Floating next to our beautiful blue planet might sound dreamy, but strip off the space suit and it’s a nightmare Hollywood can’t do justice. With astronaut Thomas Pesquet’s recent trio of spacewalks on the ISS, someone asked an excellent question: “Why do astronauts always need those bulky suits? What on Earth—or rather, off Earth—would happen if we ditched the gear just for a peek?” Strap in, because the universe is a lot less forgiving than your average day at the beach.
The First Forays: Humanity Meets the Void
Let’s take a small leap back to March 18, 1965. During the Voskhod 2 mission, Soviet cosmonaut Alexei Leonov ventured into the unknown, becoming the first human to experience the direct consequences of outer space. Dressed in a so-called “flexible” suit and linked to his ship by a modest tether, Leonov found himself surrounded by the deepest silence imaginable, pierced only by the sounds of his own body. The Earth glowed small and endearing below a jet-black sky lit by the Sun, yet the real show was inside his suit. Due to the drastic difference in pressure between his suit and the space vacuum, the suit ballooned so much it nearly trapped him. His hands and feet floated out of place; with no mobility left, re-entering the airlock was like squeezing an overinflated balloon into a bottle.
His risky, impromptu solution? He depressurized the suit enough to regain movement, barely squeezing back through the hatch headfirst. In those 12 minutes and 9 seconds, he came perilously close to becoming a cautionary tale. This inaugural walk was the first real encounter between human biology and the void—and every challenge since has followed these lessons.
No Pressure, No Atmosphere, All Problems
What actually awaits you outside the ISS? First up: no air and no gravity. Space, unlike a weightless carnival ride, is not exactly a friendly playground. The feeling of floating you see on science documentaries comes from the ISS’s rapid orbit, essentially cancelling out Earth’s gravity and making even basic movements a test.
But here’s where it gets really dicey: the most immediate, lethal risk is depressurization. The “vacuum” of space isn’t totally empty, but it isn’t breathable and certainly doesn’t contain the mix of oxygen and CO2 our bodies require. Sound waves, being mechanical, can’t travel through this void—so forget hearing dramatic explosions as in those galaxy-spanning sagas.
Now let’s talk body chemistry. All our fluids circulate at atmospheric pressure and around 37°C. Suddenly strip away external pressure, and the boiling point of those fluids drops below your body temperature. The result? Your blood and tissues start to boil—a phenomenon called ebullism. Death by ebullism is swift—hence suits are engineered to keep at least 0.3 bar pressure around the body, a literal lifesaver.
From Frozen Popsicle to Cosmic Roast
If boiling blood weren’t enough, your unsuited body would also face the full, staggering temperature gauntlet of space:
-150°C in the shadowed darkness, making you freeze in no time
+150°C basking in sunlight—think infra-red tanning, but there’s no escaping the burn
With a swing of 300°C between your sunlit and shaded sides, keeping a steady internal temperature is out of the question. The astronaut suit doesn’t just add bulk for fun: it provides breathable air, shields you from the Sun’s glare and cosmic rays, and stabilizes temperature so you can focus on floating, not cooking or icing over.
Invisible Dangers: Cosmic Rays and the Suit That Saves
As if temperature extremes and panic-inducing suit bulges weren’t enough, there’s another enemy: cosmic radiation. These high-energy particles, mostly protons and helium nuclei from the Sun or even further out, carry radiation with poorly understood but very real risks. They can mess with your nervous system and even your DNA—no thanks! Thus, the space suit’s shielding is not optional fashion, but first defense against outer space’s invisible hailstorm.
Yet, space has a knack for surprises. Just ask astronaut Luca Parmitano, whose 2013 spacewalk nearly turned into a catastrophe when his helmet gradually filled with water from a cooling-system leak. That’s why astronauts train for every scenario, always prepared for a quick dash back to the airlock if things go sideways (or upside down).
In short: ditching the suit isn’t just uncomfortable, it’s rapidly fatal. Spacewalks demand armor for good reason—protecting against boiling blood, wild temperature swings, and cosmic radiation. If your dream is to float among the stars, you’ll have to settle for looking like a well-insulated marshmallow. Trust us, it’s a small price for not boiling alive or turning into a cosmic icicle.
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David Miller is an entertainment expert with a passion for film, music, and series. With eight years in cultural criticism, he takes you behind the scenes of productions and studios. His energetic style guides you to the next big releases and trending sensations.