At first, Barbara Eden said no to NBC executives about reprising her role as Jeannie: "I had no intention of playing Jeannie again. It's a super-high risk to repeat something done well in the first place. And the series is still running in syndication". She later explained: "I read the script, and it was fun - and before I knew it, I was doing it. And I don't have any regrets".
Tony Nelson is a very unusual astronaut in that he goes into space in a Mercury capsule, a Gemini capsule, an Apollo capsule and in the TV movie follow up in the space shuttle. No real astronaut has ever flown on all four spacecraft.