James R. Moore, 70, a retired electrical engineer with the National Aeronautics and Space Administration died Dec. 22 in a Miami Beach, Fla., hospital after a heart attack.

Mr. Moore, who graduated from the University of Kentucky with a bachelor of science degree in electrical engineering and a master's degree in physics, was the holder of several patents on radar-related systems.

He began his 30-year government career in 1937.

In 1945, Mr. Moore moved to the Washington area and worked with early computers and their military application at the Navy Department. At the same time he taught at the University of Maryland.

Mr. Moore joined NASA in 1961, spent two years at the NASA tracking station in Antofagasta, Chile, working on the Apollo Satellite Program. In 1967, he retired.

Mr. Moore was an enthusiastic sailor and built a boat in the front yard of his home in Arlington. He and his son, Billy, worked on it for 13 years. It was a 56-foot, 30-ton sailing boat named "M" which was completed in July, 1966. A year after his retirement from NASA, the Moore family sailed from Virginia to Miami on their homemade craft.

Survivors include his wife, Adeline Cornish Moore, of the home in Miami Beach, Fla., two sons, William, of Miami Beach, and Dr. James R. Jr., of Rockville; five sisters, three brothers, and two grandchildren.