“The sky is definitely not the limit,” Kelly told an audience of 3,000 students, university and Bozeman community members Thursday night at Montana State University’s Brick Breeden Fieldhouse.

Kelly, 55, made four space flights, flew 143 million miles around the Earth and commanded the International Space Station. He made history when he became America’s first astronaut to spend nearly a year in space, 340 days from March 2015 to March 2016.