# Weapons on Mars?
**URL:** https://boards.straightdope.com/t/weapons-on-mars/384879
**Category:** Factual Questions
**Created:** [December 20, 2006, 3:49am UTC](https://boards.straightdope.com/t/weapons-on-mars/384879 "2006-12-20T03:49:34Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@Tristan](https://boards.straightdope.com/u/Tristan)
#### Post date: [December 20, 2006, 3:49am UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/1 "2006-12-20T03:49:34Z")
As a hypothetical, what changes would have to be made to current military issue weaponry (the M4, for example, of the M249 SAW) to make them function on the surface of Mars?
I’m saying that a specially sealed round would suffice, wheras my friend insists that we would have to scrap them completely and make new weapons.
(note: I’m aware that the mechanisms may need to be altered to take into account the severly cold weather, and the fines that blow around in the wind)
Thanks, O Teemings Millions!
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### Author:  [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)
#### Post date: [December 20, 2006, 3:56am UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/2 "2006-12-20T03:56:03Z")
A standard, unaltered firearm will function just fine in a vacuum with off-the-shelf ammunition, and will certainly function just fine on Mars. The propellants (usually some variety of smokeless powder) contain their own oxidizer and don’t need or use ambient air.
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### Author:  [@John\_Carter\_of\_Mars](https://boards.straightdope.com/u/John_Carter_of_Mars)
#### Post date: [December 20, 2006, 4:23am UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/3 "2006-12-20T04:23:00Z")
Radium rifles are the long distance weapons of choice, but swords are still favored for hand-to-hand fighting.
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### Author:  [@ultrafilter](https://boards.straightdope.com/u/ultrafilter)
#### Post date: [December 20, 2006, 4:25am UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/4 "2006-12-20T04:25:01Z")
You’re pretty much going to need 1920s-style death rays.
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### Author:  [@scr4](https://boards.straightdope.com/u/scr4)
#### Post date: [December 20, 2006, 4:32am UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/5 "2006-12-20T04:32:20Z")
[QUOTE=Q.E.D.]
A standard, unaltered firearm will function just fine in a vacuum with off-the-shelf ammunition…
[/QUOTE]
Moving parts can be a problem in vacuum - most lubricants evaporate in vacuum. At the very least you need to replace all lubricants with vacuum-compatible versions. Also, I don’t know much about explosives, but wouldn’t some component it evaporate?
But that’s for vacuum. Mars has an atmosphere, so I suspect most weapons would work there without modification. You still need to wear a spacesuit though, so I think the biggest concern is whether you can operate it while wearing bulky gloves.
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### Author:  [@Tristan](https://boards.straightdope.com/u/Tristan)
#### Post date: [December 20, 2006, 4:41am UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/6 "2006-12-20T04:41:42Z")
Well, my understanding of the surface of mars is that a full blown space-suit may not be necessary… cold, but not deep-space cold. Not much pressure, but that’s not a difficult thing to overcome these days.
I think the biggest problem is radiation, as Mars lacks most of a magnetic field. Hmmmm… maybe a metallic weave in what would essentially be a pressure suit. Interesting.
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### Author:  [@N9IWP](https://boards.straightdope.com/u/N9IWP)
#### Post date: [December 20, 2006, 4:44am UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/7 "2006-12-20T04:44:17Z")
Guns firing in a vacuum has been done before (the explosives work just fine, issues are with lubrication and cooling)
Mars is pretty close to a vacuum, but I’m thinking dust may be an additional issue.
Brian
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### Author:  [@Tristan](https://boards.straightdope.com/u/Tristan)
#### Post date: [December 20, 2006, 4:49am UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/8 "2006-12-20T04:49:43Z")
Cooling on Mars, not so much a problem. Hehehe…
Yeah, I’m thinking specially sealing weapons, to avoid fines (super fine dust) accumulating in the mechanisms would be required.
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### Author:  [@Ruken](https://boards.straightdope.com/u/Ruken)
#### Post date: [December 20, 2006, 5:02am UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/9 "2006-12-20T05:02:20Z")
[QUOTE=Tristan]
Cooling on Mars, not so much a problem. Hehehe…
[/QUOTE]
It’s cold on mars, but there isn’t much atmosphere to dissipate any heat buildup. You’re pretty much stuck with normal radiative cooling. I don’t know anything about guns, but I imagine for single, isolated shots, this won’t be a problem. Your chain-fed rotating-barrel automatic shotgun might have problems though if it doesn’t have some sort of enclosed cooling system.
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### Author:  [@scr4](https://boards.straightdope.com/u/scr4)
#### Post date: [December 20, 2006, 5:06am UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/10 "2006-12-20T05:06:48Z")
[QUOTE=Tristan]
Well, my understanding of the surface of mars is that a full blown space-suit may not be necessary… cold, but not deep-space cold. Not much pressure, but that’s not a difficult thing to overcome these days.
