Mass drivers?

[Alyrium Denryle]

I dont realy know where this one belongs but I have three questions

1.How would a mass driver work, in theory(how would it achieve asteroid acceleration)

2. Would it work, in theory

3.Would it be possible to build one with existing tech(prototype)

Thanks

[Alyrium Denryle]

Oh and when i say mass driver I mean large bombard planet/ship with asteroids type mass drivers

[Crown]

Well technically every form of rocket propulsion is a form of a mass driver of some kind. But that's not really answering your question is it?

I guess you are refering to the mass drivers from Babylon 5 yes? Well I believe that the Centauri were manipulating gravity in order to propell the asteroids into Narn. Sort of like a tractor beam only that it 'pushed away' rather than towards the ship.

The funny thing is that using Newtonian mechanics, whatever force was being applied to the asteroids, should also have been acting to the ships but in the opposite direction. We can assume two things, the first, the obvious and most reasnoble one is that the Centauri vessels were also using their propulsion to counteract the reactive force. Or more fantastically, they could somehow nulify the effect of Newton's thrid law. Obviously the first explaination is the more reasnoble of the two.

As to would it work in theory? If we could understand, control and manipulate gravity, then yes. We could use some sort of electromagnetic system instead though and this too would be operable.

As to whether or not we could build one. For something that size, and in space, not in my life time and not in yours either. Remember that it still costs anywhere between $8000 and $13000 per kilogram (or was it pounds?) to get something into Low Earth Orbit.

That is pretty heavy price tag.

[Master of Ossus]

In many games, movies, TV series, etc. Mass Drivers operate by manipulating magnetic fields in order to propel an object along the barrel of the weapon, and then towards a target. This theory works very well, to the point where Japan is designing a train to run using this method of locamotion. By rapidly flipping magnets back and forth, it is quite possible to propel something along a track, and this could quite easily be modified to be used as a weapon in an environment which has little or no atmosphere to provide resistance against the weapon. Do I think it would work as well as the ones in lots of Sci-Fi series? No. After a point, it becomes impossible to make magnets more powerful due to limitations within the metals that can be used. Mass drivers, in many series, are about the size of modern recoil-less rifles, and in many of the same series it is claimed that Mass Drivers can fire projectiles at many times the speed of sound with a high-rate of fire (Homeworld, Wing Commander, etc.). I do not think that this is possible.

[Crown]

There was an article in porular science, detailing the united states design of new type of ship that uses canons that are totally based on an electromagnetic rail gun. The projectiles would indeed by accelerated to speeds beyond Mach 1, and I assume that for use on a ship that is meant to replace conventional guns, this means that they must have at least comparable rates of fire.

I will try and find the article and explain more in detail.

[Wicked Pilot]

In the Centauri situation, remember that by virtue of the Centauri ships being in orbit, they are already traveling at high velocities. For them, it is simply a matter of destabilizing the asteroid's orbit by launching it. Not that much force is need to do the job.

If you would want to do an "end of the world" attack, you could simply look for a rouge asteroid, and steer in onto a collision path with the target planet. This however has the disadvantage of possibly taking large amounts of time for the orbits to intersect.

[Alyrium Denryle]

This was brought up because I got into a conversation with friends pertaining world domination/destruction/holding destroying political oponents. I brought up an orbital mass driver, and was wondering if I could actually do it

[His Divine Shadow]

The power of your mass drivers are nothing next to woman drivers...

[Alyrium Denryle]

[Darth Wong]

Personally, I think that mass drivers are a waste of time. The stresses and strains put upon a spaceframe and power plant by a mass driver are far greater than they would be for a nuclear weapon of equivalent yield.

Keep the following caveats about mass drivers in mind:

1. Every joule of yield must be generated by the launching platform's power source. Contrast this to nuclear weapons, where virtually all of the weapon's yield comes from inherent volatility, and no such energy demands are made.
2. Due to their nature, mass drivers will have a long firing delay, which will affect accuracy (imagine hitting the trigger and having to wait 1 second before anything comes out of the barrel). One could postulate a very high-powered, fast-firing mass driver, but remember conservation of momentum: if the mass drivers is to be extremely powerful, it must spread out the impulse over a long period of time in order to reduce structural stress on its spaceframe.
3. A mass driver-equipped starship carries far more dead weight than a nuclear missile-armed starship would carry. Since excess weight is a bad idea in anything that moves, this is yet another reason not to use mass drivers.
4. A mass driver must be quite long to be effective, and it would probably dominate the "spine" of the ship.

