What does space sound like? Explore the sounds of Netflix's 'Away'

*Spoiler alert: Some details of the Netflix series "Away" are mentioned in this article.*

For the brand-new Mars-bound series "Away," sound designers got creative to bring the "sounds of space" to life.

In "Away," a new sci-fi show on Netflix, Academy Award winner Hilary Swank steps into the role of commander Emma Green to lead an international team of astronauts on the first crewed mission to Mars. The show draws heavily from the real world of human spaceflight. 

While humans aren't yet traveling to Mars, NASA, for instance, aims to launch a crewed mission to the Red Planet by the mid-2030s. So King Soundworks in California, the sound team for "Away," had to strike a balance between fact and fiction to ensure that elements of the series like spacewalks were believable but still cinematic. 

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"It was kind of a fine balance because … it's not science fiction and fantasy completely," King Soundworks founder Greg King, the re-recording mixer (an audio engineer who mixes dialogue, sound effects and music) for "Away," told Space.com, referring to the real-life plans that agencies like NASA have for visiting Mars in the not-too-distant future. The team worked to "stay true to the technology and stay true to what space is like and what space travel is like while keeping the series' soundscape elegant," King said. 

King Soundworks is no stranger to science fiction. The team has worked on films and series including "Cosmos: Possible Worlds," "The Orville," "Hancock," "Charmed" and more. The team combines the work of composers who provide musical scores and foley teams that create sound effects to come up with dynamic and compelling audio for television and film. But the realism in "Away" presented new challenges to the team.

In the series, commander Green leads her crew on a dramatic voyage from Earth toward Mars aboard a spacecraft called Atlas. And, as you may have seen in the series (or as you could probably guess), this isn't an easy journey. From chemical leaks to critical issues with one of Atlas' solar arrays and so much more, the crew is constantly fighting to stay alive. And, for sound designers, this posed a number of unique challenges. 

More: Netflix Mars series 'Away' lifts off with nods to NASA history

Most notably: what does space sound like? 

Throughout the series, members of the crew embark on a handful of spacewalks outside the Atlas. Because space is a vacuum, sound wouldn't travel as it does through the air or through objects here on Earth. And although, moments of complete silence can be effective in emphasizing dramatic moments, King explained, too much silence doesn't always create an ideal effect.

The team felt that having these spacewalk scenes be entirely silent would feel "remarkably flat," Jon Greasley, King Soundworks sound designer and re-recording mixer for "Away," told Space.com. 

"If you go completely silent with just the voices, it can get a little bit too much focused on the dialogue and it's a little too real, for lack of a better word," King told Space.com. So, to add dimension and highlight the vast silence of space, the team added small, carefully chosen sounds in moments like when the astronauts would grab a handle or open a panel door on the outside of the spacecraft. While these moments might be silent in space, they added some sounds that were more akin to what they might sound like on Earth. 

"Those little, tiny, itty bitty, extremely quiet things that you don't otherwise hear," King said, make "the environment feel very quiet." 

They also added sounds to mimic how "it might possibly sound if you were inside the space helmet," Greasley said. For example, Greasley explained, they had the actors record breathing sounds to add to these scenes. 

From fever dreams brought on by sickness to the sounds within a decompression chamber or the raucous noises of a rocket blasting through an atmosphere, the team struck a delicate balance between realism and fantasy. While staying true to many of the authentic aspects of human spaceflight, the sound team behind "Away" reached just past reality to immerse the viewer in a heart-pounding trip to Mars.

Email Chelsea Gohd at cgohd@space.com or follow her on Twitter @chelsea_gohd. Follow us on Twitter @Spacedotcom and on Facebook.