More effective than something that has an infinitesimal chance of hitting doesn't help much.




That is a wildly inaccurate description of the universe. The universe is an extremely cold, quiet, and empty place: 2.7 K background, vast stretches of empty space with only a sparse scattering of solid objects...it is an exceptionally clean environment for sensors to operate in. We can track bits of cm-scale debris in orbit now, through an active atmosphere, without trying very hard. And though they'll almost certainly be quite hot from the mass driver, it's not any sort of "charge" that they'll be tracked by...such a launch will require them to be constructed in a way that'll also make them clearly visible on radar. But while the target is almost certainly capable of tracking the shots, they wouldn't need to...they need only adjust their trajectory a bit.




To make a wide debris cone requires propulsion that can achieve a good chunk of the velocity imparted by the mass driver itself, and to have any chance at a hit you need very high mass driver velocities. The faster the projectiles are fired, the narrower the debris cone will be or the more visible the projectiles' propulsion systems will be. The slower they are, the further the evasion maneuvers will take the target by the time they pass.

Outsider ships could literally turn around and outrun projectiles fired at them. Say a mass driver with a muzzle velocity of 100 km/s fires at a ship 16000 km away...point blank range in Outsider terms, 0.05 light seconds. They take a full 60 seconds to turn around and get their drives up to 30 g. A bit under 3 minutes later, the projectile has approached to within a couple thousand km and is now falling behind. They would only do this to show off...they could easily dodge the projectile by a wide margin by doing a much shorter burn at a perpendicular instead. Even a minor maneuver would take the target far out of any plausible debris cone, they simply have no reason to expose themselves to the risk.

Surely an improvement but let say you have an railgun of a specific size that shoot standard size ammunition. Ether you shotgun fire smaller shell or to keep the same size per "pellet" as the standard ammo you increase the size of the railgun.

You say that bullet will be small enough to not be detected. am sure ship would have "natural" defense against that, after all they fight at great speed in system were flying pieces of debris fly all around from previous battle.

yet again i take the 12ga as an example and a normal Kevlar body armor. At close range you wont like being shot might get broken bone or worst. but a long range i dont think you would get any damage.




he would probably think of it as if it was a torpedo and torpedo seem to cover a large area with particle.

If they aren't ferromagnetic then the MD won't be able to shoot them.



Not really, WE have sensors capable of detecting chunks of ferromagnetic materials at hundreds of miles IN ATMOSPHERE, space is MUCH quieter than Earth, it's not really a problem.



They aren't TRYING to evade mass driver shots, they're trying to evade beam weapons which require FAR more movement.

Hmmmmm. This seems to be a bit of a switch from what you were saying before. I need to get the old forums scraped so I can re-read what you posted before but I seem to remember you implying, if not stating, that tech like that wouldn't be applicable to MDs.



And chances are good that the Winter Tide as of Page 81 is capable of wiping out the entire TCA by itself.



Soft vest? Neither would I. Vest with ceramic plates? Bring it on...just aim for the plates please

NOw that Is a good idea

EM mass driver projectiles likely wouldn't be ferromagnetic...it's the simplest way to build a mass driver, but not particularly effective (issues of saturation, hysteresis, etc). High power mass drivers will operate more like induction motors, with a conductive projectile that the accelerating magnets induce currents in. Basically a scaled up EMALS.

They'll still be radar-visible for the same basic reasons, though.

Depends on what "high percentage of c" means. 0.1c or so? Or more directly competitive with beam weapons? But even if the latter, it might not matter...

For a given projectile energy, higher speeds require a shorter pulse of higher power. It's easier to make a high-mass, low-velocity projectile with outrageous amounts of kinetic energy. My understanding is that this would be why Terran mass drivers are terrifyingly destructive if they actually hit...even at much more limited peak power input, human ships can pile more energy into the projectile before it leaves.

But once you've built a relativistic mass driver, you've got to power the thing. If you're powering it with the same thing you're powering plasma weapons with, and firing shots at comparable velocities, your energy per shot, shot mass, and peak power output are similar...if mass drivers aren't vastly more efficient than plasma weapons, you've now got mass drivers which now have characteristics similar to plasma weapons, but require a quite different approach to ship design. Piling more energy in to get results similar to Terran mass drivers requires bigger power supplies or slower shots. They might be able to build a similarly destructive relativistic mass driver, but could they fit it and its power supply on a ship?


