Jack A. Kyger helped develop the atomic bomb, the first American nuclear submarine and heat shields on the Apollo spacecraft.
In his private life, he took up windsurfing at 70, learned to use a computer at 80 and raced sailboats until he turned 84.
“He was somebody who always wanted to keep improving skills he already had and wanted to keep doing new things,” said his daughter, Nora.
Mr. Kyger, 85, formerly of Hinsdale, died Sunday, Aug. 19, in his Punta Gorda, Fla., home after a long illness. He was a former associate laboratory director for engineering research and development at Argonne National Laboratory.
Mr. Kyger worked briefly at Mallinckrodt Chemical Works in St. Louis, Mo., before being recruited as one of the chemists who worked on the Manhattan Project, his daughter said.
As the engineering materials section chief at what would become Oak Ridge National Laboratory in Tennessee, Mr. Kyger was one of the chemists who worked on the atomic bomb.
After World War II, Mr. Kyger became chief scientist of the Department of the Navy’s nuclear-power section and won a Distinguished Civilian Service Award from the Navy for his work on the USS Nautilus nuclear-powered submarine.
He worked on re-entry vehicle projects of the intercontinental ballistics missile program, and the development of the Apollo heat shields at AVCO Corp. in Massachusetts, his daughter said. He served briefly as director of the Massachusetts Science and Technology Foundation.
In 1972, Mr. Kyger moved to Argonne, where he was in charge of reactor development, said media relations manager Catherine Foster.
Hans Fauske, a colleague at Argonne, described Mr. Kyger as a scholar who also loved sports. “He was just very active.”
After retiring in 1981, Mr. Kyger continued competitive sailing and took up windsurfing, his daughter said. He went sculling until about 1 1/2 years ago.
“He was just very open to new experiences,” Nora Kyger said. “He just really enjoyed using his mind,” she said.
Mr. Kyger also is survived by his wife, Clare; a son, John; two other daughters, Mary Norman and Elizabeth; and three grandchildren. A private service was held.
