Exactly when Carla Gugino sleeps, we have no idea.

A professional actress since childhood, Gugino has long been vying for the title of the hardest working actor in Hollywood, or at least one of the most employed. Her long list of film credits include high-profile movies such as "Entourage," "Californication," "Wayward Pines," and "Roadies."

Gugino's back on the big screen in the near-future fusion of sci-fi and YA, "The Space Between Us," playing a maternal-minded astronaut trying to ensure the safety of a teenager born and raised on Mars (Asa Butterfield) as he makes his way to Earth to meet the girl (Britt Robertson) he's fallen for from very afar. And she's already completed the much-anticipated Netflix film adaptation of novelist Stephen King's harrowing, S&M-tinged psychological thriller "Gerald's Game," a role she admits sorely tested her own psyche and physique.

And, as she chatted with Moviefone about her always-in-motion career, Gugino also took a rare look back at some of her earliest TV acting roles, which found her cast opposite the likes of Tony Danza, Neil Patrick Harris, Fred Savage, and ALF.

Moviefone: How much of a space nerd were you before taking on this movie? Were you interested in space exploration?

Carla Gugino: Not a big space nerd. I've always been so impressed and fascinated by people who would choose to do that on our behalf. It's such a noble profession. But I never have had an inkling to want to do it, and I don't even think playing this character made me feel differently, but I really love seeing the world through her eyes.

I think in this particular case, and the majesty of it I guess was something. Gary Oldman's character in this, too, I find to be influenced obviously by like Elon Musk, Richard Branson, those kind of guys, who have that really forward-thinking attitude and the wherewithal to be able to actually execute it. So I find it fascinating, but not personally something I would want to do.

Did you learn anything where you were, like, "Astronauts have to do THIS?" Was there any research aspect that surprised you?

One thing that I found out that was really fascinating to me, when I was speaking to this female astronaut -- she was really interesting, and I was asking her about it being predominantly men. None of that really phased her. She said, "I was in science class from when I was a little kid with all boys. It was always the case for me."

But what is really interesting, because I was really intrigued about like, if I had lived on Mars for this period of time, what would it be like coming back to Earth? Would it be like riding a bike? Would it be completely foreign to me? How soon would you lose memory of things? Obviously, the reason you exercise up there is to keep your muscles and everything like that. She said, "Even when you go up on the satellite, I was gone for a week, and I couldn't remember -- you lose time in space to such an extent, so quickly within a matter of days, that looking down, I was like, which way is Earth? And where on Earth is my family? Where are my kids? And what time is it for them?"

She said it almost seems like a fake life you're thinking about. Like you really lose any kind of just those tentpole things, markers of where you are, and who you are, and what your life is made up of. So she said, "If you were really on Mars for this period of time, it would be really foreign coming back," and I just thought that was really interesting.

Has it ever happened to you as an actor? Have you stepped into a world so deeply that going back to your own world felt a little strange?

There's always a little transitional period into and out of projects in that way. But yes, there was one time that it was more than I have ever experienced. I think it was because I did it for so long. I did a Eugene O'Neill play called "Desire Under the Elms," and I started it in Chicago, did it with Pablo Schreiber and Brian Dennehy, and then we moved it to Broadway. And it's a real Greek tragedy, in the sense that she murders her child. It's a very, very intense role.

That was one that I have to say, because I'm not a Method actor, really stuck with me for a good period of time after in a very intense and slightly concerning way, where I really thought, "God, will I be able to get out of this?"

And I didn't, for a little while, do a play of that nature. I think also, with a play, it's eight shows a week, so it's this strange kind of repeat, and your body doesn't really realize that it's false. So your body is going through this trauma over and over and over again, and that one did. That one did really stick.

"Gerald's Game" sounds like it could be a very intense, something you'd have to shake off before you go home.

That was incredibly intense. It's true. You know what was interesting about that is that I went in so full force, and we shot six-day weeks in Alabama. So when I was in it, I was in it. Then, I was able to shed that pretty quickly, but I think part of that was also because we shot in sequence for the most part, and that was really helpful.

