Walter B. LaBerge, 80, an aerospace research scientist who was a former undersecretary of the Army, assistant secretary of the Air Force and an assistant secretary general of NATO, died of complications from pneumonia July 16 at his home in Aptos, Calif., near Santa Cruz.

In the early 1950s, Dr. LaBerge was a member of the original Sidewinder air-to-air missile development team at the Naval Ordnance Test Station in China Lake, Calif. In 1962, he headed the Philco-Ford Corp. team that designed the instrumentation for the Manned Spacecraft Center, now the Johnson Space Center, in Houston.

Dr. LaBerge was born in Chicago. After graduating from the University of Notre Dame in 1944 with a degree in naval science, he served aboard a minesweeper in the Palau Islands and was promoted to captain in 1946. After the war, he returned to Notre Dame, where he received a doctorate in physics in 1951.

In 1971, Dr. LaBerge became technical director of the China Lake test station. Three years later, he was appointed assistant secretary of the Air Force for research and development. In 1976, he served in Brussels as assistant secretary general of NATO for defense support.

Returning to the Pentagon in 1977, he served as undersecretary of the Army. His final government appointment was as acting undersecretary of defense for research and engineering in 1980. Dr. LaBerge and his family lived in McLean and Alexandria.

In 1981, Dr. LaBerge joined Lockheed Corp. in Sunnyvale, Calif. He retired in 1989 as vice president for advanced planning. Subsequently, he served as chairman of the Army Science Board and held various academic appointments.

Dr. LaBerge's first wife, Patricia Anne Sammon LaBerge, died in 1982. Elizabeth Anne Deely LaBerge, his second wife, died in 2003.

Survivors include five children from his first marriage, Peter LaBerge of Cochranville, Pa., Stephen LaBerge of Santa Cruz, Jeanne LaBerge of San Francisco, Philip LaBerge of Coppell, Tex., and Jacqueline LaBerge Gunn of Yorktown, Va.; four stepchildren from his second marriage, Deborah Pharris of Pineville, Ark., Pamela Alexander of Irvine, Calif., Richard Baughman of Lake Forest, Calif., and Kurt Baughman of San Jose; two brothers; and a sister.