Ken Mattingly stopped by Des Moines Area Community College's West Campus Wednesday afternoon to encourage students and some other fans of space travel to always innovate.

His appearance was part of ciWeek8, a week of innovative speakers ranging from sound engineer Greg Russell of "13 Hours: The Secret Soldiers of Benghazi" fame to beatbox champion Kaila Mullady. Read a story about ciWeek8 at BusinessRecord.com.

For Mattingly, innovation meant running simulations to figure out how to get the Apollo 13 crew back to Earth on limited battery power after an explosion crippled their spacecraft and forced them to fly the lunar module home. He famously got bumped from the crew 72 hours before launch because a kid at a picnic thrown as a final public event for the astronauts had exposed him to measles — which Mattingly had never contracted. Mattingly found out in the middle of the night that the crew was in trouble. He was played by Gary Sinise in the movie "Apollo 13," and seems every bit the engineer problem solver that Sinise portrayed.

Before the measles exposure, Mattingly had been named to be command module pilot for Apollo 13. "We thought we were in hog heaven," said Mattingly, who had joined the space program in part to get virtually unlimited flight hours. "We were going to have a ball."

"A week before launch I was at a picnic that was supposed to be the last chance to be out and around." He learned that a kid he had been around came down with the measles. The astronauts were supposed to inform NASA that they had had measles — meaning they were immune. Mattingly couldn't.

"I called my mother. 'Mom, did I have the measles?' 'No, you didn't. You were lucky.' "

Mattingly laughed at the irony. He informed NASA and acted like it was no big deal. All of a sudden Jack Swigert started getting into the simulators more, but Mattingly still thought all was well.

Until he heard on the radio that he had been replaced — days before the launch.

Mattingly's luck at avoiding the measles had cost him a trip to the moon.

"Was I disappointed? Oh, you bet. Nothing's been in Shakespeare or anywhere else that could throw a fit and feel sorry for yourself like I did."

Mattingly wasn't done flying, though. He was command module pilot for Apollo 16 and also flew two shuttle missions.

He innovated when he found ways to cope with the intense vibration and heat during liftoff of Apollo 16 on the business end of a 7 million-pound Saturn V rocket, "the type of thing that makes you question the wisdom" of taking the ride, he said.

"We thought we should buy a whole box of those things (Saturn Vs) and shoot one off every Fourth of July," he deadpanned.

Mattingly urged the students to work on the fine points of implementing their plan for their innovation. "No program that you embark on is successful unless you have perfect execution," he said. "I've seen more clever ideas go down the drain because they were poorly executed. Attention to detail. In today's electronic revolution, computers are so powerful, and can do so many things, and even with all that data, mistakes can be made. You can never relax."