Paul E. Schwartz, 94, who helped develop the first operational satellite service and a precursor to today’s Global Positioning System, the Navy’s Transit satellite system, died Dec. 20 in Potomac Falls.

He died of renal failure at Falcons Landing retirement community, his son, John Schwartz, said.

Mr. Schwartz, a Silver Spring resident, worked for 32 years at the Johns Hopkins University Applied Physics Laboratory in Laurel. As a laboratory manager, he focused his work on developing the Transit satellite program and experimental space exploration rockets. He retired in 1983.

Paul Everett Schwartz was a native of Springfield, Ohio, and a 1938 engineering graduate of the New Jersey Institute of Technology.

He served in the Navy from 1941 to 1949, during which he helped design and test oxygen equipment for naval aviators in Washington. He was also a tenor in a Navy chorus. Later, he joined the Navy Reserve and retired as a lieutenant commander in 1961.

A longtime Silver Spring resident, he moved to the Leisure World retirement community in 1981 and to Falcons Landing last year.

Mr. Schwartz chaired Leisure World of Silver Spring’s chapter of the Military Order of the World Wars and the retirement community’s internal government council. He also sponsored scholarships for students interested in pursuing ROTC college programs.

His first wife, Mildred Coffee Schwartz, died in 1992 after a 51-year marriage. His second wife, Margie Harris Schwartz, died in 2007 after 13 years of marriage.

Survivors include one son from his first marriage, John Schwartz of Leesburg; two stepchildren, Linda Faith of Silver Spring and Craig Morgan of Laurel, Del.; five grandchildren; and four great-grandsons.

— Megan McDonough