Some random numbers:
10 kg@0.05c: 1.13e15 J, 270 kt TNT
Leaves a 100 m accelerator 13 microseconds after acceleration starts. Power averaged over acceleration: 85 exawatts.

10 g@0.9c: 1.16e15 J, 280 kt TNT
Leaves a 100 m accelerator 741 nanoseconds after acceleration starts. Power averaged over acceleration: 1565 exawatts.

I'm afraid I have to conclude you do not understand the laws of physics or the principles of engineering nearly as well as you think you do. Especially when you start to say that gravity 'pulls apart on pretty much the entire thing equally'. Most of what you say about guns is also incorrect. Tank guns top 5000fps. Light gas guns top 20,000fps. As an illustration, exactly what contains the engine reaction, and stops it blowing up the ship? Because once you're containing and directing such high pressures in a practical useful way... Exactly how is that different from a gun barrel?

If you want to believe that the Loroi and the Umiak are significantly more advanced than the humans of the future, who are in turn significantly advanced than us, then you can't suddenly turn around and say something is impossible for the Loroi because it's impossible for us.

If you want to say, "Rail guns don't work because this is a space opera, and they don't look pretty," then fine. But please don't try and hide behind real world physics. You look silly.

Especially when the author contradicts you.

Gravity penetrates through objects, a gun designed to pull things along by gravity at tens of thousands of gs will put enormous strain on anything fired through it. That strain would not likely be coming from directly in front of the projectile (nor would the pushing force if you were using a repulsion effect), resulting in in significant "pulling apart" effect on projectiles that would indeed be more or less equally spread out throughout the projectile.



I was referring to infantry weapons, there aren't many rifle rounds that go significantly above 3000-3500 fps, the returns start to diminish too quickly for it to be terribly practical. There are certainly rounds that do, some even top 4000 fps, but they tend to be specialist rounds that aren't very popular (some people don't like replacing their barrels every couple hundred rounds for some reason).



You're talking about vastly different things. The violence of a mass driver firing at a velocity high enough to be useful is likely to be FAR greater (and focused in a much smaller area) than the engines. For comparison consider the Saturn 5 rocket burning steadily over the course of several minutes vs. all the fuel in a Saturn 5 detonating at once. Which is easier to contain? How strong would the body of the S5 have to be to contain that force and direct it in a useful manner?

As I said before, the force needed to accelerate a ship increases linearly (give or take efficiency) with the desired acceleration. The amount of force required for a gun goes up exponentially (before efficiency losses), those engines are performing a far milder task than a relativistic mass driver.



Without massive applications of super-tech mass drivers are GOING to be out-performed by significant margins by other options, this is simply the way it is. Arioch has stated that mass drivers will be outperformed by other weapons on more than one occasion, in fact IN THIS VERY THREAD he has stated that even with the best tech the Loroi have mass drivers will be outperformed (at the very least on an ROI basis) by other weapons. So yes, it apparently is impossible for the Loroi to build a mass driver competitive with other weapons.



"Hide behind real world physics"? So I should assume that physics don't apply until I'm told that they do?



If you re-read that post you'll note that the CONCLUSION (mass drivers can't compete) is still the same, even though the details were contradicted.

If it was a gravity driven rail gun I would be tempted to go the Mass effect2 way and use a material in the liquid state as a projectile. And accelerate a short stream of it.
Probably would not hold together long but if you managed a system that could get the low mass your firing out of it to about .7 the dispersal would probably be small enough at weapon effective range that it would be a nice anti systems weapon. Probably not too good against heavy armor but hell on external weapons and sensors.

Ship design would be interesting for that weapon due to the gravity requirements of getting that much acceleration even if you go with a hybrid magnetic gravity system you still gonna have to keep it away from the main ship.

Would give Terran ships of the future a a different look if they had to mount their weapons like this. .... Forum software are some spaces but you can still see the idea.

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I still say detecting mass driver shots in a battle enviroment, in space..is silly.

If they could detect such small objects, their sensors would be beeping 24/7...cause there all kind of crap in space.

In a battle environment it would be slightly more difficult, but only slightly. Space is mostly empty, the VAST majority of space consists of a very small number of hydrogen atoms just sort of chilling. I'd be curious exactly what you think space is filled with.

Like what? You said this before and did not respond in any way to the responses you got, repeating it doesn't make it true.

