Russian cosmonauts have always been equipped with a gun whenever they go into space so that they could get out of a tight situation in a hostile country upon landing back. The same procedure is also adopted by the fighter pilots who go into the enemy territory to carry out missions. But, surely the use of guns is not allowed in space, not because of regulation but also basic science. When a bullet is fired on Earth, eventually, it will find its way back to the Earth’s surface due to gravity. So, in a way the bullet will always zoom in the form of a trajectory while on Earth. Now when we are in orbit and fire a gun, the bullet’s behavior will be very different from that on Earth.
First of all, you can fire a bullet in space. The ammunition has its own oxidizer, and there will be certainly no problems shooting it. But what happens when you do fire it? The bullet leaves the muzzle of the gun at an initial velocity ranging from 120 m/s to 1700m/s. Now Newton’s law means that you will have an equal and opposite reaction. After some quick calculations, you are supposed to have a maximum of 0.07m/s reaction backward, which isn’t much. But, what happens to the bullet itself is quite curious. Take a look at this video to find out:
Now gravity is acting on an object in orbit but in a different way. Now if you fire a projectile like the gun, there is a condition in which you could shoot yourself in the back with your own bullet. If the velocity of the bullet is 1600 m/s, the bullet will start orbiting the planet, and if you remain exactly where you are, it will complete the orbit and pierce your back. Weird, right? If the velocity is higher, it will try to escape into space, and if it is lower, it will make its way back to Earth, probably bursting into flames halfway in between due to the immense air friction.
So, if you find yourself with a gun in space, remember the consequences before firing it. You own bullet could come back to haunt you!