Sandia Labs tinkers with 'silent' mortar

[Robb]

Sandia Labs tinkers with 'silent' mortar

(snip)

"It's a step in the direction of building high-velocity (launchers), better controlled guns and other launcher applications," including ultimately being able to use electromagnetic thrust to launch satellites into space, Turman said.

The new style launcher applies a magnetic field to a coil on the projectile, forcing it through the barrel of the launcher.

(snip)

That means a mortar "that is basically silent," Turman said. "There is no large explosion when the gun is fired."

A silent launch, plus the absence of powder smoke from the muzzle after firing, makes the launch safer for the mortar crew because their location is less detectable by the enemy. There is also no safety issue from exploding gunpowder.

(more)

[Selatius]

1. A rail-gun, a more efficient way of killing people

It's funny how advances in technology owe a huge amount to the need to invent new ways to kill each other.

[daleo]

2. There might be a powerful magnetic field though

Which could tip off another high tech combatant.

[achtung_circus]

3. Anti-mortar radars

used on the battlefield to mark launch sites have been around for years.



The Cymbelline is a highly accurate mortar locating radar system which detects enemy artillery/mortar fire and directs friendly artillery/mortar fire to counter it. The system is lightweight with a built-in power supply, is simple to operate & maintain, provides high tactical mobility with rapid 'into-action' time and has built-in self test facilities and a training target simulator. In addition to the Cymbeline's primary role of locating firing weapons and directing friendly fire, this system can also be used to track & control helicopters, light aircraft, conduct ground & coastal surveillance and even establish survey grids.

[Karmakaze]

4. I was gonna say...

exactly that - these counter-battery radars do NOT detect the launch smoke or noise, they simply track the incoming shell calculate the trajectory back to the launcher and target it for destruction.

In fact I would think a shell designed to be propelled by magnetism would be far more radar reflective than even a normal shell, making it even easier to find the firing position.

[dysfunctional press]

9. plus it would probably be harder to move quickly to a new location...

and i would imagine that a rail-gun mortar is going to need a pretty large power-supply

[sam sarrha]

13. they will develope Stealth shells

[Thor_MN]

14. "The new style launcher applies a magnetic field to a coil on "

"The new style launcher applies a magnetic field to a coil on the projectile"

I think this implies that the projectile would be mostly composites and explosives. It definitely would not have a ferrous casing, so it could potentially have a very small radar signature.

That said, do we really freaking need more weapons? * and Co have already cleverly proven that we can't hold as much land as we can capture, so what's the point of more offensive weapons?

[AndyTiedye]

17. Looks Nice for Launching Satellites Though

Seems pretty useless as a weapon, but might be nice for launching satellites.

A lot cleaner than a rocket, certainly.

Less pollution, less space junk.
Way less energy needed, since you aren't launching all that fuel and rocket along with the payload.

If they have to take something genuinely useful
and pretend it is a weapon to get it built, so be it.
It wouldn't be the first time.

[StClone]

5. Not to mention shock wave

An object rapidly accelerated to speed would displace air initiating a detectable wave pattern. I wonder what precautions the operates would need to take in the presence of sudden super magnetic fields.

[Ready4Change]

6. Displaced air not so much the issue.

The two real issues are the aforementioned radar tracking of the shell, and the as yet unmentioned, but hard to avoid, electro-magnetic signature of the launch.

At least, if they are tracking your shells with radar, they are using an emission that can be detected and targeted in return. But they can locate an electro-magnetic launch passively. You wont know you've been located until THEIR shells are inbound on YOUR location.

[IndianaGreen]

7. After the nuclear holocaust, the scientists were killed by angry mobs

of survivors for they were blamed for creating the technology that brought about the world's calamities.

Walter M. Miller, Jr., A Canticle for Leibowitz (1959)

[formercia]

8. What they don't show you

is the semi-trailer sized power plant needed to power the weapon.

This is another bullshit pie in the sky boondoggle meant to waste taxpayer's money.

[NoodleyAppendage]

10. Uhhh... high electromagnetic field + unshielded soldiers = health issues

There's a reason why MRI magnets are shielded in 1 foot thick concrete enclosures. The body absorbs electromagnetic radiation in dosages proportional to the strength of the exposed field. Repeated exposure may have unknown adverse side effects.

But, then again, when have military contractors really given a flip about the long-term health exposure issues of soldiers.

J

[Thor_MN]

12. I believe that MRIs are shielded by steel, the older the better.

Concrete would do next to nothing to attenuate magnetic fields. On the other hand, concrete would be useful in preventing any ferrous items that have become projectiles in the magnetic field from hitting the very expensive machine.

As for sheilding, the older the steel, the less natural radioactivity, which causes interference.

