At one point in his life, John Herrington admits, he was an underachiever.

His grade point average was 1.72, and his only passion in life was rock climbing near his Colorado home.

“I didn’t study,” he said. “If you don’t study you don’t pass your classes. I got kicked out of school (University of Colorado at Colorado Springs) for low grades. I had a 1.72 GPA. How do you go from having low grades to being an astronaut? That’s the challenge.”

Herrington, who had dreamed of being an astronaut as a child and took his first flying lesson in the 10th grade, met that challenge. The Wetumka native and member of the Chickasaw Tribe, eventually be-came the first American Indian to fly in space.

Herrington spoke Friday at Vance Air Force Base’s National American Indian Heritage Luncheon.

His topic was “Living Your Dreams,” and he took the first step toward living his own dream when he was using his rock climbing skills as a highway surveyor in a Colorado canyon after being booted from college. The job offered him his first exposure to the practical use of mathematics. His supervisor urged him to return to school and pursue an engineering degree. He did, and this time he succeeded.

A few years later, when Herrington was a senior, he tutored a retired Navy captain in calculus. The former aviator convinced him to become a Navy pilot in part by urging him to go see the movie “An Officer and a Gentleman,” in which Richard Gere portrayed a Navy student pilot.

Herrington went on to become distinguished graduate of Naval Aviation Officer Candidate School and to log more than 3,800 hours in more than 30 types of aircraft, including a stint as a test pilot.

In 1996 Herrington was tapped by NASA to join the astronaut corps. It would be six years before he would fly in space, but Nov. 23, 2002, he lifted off on space shuttle Endeavour for a 14-day mission to the International Space Station.

“Human spaceflight is an incredibly emotional experience,” Herrington said.

He commemorated his Chickasaw heritage by taking an eagle feather and flute with him into orbit.

Herrington made three space walks totaling 19 hours and 55 minutes during his mission. He said he was too busy to even have time to look out the space shuttle’s windows during the mission, until the shuttle’s landing was delayed for three days by bad weather.

“Had we not been delayed for three days, I wouldn’t have had time to take a single picture for pleasure out the window of the shuttle, that’s how busy I was,” he said. “But I was lucky. I got a three-day vacation on the shuttle and I was able to stick my nose against the window for three days and look at just remarkable sights.”

Herrington never returned to space. After his shuttle flight he was ticketed to be commander of a crew on the International Space Station. But he was diagnosed with osteoporosis in his lower back, which precluded him from flying to the ISS on a Russian Soyuz capsule, because it lands not in water, but on land, when returning to earth. He could still fly on the shuttle, however.

But after the Columbia disaster in February 2003, the shuttle program was in limbo for more than a year. During that time Herrington left NASA to take a job with Rocketplane Global Inc., an Oklahoma company working to develop a commercial space vehicle. That venture failed due to financial problems.

After Rocketplane, Herrington embarked on a three-month, 4,200-mile bicycle ride across the country from Cape Flattery, Wash., to Cape Canaveral, Fla. He used the ride to encourage young people to participate in science, technology, engineering and mathematics.

“One of the more satisfying experiences was riding the bike across the country,” he said, “and meeting the people that make this such a wonderful place to live.”

Herrington, the one-time underachiever, now is pursuing a doctorate in education at the University of Idaho, and works for the Chickasaw Nation, in whose behalf he spoke at Vance. He also hosted and wrote a program titled “Inside Hubble’s Final Mission,” that is scheduled to air Nov. 21 on the National Geographic Channel.