Newtonian Aurora

[jseah]

RE: vacuum energy

Of note is Noether's Theorem.  To produce energy from nothing, you need to be doing something that is not time symmetric.  (and 2nd law does not count)

[UnLimiTeD]

Cost of a Sidewinder Missile: ~85k $. Cost of a 80kg chunk of pure Iron: roughly 6k $ (actually a bit less). Foolproof radarguidance seekers are quite probebly 10x the cost of an old IR missile.
The main point here is that the missile is very likely to be larger, and anything with thrusters and guidance IS a missile for that matter.
As such, you need larger guns.
Additionally, a laser-based DIRCM is pretty affordable, and can not stop projectiles, but eliminate the advantage of homing rounds.
As said, in the case where the projectile flies for over 30 seconds, given the starting velocity of the ship of possibly a 100km/s, using guided kinetic missiles will be more likely to succeed, as in the same room of a railgun, a few dozen can be fired at once, overwhelming countermeasures.
Edit: Given the extreme electromagnetic forces required to accelerate a Projectile to 70+ km/s in the brink of a second, a guided projectile with it's own terminal guidance would require electromagnetic shielding, further increasing the cost. I'm starting to think that you could just mount an extra gun for every 10 guided projectiles you fire.

[LoSboccacc]

Some form of lower velocity shotgun type weapon is definitely a possibility. In fact, throwing a large rock out the back of the ship into the path of a fast-moving enemy ship could be effective given the right circumstances. Different weapon types are going to be effective in different situations and in some of those situations high tech vs low tech may be far less of an advantage than in standard Aurora.

Steve

given the combination of ship speed and projectile speeds and enemy speeds, fire control will have an hard time to find firing solutions and the correct angle of lead to shoot at.

[chrislocke2000]

Some form of lower velocity shotgun type weapon is definitely a possibility. In fact, throwing a large rock out the back of the ship into the path of a fast-moving enemy ship could be effective given the right circumstances. Different weapon types are going to be effective in different situations and in some of those situations high tech vs low tech may be far less of an advantage than in standard Aurora.

The Lost Fleet series had some interesting ideas about this sort of thing. Basically one of the main weapons for the ships was a ton of ball bearings that got fired into the path of an enemy ship to take down shields through multiple hits. I guess slamming into 5000 1 inch diameter chunks of metal is going to give any shield a battering.

[Yonder]

Why does everyone keep calling these things missiles?  It's far more akin to a guided artillery shell.

Because artillery shells guide themselves by slightly changing their flight dynamics. Things which guide themselves by throwing out reaction mass behind them are called Rockets or Missiles. And in modern vernacular rockets generally refer to an unguided version.

It seems to be that your hangup is the assumption that missiles have to explode, when that is not the case. You can have "kinetic kill" missiles which are basically your "guided artillery shells" that solely do damage by ramming. These could get up their speed solely through their own engine (and the initial velocity of their firing ship), or get an initial boost by being fired from a rail gun.

There are three other variants of missiles being discussed:
Nuclear Missiles, which detonate at the end of their flight leaving a large sphere of damage.
Shrapnel Missiles, which create some combination of kinetic kill warheads, either modeled individually or abstracted as some sort of cloud.
Bomb-pumped lasers, which funnel their explosion as some sort of directed laser beam burst.
Any and all of these missiles could theoretically be shot out of a railgun to get an initial kick. (Hmm, it would probably be too complicated, but maybe missiles could have a "maximum" acceleration value, so that non-missile slugs could be shot out of a railgun faster than kinetic kill missiles, which would be faster than Nuclear and Shrapnel Missiles, which would be faster than Bomb-Pumped lasers. That's probably unnecessary bookkeeping though.)
Of course you could imagine still more forms of missiles, especially when you consider staging, and Steve has stated that these current missiles will also completely envelope the earlier "drone" and "buoy" categories.

[bean]

Because artillery shells guide themselves by slightly changing their flight dynamics. Things which guide themselves by throwing out reaction mass behind them are called Rockets or Missiles. And in modern vernacular rockets generally refer to an unguided version.

I disagree, but will bow to general terminology.  Whatever you call them, guided projectiles are more effective.

It seems to be that your hangup is the assumption that missiles have to explode, when that is not the case. You can have "kinetic kill" missiles which are basically your "guided artillery shells" that solely do damage by ramming. These could get up their speed solely through their own engine (and the initial velocity of their firing ship), or get an initial boost by being fired from a rail gun.

