Aeronautics
- June 27 - 19-year-old American socialite Aida de Acosta becomes the first woman to fly a powered aircraft solo when she pilots Santos-Dumont's motorized dirigible, “No. 9”, from Paris to Château de Bagatelle in France.
- December 17 - First documented, successful, controlled, powered flight of a heavier-than-air aircraft with a petrol engine by Orville Wright in the Wright Flyer at Kill Devil Hills, North Carolina.
- Konstantin Tsiolkovsky begins a series of papers discussing the use of liquid fuel rockets to reach outer space, space suits, and colonization of the solar system.
Read more about this topic: 1903 In Science