National Astronaut Day is celebrated every year on May 5 to honor those who travel to outer space and bring back knowledge about the vast unknown.

On this day in 1961, astronaut Alan Bartlett Shepard Jr. became the first American in space aboard the Freedom 7 Space capsule. The milestone achievement led to the creation of the day to celebrate the success of the heroes. Here are some quotes, courtesy keepinspiring.me, to share on this day.

1. “The Earth is the cradle of humanity, but mankind cannot stay in the cradle forever.”– Konstantin Tsiolkovsky

2. “We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win.”– John F. Kennedy

3. “Space is for everybody. It’s not just for a few people in science or math, or for a select group of astronauts. That’s our new frontier out there, and it’s everybody’s business to know about space.”– Christa McAuliffe

4. “Mankind is drawn to the heavens for the same reason we were once drawn into unknown lands and across the open sea. We choose to explore space because doing so improves our lives, and lifts our national spirit. So let us continue the journey.”– George W. Bush

5. “Never limit yourself because of others’ limited imagination; never limit others because of your own limited imagination.”– Mae Jemison

6. “I know the sky is not the limit because there are footprints on the Moon — and I made some of them!”– Buzz Aldrin

7. “To some this may look like a sunset. But it’s a new dawn.”– Chris Hadfield

8. “You develop an instant global consciousness, a people orientation, an intense dissatisfaction with the state of the world, and a compulsion to do something about it. From out there on the moon, international politics look so petty. You want to grab a politician by the scruff of the neck and drag him a quarter of a million miles out and say, ‘Look at that, you son of a bitch.”– Edgar Mitchell

9. “It suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn’t feel like a giant. I felt very, very small.”– Neil Armstrong

10. “Earth is a small town with many neighborhoods in a very big universe.”– Ron Garan

NASA astronauts Shannon Walker (L), Victor Glover (2nd L), Mike Hopkins (2nd R) and Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi (R), are pictured wearing SpaceX spacesuits in a dress rehearsal ahead of the Crew Dragon launch
NASA astronauts Shannon Walker (L), Victor Glover (2nd L), Mike Hopkins (2nd R) and Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi (R), are pictured wearing SpaceX spacesuits in a dress rehearsal ahead of the Crew Dragon launch NASA / Joel KOWSKY