Newtonian Aurora

[Mel Vixen]

Well you dont need as much mines. You can secure a sytem by 2 ways.

You set up patches of mines. Arrange them loosely in a ring or a (semi-)random grid. This way the enemy would have to asume you have a entire minefiled.  

The more sophositicated assembly is a moving minefield. The most efficient path for such a field would be a circular one like being in orbit around a massive object. I propose you set up some small patches of mines to orbit a star. Supposed you have enough speed and a enough mines (you need more mines at lower speeds and higher radie to get the same amount of defence) you can put up a huge defence ring at compareable small costs.

Since everything that you chug out of your spaceship will have roughly the same speed and course as your spaceship the deployment of engineless mines works very well. Suppose you go from earth to Jupiter to perform a swingby and then another around the freaking sun your momentum could be pretty high. Give your mines a gentle push in the right direction (or some steering thrusters) and they would get into a defensive orbit for the virtual eternity ... that is if your calculations where right.

For a passive field you would need thin long "strip" that is perpendicular to the source of graviation. For small corrections (like avoiding spiralling into the sun or out of the system) you could still use your thrusters. Same goes for aiming at the enemys ship if you want a "active" minefield this would need sensors thought.

Damn you could use just some rubbish say a ton of compressed cat-litter or for simplicitys sake rocks. Shaped, hardened and rather dense projectiles would still be more effective.

The defense value depends on some things. Mostly on the speeds of your mines and the target. Also on the size and number the strips in a passive field respective on the number of packages on a single orbit and how good your sensors are. These sensors could themself be part of the "minefield" or could be stationary which i atleast would prefer.

It could also be dangerous to you. Blowing up enemy ships or old satelites (i am looking at you china) could create a cloud of spacejunk that could have effects from sanding of your paintjob up to making pretty speed holes into your hull.

[Steve Walmsley (OP)]

EDIT: As for not-always-on active sensors, I see that as a potential source of undesired micromanagement... What about if not enough power exists to run it constantly, it supports lower power or delayed modes?  Lower power might be the ability to lower the sensor sensitivity in exchange for less power use.  Delayed mode might be switching on the sensor for 5 minutes, off for 5 minutes to reduce power use, though in this case it will result in a delay of up to 5 minutes before a new contact is spotted, potentially fatal for warships but of less concern for expendable scoutships.

I have also come to the conclusion that "not-always-on active sensors" are a bad idea. Instead, systems such as active sensors that have a constant power requirement rather than the "large amount of power occasionally" requirement of weapons, will draw that power directly from reactors. So if you have a sensor that requires 250MW and you have a 400 MW reactor, the power from the reactor will run the sensor and the remaining 150 MW will be sent to the capacitors (homopolar generators) if there is capacity available. On the class summary, any system with a constant requirement, such as active sensors, will have that shown in Megawatts (MW) while systems with a requirement for energy from the HPGs, such as weapons and shields, will have that shown in Megajoules (MJ)

Steve

[Steve Walmsley (OP)]

I'd put this in a seperate topic, but as these pretain directly to Newtonian Aurora, I thought it would make more sense to post them here.

Now that we have ships with accelerations, what about having those limited by crew type/technology, etc. Races from high grav planets would have an advantage here, which is a fair tradeoff given that they have less planets to colonize in return. Essentially, at G levels above say twice the races natural maximum (ie, 3.4g for humans) an extra delay is added to order changes; until at around 6x (10.2g for humans), order changes are not possible. So you could program in a high acceleration manuever, but once it starts you cant do anything until its over. Obviously, AI cores might no have the same issue, but could have other downsides, like limits to crew bonuses, no commander bonuses, high power requirements, susceptibility to microwave and EW weaponry.

These effects on crews could be mitigated though technology, either through bioegineering your crews to be more grav resistant, or through some alternative method like gravitic reduction systems.

Regarding sensors from the last poster, a low power mode might be an option, along with a pulsed mode that could be automated. Ie, On 1min, off 2min, etc. If you're looking at sensor changes, I thought I'd bring up the ability to activate sensors independently of each other on a ship with multiple systems. Would make power management more interesting too.

Any plans to have passives require some low amount of power to run? Same for lifesupport etc.

Interesting idea about the crews G resistance. The order delay might not work because players would tend to cease acceleration before giving orders. Perhaps instead crew grade could be reduced while under high acceleration so a ship would fight less effectively.

