J. Robert Beyster, who started a small defense contracting business in a La Jolla building shared with a ballet studio and built that business into a Fortune 500 company, died of natural causes at his home in La Jolla early Dec. 22. He was 90 years old.

Beyster founded Science Applications International Corp., better known as SAIC, which grew to $11 billion in annual revenue, and might be better described as a federation of small, advanced-technology businesses. The employee-owned company went public in 2006 and moved to the Washington, D.C. area in 2009. Since then the company has split into two Virginia-based firms: Leidos Inc. (NYSE: LDOS) and the new SAIC Inc. (NYSE: SAIC).

Beyster served in the U.S. Navy during World War II and went on to become a nuclear physicist. His personal passions included sailing. He celebrated his 90th birthday earlier in the year. His family said he died wearing his favorite sailing clothes, including an America’s Cup jacket and a University of Michigan cap.

A private family service is planned. A public memorial will be held in the new year, his family said.