In reality, space is an extremely cold, quiet, and empty environment, ideal for this task. We can already track tiny bits of debris in earth orbit, and that's randomly moving objects viewed through an active atmosphere, with present day equipment and minimal funding. Even in a tremendously dirty and noisy region of space like the proplyd they're in now, radar returns from mass driver projectiles would be trivial to pull out of the data due to their vastly higher closing speeds. The only solid objects out there moving at such relative velocities would be projectiles and ships...nothing else.

I'm reminded of the first chapter of Starship Troopers, where the troopers dropping onto a planet from orbit shed huge amounts of chaff into the atmosphere to give ballistic computers a breakdown.

A barrage of ball-bearing sizes chaff with a high radar signature would probably be quite useful at close distances like the ones we're seeing in the comic now, and could effectively mask railgun shots, as well as missiles. Combine this with dummy missiles (an engine stuck to an inflatable missile shaped balloon) and you could turn the battlefield into a complete madhouse. To be honest I'm surprised the Umiak don't already do this since they seem to rely on brute-force methods. Just send out random barrages of fake missiles and watch the Loroi go crazy expending ammunition on them.

Welcome to the board, dfacto.

An Outsider torpedo is essentially just an engine and a guidance system; the matter-conversion reactor that powers the engine is also the warhead. So a dummy with a real engine isn't a dummy at all, but a real torpedo. A less expensive chemical engine would probably have a very different signature from a real torpedo, but more the point, it wouldn't be able to keep up with the acceleration of the real torpedoes.

Chaff really wouldn't be of any use for hiding projectiles (and ball bearings would be a horribly inefficient way to produce it, you want stuff with a large radar/lidar cross section for its mass, like foil strips). If it's not fired at the same velocity as the projectile, the projectile will quickly exit those chaff clouds. If the chaff is fired along with the projectile, it only serves to make it easier to track...it's right there in the middle of that cloud of chaff, which can for all practical purposes be tracked by the computers and evaded as a single object.

If you just cut out all returns that aren't severely shifted to shorter wavelengths, the only thing remaining will be the projectiles heading toward the ship (and any chaff fired along with them for whatever reason). This can be done just by looking at returns in a particular frequency band...computers don't have to individually pick out and discard each return that's not headed toward the ship.

Chaff is even less useful for missiles, because they continue to accelerate...the chaff cloud will be stuck on a ballistic course and be left behind. As for dummy missiles, a smaller engine pushing an empty shell instead of a warhead would probably be rather obvious to the target's sensors, and filling magazines with dummy missiles takes up room that could be dedicated to actual weapons. Plus there's the issue of taking production away from actual missiles/torpedos. About the only thing you could realistically make "dummy" versions of would be mines, which themselves are of rather limited use.

Depnds on the regions of space. But given all the asteroids and comets, there's plenty of tiny objects. small clumps of rock or ice that broke off....space debris, etc..

As for detecting mass driver shots - it's like detecting bullets. Can we detect bullets in flight with a radar?

That's not "plenty", as evidenced by the faintness of gegenschein and the fact that we can still see stars. In all but a few unusual systems, such debris will be extremely sparse as it is in ours, where probes and satellites regularly travel tens of thousands of light seconds and operate for decades without a major impact. And it has dramatically different characteristics from mass driver projectiles...it's not on a collision course with your ship at some enormous relative velocity.




Yes. It's a common way of measuring external ballistic characteristics of bullets. The Weibel 1000e for one example.

And I'm repeating myself, but you keep ignoring the fact that we do currently detect and track space debris in the cm size range in Earth orbit, with present-day equipment stuck at the bottom of an active atmosphere built and operated on a rather limited budget.

Yes. But we don't know every object. It is just that when something is found, then it is searched from catalog. If it is not there, it's trajectory is followed until it is known and added to to catalog.
Couple of years ago they found about 10+ meter object, which is probable part of moon mission rocket from 50-60. It was not found before, because most of time it is somewhere between earth and moon.

We don't know every object because the debris is constantly being perturbed by atmospheric drag, light pressure, and the moon's gravity and constantly being added to by collisions and new launches, and because resources for tracking such things are very limited. The fact is that we can detect and track such objects now...future military spacecraft would better positioned and better equipped to do so.




J002E3. It's in solar orbit, most of the time it's nowhere near either Earth or the moon...it was detected when it was briefly in a semi-stable orbit around the Earth-moon system.

I bow in front of your knowledge.

Additionally we don't know every object because it costs money and there's no money to be made in knowing every object. Astronomers can spend their grant money on something fairly pointless that no one cares about, or they can spend their grant money on something interesting that can advance our knowledge and their career.