We’ve all seen it. Someone has upset the captain of a spaceship who has sentenced them to death by throwing them into outer space. It’s the sci-fi equivalent of walking the plank.

This form of execution can be found in countless sci-fi tales, including Firefly, The Expanse, 2001: A Space Odyssey, and more. Most of the time, the character steps into an airlock, has a few moments to contemplate how they got there, then the airlock doors open, and the person is sucked violently into space where they instantly freeze.Pictured: Childhood trauma

Or, in one of the most upsetting examples — at least for those of us who grew up with the show — the scene from The Magic School Bus where Arnold takes off his helmet and instantly freezes.

Throwing people out of an airlock or them freezing instantly in space is such a recurring event in fiction that it even has its own entry on TV Tropes.

But what really happens? Do people get sucked into space and freeze? Is it really that intense?

It’s actually a lot worse, but not in the ways you might think. Let’s take a closer look, and put you, dear reader, in the shoes of some of our favorite space-bound characters.

So You’ve Been Sentenced to Death on a Space Ship

Okay, let’s start at the beginning. You get thrown into an airlock. We’re talking the typical sci-fi story airlock here. It has two doors. One leads to space and the other back into the main body of the ship. It’s a lot like a lock and dam system, but, you know, for space. Here’s how the airlock works on the ISS, in case you are curious.

After saying a few last words, the doors to space began to open… slowly?

Yes, despite the sudden whoosh that accompanies the fictional versions, a real airlock would probably suck the air out of the room while pressurizing the space inside. This means that the doors would open slowly after the chamber was fully pressurized. Again, think of the lock and dam. The gates don’t open up all of a sudden to a rush of water.

This also means that you’re probably already suffocating to death or have died.


Since that’s no fun, though, let’s play along and say that the captain has installed a murderous airlock that achieves all of the greatness we see in fiction. You’re thrown in, the door is locked behind you. A bunch of unfriendly faces peers in at you from the other side of the door until the captain says the word and boom, the outer doors open and you are ejected into space.If only you had a space suit, which you don’t. (Credit: Epitaph Records)

Now You’ve Been Ejected Into Space. What’s Next?

It’s all bad news from here.

No, you aren’t going to explode or turn into a human ice cube (yet), as Arnold did, but you are definitely in for a rough ride. One that is going to last a bit longer than you probably think.

Since this is a topic that is above my pay grade as a lowly Sci-Fi/Fantasy editor and fan, let’s turn to an expert. Enter, Paul Sutter, an astrophysicist who is a research fellow at the Astronomical Observatory of Trieste among other places.

Sutter knows a thing or two about the human body in space. He says that the idea that your blood will instantly boil or that your body will explode is unfounded because of a handy little thing called your skin.

Your skin and blood pressure keep your internal organs internal and your blood from boiling after the sudden drop in pressure.

Good news, right?

Not so fast. You know what the skin doesn’t cover? Your eyes, which will boil. Oh, your tongue will boil, too. Fun!

But that’s not even the worst of it because it’s ebullism time.

Oh No, You’re Turning Into a Gross Balloon

Despite the fact that you are in one piece, your body is about to do something very weird: inflate.

Yes, thanks to the nitrogen in your bloodstream, you’ll start to literally blow up like a meat balloon.Kinda like this but way grosser.

“The nitrogen dissolved in your bloodstream near the surface of your skin will collect itself into little bubbles,” Sutter explains.

“These bubbles expand, puffing you out to around twice your size, starting at your hands and feet and moving in.”

Sutter goes on to that yes, you will be in miserable pain, but you definitely won’t explode and you’ll still be alive. I’m not sure if that’s a good thing, though. Freezing instantly is sounding really good right now. So what’s taking so long?

Freezing Isn’t Going to Happen, Sorry

Contrary to popular belief, space isn’t actually cold. It has no temperature at all.

This doesn’t mean that you’ll be fine, quite the opposite. You’ll eventually freeze because you will basically run out of the internal heat.

“Any heat your body’s metabolism produces gets sucked away. That’s why scuba divers wear wetsuits: to trap a layer of water and prevent it from carrying away that precious body heat,” Sutter continues.

“In a vacuum, there’s no convection — and no conduction, either. That only leaves radiation.”

Your body is radiating heat out into space. Sutter says, in general, humans radiate about 100 watts of heat, which isn’t that much, but it’s still enough for you to freeze after a while.

How long it takes to freeze generally depends on where you are in space. Some say it can take from 12 to 26 hours to completely freeze.

“Even if you were dropped off in deep space where a thermometer might read 2.7 Kelvin (-455°F, the temperature of the “cosmic microwave background” leftover from the Big Bang that permeates the Universe), you would not instantly freeze because heat transfer cannot occur as rapidly by radiation alone,” reports Mark Springel, a research assistant in the Department of Pathology at Boston Children’s Hospital, in a post for Harvard.

Fun fact: you may not freeze immediately, but you will instantly be sunburned. In the openness of space, there’s nothing to protect you from all of that solar radiation.

So freezing isn’t your quick escape. But you won’t be awake too long to really think about it.

Oh No, You’ve Blacked Out

The real killer is asphyxiation.

Just 15 seconds after you leave the spaceship, you’re going to black out due to lack of oxygen. Oh, and you can’t fix this issue by taking a big gulp of breath before getting shot into space. If you did, your lungs would explode as soon as you left the craft.

What kills you is that your heart keeps pushing blood into your lungs trying to pick up oxygen, which isn’t there.

“Contrary to how the lungs are supposed to function at atmospheric pressure, oxygen diffuses out of the bloodstream when the lungs are exposed to a vacuum,” Springel says.

“This leads to a condition called hypoxia, or oxygen deprivation.”

This will go on for a while even though you’re passed out. As your heart continues to pump blood, you’ll be marching slowly toward death, which should take about two minutes or so.

“Unfortunately, if you’re left in space past the 2-minute mark, all your other organs will have to shut down from the lack of oxygen too, which in medical circles is called ‘dead,’” Sutter says.

And that’s that.

Your Quick Space Death: A Recap

The moment you are ejected into space, your body will suffer instant sunburn while the liquid on your eyes and tongue will boil from the pressure change. If you held your breath, your lungs probably just exploded. If you didn’t, you have a few more seconds of agony.

You’ll start to inflate from ebullism, which is fatal after a while but you’ll be dead long before that. After 15 seconds that probably feel like an eternity, you’ll black out. About two minutes later, you’ll die from lack of oxygen.

Depending on where you happen to be in the universe, your body will likely freeze in about 12 to 26 hours. Since your body won’t really decompose in space, your corpse will float on until it smacks into a planet or comes too close to a star, but who can even guess how long that will take?

So, in the end, you just become a frozen piece of space meat. Maybe you should just obey the captain’s orders next time.

Josh is the founder and Editor-in-Chief of The Arcanist. He has previously worked as a staff writer for ScienceAlert and Modern Notion. You can read his other works on sites such as Cracked, Popular Science, Geek & Sundry, and more.

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