National Space Day is a day that celebrates the achievements, benefits, and opportunities in the exploration and understanding of space. It is observed on the first Friday in May each year. The day was created to inspire people to pursue knowledge and progress in the field of space exploration. National Space Day was first established in 1997 by the Lockheed Martin Corporation as a one-off event, and it was later expanded to International Space Day in 2001 by former astronaut and senator John Glenn due to its extreme popularity.

National Space Day is not associated with any specific historical event. It is a day to celebrate the mysteries and beyond of space, promote the importance of space exploration, and inspire people to continue advancing our understanding of the universe.