Will a bullet fire in outer space?

[BladeVenom]

nerd

If he was a real nerd, he would have checked the date of the post.

 

[Farmer]

Any engineer who has taken heat mass transfer knows that radiation is the slowest method of heat transfer with the same source and sink temperatures in general.

In everyday situations (~300 K), natural convection can be comparable to radiation.

I happen to be an electrical/thermal flight controller for the ISS. We see temperatures down to -60 C on the radiators and occasionally up to 30 or 40 C on our external powered equipment depending on attitude, solar beta, and how well the cooling system is working.

Well had you said that the first time I wouldn't have asked you. An exaggerated example of what you said regarding orbits would be like this: "2+2=4. <- Is Stephen Hawking."

 

[techs]

If he was a real nerd, he would have checked the date of the post.

I was the OP and I did a WTF? when I saw this old thread resurrected.

 

[WaTaGuMp]

We have had quite a few thread necro's lately.

 

[Paratus]

In everyday situations (~300 K), natural convection can be comparable to radiation.



Well had you said that the first time I wouldn't have asked you. An exaggerated example of what you said regarding orbits would be like this: "2+2=4. <- Is Stephen Hawking."

Well now yinz is just being a jagoff.

Plus if you didn't notice, the correct response was given to the freezing question and there were still folks saying it probably freeze or might freeze in a minutes. I don't want that line of discussion to start back up.

 

[Lemon law]

Kind of dub question IMHO, of course a modern conventional firearm will fire in outer space even when cooled to near absolute zero. And because a modern gun cartridge consisting of a casing, a primer, and a propellant to pressure power the bullet down the chamber and barrel, with nothing else required, we should instead ask why such a gun work equally well without an atmosphere.

As I maintain no one has asked any of the proper questions yet, especially if such a gun is cooled to near absolute zero.

At all earthly conditions, the initial firearm firing sequence is to pull the trigger, which release a firing pin to strike a primer, which cause the primer to ignite, which in turn ignites the smokeless or black powder charge that then by pressure causes the bullet to attain rapid acceleration. As we can also ask what can go wrong with that firing sequence on earth.

(1) We assume on earth, when the firing pin hits then primer, the primer will ignite. But where does this untested assumption come from, that our primer will ignite at near absolute zero conditions of outer space where all Chemical reactions are greatly slowed. If nothing else, new primer formulations may be needed. (2) Then we can talk about the properties of materials at extremely cold temperatures, as two safety requirements present themselves. (a) At earthly temperatures we assume the material of the cartridge will expand and prevent hot high pressure gases from escaping out of the breech to injure the shooter. (b) In earthly conditions we also assume the metal of the barrel will contain the pressure of the exploding powder charge. Facts the wise handloader already know. Reuse a cartridge case too many times without annealing the brass and you court disaster if the rear of the cartridge case ruptures. Or pack too much fast burning powder into a cartridge and you risk the barrel rupturing. But at temperatures near absolute zero, metals can shatter like glass and so can the cartridge. cases.

Just my two cents on a thread that is worth even less.

 

[LTC8K6]

We've already fired ordinary guns with ordinary ammo at very high altitudes from airplanes in WW2. There was much less oxygen and it was very far below zero way up there. The guns worked fine even after long soaks at well below zero.

At 40K feet, you have about 80% less oxygen available and it's something like -60F.

 

[Braznor]

A gun will be far more accurate and deadlier in space than on Earth itself. Remember a bullet fired in space is less influenced by Earth's gravity than one fired on the surface of our planet. So bullet shot in space will keep moving at its peak velocity throughout its journey until it hit something or gets sucked into a gravity well.

Also low gravity and lack of atmosphere ensures greater accuracy for the projectile i.e it will not deviate from its path so quickly unlike one fired on the surface of the Earth.

I also believe the recoil of a gun fired will apart some kinetic velocity to a body floating in near zero gravity. I would appreciate it if someone explain to me, if these assumptions of mine are right or wrong.

