Sci-fi films have been stuck in a rut in Korea, but upcoming film “The Moon” attempts to break through that barrier.

Starring Do Kyung-soo, better known as D.O. of boy band EXO, Sul Kyung-gu and Kim Hee-ae, this space survival story is one of four domestically produced films hoping to revive the film industry this summer, along with “Smugglers,” “Ransomed” and “Concrete Utopia.”

Set both on Earth and the moon, “The Moon” tells the story of a group of scientists and astronauts who have to rescue an astronaut stranded on the moon, alone. Do plays Seon-woo, the astronaut stranded by himself, and Sul plays Jae-guk, the head of the team on Earth who goes to all lengths to try and get Seon-woo home.

“Our film has a lot of layers, and we sought for the story to have sadness as well as delight, to have little bits of hope in between the characters suffering,” director Kim Yong-hwa said during a press conference for “The Moon” at CGV Yongsan in central Seoul on Tuesday.

Kim has previously directed two films that each sold 10 million tickets: “Along With the Gods: The Two Worlds” (2017) and “Along With the Gods: The Last 49 Days” (2018). “The Moon” is Kim’s seventh feature film, and all his films have been about condolence and forgiveness, according to the director.

“I used to deny the saying that all film directors tell one story about one theme before they die, but I think now that that’s true,” Kim said. “’The Moon’ is a sci-fi film, but I think it’s also about condolence and forgiveness.”

Because a sci-fi film about a stranded astronaut could draw comparison between famous Hollywood films such as “The Martian” (2015), “Interstellar” (2014) and “Gravity” (2013), Kim intentionally refrained from watching these films while preparing for his own.

“All space films could have been a reference point for us, but I didn’t want to become biased,” Kim said. “I did not even research films with plotlines where the characters try to rescue someone.”

Regarding the filming process that included Do floating for minutes in “space,” Do said that he went through three months of training in preparation for such scenes.

“Everything that we thought an actor could do by hand we tried to perform ourselves by hanging from wires,” Do said during the press conference. “The parts that we couldn’t do ourselves, an animator made cut by cut. Hanging from a wire was actually pretty difficult, because it wasn’t just one wire, but five to six special wires. But the set and astronaut attire was so similar to an actual space station that I could immerse myself well.”

Playing a space expert and head of the team that is tasked with rescuing Do’s character was another challenge for Sul, according to the actor.

“Memorizing all the space and science jargon was very difficult for me,” Sul said. “And the rest of the parts I tried to act by thinking of it as reacting to Do’s performance, which helped.”

The next challenge for the cast was Kim’s, who plays a NASA director and who had to speak most of her lines in English.

“I have never felt that my scenes were so long,” Kim said. “It felt long because I was having a hard time speaking in English, but when I watched the final cut of the film it wasn’t so. But near the end of filming, I got over the language barrier and could act from my heart.”

“The Moon” opens in theaters on Aug. 2.

BY LIM JEONG-WON [lim.jeongwon@joongang.co.kr]