Harris was the first African American to walk in space.
He told the kids they can be whatever they want to be in life, as long as they choose to be successful.
"You might wonder why people are successful; they're successful because they choose to successful, so you have to choose to be successful and we're urging you to start to choosing to achieve and be successful," Harris sai.
His advice was more than just words from Harris; he came from humble beginnings in Texas and persevered through hard work and tenacity.
Harris encourages people to focus on math and science, saying they build the skill sets needed to succeed in the 21st century.