In his six months on the International Space Station, Chris Cassidy saw something special: clouds of dust moving from the Sahara Desert to the Amazon, providing key nutrients needed for the rainforest there to grow.

But it wasn’t all science experiments and research. Cassidy said he and his crew mates squeezed in some fun, including a friendly competition: Who could swing from one end of the station to the other the fastest, without touching anything?

Cassidy said Canadian astronaut Chris Hadfield, first to record a music video in space, was pretty good. “We all won different days, because sometimes you’d put stuff in the aisle … ”

Chris Cassidy, in blue jumpsuit, signing autographs for children (Flavio Carvalho)
Astronaut Chris Cassidy meets with students at a library in the Rocinha favela in Rio de Janeiro. (Flavio Carvalho)

Cassidy traveled to Rio de Janeiro in November to share with schoolchildren stories of his work — and the fun he had — on the space station.

He visited Rocinha, the city’s largest favela and one of Rio’s poorest areas.

Cassidy encouraged the students to stay positive and not give up, noting that NASA rejected his first astronaut application in 2000. So Cassidy tried again. He earned a graduate degree and more experience, and then he was accepted. Two years of NASA training led him to 16 days on the space shuttle in 2009 and then six months on the International Space Station in 2013.

Cassidy is now back on Earth as NASA’s chief astronaut. That means he selects compatible crews for space missions.

And what about technology and the rockets needed to take people to Mars?

“All of that will be an international effort,” he said, hoping to inspire the next generation of astronauts.

Cassidy spent time with 50 schoolchildren who shared winning essays about becoming astronauts.

“Kids, no matter where they’re from … they’re all just curious. It’s refreshing to see.”

So if you’re training to become the first person on Mars, don’t forget to preserve an important part of your childhood: a sense of fun.

Cassidy’s trip was sponsored by Spread Positivity, a nonprofit campaign that’s focused on finding ways to put down distractions and seek meaningful, real-world interactions.