What does the letter 'S' stand for in 'NASA'?

The letter "S" in NASA stands for "Space." NASA, the National Aeronautics and Space Administration, is a United States government agency responsible for the nation's civilian space program. The inclusion of "Space" in the acronym reflects the agency's primary mission, which involves the exploration of space, advancement of aeronautics, and the study of the Earth and the universe beyond. By focusing on space research, NASA plays a crucial role in expanding our understanding of the cosmos and opening up possibilities for human space exploration.