Popular Mechanics Claims Astronauts Can Carry M16s on the Moon But Quote Unquote With A Catch

a reply to: ANNED

My AR certainly would make your jaw sore.

This would be a great example of the strategic value of "cover fire".

Every time you stick your head, errrr, helmet up, I'm going to make you dive back down into the sharp rocks and jagged sand for cover. Before long, I don't even have to hit you! Your ass will be leaking so bad you're gonna' have to sprint back to the ship, or else you better have a really, really, good roll of duct tape handy!!

LOL!

BTW - Some responders here have talked about dust being kicked up. Would it? Dust requires air pressure, or a direct impact. On the Moon, there is no air, so how would dust get kicked up? I don't think it would.

Certainly running around through the dust would kick up some debris, and yes it would stay aloft longer, but short of that the concussion of a firearm wouldn't really have any impact on dust, I wouldn't think. Maybe I'm wrong, just my thought.

a reply to: Flyingclaydisk

Well this was filmed on earth, so there was air. But....

BTW - Some responders here have talked about dust being kicked up. Would it? Dust requires air pressure, or a direct impact. On the Moon, there is no air, so how would dust get kicked up? I don't think it would.

What about..

in·er·tia

/iˈnərSHə/

noun

1.

a tendency to do nothing or to remain unchanged.

2.

PHYSICS

a property of matter by which it continues in its existing state of rest or uniform motion in a straight line, unless that state is changed by an external force.

"the power required to overcome friction and the inertia of the moving parts"

But

Newton's first law of motion teaches us that “An object at rest stays at rest and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force.” 

Conclusion... dust will fly from impact of a moving object in which case is a bullet or small meteor. ??

No air yes, but with less gravity to keep that object or dust in place. I would think it will move some.

a reply to: Bigburgh

Several posts up, someone suggested the dust kicked up by the concussion of firing would quickly foul the weapon.

What I intended to suggest was...there is no dust kicked up from the concussion of the weapon firing. Stomping around maybe, yes, but not from the weapon itself.

a reply to: Flyingclaydisk
The dust is from walking and any other activity. It falls down quickly as there is notheng to hold it up. All particles have a ballistic trajectory.

The problem is, it stickes to everything by just being sharp or static electricity. It is very abarsive. The act of moving makes the space suit fabric wear out once exposed to Moon dust. It works in to several layers of the fabrics. Kevlar slows it down but dosent stop it. The outer layer of the Apollo suits was teflon coated nylon and that did not even slow it down.

Metal on metal will be ground away quickly. Just carrying a M 16 on the sutface would wear it out.

Think about leaving all the loose parts of a M 16 in a running rock tumbler for a month. That would probably simulate a years carrying it on the Moon.

I'm not at all convinced an m16 would not work on the moon, there is some gravity, and I'm not thinking gravity has much to do with operation, it's gas pressure and springs, all that can be modified.

a reply to: beyondknowledge

Yeah, I can imagine all of that. I've worked in the desert a bit and it's kind of the same, but not that harsh because there is wind. But that sand will get into everything, especially the fine stuff, and there is no way to keep it out.

In the case of the Moon, the granules don't even have to get inside, they can wear down most materials just from the outside.

Sand and fine sharp aggregate is a major problem!

originally posted by: Flyingclaydisk
a reply to: beyondknowledge

Yeah, I can imagine all of that. I've worked in the desert a bit and it's kind of the same, but not that harsh because there is wind. But that sand will get into everything, especially the fine stuff, and there is no way to keep it out.

In the case of the Moon, the granules don't even have to get inside, they can wear down most materials just from the outside.

Sand and fine sharp aggregate is a major problem!

I can believe that! wasn't the M16 initially problematic in the field, I have read they got a bit dirty..or maybe a lot dirty, would not fire, dudes were picking up AKs. I'm not sure anything changed design wise..other than cleaning protocols

originally posted by: PapagiorgioCZ
Indeed, gravity doesnt change the mass of anything either. It's full of bogus claims.

There is a catch tho. No atmosphere means evaporation of any lubricant and also cold welding of internal parts. I knew I've seen it before. Here's the vid explaining everything.

Cool video, thanks for sharing.

The video creator explores something that I'd been thinking about, which was the idea that the US military must've at some point fielded some report or study or research project to delve into how "slug throwers" (I like that moniker!), projectile weapons, would work in space.

I bet there are even more recent projects to investigate all kinds of various weapons technologies, and as a common theme that's been raised in this thread, the damage threshold needed to incapacitate or destroy things in space, especially biologics packed into space suits, is much lower than on Earth, given the harsh environment in space.

originally posted by: vonclod
I'm not at all convinced an m16 would not work on the moon, there is some gravity, and I'm not thinking gravity has much to do with operation, it's gas pressure and springs, all that can be modified.

I think the key point here is the definition of the term "work".

If your only criteria here is ejecting a projectile out of the barrel in the general direction your aiming it a small number of times, yeah that seems like it'd be possible to get right, in terms of engineering the components of the riffle, even changing some things around on the current platform.

If, however, you want the rifle to be an effective weapon, i.e. can be precisely aimed, can maintain a reasonable rate of fire, we haven't even talked about reloading yet, I think the biggest problem is going to be recoil management, and the way that the recoil is going to impact the astronaut pulling the trigger. I don't believe this was a topic even broached in the P.M. article (I re-read and word searched and still found no trace of it).

