Hi,
  I read were several Navy SEALs had been on Space Shuttle missions.  That got me to think.  Is NASA experimenting with combat in Orbit???  If so what kind of weapons would work out there???
  I don't think you'd be able to make a lazer small enought to tote around with you.  A projectile weapon would send you spinning around when you shot it (micro gravity)
  What could you do???
Thanks
John

holy cow, i thought i was the only one who has given this thought.  what most people don't realize is that television sci-fi stuff will not work in a zero gravity zero oxygen environment.

think gyrojet. made during cold war when people belived one day thier would be land war on the moon, fighting over ICBM bases. i guess thats IPBMs. anyway, it was a pistol that used a rocket powered projectile. it didnt work so well in gravity, but in spacei suppose it would.

Was McUzi building a gyrojet?

I'm more partial to "Pigs in Space"

As a matter of fact, ALL weapons are banned from space by international treaty.

But, current firearms will work just fine in a vacuum, recoil will be problem however. I would not be hard to add a counter-reaction device to attenuate recoil to a managable level, however.

The Gyrojet would also have "some" recoil due to the fact the round "pushes off" the blast shield of the weapon...a "Recoilless Rifle" style weapon would work well, however...

Quoted: Was McUzi building a gyrojet?

yes he did.

There are burning lasers small enough to carry around with you, it just wouldnt be an effective weapon because we have yet to develop star trek like weapons, Lasers will take a long time to burn through some one.

Think standard firearm with a muzzle brake.  The only thing that would need to be changed is the sights.  They would need to be same as line of bore.

Acheron.....how can regular firearms work in a vaccum?  There is no oxygen to burn the powder....unless you ahve a real good crimp seal on the bullet....then of course what keeps the bullet from "exploding" due to lack of air pressure.


Just curious.

Both Smokeless and black powders already contain oxydizers, so, even if there were no air trapped in the cartridge, they will ignite fine, so I'm told.

Quoted: Acheron.....how can regular firearms work in a vaccum?  There is no oxygen to burn the powder....unless you ahve a real good crimp seal on the bullet....then of course what keeps the bullet from "exploding" due to lack of air pressure. Just curious.

There is no way that there is enough gaseous oxygen in a loaded round to burn all of the powder.  The powder must contain all of the necessary ingredients for the full burn.

Air pressure at sea level is only around 14.7 psi.  Design pressure of some rounds is in the mid 40,000 psi range.  Atmospheric pressure on the exterior of a round is negligent, and doesn't have anything to do with keeping the round from exploding.  

Rounds would likely be propelled more quickly if fired in a complete vacuum.  The reason for this is that the barrel would not be filled with air.  By the time a bullet exists a rifle barrel, the air that the bullet is pushing out the end of the barrel has got to be pushing back very hard.

I've loaded rounds in a nitrogen filled glove box.  One of my silly experiments just because I could.  They fired fine within an hour of loading.  Nice tight primers and taper crimped .45 ACP.    

No oxygen in those.  In black powder, the KNO3, potassium nitrate, is the oxidizer.

Recoil is another thing.

Quoted: Quoted: Acheron.....how can regular firearms work in a vaccum?  There is no oxygen to burn the powder....unless you ahve a real good crimp seal on the bullet....then of course what keeps the bullet from "exploding" due to lack of air pressure. Just curious. There is no way that there is enough gaseous oxygen in a loaded round to burn all of the powder.  The powder must contain all of the necessary ingredients for the full burn.

You dont need O2 at all. The smokless powder has all the elements to burn inside it already, just like blackpowder. Its a chemical reaction without O2.
GG

Lasers work well in space because of it is devoid of atmosphere which scatters the beam. No recoil with laser weapons either.

Gunpowder has oxidizer as a required component.  Gaseous O2 is not present in sufficient quantity to sustain requisite burn rate.  Now about recoil...there's a shotgun called "Space Gun" developed many years ago that has recoil-compensating action.  I have a friend with one he uses for trap shooting.  I believe it was developed for NASA for who knows what use.  It really shoots with little to no felt recoil.  Strange looking and expensive.

photon stun guns and blasters are for space.

