Don Thomas tells students at Collegedale Academy about his journey to become an astronaut Wednesday, March 14, 2018 in Collegedale, Tenn. Thomas is a former astronaut, engineer, professional speaker, educator, and author of "Orbit of Discovery" about his STS-70 mission aboard space shuttle Discovery.

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Retired astronaut visits Collegedale Academy

Gasps and giggles filled a Collegedale Academy auditorium as a retired astronaut spoke to children for National Pi Day.

Pi Day falls on March 14 every year. It's a celebration of the representation of the infinite sequence of pi, 3.14, that represents the ratio of a circle's circumference to its diameter.

For its celebrations, Collegedale Academy invited retired astronaut Don Thomas to talk to students about what it is like to live and work in space and the importance of persistence and good work ethic. Thomas has been retired for about 11 years now and travels around the world speaking to students about space. As an astronaut, he's been on four missions totaling 44 days in space and orbited the earth 692 times.

But becoming an astronaut is no easy task, Thomas said. It took him four tries before NASA finally hired him.

"I thought by working hard, doing my best, going to good schools, working for a great company, I thought I would be a shoe-in," he said. "But that wasn't going to be the case."

After his first two tries, Thomas studied the backgrounds of the people who were being accepted. He learned what kind of experience NASA was looking for, and he worked to get those qualifications. It wasn't until he was 35 years old that NASA finally hired him, and he didn't make it to space until he was 39.

"[That's] pretty much an old man, right?" he asked the children. They laughed.

He told about the detailed reference check he went through.

"NASA was doing a security background check on me," he said. "They talked to every employer wherever I worked from high school on."

Thomas said they contacted former bosses to ask about his work ethic. They reached out to friends and neighbors for character references.

He asked the children what they thought the lesson was.

"Don't give up on your dreams," some said.

"All good things happen to those who work for it," others said.

"It takes a lot of hard work, and it takes time to get there as well," Thomas told them. " ... You can accomplish anything you want to in your lifetime."

After he explained how he became an astronaut, he shared photos and stories of his missions and what his job entailed.

On a mission, he said he and his crew mates would work on 100-200 science experiments. As an example, he explained how studying the effect of gravity on fire is important. With gravity, hot air rises because it's lighter. The hot air rising is what draws the flame into a point. But in space, there is no gravity, so the flame burns in a perfect sphere.

"They're trying to understand the basic fundamentals of combustion," Thomas said. "And maybe from these experiments up in space we can improve our burning process here on earth for automobiles, power plants, things like that."

One child asked if astronauts play pranks on each other. Thomas said they tried not to do that because it's "kind of a hazardous environment up there." But they do goof around, he said.

"When we have free time, sometimes the astronauts like to play catch," he said. "But we don't have [balls] in space, so what we'll do, we have one of the astronauts tuck themselves into a ball. It's pretty wild to see two people playing catch with another human."

At the end of the presentation, sophomore Makayla De Wind said Thomas made her realize that what she does in high school really does matter for her future.

"My biggest takeaway was definitely the fact to never stop going for my dreams, no matter how hard they might be," she said.

De Wind said she's thinking about being a veterinarian when she's older, but the stars and space have always interested her.

Thomas said he hopes the future of space travel holds a Mars landing sometime soon, and he hopes to have inspired at least one student to become one of the astronauts on that mission.

"To know that you had that kind of impact on somebody, that would make my whole life worthwhile," he said. "If there's just one student that I connect with that I change their life because of what they heard, that would be amazing."

Contact staff writer Rosana Hughes at or 423-757-6327 with tips or story ideas. Follow her on Twitter @HughesRosana.