A mission to space also means a long journey from home. It's a rewarding yet lonely part of the exploration, far from Earth. A new documentary, Space: The Longest Goodbye, shares an intimate look at the reality of human behavior in isolation and what scientists are researching and developing to prepare future astronauts. Take a look.

I remember they're counting down. Then as soon as it lifts off, you can feel it in your chest. My mom is not on the planet. She's really gone.

Joining us here today is a former astronaut and retired US Air Force Colonel Katie Coleman. Thank you so much for being here today. You went on three missions to space. Judging by your background, we think you're on Earth. We're not sure, though. This is the question I'm sure you've gotten a million times. What is it like to see a glimpse of home every time you were away from Earth?

Looking When I came back, it made me actually feel... I always thought space would be far away. And yet when you get there, I felt no less home. It's just a home is a little bigger than we thought. And I really felt at home on the space station, but I sure missed Earth.

And in the film, they also interviewed your son. Did you ever feel like a gradual change in your relationship with him while you were away?

I actually still have a hard time watching that part of the movie and not crying, actually. It's hard. And It's been a wild adventure, really, to be part of this film and get to watch it, essentially, with my 10-year-old and my 23-year-old. I wouldn't say that things changed so much over the course of, it was about six months that I was in space, but it's been interesting to, in the years since, and especially this year after the film came out, understand what that really meant to both of us.

That is so fascinating. Can't imagine what that must be like, that dynamic. The preparation and the journey is it takes to become an astronaut, obviously physically challenging, but how do you mentally prepare yourself to face isolation in a confined space, or are you ever really prepared?

It's actually a huge, big place up there. It's the size of the inside of a 747, so it's really big, many modules. At the same time, you can't leave and you don't get to pick who you go with, and you don't get to have that person that you just love to talk to at the end of the day. Although we did have an Internet protocol phone, and that's what you and then video once a week was what we got to do. You do get to actually connect with those people. But you talked about people getting prepared. How do you prepare for this? It's really exciting right now because NASA is taking applications. I'm a former astronaut I'm retired, but they are taking applications for brand new astronauts. I think it's a perfect time for a film like this because you might think that we're just people like you saw in those old films that you don't get to see that much of a glimpse of what it was really like for them.

To that end, did you ever feel feel like a sense of connection seeing other astronauts in the film who shared those similar stories as you?

Absolutely. Even looking the other way around, I've had military kids come to me, two of them actually, and just say, My whole life, I felt bad that I didn't always want to talk to my dad or my mom when they were away and here was this little chance to talk. And yet our family, my 10-year-old didn't always want to say hi to his mom on the phone. And I really wanted to. It's just human. It's just part of families. I think finding out that we all face the same challenges and even looking at these compared to the pandemic and what that isolation was like for all of us then, you start to realize that you can make those connections. It's not the same, but it's still, it's real.

Looking ahead here, one more question for you. From artificial intelligence, virtual reality, and travel hibernation, what does the future future look like in space travel? And how prepared are we to send astronauts to Mars?

Well, I'd say we're not ready yet, but we are getting ready. And the moon is the place to actually start doing that when it's three days away to solve our problems. But when it comes to how can we prepare people for when you can't have that live conversation, I'd say, entertain the possibilities. I have been surprised, really, at some of the things I've gotten to take part in where I'm like, I'm never going to like that. It won't mean anything. When you let it in, you'd be surprised at what can make you feel better.

Incredible insight. Thank you so much for joining us. We're all looking forward to this one. Space the Longest Goodbye is out now in theaters as well as streaming platforms, Apple TV and Amazon.

Hi, everyone. George Stefanopouls here. Thanks for checking out the ABC News YouTube channel. If you'd like to get more videos, show highlights, and watch live event coverage, click on the right over here to subscribe to our channel. Don't forget to download the ABC News app for breaking news alerts. Thanks for watching.