Which Soviet cosmonaut became the first human to travel into space?

Yuri Gagarin became the first human to travel into space.

On 12 April 1961, the Soviet cosmonaut launched aboard Vostok 1 from Baikonur Cosmodrome. His flight lasted 108 minutes and completed one orbit of Earth before landing in the Soviet Union. Gagarin's radio call, “Poyekhali!” meaning “Let's go!”, became closely associated with the mission.

Gagarin was 27 years old and held the military rank of senior lieutenant at launch. His achievement made him an international symbol of the Space Age and a national hero in the Soviet Union. He later visited many countries, including the United Kingdom, to promote the Soviet space program.

Alan Shepard became the first American in space, but his first flight was a shorter suborbital mission in May 1961. John Glenn later became the first American to orbit Earth. Valentina Tereshkova became the first woman in space in 1963.