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Can Firearms be Fired in Space

Discussion in 'Rifle Country' started by Life During Wartime, Jul 22, 2013.

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  1. Life During Wartime

    Life During Wartime Member

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    Can Firearms be fired in outer space such as on a space station or on the moon
    and if so
    can it cycle actions
    and
    how far would it go
    endlessly or like in water

    also what about rocket launchers

    I have heard of the russians issuing their cosmonauts a gun the tp82
     
  2. jim243

    jim243 Member

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    Yes they can. Gunpowder carries it own oxidizer and will work in outer space. The "Space Station" has a oxygen rich atmosphere and would start a flash fire, so the answer would be no on the space station because of fire hazards. Since the moon has 1/3 the gravity of the earth, you should be able to get 3 time the distance you would on earth, but it would actually be a little longer since there is no wind on the moon to slow down the bullet.

    As to distance a bullet will travel in outer space is a little harder to answer. Newton's law of opposite and equal reaction would make the bullet go forward but you would also go backwards, so half the energy would be used to propel you in the opposite direction. How much energy would the bullet still have? I don't know, but in theory it would travel until it comes into a gravitational field of some planet, moon, comet or asteroid.

    Hope that answers your questions.
    Jim
     
    Last edited: Jul 22, 2013
  3. Torian

    Torian Member

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    I would prefer to talk about the proper use of commas and semicolons in this post, but with great effort, I will refrain from doing so.

    :evil:

    I was not aware that gun powder could ignite in a vacuum. I guess you learn something new every day.
     
  4. OptimusPrime

    OptimusPrime Member

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    It's not a vacuum, it's a self-contained capsule that has its own oxidizer.
    To the OP's question, a rocket launcher like an AT4 or LAW should work on the same principle; they are sealed and should ignite just fine. However, I do believe the rounds will go much farther than only 3x the Earth distance because there is also no atmosphere and therefore no air resistance on the projectile.
     
  5. Life During Wartime

    Life During Wartime Member

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    If you fired either a rocket launcher or a firearm on the moon would it follow the curve of the planet or just go off into space would u think


    plus, what were the russians thinking! :eek:
     
  6. Torian

    Torian Member

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    I'm not sure that "self-contained" capsule would hold a perfect seal in a vacuum.
     
  7. jaysouth

    jaysouth Member

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    Since it's not in a forest, will anyone hear it?
     
  8. beatledog7

    beatledog7 Member

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    It would curve downward and hit the surface. Gravity exists there, too.
     
  9. rkite

    rkite Member

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    I would think the cartridge case would bulge or split in a vacuum. If air could escape the case or it was loaded in a vacuum then maybe not.

    Escape velocity of the moon is about 3280 feet/second so a fast enough round could escape the moon entirely otherwise it would go into a temporary orbit. If shot straight up the bullet would either escape the moon entirely or drop back to the moons surface.

    With little or no atmosphere a bullet would hold its speed much better only having gravity to deal with.
     
  10. Schwing

    Schwing Member

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    I am referring only to the idea of firing a gun in the vacuum of space here:


    Physics was a long time ago but a similar topic actually came up about whether a dynamite explosion would expand forever and the professor gave an explanation that was not what I expected. According to him, since space is a vacuum, the explosion would occur, (Just like gun powder, dynamite has all of the essential chemicals required to oxidize),but it would quickly retract back in onto itself once the initial energy was expended and the force (or lack thereof) of the vacuum was greater than the remaining energy in the explosion. It was his opinion that most of the debris ( Mostly paper and carbon I would expect) would retract back into the vacuum.

    I believe that the bullet would gain a lot of momentum and would continue to travel much further than it would on earth but I do not believe that the expansion of gases would reach near the same level that it would within an atmosphere and the bullet would not achieve near the same max velocity.

    Just my own logic. But this would be a great experiment just for giggles.
     
  11. rcmodel

    rcmodel Member in memoriam

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    It doesn't need a perfect seal, any seal at all, or any air inside it to fire.

    There is very little oxygen inside a cartridge in the first place, or any air inside a barrel as the bullet push's it out of the way as it accelerates down the bore.



    The smokeless powder is able to produce it's own oxygen to support the combustion of the powder.

    Just like a Solid Fuel rocket fired into space.

    SO, space or no space, vacuum or no vacuum??
    You pull the trigger, it's going to go Bang just like it would on earth.

    The bullet will go one way at mostly normal velocity.

    And you will go the other way at unnatural velocity, due to the recoil and no gravity holding your feet on the ground.

    rc
     
  12. AethelstanAegen

    AethelstanAegen Member

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    The gun was not really intended for use in space but as others mentioned would likely work there. The gun was included as a survival tool for when the cosmonauts returned to Earth and could potentially be stranded in the middle of Siberia for a while until they could be picked up. I'm not sure if it was ever used or if they even still include it on launches today. That's the reasoning though and explains why it's basically a drilling.
     