Duh.

everybody knows that.

I read a science fiction book back in high school (but can't remember what I was supposed to get at the grocery store).  The space guys used CO2 fire extinguishers to duel with on spacewalks.  They had to use a combination of blasts to maintain their own position/velocity/orientation and try to hit the other guy with a blast to push him around.  

Sounds like great fun.  It could happen!  

Recoil operated weapons wouldn't work very well because they need something to act against. If you weren't solidly braced on something when you fired, the weapon wouldn't cycle, much like when a shooter induces a malfunction in a handgun by "limp-wristing."

Revolvers and gas-operated weapons would work, but recoil would need to be dealt with. You would also need to pay attention to several other factors. All of the lubricants would boil off the weapon in vacuum. You'd have to use something like the lithium grease the army uses for some weapons. The tempature extremes would be severe enough to cause serious metal damage (the cold and brittle metal) and spring failures, warping and bent barrels (the heat). Ammo would also either become hyper-sensitive to the tempature extremes, possibly even  detonating prematurely (slam fires or spotaneous) or refusing to go off at all. Some ammo might even be sealed tightly enough but have thin enough walls that the rounds could rupture in vaccum from internal pressure, or enough powder could escape to render some rounds into squibs. Gas-operated weapons would have some pretty weird pressure changes as well, since their operating ranges are based off of earth-normal pressures; vacuum will really screw things up and cause al kinds of cycling troubles. Lack of penetration is another issue. Space suits are tough, and incorporate lots of kevlar and other very durable materials. Handgun caliber rounds would probably be ineffective against against space suits. The weapons would also need to be redesigned with large enough (or no)trigger guards and adjustments to trigger pulls (or a comletely different actuating system) to account for the firer's heavy guantlets. Aiming would be problematic, at best) (no cheek welds, different point of imact). After you deal with all of those factors, then you can worry about what to do with recoil.

It could be done, but to get safe, reliable and accurate weapons, you'd have to have a dedicated research effort and weapons specifically designed for the special environment at-hand. I bet the Soviets built something along those lines, because they were very good at engineering that kind of stuff. I think you'd probably be best off shooting a simple .357 revolver with the trigger guard hacked off, a ported barrel and maybe some kind of laser pointer, loaded with an AP round for outdoors work. Discard after six shots, and go for your sword. Maybe an AK74 would work (that muzzle brake is pretty good) and AKs are extremely reliable under the most extreme conditions.

Hummmm......should I just get my sling shot or my long stick w/ a knife on the end of it?

I think any projectile weapon in space is horribly impracticle.  I'm sure most conventional guns would work fine, but down here in the atmosphere, we've got a lot of forces acting on the bullet once it's in flight -- mainly aerodynamic drag and gravity.  In orbit (which is not a total vacuum), aerodynamic drag becomes negligible and the effects of gravity are greatly diminished.  The effective range of the bullet would be dramatically greater, but the exterior ballistics are nothing like you're used to.

Imagine an orbital combat engagement of a few hundred yards.  Zip off a few hundred rounds in each direction and any bullet that doesn't impact still has near muzzle velocity several thousand miles away.  Any that do impact, but are not captured by their target are now on an unpredictable course with an unknown energy.  I don't think either side could afford the risks.

There is a lot more to the SEALs than just conventional weapons, though.  I suspect that if it were true that some had flown on the shuttle, the mission would have had nothing to do with firearm testing or anything of the sort.

Hmmm, a SEAL mission to space.  Could be a rescue or maybe an assasination?  I'm sure we'll eventually find out on the X-Files.  

There are significant complications to the use of projectile weapons in space.  Ballistics and orbital mechanics together are strange birds indeed.

If an astronaut loses a tool on a shuttle mission and it goes overboard, the shuttle gets moved.   Do you know why?

Because it'll come back.

