren enter an office and wave off a group of subordinates who had stood to salute him.
“He was not as serious as I thought, but instead very amiable,” Mr. Zhang told the newspaper China Space News in 2015.
Days later, Mr. Zhang said, he received a notice about office protocol. Effective immediately, the notice said, saluting superiors within office buildings was no longer necessary.
An earlier version of this obituary misstated Mr. Ren’s age. He was 101, not 102. The error was repeated in the headline.