The hangup is nothing of the sort.  I'm fully aware of the potential of kinetic-kill weapons.
The definitions I have been using are based entirely on the method by which the weapon gains the majority of its Delta-V.  If it uses a rocket, then it's a missile.  Any form of kinetic projectile is referred to as a kinetic.

[Yonder]

I’m not sure if Newtonian Aurora suggestions should be going in this thread or in the Suggestions section, but my gut says to keep the Newtonian stuff here.

I’ve been thinking for quite some time (actually done itsy bitsy pieces of my own game about it) about attacking things in space far away from you. This is how I believe that the automatic form of weapon targeting should be accomplished:

When a Fire Control targets an enemy and is about to fire it should calculate (using its projectile speed, whether light speed for a laser, or some smaller value for a plasma bolt, slug, or inert missile) where the enemy would be at the point the projectiles would hit it if the enemy drifted. We will call this the target point. It should then estimate the target bracket in a simplified way, calculate the distance travelled under the targets estimated maximum acceleration (probably whatever the highest acceleration you’ve seen the class accomplish thus far) in the time between the firing time and the impact time. It would add this distance to each direction to get the total width of the target bracket.

Let’s say that the leftmost part of the bracket is called 0, the center (“target point”) is 50, and the rightmost edge of the bracket is 100.

The Fire Control would then look at all the beams under its control (a quad turret would count as four) and divvy up the shots as follows:
Beams: Target Spots
1: 50
2: 25, 75
3: 0, 50, 100
4: 20, 40, 60, 80
5: 0, 25, 50, 75, 100
6: 14, 28, 43, 57, 71, 86
7: 0, 16, 33, 50, 67, 83, 100
Etc, etc.

Now if this bracket represented the offset in the angle the firing ship had to aim its beams than you have the firing solution for that one ship. If you had multiple fire controls on the same ship with the same weapon (maybe just same projectile speed) they could also sum their beams together to best divvy up their shot spread. It’s all coming from the same ship so the same angle offsets would work.

However this wouldn’t be the easiest way to optimize target spread amongst a whole fleet. The easiest way I can see to do that is for the target bracket to not refer to the angular offset, but to instead find that maximum evasion distance from earlier, and then draw a line from your fleet’s current position to your target’s estimated position (assuming drift). Your target bracket now becomes a shorter line perpendicular to this line from your fleet, with a length of twice the evasion distance and centered on this fleet line.

Now count up your beams and divvy up the targets along this new line, and you can use that to get a firing solution for your whole fleet.

For example, a fleet of five ships with two quad turrets each could now cooperate to evenly distribute there 40 shots among the (reasonable approximation of the) entire region their target ship could be when their projectiles reach him.

I think that the same system would be useful for targeting launched missiles (either launched slowly or fired from a railgun). This would naturally make your missile salvo spread out, helpful to conserve losses from your enemies’ defensive nuclear explosions, and ensure that at least some of your missiles will be on a very close vector to your enemy when they light up for final course correction.

[Goron]

That firing solution looks very much like a torpedo spread in a submarine.

[Sloshmonger]

Let’s say that the leftmost part of the bracket is called 0, the center (“target point”) is 50, and the rightmost edge of the bracket is 100.

The Fire Control would then look at all the beams under its control (a quad turret would count as four) and divvy up the shots as follows:
Beams: Target Spots
1: 50
2: 25, 75
3: 0, 50, 100
4: 20, 40, 60, 80
5: 0, 25, 50, 75, 100
6: 14, 28, 43, 57, 71, 86
7: 0, 16, 33, 50, 67, 83, 100
Etc, etc.

Like the thought, but you'd probably want to change those numbers to something like.

From -10 Size Deviations to 10 SD, where 0 SD is on a straight line centered through the target ship's heading at 0 acceleration, and one Size Deviation is the target ship's diameter.

From that, you get:
1 beam weapon: 0SD
2: 1/2 SD, -1/2 SD
3: 1SD, 0SD, -1SD
4: 1 1/2 SD, 1/2 SD, -1/2 SD, -1 1/2 SD
etc...

If targetting range is still limited to 5 lightseconds, then you don't really need this though.  You'd want to put as many points of damage as possible within the target window, and it's not going to change that much.

Using Steve's Daring Class from the first post, it's got a size of 6873 Tons.  That's 68730 m³, or approximately 109m diameter.

The most it can accelerate at 21.83 m/s².  Looking at a 1 dimensional line, at 5 seconds the center of the ship can be at most 117.15m off from where it would be with no acceleration.