Along the line of an orbit, there is a forward and back line, there is an up and a down (referenced to the planet) and there is side to side movement as well.

Due to the effects of orbital mechanics, if you were in space in a suit and tossed a tool straight up or down, that tool would assume an elliptical orbit and if it was thrown PERFECTLY up or down, and your orbit didn't change, it would come right back into your hand.

As the tool leaves your hand (assume a DOWN throw), it has the same orbital velocity that you do.  Say it's an even 18,000 miles per hour. By throwing it down, it goes into a lower orbit, but an elliptical one.  If you can keep the tool in sight, it will appear to draw AHEAD of your position as it falls.  At some point it will stop moving downwards and being to fall UP toward you, moving back as well.   It will land in your hand, if your hand didn't move.  This will occur in one orbital period.  Roughly 90 minutes at an 18,000 MPH optimum orbit.

Throw the tool UP, and it will climb and fall behind your position, then it will drop and gain on you, again landing in your hand.

Viewed from the side, if you were to toss a tool and then get out of the the way, the tool would describe a figure 8 pattern around the point where it was launched.   It will cross the point at which it was launched at the same velocity it was launched at.   That is what makes projectile weapons in space a very BAD idea.

Fire a weapon sideways, and the same thing happens.

Fire one forward, and the bullet will climb to a higher orbit that is elliptical, with the low point being where it was fired from.  It'll shoot the shooter in the back of the head.

Fire one backward, and it'll assume an elliptical orbit with the HIGH point of the orbit being where it was fired from.  It'll hit the shooter in the face.

CJ

Maybe the SEALS were doing a really extreme HALO jump

Quoted: Quoted: Acheron.....how can regular firearms work in a vaccum?  There is no oxygen to burn the powder....unless you ahve a real good crimp seal on the bullet....then of course what keeps the bullet from "exploding" due to lack of air pressure. Just curious. There is no way that there is enough gaseous oxygen in a loaded round to burn all of the powder.  The powder must contain all of the necessary ingredients for the full burn. Air pressure at sea level is only around 14.7 psi.  Design pressure of some rounds is in the mid 40,000 psi range.  Atmospheric pressure on the exterior of a round is negligent, and doesn't have anything to do with keeping the round from exploding.   Rounds would likely be propelled more quickly if fired in a complete vacuum.  The reason for this is that the barrel would not be filled with air.  By the time a bullet exists a rifle barrel, the air that the bullet is pushing out the end of the barrel has got to be pushing back very hard.

I know that atmospheric pressure is only 14.7 psi...

Perhaps I misswrote...by exploding I meant that the bullet would BLOW out of the case due to expansion of the gases trapped behind it.

You mean before it's fired?   Not likely, not if it has even a minor crimp on it. A 30 caliber bullet has less than one sixteenth of an inch of area across the neck, which at 14.7 PSI means that less than one pound of pressure would be pushing on the bullet from inside.  Any half-assed crimp is much stronger than that requires.

CJ

Quoted: Perhaps I misswrote...by exploding I meant that the bullet would BLOW out of the case due to expansion of the gases trapped behind it.

A 40,014.7 psi pressure difference wouldn't be much different than a 40,000 psi difference.  Or to put it another way, if you've got 14.7 psi on the outside and 40,000 psi on the inside, it wouldn't make any practical difference if you reduced the exterior pressure to 0 psi.

Even if it didn't have oxygen you could add bromine, iodine, halogen, or oxidizer. Any of these will burn in the complete absence of oxygen.

Viewed from the side, if you were to toss a tool and then get out of the the way, the tool would describe a figure 8 pattern around the point where it was launched.   It will cross the point at which it was launched at the same velocity it was launched at.   That is what makes projectile weapons in space a very BAD idea. Fire a weapon sideways, and the same thing happens. Fire one forward, and the bullet will climb to a higher orbit that is elliptical, with the low point being where it was fired from.  It'll shoot the shooter in the back of the head.

