Louis Blériot was the first person to fly across the English Channel on July 25, 1909, in his Blériot XI aircraft. The question only provides the first name 'Louis' without the surname 'Blériot', which is insufficient for complete identification. The other options (Richard, Chiaki Mukai, Alexei) are incorrect - Chiaki Mukai is a Japanese astronaut and Alexei Leonov was a Soviet cosmonaut.