[/quote]
Atmospheric pressure on Mars is about 1/100 atmospheres. At that pressure, even pure oxygen won’t keep you alive. And you can’t pump pressurized oxygen into your lungs without also applying pressure to the outside of the lung, to keep it from exploding. In other words, you need a pressurized suit.
> [@](#):
>
> Cooling on Mars, not so much a problem. Hehehe…
It can be. On a warm summer day it can be warm enough to get liquid water. And if the weapon is designed to be air-cooled, it will cool much less efficiently in the thin air.
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### Author:  [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)
#### Post date: [December 20, 2006, 6:19am UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/11 "2006-12-20T06:19:55Z")
As a minor note, the gravity on Mars is only about a third of Earth, so recoil becomes an issue. I can easily imagine a shotgun knocking you over backwards if you weren’t braced for it, though this is best resolved with practice. Picture a 180lb man firing off round after round in his manly manner. Now picture a 60lb eight year-old doing the same.
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### Author:  [@Tristan](https://boards.straightdope.com/u/Tristan)
#### Post date: [December 20, 2006, 7:44am UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/12 "2006-12-20T07:44:04Z")
Hmmm… that’s an interesting idea. I hadn’t thought of that…
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### Author:  [@Polycarp](https://boards.straightdope.com/u/Polycarp)
#### Post date: [December 20, 2006, 12:12pm UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/13 "2006-12-20T12:12:42Z")
[QUOTE=Bryan Ekers]
As a minor note, the gravity on Mars is only about a third of Earth, so recoil becomes an issue. I can easily imagine a shotgun knocking you over backwards if you weren’t braced for it, though this is best resolved with practice. Picture a 180lb man firing off round after round in his manly manner. Now picture a 60lb eight year-old doing the same.
[/QUOTE]
Well, yahbut. The manly man firing his weapon on Mars still has a **mass** of 180 pounds, but only **weighs** 60 pounds. The same application of force (recoil) will have three, or perhaps nine (3[sup]2[/sup]) times the effect. Firing while standing erect in the best marksman posture will land him on his manly behind halfway to the opposite horizon; firing while lying prone in the best sniper position (though Mars has a scarcity of grassy knolls ;)) should result in the body and its ground contact dissipating the recoil impact and permitting him to continue shooting thoats, banths, zitidars, and related areofauna.
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### Author:  [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)
#### Post date: [December 20, 2006, 12:50pm UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/14 "2006-12-20T12:50:26Z")
[QUOTE=Tristan]
Well, my understanding of the surface of mars is that a full blown space-suit may not be necessary… cold, but not deep-space cold. Not much pressure, but that’s not a difficult thing to overcome these days.
[/QUOTE]
:rolleyes: I’m not sure why I’m continually surprised at how people so casually dismiss of things like “minimal atmospheric pressure”, “complexity of internal organs”, or “difficulty of traversing interstellar space” as trivial challenges to be solved with a few simple engineering man-hours of work. Developing a long-term environment suit–especially one that can deal with the rigors of combat–is far from “not…difficult.”
Regarding weapons, as others have noted, atmospheric oxygen isn’t required for firearm propellants (which contain their own oxydizer in the form of potassium nitrate). However, the functioning of weapons over an extended period may be affected by the extreme temperatures, lack of atmospheric convection, environmental contaminants (the fine Martian sand), et cetera. I suspect that, while a brass-cased firearm might work, it’ll probably need to be designed to withstand Martian conditions.
[QUOTE=scr4]
Moving parts can be a problem in vacuum - most lubricants evaporate in vacuum. At the very least you need to replace all lubricants with vacuum-compatible versions. Also, I don’t know much about explosives, but wouldn’t some component it evaporate?
[/quote]
There are lubricants–like [Dri-Slide](http://www.russack.com/view_doc.php?view_doc=7&PHPSESSID=0586b1db94228b690c5dd2a9b1b9cb6c)that are designed to work without a liquid medium. (I believe Dri-Slide is actually the brand used on some exoatmospheric mechanisms, but can’t provide evidence offhand.)
Stranger
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### Author:  [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)
#### Post date: [December 20, 2006, 1:07pm UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/15 "2006-12-20T13:07:56Z")
One of the things I find interesting (and a little troubling) is that in two of the circa 1960 movies about Mars, the explorers from Earth bring guns with them. And use them, in at least one case. They fire fine.
**It! The Terror from Beyond space** was the best-known of Jerome Bixby’s 1950 science fiction screenplays (and a major inspiration for 1979’s **Alien** ), featuring an alien monster picked up by accident on Mars. The dialogue tells you that during an earlier expedition something attacked the explorers in a sandstorm, and guns were fired, one shot killing an explorer. Later on, when the beast attacks people on the ship, they retaliate with guns and even with grenades (!!! I wouldn’t want to be on this ship even without the monster. These people also smoke cigarettes on board)
In **Robinson Crusoe on Mars** the lead character has a gun with him not only on board the ship, but also when he uses the escape pod, which he pulls out the first time he sees something suspicious on the surface (which turns out to be the expedition monkey).
