we return to the Moon or go onto Mars?

You are one of only seven people who have been isolated, in orbit around the Moon [the others are the command module pilots of Apollo 10, 11, 12, 14, 16 and 17 and only Apollo 15, 16 and 17 pilots spent three days alone in lunar orbit]. Are there lessons that astronauts in the future can learn, if and when we return to the Moon or go onto Mars?

I think there probably are, although we all had different experiences. The lesson I got was don’t get too friendly with your crew. With the long periods of time you spend with the other two, I found that I was more tuned to doing the job I had to do than I was with interfacing with them. We really worked well together professionally but we were not particularly great friends and I think that was a benefit.

How does that work then? It’s hardly a nine to five job when you can go home at the end of the today, away from your work colleagues?

That’s why you need to maintain a distance between people. If you get to a point in a flight where it’s time to take a rest, not do anything for a while, you need to be comfortable that you can enjoy the solitude without having to feel you have to talk to everybody.

I guess we all expect you to be chums, are you saying that’s not necessarily the case?

Apollo 12 they were always buddies – Pete Conrad treated his crew like brothers. If you saw one, you saw all three because they were always together. We were the opposite of that, we trained together but we didn’t socialise a lot together and I think that made us a more effective crew.

Your colleagues Dave Scott and Jim Irwin left footprints on the Moon – which will be there for millions of years. Will you have left anything behind as a memorial to your mission? Your urine maybe?