 

[dawp]

I've heard that it will fire but it wont work for very long as the vacuum affects the oil used to lube the gun. the gun will seize in a short time.

 

[T_Yamamoto]

Inb4lock

 

[Nintendesert]

The gun would freeze before they even shot it. It's -455*F/-270*C out there.

That's just stupid. They are in a vacuum. Where is all that heat that the gun has going to go? Hmm?

 

[Nintendesert]

You, in zero gravity, are no acting force other than your mass. So I guess it would all come down to one's mass and the springs force. You're right though, it's all a question of acceleration/mass. I misspoke when I said "all of the energy", it's between you and the spring.

dammit, don't make me think.

That leads me to believe a gas assist would have a higher chance as the spring is much weaker.

It would push you back but the spring will push back first. It's not like the spring has the strength of your entire mass. If it did it would throw your ass backwards just as easily here on Earth.

 

[Farmer]

I guess I'm a jagoff.

It would push you back but the spring will push back first. It's not like the spring has the strength of your entire mass. If it did it would throw your ass backwards just as easily here on Earth.

You don't even have to think about the spring. It's a collision in reverse, I guess that's a decay (or explosion). The center of mass f bullet-man-gun stays the same.

 

[Paratus]

I've heard that it will fire but it wont work for very long as the vacuum affects the oil used to lube the gun. the gun will seize in a short time.

Now that is possible. Sublimation is a problem so we generally have to use dry lubricants or very expensive greases on the ISS.

http://en.m.wikipedia.org/wiki/International_Space_Station_maintenance#section_6

During STS-120, a problem was detected in the starboard Solar Alpha Rotary Joint (SARJ). This joint, together with a similar device on the port side of the station's truss structure, rotates the large solar arrays to keep them facing the Sun. Excessive vibration and high-current spikes in the array drive motor were noted, resulting in a decision to substantially curtail motion of the starboard SARJ until the cause was understood. Inspections during EVAs on STS-120 and STS-123 showed extensive contamination from metallic shavings and debris in the large drive gear and confirmed damage to the large metallic race ring at the heart of the joint.[13] The station had sufficient operating power to carry out its near-term programme with only modest impacts on operations, so to prevent further damage, the joint was locked in place.[13]

On 25 September 2008, NASA announced significant progress in diagnosing the source of the starboard SARJ problem and a programme to repair it on orbit. The repair programme began with the flight of the Space Shuttle Endeavour on STS-126. The crew carried out servicing of both the starboard and port SARJs, lubricating both joints and replacing 11 of 12 trundle bearings on the starboard SARJ.[14][15] It was hoped that this servicing would provide a temporary solution to the problem. A long-term solution is a 10-EVA plan called 'SARJ-XL', which calls for the installation of structural supports between the two segments of the SARJ and a new race ring to be inserted between them to completely replace the failed joint.[16] However, following the cleaning and lubrication of the joint, the results that have been noted so far have been extremely encouraging, to the point that it is now believed that the joint could be maintained by occasional servicing EVAs by resident station crews. Nevertheless, the data from the SARJ will require some time to fully analyse before a decision as to the future of the joint is made.[17]

The grease we used, a Braycote, was good for over -100F to +400F in a vacuum and costs like $2500 a pound.

 

[Pray To Jesus]

physic nerd

 

[BladeVenom]

Here's a gun fired at -110 F http://www.youtube.com/watch?v=mlZ4R-bXpgI

 

[IronWing]

The sun burns, don't it?

 

[Ferzerp]

I don't think I've ever seen so many elementary physics and chemistry fails in one place before.

 

[techs]

Mythbusters needs to get on this.

 

[Hayabusa Rider]

People actually thought that bullets need atmospheric oxygen??
What? Does it magically seep through the brass casing to get to the gunpowder after the primer has been struck? And seep quickly at that!

There's a sucking sound when you buy ammo these days. People think it's money, but it's atmospheric oxygen being pumped in.

Yeah, it's true!