In 1961, Yuri Gagarin became the first person to venture beyond Earth's atmosphere. Since his journey, about 450 people – astronauts, civilians, and "space tourists" – have explored space. Follow this slideshow to learn about notable firsts for space exploration.
![yurigagarin yurigagarin](/sites/default/files/collection-item/yuri-gagarin.jpg)
Photo source: NASA
![alanshephard alanshephard](/sites/default/files/collection-item/alan-shephard.jpg)
Photo source: NASA
![johnglennkennedy johnglennkennedy](/sites/default/files/collection-item/john-glenn-kennedy.jpg)
Photo source: NASA
![valentinatereshkova valentinatereshkova](/sites/default/files/collection-item/valentina-tereshkova.jpg)
Photo source: NASA
![leonov leonov](/sites/default/files/collection-item/leonov.jpg)
Photo source: NASA
![spacewalkfirst spacewalkfirst](/sites/default/files/collection-item/space-walk-first.jpg)
Photo source: NASA
![neilarmstrong neilarmstrong](/sites/default/files/collection-item/neil-armstrong.jpg)
Photo source: NASA
![sallyride sallyride](/sites/default/files/collection-item/sally-ride.jpg)
Photo source: NASA
![bluford bluford](/sites/default/files/collection-item/bluford.jpg)
Photo source: NASA
![maejemison maejemison](/sites/default/files/collection-item/mae-jemison.jpg)
Photo source: NASA
![eileencollins2 eileencollins2](/sites/default/files/collection-item/eileen-collins2.jpg)
Photo source: NASA
![AstronautAndyThomas AstronautAndyThomas](/sites/default/files/collection-item/andy_thomas.jpg)
Photo source: NASA
![johnglenn johnglenn](/sites/default/files/collection-item/john-glenn.jpg)
Photo source: NASA
![dennistito dennistito](/sites/default/files/collection-item/dennis-tito.jpg)
Photo source: fas.org
![yangliwei yangliwei](/sites/default/files/collection-item/yang-liwei.jpg)
Photo source: spacedaily.com
![whitson whitson](/sites/default/files/collection-item/whitson.jpg)
Photo source: NASA
![chinaspacewalk2 chinaspacewalk2](/sites/default/files/collection-item/china-spacewalk2.jpg)
Photo source: spacefacts.de