Harry D. Zink, 79, an electrical engineer who designed satellite navigation systems, died June 17 of pneumonia at Holy Cross Hospital in Silver Spring.

Mr. Zink worked for more than 30 years at the Applied Physics Laboratory of Johns Hopkins University in Laurel, beginning in 1953. In the 1950s, he was instrumental in developing antenna and radar systems for missiles. Later, he was an engineer with the laboratory's space research division, analyzing electrical systems used in the Gemini, Apollo and Skylab programs.

He also helped develop satellite tracking systems for NASA, and at the time he retired from the laboratory in 1990, he was working on a space satellite receiver.

Mr. Zink was born in Marion, Ohio, and graduated from Ohio State University in 1946. From 1946 to 1950, he worked in antenna research in Columbus, Ohio. He was a project engineer at RCA in Rocky Point, N.Y., from 1950 to 1953, when he came to Johns Hopkins.

He was director of research at Frederick Research Corp. in Wheaton from 1961 to 1963, at which time he rejoined Johns Hopkins.

He had many hobbies and was an inveterate tinkerer with mechanical and electrical objects. At one point, Mr. Zink built seven tall antennas in his yard in Silver Spring, enabling him to receive television signals from across the country. He had model railroad and auto racing tracks in his house, plus a basement recording studio, which he built himself. He also collected sports cars, including early-model Corvettes, Camaros and British roadsters.

He lived in Silver Spring from 1953 to 1996. From 1996 to 2000, he lived in Potomac with his niece, Janis Zink Sartucci. Since 2000, he had been in the Althea Woodland Nursing Home in Silver Spring.

Survivors include a brother, Jim Zink of Silver Spring.