Riverside Military Academy cadets were given a glimpse into space travel Wednesday from a man who's been there.

Astronaut Randy Bresnik, who joined the NASA program in 2004, shared highlights of his trip to space, including docking with the International Space Station and eating in zero gravity.

He also urged his young audience to become good leaders.

"The most valuable leadership trait I've seen over my years in this environment is humility. It's not about you, it's about accomplishing your mission with the people around you," Bresnik said.

The astronaut was greeted by more than 300 students in the Sandy Beaver Center theater.

Students learned about Bresnik's 2009 shuttle Atlantis mission and how he walked in space twice to help replace systems parts on the space station.

Bresnik told the students he trained in water at the large NASA pool in Houston to simulate the space walk, which has a full-size mock-up of space station components.

"Anytime we reach for a tool, we've done it several times underwater so that it's executed flawlessly," Bresnik said.

He also made himself available for questions that ranged from, "How do you work out in space?" to "Why are space suits white?"

The answers: astronauts in space work out two to three hours daily on exercise machines to prevent the loss of bone density, and he wasn't sure why the suits are white.

"Maybe the U.S. government got a good deal on white fabric," he said. "The Russian suits are actually tan."

In response to a student's question about sleeping aboard the space station, Bresnik said sleeping bags are tethered to the wall. He also found some creative ways to rest.

"At first, I had my sleeping bag at normal orientation, so I would wake up and everything was where it should be," he said. "By the second or third night I put it on the ceiling."

Bresnik said he began his career as a pilot in the Marine Corps where he was promoted to lieutenant colonel before applying to the NASA program during a mission to Iraq.

"I never thought when I was growing up in Santa Monica, Calif., that I'd have a chance to do this," Bresnik said, as he pointed to a slide of his mission.

He told the students hard work and confidence can lead them to their goals, too.

"I learned that the only limits I had were the ones I put on myself," Bresnik said.

Student Paul Ribeiro, 18, said he wanted to become a pilot one day and was impressed with Bresnik's speech.

"I thought it was great when he said good leadership is something you try to emulate and bad leadership is what you learn from," Ribeiro said.

Bresnik said he has embraced the task of inspiring younger generations, which is one reason he accepted Riverside's invitation to speak. He said he also still trains for space travel and hopes to sign on for a long-term mission in the future.