The good thing about mass drivers is that the ammo itself is cheap. Unlike nuclear missiles, it does not require toxic/radioactive substances or complex detonation sequences and safeguards. I just have trouble seeing this advantage as a sufficiently big reason to overlook all of the problems.

[David]

Mass Drivers appear to be more of a terror weapon than anything else.

[Howedar]

Or potentially a cheap bombardment weapon when no opposition is expected.

[Alyrium Denryle]

I know they arent practical, but it would be very demoralizing to a planetary population to have asteroids hitting major cities

[Crown]

Originally posted by Alyrium Denryle
I know they arent practical, but it would be very demoralizing to a planetary population to have asteroids hitting major cities

One other advantage of a mass driver that I think is plausible is that unlike nuclear weapons they don't tend to irradiate the area where they are used. You can totally destroy and cripple a planet, but after the dust settles down, you could move your own population in without fear of radiation. Is this right?

[Graeme Dice]

The good thing about mass drivers is that the ammo itself is cheap. Unlike nuclear missiles, it does not require toxic/radioactive substances or complex detonation sequences and safeguards. I just have trouble seeing this advantage as a sufficiently big reason to overlook all of the problems.

The mechanism itself can also be very simple if you have the right environment for it to work in. With a small ambient magnetic field, two long rails, a metallic conductor for the ammo, and lots of current, you can make yourself a nice railgun. I'd think you'd be more likely to use them for planetary space catapults though, as it's not unfeasible to build a thousand kilometre set of rails here on Earth. That also adds the benefit that there's already a magnetic field here. Then all you need is an immensely powerful energy source. If you can miniaturize these, then just put them on the ships themselves. Otherwise, a planetary catapult might be profitable.

[His Divine Shadow]

[*]Every joule of yield must be generated by the launching platform's power source. Contrast this to nuclear weapons, where virtually all of the weapon's yield comes from inherent volatility, and no such energy demands are made.

Really? What about using gravity wells of planets and slingshot maneuvers?
Let's say putting engines and shields on a large asteroid and sending it on a course that takes it through several heavy gravity wells it can gain speed around until it's off on final approach for the planet, also the planet's gravity would give a few extra G's wouldn't it?

Ofcourse this would not work as a tactical weapon, only as a planet killing weapon on primitive civilizations.

But I was merely addressing the principle here, not trying to bring this forth as a viable tactic or anything.

[Darth Wong]

That's not a mass driver in the context of this thread, which is about devices which accelerate a slug to high speed. That's just dropping something and watching it land.

[Gil Hamilton]

Larry Niven proposed an interesting use for mass drivers. (I hope I remember all the details).
Someone lands a power plant and a mining/construction robot on an asteroid (or a railgun kit). The robot beings to mines the asteroid and contructs a simple railgun (or assembles the railgun kit). The railgun is inserted into the asteroid through the center of mass. The robot then gathers minerals, drops it into it's reactor and smelts it. The slag is dropped into the rail gun and the its launched away. This pushes the asteroid in the other direction. Do this enough and it will push the asteroid into an orbit that will take it to civilization. When it arrives, you have a bunch of already refined materials heading to where they are needed without have ships go out and collect it.

[LordShaithis]

I never bought into the idea of using impractical weapons for "terror" purposes. Nuke a city flat, and the rest of the planet will be just as terrified as if you had dropped an asteroid on it.

[David]

Creating ultra-expensive terror weapons always did seem inpractical to me, so I'd agree.

[Darth Wong]

Obviously, you've never gone to the James Bond Super-Villain school of pointlessly impractical uber-weapons

[Gil Hamilton]

Obviously, you've never gone to the James Bond Super-Villain school of pointlessly impractical uber-weapons

Very few people have that villainous refinement. It takes a special kind of evil genius to go there, reserved for those rare few who aim the Unnecessarily Slow Moving Laser at 007s crotch rather then his head.

[His Divine Shadow]

That's not a mass driver in the context of this thread, which is about devices which accelerate a slug to high speed. That's just dropping something and watching it land.

Curses, foiled again!
I'll get you someday... And your little dog too!
*runs away*

[Graeme Dice]

The advantage of using a large rock to destroy a city over using a nuke is that the rock is cheaper, and harder to deactivate.

[Alyrium Denryle]

Very few people have that villainous refinement. It takes a special kind of evil genius to go there, reserved for those rare few who aim the Unnecessarily Slow Moving Laser at 007s crotch rather then his head.

I may be neutral with lawful tendancies but I do have that evil genius! Bwaha, bwaha, Bwahahahahah!