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

The fascination to go into space has existed for hundreds of years. But as we do things and they're successful, people get bored.

I was only a hero by default. The flights were few and far between. There weren't that many astronauts. The moon flights were so interesting and exciting.

In space-flight terms, six landings on the moon back in the Sixties and Seventies doesn't mean much.

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.

The lunar flights give you a correct perception of our existence. You look back at Earth from the moon, and you can put your thumb up to the window and hide the Earth behind your thumb. Everything you've ever known is behind your thumb, and that blue-and-white ball is orbiting a rather normal star, tucked away on the outer edge of a galaxy.