There were some things we had to shoot out of sequence, but really a large portion of it we shot in sequence, so I was able to have that kind of natural process, I guess. But no, that was one of the most challenging -- in all the right ways -- roles that I've ever played.

Was it tough material for you to sit with?

It was very tough material. Do you know the story? Yeah. [filmmaker] Mike Flanagan had been wanting to make that movie since he was 19. Then he did a film called "Hush" for Netflix that I guess Stephen King saw, loved, and Tweeted about. And they connected through that experience.

And Mike said, "I've been wanting to make 'Gerald's Game' for this period of time, but it's always been considered unfilmable because it is such a tricky story." And Stephen King said, "If you give me a script, if you give me something that could work, I'd love for you to do it." So Mike wrote this script.

It's so interesting because this obviously is a thriller with some horror elements, but then also is dealing with child abuse, and that kind of childhood trauma. And, tonally, it's really challenging. So I felt like, "Boy, we have to have somebody who really has that delicate touch and understanding of the material, and of the genre." So when I actually spoke to Mike, I really felt like 'This is the guy. This is the guy to do it, and he feels so passionately about it." I think it's going to be really good. I'm really excited about it.

And I play two versions of myself of this character, and that was also really bizarre and surreal, especially with how quick we were shooting it. We had 23 days, I think, to shoot the movie. 24, maybe.

I bet that helps.

Yeah. I think in this particular case it did. Also, because just physically, I'm in handcuffs for half of it. I have bruises all over my back from the headboard of the bed. It was a physically and emotionally extremely difficult experience, but also in a profound way and a way that appropriate for the material. And I loved working with Bruce Greenwood. Everybody that I worked with on it, I felt so blessed to be doing that with them.

So it was all worth it, but I agree with you that if that had been a four-month shoot, that would have been a different thing, and a different thing for the movie. I think it gives the movie this sense of urgency as well.

Like Hitchcock -- the lean and mean way he shot "Psycho."

Exactly. Or "Rope." Yeah.

I was looking at some of your old credits from when you first started out as a child actor. What was it like to drop in on some of those now-classic sitcoms? "The Wonder Years," "Doogie Howser, M.D.," and "ALF." You were on "ALF!"

I know -- "ALF" was my very first job! That's not true: "Webster" was my very first job. "ALF" was my second job. It was amazing because those were the big shows at that time. So as a young actress, I had one line on "Who's the Boss?" I had a bigger role on "The Wonder Years." "Doogie Howser" -- they were exciting to get.

It was funny because I had considered, the reason that I wanted to act was because of Meryl Streep in "Silkwood" and "Sophie's Choice." I had seen them both in the same year, and I was so blown away by these two completely different women, and women who I felt that I therefore somehow understood, even though as a 12-year-old, I had had no experiences like either of these women. And it really made me think, "Oh my gosh, acting can teach you empathy," and I want to get inside people that are different than me and see life through their eyes.

So those sitcoms weren't the kind of work I thought I would be doing, but I also was a working actor who was getting jobs. And they were all very helpful to me because the thing is the only way to learn anything is to actually start doing it. So those were also kind of nice ways to dip my toe into the water.

I love that you still come back to TV. I thought "Roadies," which got some rough reviews, was well worth the trip by the end.

Thank you. I so appreciate that. The people who love "Roadies" really love "Roadies." I don't know quite why people are so harsh on Cameron [Crowe], because he's so extraordinary, and he has this amazing innocent heart, and I almost feel like that's part of what people go for or something, because we're in a time that's a bit more jaded, or I don't know, self-referential or something, kind of meta. But I love that show, and I love doing that show.

And I've always felt ... I remember when I did "Spin City," I went from "Spin City" to doing "Snake Eyes" with Brian De Palma and Nicolas Cage, and I do the theater. So for me, it's about how all three mediums teach you different things, are different experiences, and it's always about the role and the people. So I will hopefully be able to continue doing that. I really do love it.