What Happens If You Shoot a Gun in Space?

Space programs have spent decades figuring out how terrestrial activities would work outside of Earth’s atmosphere. Will plants grow? Do muscles atrophy? Will astronauts ever be able to do laundry?

A less-researched but no less important question: Could you fire a gun in space? And has anyone ever tried?

Technically, it should work just fine. According to BBC Science Focus, guns don’t require oxygen to fire. That’s because they already have an oxidizing agent in the sealed ammunition cartridge that can ignite the gunpowder. Nor is gravity needed to chamber a bullet: a spring forces that.

It’s not a lack of gravity that poses the biggest problem. Instead, environmental factors might prevent a space shooting. Extreme temperatures could cause the weapon to overheat and malfunction. If the weapon gets too cold, the firing cap primer might not go off; metal gun parts could lose their structural integrity, leading to jamming.

Suppose those problems are resolved. If a gun can successfully fire, what would happen to the bullet? If it’s not hitting a target, the shooter may never find out. On Earth, a bullet that doesn't strike a target will eventually be pushed down by gravity. Depending on the caliber and environmental factors, it could travel for well over 1 mile. Because space lacks gravity and its drag, however, there’s nothing stopping the bullet from traveling indefinitely, or at least until it makes contact with a surface.

The shooter would also have to contend with recoil. On the ground, gravity and planted feet help absorb kickback. In space, the astronaut-slash-gunslinger would be propelled backward after firing. This wouldn’t be rapid—probably less than walking speed—but it would put the shooter in motion, and they would need a counteracting force (like thrusters) or the wall of their spacecraft to halt their movement.

So has NASA ever tried experimenting with galactic gunplay? No—but the Soviets did. Kind of. In the 1970s, amid the Cold War, Russia was concerned their satellites might be targeted by foreign adversaries. In 1975, they equipped their Salyut-3 space station with a R-23M rapid-fire cannon and scheduled a test shoot as the station was de-orbiting and after departure of the crew. Reportedly, the weapon fired 20 shells in total that burned up in the atmosphere.

It remains the only known weapon discharged in space, thought not the only weapon brought into space. Soviet cosmonauts once carried triple-barrel shotguns as part of an emergency kit in the event they ever touched down in hostile terrain and had to fight off wild animals.

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