  13. YZ

    YZ member

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    You mean no atmosphere.
     
  14. jungle

    jungle Member

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    If the Russians did in fact issue a firearm to their space crews it is because they land in what is now Kazakhstan, the largest land locked country on Earth.

    A very small error on reentry might place the crew in a land survival situation requiring a firearm for food procurement.

    They ran into the same problem with aircrew, vast country and limited SAR capability.
     
  15. Willie Sutton

    Willie Sutton Member

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    Well, "outer space" and the moon are not the same. In one case you have near zero gravity and a vacuum, and on the other hand you are subjected to nearly normal gravitational forces (1/6 earth G) as opposed to nearly 0 G in space. 1/6 sounds like a small number, but compared to zero, which you cannot divide by, it's a nearly infinite increase in G as compared to "outer space".

    So there are three questions:

    1: How does a projectile act in 0 G?

    2: How does a projectile act in reduced G?

    3: How does a firearm and it's cartridge act in a vacuum?


    So, let's examine each:

    In zero G: In space, a projectile would travel indefinately, slowed only by a few small physical effects: Gravity (there is *always* gravitational pulls in space, towards *something*), and the drag effects of subatomic particles impacting on the object. But basically it would keep on moving in a straight line until it eventually was either captured into orbit by some sort of body, or drawn into reentry onto the surface of some sort of body. For an astronaut firing a frearm in 0 G: Newton tells us that if you fire a firearm, half of the energy is ALWAYS in an equal and opposite vector to the projectile fired. If YOU are on a frictionless surface (IE: are an astronaut on an EVA), the force applied will drive you rearwards at a rate governed by the foot pounds of force applied, and your mass. That's a simple equation. You will stop when either drag or gravitational forces come into equalibrium with your new vector. Drag will be small, gravitational forces also small, and your distance travelled will be large. Velocity would not be very large since force = 1/2 mass times the square of the velocity of the projectile, and that mass would be small.


    In reduced G: The moon has a gravitational pull of 5.2 ft/sec2, as opposed to the earths 33 ft/sec2, meaning that a projectile fired parallel to the moons surface will fall towards the surface and impact the surface about after about 6 times the length of time as the same projectile fired on the surface of the earth. The ballistic coefficient of the projectile will be a major player in decelleration on earth, but this will not be a large factor on the moon. The bottom line is that between taking 6x the length of time to fall to the surface, and the fact that the projectile will not be decellerating very much as it goes downrange, a projectile on the moon would be a LOT further downrange when it struck the surface, and it would have a LOT more retained energy when it did so. The astronaut firing the firearm would sense normal recoil forces as the kinetic energy imparted as recoil would be the same.

    In a vacuum: A firearm fired in a vacuum will behave normally. This has nothing to do with zero G or reduced G (space = 0 G and moon = 1/6 G). A semiauto would cycle normally. Propellant would burn normally. Velocities would be normal, but would not drop off due to frictional effects (drag).



    OK, you want to shoot at the passing bad-guys space vehicle?

    In orbit: Firing a projectile from one space vehicle toward another in a dissimilar orbit is a problem of orbital mechanics. It's not nearly as simple as aiming and shooting. Google orbital rendezvous equations for some answers. Start here:

    http://www.braeunig.us/space/orbmech.htm



    What else? Yes it is rocket science.

    (And greetings from Edwards AFB where we teach this stuff at the test pilots school).


    Willie

    .
     
    Last edited: Jul 22, 2013
  16. YZ

    YZ member

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    Do you teach that the projectile will go farther in a vacuum+reduced G than in an atmosphere+reduced G?
     
  17. Sam Cade

    Sam Cade Member

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    Fails at pretty basic physics.
    :banghead:



    Ignoring temperature (and a few other twitchy variables) a bullet fired in a vacuum will achieve the same nominal velocity as one fired in an atmosphere.

    Newton states that:
    An object that is in motion will not change its velocity unless an external force acts upon it.

    Lacking an atmosphere or gravitational field our bullet will continue in a perfect line at the speed it attained as it left the muzzle ad infintum


    Ninjaed by Willie Sutton. ;)
     
  18. Sun Tzu warrior

    Sun Tzu warrior Member

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    I'm with RC; the equal and opposite reaction would be my biggest concern.
    In other words, I wouldn't be concerned if the round would go into orbit, I would worry about me, as the shooter, going into orbit!
    torian; nice try at refraining.........It didn't work. ....... Thougt I might mispel a word or too so you could have a reasn to try an get us bak to english clazz, or just complain whichever yu prefer. Cheers!
     