Strong magnetic fields have not proven to have any health effects. MRIs use a combination of a strong magnetic fields and a Radio Frequency field to producing imaging. Equating an MRI with rail gun is not all that valid. Beyond the fact that a rail gun does not use an RF field, consider efficiency. The focus (tiny pun intended) of an MRI is to put the subject being imaged into a strong magnetic field. A rail gun puts its field to use in accelerating the projectile. In either, any energy expended outside the device is waste.

The principle health concerns around a rail gun would likely center around ferrous foreign objects in the body like shrapnel, prostheses or fragments from a metal working accident.

[NoodleyAppendage]

15. The casing for MRIs must be something else other than common steel.

I don't think the support beams surrounding an MRI can be even marginally ferrous because the strength of the magnetic field over time could structurally weaken the housing. Whatever the materials used, it isn't traditional steel as the housing surrounding the 4T magnet we use for research cost almost as much as the magnet itself (2mil.). Maybe cobalt chromium or titanium...

Radiofrequency perturbation of the magnetic fields generated by some of the stronger MRI magnets (4 and 7 Tesla) is well-known to produce localized heating of the tissue, particularly when there may be a loop created by body position. Often times this heating can be minimized by tweaking the radiofrequency pattern and speed of image acquisition. Also, the gradient field in these magnets can cause interesting sensory and motor phenomena with the most common being myoclonic leg jerks or visual perceptions of moving specks of light (as field affects phosphenes in eye).

While you are correct that high field electromagnetic field exposure is not known to cause health effects, there's also a reason why pregnant women are verboten from receiving MRI. It is the possible field action on basic cell division mechanisms (telomeres) that worry many and is the justification behind limiting MR exposure in women of childbearing years. This concern, to me, seems to reveal a general uncertainty about MR exposure in general. If perfectly safe, why the need to "hedge bets" by not scanning pregnant women?? And, this is coming from someone who works extensively with the technology.

J

[Thor_MN]

16. By shielding, I thought you were refering to shielding the magnetic field.

I think that banning pregnant women from rail gun weapon crews would be highly desirable for more than one reason, but that a crew member wouldn't likely have cell division at anywhere near the rate of a fetus.


Any ferrous material in close proximity to the magnetic coils of an MRI would be very bad. The instrument housing would certainly be non-ferrous.

I think I remember reading that old steel was desirable as shielding outside the structure (the foot of concrete you mentioned) to reduce interference from natural radioactivity. The shielding itself I assume is dual purpose: to attenuate the magnetic field so that keys in the pockets of people passing by the building don't get launched and to reduce RF interference from outside.

How would they safely operate such a weapon? Are the going to have crews outfitted with only plastic, ala the X-Men cell to house Magneto? No zippers, only velco? No metal objects anywhere near? Imagine the effects of setting up near a barbed wire fence...

Other than that, I think that we have more than enough weapons right now. Who are we tring to outdo in weapon development? Anything we develop is only going to get copied, so why are we spending money on this? We have enough firepower to kick the collective behinds of most of the world, but can't safely occupy a county the size of California. I like the idea of rail gun technology to deliver materials to orbit, but as a weapons platform, we just don't need it.

[Nihil]

18. Yeah ...

> How would they safely operate such a weapon? Are the going to have
> crews outfitted with only plastic, ala the X-Men cell to house
> Magneto? No zippers, only velco? No metal objects anywhere near?
> Imagine the effects of setting up near a barbed wire fence...

It's not as if soldiers are normally found near ferrous objects
(guns, knives, watches, belt-buckles, bullets, ...)

Even if they have "plastic" operators, I'd like to see how they intend
to defend the emplacement as the guards would obviously have to be a
certain distance away ... oh the irony, box-cutters anyone?

[billyoc]

11. The schoolkids will never know what hit 'em. n/t

[sweetheart]

19. EMF research is their thing

If you fly in to albuquerque airport from the right direction, you'll pass over
this giant wooden structure with a small airplane sitting on it. Well, it turns
out it is the world's largest wooden structure, and what looks like a little cessna,
is a B52... or as i last saw it.

They've been hiring and developing EMP hardening, and obviously have a lot of test
and playground gear laying around the place. So, as los alamos gets all the focus,
sandia has to make the periodic announcement, just so they don't get made redundant
to find jobs in the real economy.

I could build you a missile that would hit this gun. A magnetic field that strong
is visible to other weapons systems. As it has a huge powerpack, liekly it is more
a sort of weapon for a ship, or a railroad, but the bigger the platform, the most
is at risk from the broadcast of a mega powerful magnetic field and a burst electric
field as well. Oh oh, a wild weasel would be diggin a field of theze guns.

[truthisfreedom]

20. ahh, the benefits of civilization. no mortar rounds to wake us up, just

the lovely explosion as the device hits its target. we are oh-so civilized, aren't we?