How about we give Sarah brady an AK-47 and send her into space to shoot it. That should take care of her.

Fire one backward, and it'll assume an elliptical orbit with the HIGH point of the orbit being where it was fired from.  It'll hit the shooter in the face.

Hmmm, I wonder if the FBI realizes this ? Your honor, we didn't shoot the motorist in the face. Apparently, the laws of gravity ceased during the split second when he fired to his rear opposite us.

You know, this MIGHT be good basis for the
"single bullet theory" associated with the Kennedy assassination!

CJ

Damn-
The amount of knowledge here never ceases to amaze me.

CMJ is right, but there are ways out. Gravity has a escape velocity, and at 18,000 mph you are much closer to that escape velocity than when you were sitting on the ground.

and this escape velocity is 1/6th lower in lunar orbit. Not sure what the ratio is around the Lagrange points. Point is that the things worth fighting for in space are not in Low Earth Orbit, and places that there are things worth fighting for are in a zone where most objects fired at any reasonable velocity would leave the system or fall into the Earth or the Moon and be destroyed.

Also, in space its a lot easier to see things, anything big enough to hurt can be dodged or shot down.

But the ultimate reason projectile weapons will appear in space- is that we dont have very many other workable options and eventually they will be needed.

Quoted: Damn- The amount of knowledge here never ceases to amaze me.

i have a question.
why the hell do i feel like the only one on this board who is NOT an astrophysi--- (rocket scientist)?????  i THOUGHT i was pretty smart.

Fire one backward, and it'll assume an elliptical orbit with the HIGH point of the orbit being where it was fired from.  It'll hit the shooter in the face. CJ

The escape velocity at that altitude is much less than on earth.  If you used a firearm the bullet would leave the earths orbit.

Quoted: Fire one backward, and it'll assume an elliptical orbit with the HIGH point of the orbit being where it was fired from.  It'll hit the shooter in the face. CJ The escape velocity at that altitude is much less than on earth.  If you used a firearm the bullet would leave the earths orbit.

At the altitude the shuttle flies it would have to be a pretty extreme firearm. But 10-X is close

Any firearm fired dead ahead or dead behind would fall into either a higher or lower orbit. I bet that there is a way to make the orbits cross, but it would be only one angle out of many it would have to be angele that cut across a chord of the vheicles orbit.

The orbit is determined soley by the interaction of gravity and centrifical force not its point of origin. And the faster the orbiting object the greater the radius of its orbit.

Quoted: Also, in space its a lot easier to see things, anything big enough to hurt can be dodged or shot down.

Not necessarily so.  Right now, NASA is having a problem with simple debris orbiting Earth.  With no air to slow things down, and the fact that they were in orbit when they went flying, these things are moving VERY fast, and a lot of them are too small to track.

Early in the 80's, the shuttle Challenger was hit by something in orbit that cracked its 'windshield'.  It was a fairly close call.  It was determined to be a tiny fleck of paint from some rocket or satellite.  That's how fast things are moving up there.

Escape velocity for Earth is 11.2 Km/second, or about 6.7 miles per second, or roughly 25,000 miles per hour.

Orbital velocity is in the general range of 17,500 MPH, depending on orbit height.

Higher orbits require higher velocity, but as you get farther away from the planet, the strength of the earth'a gravitational field weakens as well, so beyond a certain point, you have to slow down to maintain a high orbit.  

For example, the moon has a mean (average) orbital velocity of   1.023 km/sec.   That's only about 2200 MPH!   If it were to fly by earth at a range of just a few hundred miles at that speed, it'd smash us!

So, no, from a low earth orbit in the 17,000 to 18,000 MPH range, a fired bullet would not achieve escape velocity.  It would assume an elliptical orbit with the high or low point of the orbit being where it was fired from.  But
that itself is a moving point.