  19. OptimusPrime

    OptimusPrime Member

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    Yeah, exactly what I said. :scrutiny:
     
  20. Willie Sutton

    Willie Sutton Member

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    "Do you teach that the projectile will go farther in a vacuum+reduced G than in an atmosphere+reduced G?"


    Atmosphere = drag.

    So the more atmosphere, the more drag. The more drag the more rapid the decelleration of the projectile.

    In a vacuum, there is no aerodynamic drag, so.... velocity will be retained nearly indefinately.

    G simply effects the "drop" of the projectile. With 0 G, the projectile travels in an straight line. Under gravitational influences, it falls towards the body exerting the force. Imagine this: Shoot a .30-06 parallel to the earths surface and at the same time the projectile exits the muzzle, drop a golf ball from the same height. Both will strike the ground at the same time, as both are falling towards earth at the same rate. Do that on the moon and they will take 6 times the length of time to strike the moons surface. Now EVEN IF THE MOON HAD THE SAME ATMOSPHERE AS THE EARTH (IE: the same aerodynamic drag), the projectile would travel a lot further. Now remove that drag and it'll travel a LOT LOT further.

    Make sense? It's two different things. You can have one, the other, or both.



    Answer these:

    In a vacuum on earth, meaning in a vacuum chamber, if you drop a feather and a lead ball from the same height, which will hit the bottom of the vacuum chamber first? What would the difference be on the moon, if any?

    If you had a LONG vacuum chamber on earth, and shot a .30-06 horizontally and dropped a feather at the same time, which would fall to the bottom of the vacuum chamber first? Amy difference on the moon?

    If you shoot that .30-06 in a long vacuum chamber at a muzzle velocity of 2200 FPS, what will the velocity be when it strikes the bottom of the chamber on earth? On the moon? If I was able to fire a badminton birdie at 2200 FPS in a vacuum how would it compare to a boattail spitzer bullet? A round musket ball?

    If you shot a bullet at 2200 FPS from a height of 1 meter from the bottom of the chamber, how far downrange would the projectile be striking the bottom of the chamber on earth? How about on the moon?


    Hmmm...


    And Schwing's professor obviously got thru about 3rd grade...


    Willie

    .
     
    Last edited: Jul 22, 2013
  21. Black Butte

    Black Butte Member

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    This is not entirely true because the time it takes a bullet to fall is not linearly dependent on gravity.
     
  22. Willie Sutton

    Willie Sutton Member

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    ^^ the post you are replying to is wrong on three points:

    1: Moon = 1/6 gravity,

    2: Moon atmosphere has far lower aerodynamic drag decellerating the projectile,

    and

    3: And to your reply-point, the fall-rate is exponential, not linear. It's 33 feet per second squared on earth, and 5.3 feet per second squared on the moon. Hypothetically a falling body on earth falls 33 feet the first second, 66 feet the second, etc. On the moon 5.3 feet the first, 10.6 the second, etc. BUT: On earth there is also atmospheric drag on the fall of the object, and this is not true on the moon. A human, for example, accellerates to about 100 MPH on earth (parachutist in freefall) before the force of gravity and the drag from the atmosphere balance each other, and then he stops accellerating. On the moon the accelleration would be far more constant in the near zero atmosphere condition.



    Q: If you shoot a .30-06 straight up on earth at 2200 FPS, what will the velocity be when it strikes the earth? What will the slowest velocity of the projectile be during it's entire flight from muzzle to earth when so fired? How would doing this on the moon change the velocity at impact and the minimum velocity of the projectile on the flight? How about the apogee altitude of the projctile in both cases?


    Willie

    .
     
  23. climbnjump

    climbnjump Member

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    Would you not already be in orbit anyway? ;)

    Still, F=MA in space just as it does on earth. Assuming you were floating in free space and not constrained, yes you would move in the opposite direction of the bullet. But since your mass plus the mass of the weapon you fired is much greater than the mass of the bullet and the burned powder, your acceleration and ultimate velocity will be much lower than that of the bullet.

    And, if you fired the weapon from your shoulder like you would on earth, the recoil is going to be acting on you some distance above your center of gravity. So while you will be propelled backwards, you will also be spinning about your center of gravity.

    ETA:
    But since your mass is distributed on your body and not concentrated at your center of gravity, it won't be a "pretty spin", but more of an eccentric flopping motion...
     
    Last edited: Jul 23, 2013
  24. Willie Sutton

    Willie Sutton Member

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    "Would you not already be in orbit anyway?"


    You're in orbit NOW... around the sun... which itself is in orbit... around the center of the Milky Way Galaxy...

    ad infinitum, ad astra...

    :neener:


    Best,

    Willie


    .
     
  25. YZ

    YZ member

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    Willie, Occam is calling.
     
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