PDA

View Full Version : Could a grenade work in space?



Thomas_Anderson
01-28-2009, 08:51 AM
Obviously the shrapnel would fly, but would the concussive force work? There's no sound in space because there's no air molecules to vibrate and carry it, so would the concussive force of a grenade not work for the same reason a sound gun wouldn't work?

Dommo
01-28-2009, 09:30 AM
No, there'd be no concussive force. Just the KE from the shrapnel. However, a grenade would still go boom(except you wouldn't hear anything).

MargueriteMing
01-28-2009, 10:32 AM
Depends on the range. The explosive compound contains all the oxygen needed for it to explode, so it will still do that. The rapid expansion of the gases created by detonation creates a shock wave through the air. With no air, no shock wave. However, the gases created will still expand with tremendous force (although they will disipate more quickly because there is no atmosphere to contain them). So, if you are close enough, you will be struck not just by the shrapnel but by the rapidly expanding gases from the explosion, as well. That's probably not a real big deal compared to the shrapnel, but it will propel you away from the explosion, as there is no air around you to dampen the motive effects, either. You could find yourself rapidly adrift, which will make it harder for anyone to aid you, should you survive the detonation.

MelancholyMan
01-30-2009, 01:15 AM
Grenades kill with shrapnel. The concussive force is negligable unless you are very close. A grenade would make an excellent weapon in space. Especially one specifically made for use in space. Space craft are, by necessity, light weight and unarmored. All you need to do is puncture the hull to create a problem. A grenade designed to blow many tiny fragments out at high speed, as opposed to a smaller number of larger fragments, would really be effective.

Pthom
01-30-2009, 03:49 AM
Isn't it only those spacecraft that must lift from a planet, or which must accelerate very rapidly, that must be relatively light weight?

Bartholomew
01-30-2009, 10:16 AM
Isn't it only those spacecraft that must lift from a planet, or which must accelerate very rapidly, that must be relatively light weight?

Yeah-- the type of spacecraft engaging in space warfare would have armor, mass, and they'd probably never physically touch a planet.

(Ideally.)

(Boom.)

dpaterso
01-30-2009, 11:31 AM
The blast would be effective if the grenade were alongside and in contact with an object, e.g. shuttle spacecraft skin, spacesuit, helmet.

I'm using recoilless shotguns and grenade launchers in my latest Sci-Fi adventure. Thinking about the design was fun.

-Derek

MelancholyMan
01-30-2009, 07:24 PM
Yeah-- the type of spacecraft engaging in space warfare would have armor, mass, and they'd probably never physically touch a planet.

(Ideally.)

(Boom.)

It's fun to think about. Changing direction in space takes a lot of energy because you don't have aerodynamic forces to use. Any spacecraft that wanted to be able to turn quickly would have to be low mass. But that is getting into the realm of 'Realistic Space Warfare' which is so different from aerial combat as to be unrecognizeable. And space warfare in the presence of a gravitational field would be totally different from space warfare in 'free' space, if there is such a thing.

When thinking about hand grenades in space warfare the only scenario that makes sense is ground forces on a planet with no atmosphere or troops fighting outside a large structure either in orbit or in free space in which case the grenade would effect the troops but probably not the ship (much.) It doesn't make sense from the standpoint of ship to ship combat unless it is during boarding or something like that.

GeorgeK
02-17-2009, 06:26 PM
Would a grenade in space freeze to the point that either the lever would not release or that the chemical processes involved could not initiate?

Pthom
02-17-2009, 11:45 PM
These comments are based on the WWII/Vietnam era hand grenades; things could be different using other mechanisms. There would have to be some moisture, methinks, to cause the lever itself to stick. It's a simple clevis arrangement. The safety pin holds the lever in place and the lever in turn holds a spring in compression that, when released, causes a firing pin to activate the primer. All the constituents necessary for ignition and subsequent combustion of the explosive are present (which is why hand grenades can explode just fine under water). That's some cold, to prevent a rather powerful steel spring from decompressing, but not inconceivable. I don't know enough chemistry to say whether extreme cold would prevent violent chemical reactions. But my gut feeling is that the temperature would have to be very near absolute zero for that to occur.

And as far as I'm aware, it would be pretty tough to pull the pin on a hand grenade at those temperatures, let alone throw one. :D

GeorgeK
02-18-2009, 12:10 AM
Nah, you just flip up your visor and grip the pin with your teeth.

(in British accent) It's not a question of where you grip it. ;)

scottVee
02-18-2009, 12:13 AM
Funny about spacecraft being lightweight. Sure, if they need to escape gravity, that limits their mass. But a spaceship made for long-term use in space would need radiation shielding, would need to survive constant bombardment by high-velocity dust and rocks, and it would take a heck of an explosion to hurt it. If it's meant for battle, add even more armor. Such a thing could never lift off from a planet, but it wouldn't need to. You don't see aircraft carriers on the freeway either.

Lhun
02-19-2009, 01:48 AM
That's some cold, to prevent a rather powerful steel spring from decompressing, but not inconceivable.Material science is not my area of expertise but i could envision that the spring might break when the metal crystallizes due to the cold. (since all that kinetic energy is still stored) Though i really cannot say if that would happen or not.

I don't know enough chemistry to say whether extreme cold would prevent violent chemical reactions. But my gut feeling is that the temperature would have to be very near absolute zero for that to occur.The keyword is threshold energy. If the explosive is to cold, the energy available to ignite it might not be enough. A candle won't burn until it is heated to ignition temperature either. Though it's unlikely to happen, even 0K isn't all that cold, and there's usually a lot more energy available than necessary. And electric ignition might malfunction unless you turn up the volts.

And as far as I'm aware, it would be pretty tough to pull the pin on a hand grenade at those temperatures, let alone throw one. :D
Well, since you carry the grenades on your body they'll generally have body temperature anyway. :D