CJ

Quoted: Escape velocity for Earth is 11.2 Km/second, or about 6.7 miles per second, or roughly 25,000 miles per hour. Orbital velocity is in the general range of 17,500 MPH, depending on orbit height. Higher orbits require higher velocity, but as you get farther away from the planet, the strength of the earth'a gravitational field weakens as well, so beyond a certain point, you have to slow down to maintain a high orbit.   For example, the moon has a mean (average) orbital velocity of   1.023 km/sec.   That's only about 2200 MPH!   If it were to fly by earth at a range of just a few hundred miles at that speed, it'd smash us! So, no, from a low earth orbit in the 17,000 to 18,000 MPH range, a fired bullet would not achieve escape velocity.  It would assume an elliptical orbit with the high or low point of the orbit being where it was fired from.  But that itself is a moving point. CJ

That is the escape velocity from the surface of the earth.  You are right, normal rifle velocities will not reach the escape velocity unless you are at twice the altitude of the moon.  A battle with firearms in space would be good for no one because the bullets would still be flying years later threatening satellites and other space craft.  Weapons would need to have a muzzle velocity of 36,000 ft/s to avoid this.

You fellas all need to send your resumes to the Kennedy Space Center, I believe they have openings for you all.

Quoted: . . . the things worth fighting for in space are not in Low Earth Orbit . . .

Aha!  This explains why the inexpensive 30-round magazines are marked "Government/LEO".  They are for the government to use in a low earth orbit!  I'm starting to understand the gravity of the situation.

Quoted: There are significant complications to the use of projectile weapons in space.  Ballistics and orbital mechanics together are strange birds indeed. If an astronaut loses a tool on a shuttle mission and it goes overboard, the shuttle gets moved.   Do you know why? Because it'll come back. ...SNIP...

Now THAT has to be the most interesting post I've read in years!  I never thought of this!  Good show!

Quoted: Quoted: Also, in space its a lot easier to see things, anything big enough to hurt can be dodged or shot down. Not necessarily so.  Right now, NASA is having a problem with simple debris orbiting Earth.  With no air to slow things down, and the fact that they were in orbit when they went flying, these things are moving VERY fast, and a lot of them are too small to track. Early in the 80's, the shuttle Challenger was hit by something in orbit that cracked its 'windshield'.  It was a fairly close call.  It was determined to be a tiny fleck of paint from some rocket or satellite.  That's how fast things are moving up there.

NORAD tracks "EVERY" thing in orbit, from nuts to bolts and yes, even John Glenn's glove that went out the hatch. Now Im realistic on a chip of paint. But who knows?
GG

I can't remember where I heard it, but I'm sure Norad tracks everything bigger than a softball.  The Russians had to mount shutters  on Mir because of particles the size of .22's damaging viewports.  A couple of shuttle missions ago there was materials-observance project, where they attached several different building materials on a panel, then attached it to the international space station.  I'm curious to see what the results were.

As for a plausible battle scene on the moon, it's long overdue.  A well-consulted scene, not the regular special effects blowout seen in summer blockbusters.  Rail guns or gauss rifles would be way to go, since there would be no recoil or reliance on chemical ignition.

Quoted: I can't remember where I heard it, but I'm sure Norad tracks everything bigger than a softball.  The Russians had to mount shutters  on Mir because of particles the size of .22's damaging viewports.  A couple of shuttle missions ago there was materials-observance project, where they attached several different building materials on a panel, then attached it to the international space station.  I'm curious to see what the results were. As for a plausible battle scene on the moon, it's long overdue.  A well-consulted scene, not the regular special effects blowout seen in summer blockbusters.  Rail guns or gauss rifles would be way to go, since there would be no recoil or reliance on chemical ignition.

Rail guns and gauss rifles have recoil!  It is just that they are normally so big and bolted down that it is never an issue.

Quoted: As for a plausible battle scene on the moon, it's long overdue.  A well-consulted scene, not the regular special effects blowout seen in summer blockbusters.  Rail guns or gauss rifles would be way to go, since there would be no recoil or reliance on chemical ignition.