Despite the titles, these are two of the better – much better – science fiction films of the period. It’s likely one or both looked into the question of whether guns would work on the surface (which was thought to have more of an atmosphere back then).
But it bothers me tremendously that they thought guns would be _necessary_ on Mars. Of course, in the films, they did. But in real life it would be hard to justify, I think. Armstriong and Aldrin didn’t bring guns to the Moon.
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### Author:  [@Bosda\_Di\_Chi\_of\_Tricor](https://boards.straightdope.com/u/Bosda_Di_Chi_of_Tricor)
#### Post date: [December 20, 2006, 1:30pm UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/16 "2006-12-20T13:30:55Z")
The gun might work, but why bother?
The Martian climate also includes wind speeds of over 300 miles per hour. Sand becomes a lethal weapon. Any space suit or native organism that is decently armored against _that_ might not be bothered by your bullets.
Fine dust will cause jamming as well.
Go with a crossbow, one with armor-piercing bolts. Or even better, the old [M79 Grenade Launcher](http://en.wikipedia.org/wiki/M79_Grenade_launcher).
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### Author:  [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)
#### Post date: [December 20, 2006, 1:38pm UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/17 "2006-12-20T13:38:56Z")
[QUOTE=CalMeacham]
But it bothers me tremendously that they thought guns would be _necessary_ on Mars. Of course, in the films, they did. But in real life it would be hard to justify, I think. Armstriong and Aldrin didn’t bring guns to the Moon.
[/QUOTE]
That’s nothing; in Niven, Pournell, and Barnes’s [Legacy of Heorot](http://www.amazon.com/Legacy-Heorot-Larry-Niven/dp/0671695320/), the colonists are better armed than an assault team lead by Arnold Schwarzenegger in the Nicaraguan jungle. I’m not sure why interstellar colonists would be bringing submachineguns, but whatever.
In _Alien_, the crew had some kind of laser weapon for their excursion (I think) but improvised the flame units out of some kind of portable incinerators, and in _Aliens_, the Colonial Marines were well armed for obvious reasons. “Independently targeting particle-beam phalanx. Whap! Fry half a city with this puppy! We got tactical smart missiles, phase plasma pulse rifles, RPG’s… we got Sonic Electronic Ball-Breakers! We got nukes. We got knives, sharp sticks.”
The only reason to have weapons on Mars would be to face down other competing human crews or colonists. In any foreseeable scenerio, this is fan-boy fantasy rather than credible reality.
Stranger
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### Author:  [@Sapo](https://boards.straightdope.com/u/Sapo)
#### Post date: [December 20, 2006, 5:13pm UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/18 "2006-12-20T17:13:21Z")
other than dust, are there any special challenges for a gun firing in Mars that haven’t been addressed already with orbiting machinery (on the assumption that satellites are mechanically more complex than guns, which I don’t know)
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### Author:  [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)
#### Post date: [December 20, 2006, 5:22pm UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/19 "2006-12-20T17:22:18Z")
[QUOTE=Sapo]
other than dust, are there any special challenges for a gun firing in Mars that haven’t been addressed already with orbiting machinery (on the assumption that satellites are mechanically more complex than guns, which I don’t know)
[/QUOTE]
Mars is actually a more corrosive (chemically-reactive) environment than that seen by satellites. That being said, I don’t think there’s anything (aside, perhaps, from protection of cased ammunition) that can’t be addressed by conventional corrosion protection technology.
Recent experiences in desert environments (Iraq I & II) have indicated that grit contamination is a significantly greater problem than generally considered by weapon designers. However, avoiding mechanisms that are sensitive to contamination (like roller locking mechanisms in the H&K G3) can avert these problems.
Problems with recoil and inertia are real and considerable. Some kind of compensation/damping system would be necessary for any high recoil firearm in a low-G/freefall environment.
Stranger
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### Author:  [@matt](https://boards.straightdope.com/u/matt)
#### Post date: [December 20, 2006, 6:27pm UTC](https://boards.straightdope.com/t/weapons-on-mars/384879/20 "2006-12-20T18:27:57Z")
[QUOTE=Stranger On A Train]
That’s nothing; in Niven, Pournell, and Barnes’s [Legacy of Heorot](http://www.amazon.com/Legacy-Heorot-Larry-Niven/dp/0671695320/), the colonists are better armed than an assault team lead by Arnold Schwarzenegger in the Nicaraguan jungle. I’m not sure why interstellar colonists would be bringing submachineguns, but whatever.
[/QUOTE]
To be fair, they were colonists on an unexplored world teaming with life. Personally in that situation I’d like to have weapons powerful enough to cope with a co-operating pack of the biggest baddest predators we know to have existed. That means a T-Rex gun, to me anyway!
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