From the distance of the moon, Earth was four times the size of a full moon seen from Earth. It was a brilliant jewel in the black velvet sky.

I think there would be no shortage of applicants to the government astronaut corps to be settlers on the planet Mars. And I think this would be very inspiring.

Mars has been flown by, orbited, smacked into, radar examined, and rocketed onto, as well as bounced upon, rolled over, shoveled, drilled into, baked and even blasted. Still to come: Mars being stepped on.

My expertise is the space program and what it should be in the future based on my experience of looking at the transitions that we've made between pre-Sputnik days and getting to the moon.

I don't believe any pair of people had been more removed physically from the rest of the world than we were.

I am excited to think that the development of commercial capabilities to send humans into low Earth orbit will likely result in so many more Earthlings being able to experience the transformative power of space flight.

I've been to the Titanic in a yellow submarine and the North Pole in a Russian nuclear ice breaker.