How did the supersonics get their name?

Answer 1

When the expansion franchise in Seattle joined the NBA in 1967, Boeing, the airplane manufacturer then headquartered in Olympia, Wash., was working on supersonic jet that would rival the Concorde. The plane never took off, but Seattle fans voted for the name anyhow.

Answer 2

Boeing aerospace manufacturing was based out of Seattle, and at the time it was thought in the industry that all new airplanes would travel at supersonic speeds.