The last time we talked, when you were promoting Millions, you were just starting prep work on Sunshine. You sounded excited, but also a little apprehensive about working with special effects and the scope of the movie. Did it turn out the way you expected?

Back then, I had no idea about how difficult it was to do a film like this. All movies are a challenge, obviously, but there are really tough. You suddenly become aware that, unless it's a franchise deal, no director ever goes back into space after having done one. [Laughs] The demands that are set by your predecessors—the really good movies—they sort of remain in the audience's brain in a way unlike any other genre. Technically, you have to be on a certain level, which is terrifying. You realize, quite quickly, that your initial naïve conception isn't good enough, and you really have to ratchet things up. So it's a very grueling experience, and you always feel that what you're doing isn't quite good enough. If any of the crew is reading this, I apologize. [Laughs]

Talk a little about how the project got started.

Well, it was the writer, Alex Garland; we'd worked together on 28 Days Later and wanted to do something else. After I did Millions, he sent me the first draft, and I just thought about how much I loved space movies. Little did I know, at that point, what it was all going to be like. (Laughs) But I did love watching them. I realized that, more than any other genre, I'd always go catch space movies in the theater. And that's not usual with me; I'll usually catch up with things, but I don't normally go to the opening weekend, you know? So the chance to do one, and especially with this original idea about the sun, fascinated me. In a funny sort of way, I think we've forgotten about the sun. Ever since our species came up with electricity we've felt independent, and I think that it's only now that we've realized that we're not, really. We've made a slightly contrary film in that regard, as it's about the opposite of global warming, but it still makes you realize how fragile and vulnerable we are. I mean, the sun has burned for four billion years, but that's no guarantee. It was only 300 years ago when he had a mini Ice Age and the Thames froze over. Before that, the Vikings had to leave Greenland. So it's like, you know, wow, it could happen at any moment.

What were the films that really inspired you?

Well, there are three huge ones: 2001, of course; the first Alien film becomes, I think, more and more of a landmark with every year that goes past; and then Tarkovsky's Solaris. All three of those are just titans that you cannot help but be inspired by. You can set out to avoid them but you're eventually going to end up slamming into them. So what we tried to do is acknowledge them and sort of doff our cap. There were a lot of other films that we used that weren't based in space, actually. Rather than research every film set in a spaceship, we went more to films like Das Boot and, especially The Wages of Fear, where they had to drive trucks filled with nitroglycerine through the mountains. That last one was a big inspiration because we always saw our film as, basically, eight astronauts strapped to a bomb. So we drew ideas from a lot of different places, really. But I have to say, what we tried to do was then abandon all that research once you actually start filming. You never want to become slavish. The tricky thing with this genre, I found, was that there are certain rules that you can try to contradict but really can't.

What are the rules?

Well, we would try to do things in a more realistic fashion, and then ultimately have to reshoot, because we would find that, although they were real, once you put them on the screen they looked less convincing than the movie version. Like for example, seeing star fields in space. If you're actually in space, especially if you're flying towards the sun, all you'd see is black. So I, you know, said, "Why do all these idiots use star fields in their movies? I'm not going to do that!" But of course, once you do that, you realize that without star fields as a backdrop, nothing moves, because there's no way to suggest movement in a vacuum without it. So that's why every space movie you've ever seen has stars. The other big rule was weightlessness. If you look at footage of the space station, the weightless astronauts move at the same rate as people on earth. When they make a gesture or pick up a screwdriver, they're moving at the same speed as they would with gravity. But we're so accustomed to see them moving in slow motion in movies, that to do it realistically makes it look funny and speeded up, like a silent movie. I wanted to do it, but it just wouldn't work. There's a bunch of stuff like that which you don't think about until you actually have to shoot it.

So a totally realistic space movie would have astronauts moving around in total blackness, at Benny Hill speeds.

Basically, yeah. [Laughs] One real thing that I especially tried to get across was how hard it is to work in space. I think it was Buzz Aldrin who came back and said the effort of doing things in a weightless environment was just phenomenal. You know, you'd go out for a six-hour spacewalk and be completely fucked after an hour, no matter how much you'd trained. But it's difficult to do that in movies, because you have to be all floaty. On the other hand, one of the rules that I do really love about space movies is how everybody is made equal. It isn't a genre that really suits big movie stars. You think about Alien, and one of the great things about it is that none of the characters have any special status, and you can kill them off in any order. That freedom is one of the joys of this type of movie, I think.

I wanted to touch on the quasi-religious element that comes in toward the end of the film, as the characters get closer to their destination. Any thoughts?

Well, it's interesting, really. Alex, the writer, is a convinced, confident atheist. I'm an atheist as well, although not quite as confident as him. I can say for certain that that religious element wasn't in the first draft of the script. But I think the process of making a film like this makes you think about things. I mean if you're making a movie about flying to the nearest star, about knowing the unknowable, there's a feeling of wonder that your characters have to experience, something there that's beyond their scientific reasoning. And I think you have to go there as a filmmaker as well. It doesn't mean that you're going to convert to Catholicism or anything, but there's something there.