Someone (I think it was Ben Bova) did a Cold War era story about Soviets and Americans in a long-term DMZ-type stand off on the Moon. I remember the troops had to take cover a few times a day becuase the rounds they fired in a firefight a couple of years before were all in a low orbit around the Moon and came back to visit periodically. The mechanics involved in this sort of thing are retty incredible when you think about it.

Currently, there is a series by John G. Hemry about US troops on the Moon who rebel against corrupt and incompetent leadership. The whole thing winds up being led by a crusty senior NCO. Pretty good reading.

Re rail guns/Gauss guns & recoil:

I'm not sure they'd have *that* much recoil, definately less than a conventional gun.  Deepends mostly on the slug fired.  Back when I used to play RPG's the SciFi game Traveller had rules for low & zero G combat.  The Gauss rifle used in the game was one of the most effective non energy weapons available.  Their version fired a steel alloy core needle like bullet with a soft alloy hollowpoint jacket.  No muzzle flash & virtually no noise other than rounds whistling by.  Another option in the game was a large caliber low velocity revolver firing explosive slugs.  Something like a .60 S&W Short at 400fps muzzle velocity.  

Originally Posted By Gun Guru: NORAD tracks "EVERY" thing in orbit, from nuts to bolts and yes, even John Glenn's glove that went out the hatch. GG

Perfect!
If I can somehow launch Al Gore into  low earth orbit, then NORAD can keep track of him so I don't have to worry about where he is or what he's doing

14.7 psi exerted over the base of, say, a 9mm bullet... .355" dia, that is only .09898" sq inches.  14.7 #/in2 x .09898 in2 = 1.46# of force.  A crimped case can easily withstand that tiny force.  The bullet would not pop out due to internal air pressure.

And terminal velocity will equal muzzle velocity, as there is NO DRAG!!!

And the figure 8 orbit described above is correct.  Weird, huh?

Quoted: Re rail guns/Gauss guns & recoil: I'm not sure they'd have *that* much recoil, definately less than a conventional gun.  Deepends mostly on the slug fired.  Back when I used to play RPG's the SciFi game Traveller had rules for low & zero G combat.  The Gauss rifle used in the game was one of the most effective non energy weapons available.  Their version fired a steel alloy core needle like bullet with a soft alloy hollowpoint jacket.  No muzzle flash & virtually no noise other than rounds whistling by.  Another option in the game was a large caliber low velocity revolver firing explosive slugs.  Something like a .60 S&W Short at 400fps muzzle velocity.

Recoil can be described by the conservation of momentum.  

Momentum:  p=m*v

If a system of a gun and a projectile has 0 momentum before it is fired it will have 0 after it is fired as well.

Mgun * Vgun + Mprojectile *Vprojectile = 0

So the gun will have a negative velocity (opposite direction from the projectile) when it is fired.  Most rail guns today are large but if one could be developed to be man portable in space it would have to be light and small enough to weld.  The velocities of the most powerful rail guns are over 50,000 ft/s.  It would not take a very massive projectile to cause a lot of recoil.  The projectile size also needs to be fairly large for a rail gun to work.

Heat would be another problem in space.  With little air gun barrels would not quickly cool lowering the maximum rat of fire.

From 10-X
So the gun will have a negative velocity (opposite direction from the projectile) when it is fired. Most rail guns today are large but if one could be developed to be man portable in space it would have to be light and small enough to weld. The velocities of the most powerful rail guns are over 50,000 ft/s. It would not take a very massive projectile to cause a lot of recoil. The projectile size also needs to be fairly large for a rail gun to work.

Why would a man portable electromagnetic "rifle" need that much velocity?  Something along the lines of 4000fps for a >100grn bullet would be just fine.  Why the need for a large projectile?  More surface area for the magnetic field to grab?  


Also from 10-X
Heat would be another problem in space. With little air gun barrels would not quickly cool lowering the maximum rat of fire.

Liquid/cryrogenic cooling.  Since the thing will need an electrical source to work anyways adding a compressor/pump & barrel jacket shouldn't cause that much more hassle.