So you can look at this from a table standpoint:

Time	Max Ship Deviation(s)
1	0
2	0
3	0
4	0
5	1
6	1
7	2
8	2
9	3
10	3
11	4
12	5
13	6
14	7
15	8

Remember, this is for a military ship with midgrade engine tech.  Higher engine tech would be tougher to hit when accelerating, just as lower tech is easier -- the Atlas freighter from the first post doesnt' hit 1SD until 8 seconds.

So I can see why 5 lightseconds distance was the max range for regular Aurora, and I can see how that may not change.

[Yonder]

But the spread system scales at any range. (There should probably be some sort of "Expected projectile hits" number when your FCs calculate a system before you tell them to fire. If the number is .0003 it's probably not worth the energy, if the number is .37, and at the speeds involved one shot would cripple or destroy the enemy... fire away!)

If the ship is so close to you that it actually can't get away (aka the "Evasion Distance" is less than the target's radius) then whether or not you spread or not doesn't matter, all of your shots will hit regardless.

(This is assuming that Steve keeps his "any hit does armor damage at random location" methodology. If he actually starts keeping track of where the ship gets hit, than you wouldn't want to spread if a hit was guaranteed, so that all shots hit as close together as possible. I sort of hope he keeps the current simple solution, but the ships will have actual facings now, so who knows.

[Dutchling]

I sort of hope he keeps the current simple solution, but the ships will have actual facings now, so who knows.

They do? I guess I missed something, quote pls?

[Yonder]

They do? I guess I missed something, quote pls?

No quote as such. But with Newtonian Physics you have to have a thrust vector. At the very least whenever a ship's engine is on it has a facing. However he's still stated 360 degree sensors and made no mention of turrets pointing or not pointing at a target, so it seems like he is still ignoring all facing mechanics except for the required thrust vector. (Which I think is wise).

[UnLimiTeD]

Yup, he repeatedly said we won't go into facing, as this at it's core is still a strategy game and not a tactics simulation.

[Dutchling]

No quote as such. But with Newtonian Physics you have to have a thrust vector. At the very least whenever a ship's engine is on it has a facing. However he's still stated 360 degree sensors and made no mention of turrets pointing or not pointing at a target, so it seems like he is still ignoring all facing mechanics except for the required thrust vector. (Which I think is wise).

Well I thought it would be something like that, just wanted to be sure.

[Sloshmonger]

But the spread system scales at any range. (There should probably be some sort of "Expected projectile hits" number when your FCs calculate a system before you tell them to fire. If the number is .0003 it's probably not worth the energy, if the number is .37, and at the speeds involved one shot would cripple or destroy the enemy... fire away!)

If the ship is so close to you that it actually can't get away (aka the "Evasion Distance" is less than the target's radius) then whether or not you spread or not doesn't matter, all of your shots will hit regardless.

Not only would you want to hit, but you'd also want to have the most hits, though.  So if you had 1 shot, you'd take it down the center.  For 2, you'd split it fairly close to the center.  For three, four.... continue on.  But say you have 20? I'd still cluster my shots around the center, probably looking fairly bell-curve shaped. Putting 4 massive alloy rods through a ship is better than putting just one. Because, as the saying goes: "There is no overkill.  There's just 'Open Fire' and 'I need to reload'."

That being said, we may be being a little silly.  Looking deeper, it probably isn't worth it to compute it.  Straight up hit/miss is tough enough.

Take the Daring class again.  At 1,400,000 km away (current max beam), that 109m diameter equates to 0.016 arcseconds, roughly 1/2 the apparent size of Eris.  At that range, 21.83 mps² acceleration can result in a deviation of 237m diameter from projected location with no acceleration.  That equates to approx the same apparent size as Eris.

On a 1 dimension line, that's a target that's 45.86% of the area.  On a 2 dimensional area, that's a target that's 21.03% of the area. I don't know which is used for computing hit/miss chances, but since in current Aurora you can stop on a dime, I don't think it's taken into account.

Now, granted we're talking about a game about spaceships which does involve some handwavium, but that's awfully precise to hit at that range.  And even more so at greater ranges.  If you double the range, you halve the apparent size of the ship, but double the potential deviation.  If you quadruple the range (5.2m km), you have 0.004 arcseconds of target to hit in .130 arcseconds of potential, or approx 3%.  Going backwards, at 1m km you're aiming at a .022 arcsec target in a .025 arcsec field, so pretty good odds to hit.  And at 60k km, that target is .37 arcsecs big, or the approx apparent size of the asteroid Ceres.  And at 595km (same as Hubble) that ship would be the same apparent size as Jupiter, and visible to the naked eye.