As climate change, scarce resources, and ever-advancing military technology push the boundaries of
humans towards deadlier and protracted conflicts, they look to other domains to gain a competitive
edge.
With the world devastated by years of war and depleted of most of its natural resources,
the global powers have turned space into its final battlefront.
While these battles have not reached the point of firing lasers and other nifty space gadgets
like from an unnamed popular science fiction franchise, at this point in the future, due
in no small part to Dogecoin billionaires, outfitting large armies of space soldiers
has become possible.
While there are many possibilities for this war to be fought in space, let's look at the
first and most likely battlefield: the Moon.
However, before we can even begin to see how this battle would play out, we first need
to tackle the major question of if a gun can even be fired in space.
When you pull the trigger of any gun, a firing pin strikes the primer that ignites the powder
inside the cartridge.
These expanding gases force the bullet out of its casing and propel it down the barrel.
While there are quite literally hundreds of different powder combinations used throughout
the centuries, one of the basic physics principles that remains constant though is the ability
of the powders to combust.
For that to happen there must be air.
Now, I know what you are thinking- there is no air in space so you cannot fire a gun in
a vacuum.
But you see if you thought that you would be sorely mistaken.
Inside each cartridge, you would find that the tiny amount of oxygen contained in each
air-tight and self-contained cartridge would still allow the gun to be fired.
However, once you do fire that gun in space that is where the otherworldly physics starts
to take place.
Firstly, no matter where you fire a gun in space you would not hear it, since there is
not a medium like air or water for sound to travel.
However, you would still hear a small yet very altered sound due to the small vibrations
firing the gun would have in your ear drum.
But when other people shoot a gun, because the sound vibrations cannot travel, you would
not hear them so if you forget to bring that hearing protection with you on your spaceship
do not fear since it would not make a difference anyway.
Once the bullet leaves the barrel of the gun, gravity starts to take effect immediately.
That is why when you fire a bullet it will eventually drop to the ground.
However, on the moon, gravity is one-sixth the strength of the gravity on earth and this
would make for some very interesting dynamics.
Taking a look at three of the most common military cartridges, one can see how the ranges
at which firefights can take place in space become exponentially increased.
The standard-issue pistol round for the US is 9mm, the standard rifle round is 5.56 mm,
and the standard machine gun round is the 7.62mm cartridge.
These rounds will travel a maximum of 1900, 3400, and 4500 yards respectively.
While their effective ranges are much shorter than these, these are the maximum ranges that
when fired on a completely flat plain, gravity will eventually pull them down into the ground.
Because the moon’s gravity is one-sixth the strength of the gravity on earth, that
means you could multiply these distances by a factor of almost 2.5 times greater!
So that means for a 9mm pistol, a space cadet could fire a 9mm bullet up to almost 4700
yards, snipe at an enemy with his rifle at almost 8300 yards, and suppress their positions
with machine-gun fire at 11000 yards!
Surely these numbers are all theoretical since the military, at least publically, has never
tested its weapons in space.
But if we are going off just the straight math then it should work out this way.
Of course, these numbers are just the maximum range and do not factor in things like the
ability to aim or the fact that the visible horizon for the human eye is around 11 nautical
miles or about 22000 yards, so shooting at a target over the horizon would be impractical
for the average space soldier.
Or would it be?
You see, space does some weird things and one of those is the pull of a gravitational
field.
Unlike on earth where the atmosphere is tens of thousands of meters up, if you are already
in space or on an astral body with a limited atmosphere like the moon, or a very strong
atmosphere like say, Jupiter, then bullets can easily get sucked into these atmospheres.
As one scientist described it, if you wanted to shoot yourself on the moon you would simply
need to stand on a mountain at least 1600 meters up and then fire straight ahead.
Now, granted the bullet would have to not impact any other mountains or debris but by
doing this the bullet could eventually circumnavigate the moon and come back to hit its hapless
shooter, eventually.
If you fired your gun while in the void of space, it also has some weird physics that
would go on.
One of those would be its ability to keep moving forever, at least sort of.
You see, as discussed previously space being a vacuum, if there were no forces such as
gravity, wind, or weather that could impact a bullet’s path and sap its energy, it would
go on forever.
In an ideal scenario, this would be the case.
However, the likelihood of your bullet traveling forever in the cosmos with no other forces
acting on it would be next to nothing due to all the planetary bodies acting on it.
