For some time, I thought Apollo 13 was a failure. I was disappointed I didn't get to land on the moon. But actually, it turned out to be the best thing that could have happened.

Back in those days, going to the moon, geology was important, ... But how do we train pilots to be geologists? We concentrated on observing, not the analytical parts of the rocks.

We didn't slow down, unlike the others, when we got to the moon because we needed its gravity to get back, so we hold the altitude record. I never even thought about it. Records are only made to be broken.

Mars is a long ways away. The moon is only 240,000 miles, but Mars is in the millions. It's too risky without spending more time going to the moon.

If you're going to go into space, you have to have an objective, a mission. Where do you want to go? Earth orbit? The moon? Mars? What's the technology to get there? You develop the technology for the mission.

After six successful Apollo flights, including two lunar landings, people were getting bored.