The fellow in PapagiorgioCZ's video does a good job explaining not only the backwards force but the spin/rotation that firing the rifle (particularly more than several rounds) would impart on the shooter if they weren't properly braced. This is also mentioned in the StackExchange link in my OP. If one wasn't paying attention, practically any venting/projecting/throwing of even small amounts of material, maintained over time, will move you around in unintended ways in low G environments. The thought of firing 20 rounds and achieving about 15-20 RPMS makes me nauseous thinking about it!

a reply to: vonclod

This is a pretty good article explaining the early stages of development of the ar15/m16 and the ultimate cause of jamming.
Basicly the army went over Eugene Stoners head and made changes to his design and the ammunition it used despite his repeated objections.

www.theatlantic.com...

a reply to: SleeperHasAwakened

In my completely uninformed opinion

The solution will be around the springs, the gas pressure..and the load! could get away with lighter loads..depending on what you're try to put holes in I suppose. I guess smoothbore might deal with the rotational issues, or less twists?..would rifling be redundant in 0 Gs?.(I know the moon not 0Gs)

originally posted by: caterpillage
a reply to: vonclod

This is a pretty good article explaining the early stages of development of the ar15/m16 and the ultimate cause of jamming.
Basicly the army went over Eugene Stoners head and made changes to his design and the ammunition it used despite his repeated objections.

www.theatlantic.com...

Thanks..I will read it

M16's on the moon, not one of my going concerns.

originally posted by: Tempter
M16's on the moon, not one of my going concerns.

If you were on the moon and an angry mob of Kalashnikov carrying ruskies were hot on your tail it would be.

While it's not a small arm, how about a Carl Gustav 84mm recoilless rifle? Attach an FWS-I (Family of Weapon Sights-Individual) to it and your ENVG-B (Enhanced Night Vision Goggles-Binocular) will wirelessly receive and display whatever the former sees, with a nice reticle to place on your target. You could fire it from your hip, or resting on top of your shoulder, while lying next to it in the regolith, or better still, while sheltering behind a boulder or in a crater with just the Gustav held out in the open. Whatever you put the FWS-I reticle on, you will hit, with devastating results. The ENVG-B fuses thermal and light-enhancing imagery, so no chink or russki can hide in shadow. You have a 70 percent chance of IDing a man-sized target at 960 meters with the FWS-I. Just be careful you don't fry your buddy with the ferocious backblast, and the blast wave might be much worse on the moon. I assume there would be no shock wave in a vacuum; I really don't know. I suspect the projectile would fly much farther and flatter than it would on Earth thanks to the one-sixth Earth gravity and total lack of friction in a vacuum. 

I think it would work very well.
space is a vacuum.
so it would have Mores pressure from the explosion.
the gun powder ! does not need air.

Just dont empty the clip!
it would work like a rocket
if you have lots of ammo you could fly with it.

originally posted by: buddha
I think it would work very well.
space is a vacuum.
so it would have Mores pressure from the explosion.
the gun powder ! does not need air.

I don't think the debate is whether or not an individual cartridge would ignite and exit the riffle. The problems would manifest in the internal components (how the spring mechanisms re-chamber new rounds), managing recoil, "siting" in riffle where the bullet ballistics are different for the moon's gravity, manipulating the safety/charging handle/forward assist with huge space gloves, basically how to operate the weapon.

It is a weapon designed for terrestrial use. In my opinion no way would soldiers operating on the moon just be issued re-calibrated M-16s for use there. There are enough design challenges where it'd make sense to simply design an entirely different platform for use in space.

The more I think about it, the more I like the M4 Carl Gustaf. Its weight would feel like 2.5 pounds (1.1 kg) on the moon. It has a laser rangefinder. It fires a wide variety of munitions weighing about half as much as the weapon itself, so they'd each feel like 1.25 pounds or slightly less on the moon.

One variant is a close range anti-personnel round that sprays 1,100 flechettes over a wide area. Another is laser-guided, supposedly able to hit a moving vehicle at 2,000-meters on Earth, so probably much farther on the moon. If you're assaulting structures with regolith piled on them, there are two kinds of rounds designed to destroy buildings and bunkers; you can set their fuzes for impact or delayed detonation. There's even a round that can be fired from within confined spaces, though I'm not sure that's feasible on the moon for a soldier wearing a pressure suit. A round could be developed that explodes precisely above a defiladed position, or just beyond the side of a bolder an opponent is hiding behind.

That was the modus operandi of the XM25 Counter Defilade Target Engagement System (nicknamed "the Punisher" in Afghanistan). You use its laser rangefinder to get the precise range of a machine gun nest or the corner of a building the enemy's sheltering behind. Then you press a button one or two times to program your 25mm grenade to explode either one or two meters over or past the obstruction you lased.

Maybe the XM25 would be another good lunar weapon, although it's going to have some recoil, unlike the Carl Gustaf. But it's slightly lighter than the CG and its rounds are much lighter and less bulky. It also has a computerized firing system; it won't fire until you aim it precisely where necessary to place a grenade precisly where it's needed. The smart grenades count their revolutions to determine exactly when to explode. It can hit a point target at 500 meters on Earth, so probably a lot farther on the moon.

I bet you could modify the M4 CG and XM25 quickly for use on the moon. They'd probably need insulation and maybe a warming and cooling system for various lunar conditions like shadow and direct sunlight. Munitions might need to be stored in insulated and perhaps actively cooled or warmed containers. The trigger and other switches and buttons would have to work with astronaut gloves, but maybe a voice-activated operating system could replace manual controls.