Going back to our earlier example of firing a gun at a planet, if during your lunar firefight
you happen to miss your target and the bullet eventually makes its way towards say, Jupiter,
you could count on its strong gravitational pull to suck in your bullet.
At about three times the strength of the earth's gravitational pull, you could expect that
even at distances up to tens of thousands of meters away the bullet would feel the effect
of its gravity and eventually get sucked into orbit.
Here, after getting trapped in orbit, the bullet could expect to travel at speeds of
more than 17000 miles per hour!
That is because the speed of objects in orbit is dependent upon their mass, gravity, and
altitude among a few other factors.
While this would change from planet to planet, one would see the velocities of these bullets
increase in magnitudes of ten or more when placed in such scenarios.
Another interesting aspect of firing guns in space is just how hot or how cold they
would be when impacting a target.
On earth, heat is transferred through a variety of radiation, convection, and conduction,
which gives bullets, though hot, a more graduated temperature to its environment than space.
In space, heat only exists as radiation.
So if your bullet travels through say a patch of solar wind, it would instantly be melted
since the melting point of lead is around 320 degrees Celsius while solar wind can reach
temperatures of a million degrees Celsius!
However, all of these data points and figures revolve around firearms that are currently
used on Earth that are repurposed for space use.
After all, if the human race were ever to fight a war in space then it is probably safe
to assume that the gun designs would also have to be upgraded.
But what exactly would the ideal gun in space look like and be made out of to operate in
such a harsh environment?
First of all, that space assault rifle or pistol with wooden grips would probably best
be left back at home.
The obvious reason for this is that you should not bring highly flammable things into space
as due to the intense amount of heat that can be present, a material like wood would
instantly catch on fire if exposed to such extreme temperatures.
Additionally, the water inside wood would expand and evaporate inside a vacuum.
What that means for our hapless space warrior is that potentially in the middle of the action
their gun could literally start falling apart with the screws and anything else banding
the stock to the gun coming apart.
But what about the material that makes up the gun itself?
Though many people might suggest Tungsten, as it has the highest melting point of any
naturally occurring metal yet is still malleable enough to be bent into shape, you might be
mistaken.
Rhenium is probably the best metal to make guns out of that would fire in space for a
few reasons.
Firstly, it is still the second highest heat resistant metal known to humankind.
It also has strong electrical resistance properties in space, which is great since everything
that goes into space has to be able to dissipate electrostatic charges that are everywhere
up there.
It is commonly used in the construction of aircraft so it already has a good track record
of good performance in harsh environments.
Though people might point out that Tungsten has also been used in a number of high speed
and highly successful jet aircraft programs in both the US, Russia, and elsewhere, they
would be correct.
However, though Tungsten does have a slight edge over Rhenium in melting point, the metal
still beats it out in areas of ductility, electrical resistance, and creep resistance.
Despite these advantages, Rhenium is usually combined with Tungsten to make an alloy to
get the best properties of both and it is this combination that might actually make
the best material to manufacture firearms out of for space combat.
But what about the bullets that are fired?
After all, these bullets would have to survive their flight to their target through potentially
much more extreme temperatures and conditions due to the increased distances that space
combat can occur at.
The answer to this problem might actually be an experimental alloy that was designed
in 2015 that, to this date, has the highest melting point of any experimental or natural
substance discovered so far.
The alloy that was created was a combination of three elements: hafnium, tantalum, and
carbon.
The resulting concoction allowed for a blistering melting point of about 7500 degrees Fahrenheit
or about two-thirds the surface temperature of the sun!
Such a metal would be perfect to use for space combat since they could handle almost everything
space could throw at them save for maybe solar wind and a black hole.
Though this experimental alloy is still being developed at the University of California,
there is real hope that it could be used in military applications in the future since
a good portion of the funding for this research has come from the US Navy.
Despite this influx of cash from Uncle Sam, the last report from 2015 was that scientists
were only able to make 100 grams of the material so it is unlikely such bullets would be available
anytime soon.
Overall, while firing guns in space might seem like a commander's dream with the increased
ranges and zero noise, when one factors in all the harsh realities of space, firing guns
might not be as simple as one might think.
But who knows, maybe by the time humans actually start fighting space battles guns might be
obsolete anyways!