Good point about individual sensors being on/off. I should add that to both standard and Newtonian at some point.

For the moment, I have no plans to use power requirements for passive sensors and life support. I am aiming to have power/energy requirements for major systems only.

Steve

[Steve Walmsley (OP)]

Railguns

Railguns have changed completely from standard Aurora. There are now six parameters in the design window:

Railgun Maximum MJ Per Ton: The muzzle energy in Megajoules (MJ) of the railgun is based on its size in tons (not HS as I am moving away from HS) multiplied by this number. So a 200 ton railgun with an MJ per Ton of 12, would have a muzzle energy of 2400 MJ. Damage in Newtonian Aurora will be calculated based on the MJ output of a weapon. For comparison, the recently tested US Navy railgun has a muzzle energy of 33 MJ. This is a tech line starting at 5 MJ per ton.

Railgun Energy Conversion Rate: The efficiency with which the railgun transfers energy stored in homopolar generators (HPG). If this was 35% for example, the 2400 MJ railgun would require 6857 MJ of energy to fire. This is a tech line starting at 25%

Railgun vs Projectile Maximum Mass Ratio: This is the ratio of the total railgun mass compared to the mass of the projectile. The kinetic energy of each shot is based on the muzzle velocity squared multiplied by half the mass of the projectile (real physics - not my formula). This means that greater velocity is more important than larger projectiles. Also, greater velocity makes fire control easier. So, the question becomes why not spend your muzzle energy on smaller, faster projectiles? Because with a smaller 'calibre' the actual rails become longer and narrower and there is a limit to the aspect ratio between 'calibre' and rail length. As Aurora doesn't really consider how 'long' something is, that design consideration is handled by this parameter. You can exceed the mass ratio if you wish (and therefore increase muzzle velocity) but your energy conversion rate is reduced by maximum mass ratio/actual mass ratio. I'll show an example of this later on. This tech line starts at a mass ratio of 100,000, which is a 1 kg projectile for a 100 ton railgun.

Railgun Heat Dissipation Rate: When a railgun fires, it generates a huge amount of heat. The parameter covers how rapidly the railgun cools down to the point at which another shot can be fired. It is based on the surface area of the railgun, which is based on its mass. The value of the parameter is how much MJ/s per square meter will be dissipated per second (assuming 1 ton = 1 cubic metre). Smaller railguns will have a greater surface area vs volume than larger railguns so they will cooldown a little faster. For example, if this parameter was 0.6 MJ/s and the railgun was 200 tons and 2400 MJ, the surface area would be 165.4, the dissipation rate would be 99.24 MJ per second and the total cooldown period would be 2400/99.24 = 24.18 seconds, rounded to 24 seconds. You can increase rate of fire by either researching this tech line, or you can also reduce the MJ per Ton parameter to create a less powerful but faster firing railgun. For example, changing it from 12 to 5, would create a 1000 MJ railgun that fired every 10 seconds (albeit at about 2/3rds of the muzzle velocity).

Railgun Size: The size of the railgun in tons

Projectile Mass in Kilograms: The size of the projectile, starting at 1 kilogram with 0.1 kg increments to 5 kg and then 0.5 kg increments. When you hit the mass ratio limit described above, if you wish to create a more powerful railgun while retaining as much energy efficiency as you can, then increasing the size of the projectile becomes the best option. However, if muzzle velocity is deemed more important than energy efficiency then increasing mass ratio would be more effective. The following examples assume MJ per Ton of 12, a 200k mass ratio, a conversion rate of 35% and a heat dissipation rate of 0.6 MJ per m2.

Below is a 200 ton railgun with a 1 kg projectile. This makes full use of the maximum mass ratio of 200k. Note that Vendarite is now the required material for kinetic energy weapons (also, the existing research field of missiles and kinetic weapons has been split into two separate fields). The railgun has a Muzzle Velocity of 69,282 m/s (69.3 km/s), which is the maximum that can be achieved with the available technology without sacrificing energy efficiency. While this doesn't seem to be a very high velocity compared to standard Aurora, bear in mind most ships at a similar tech level would require several hours of acceleration to reach this speed from a standing start and if they are moving faster, their own speed may (depending on the ship's heading) increase the relative speed of the projectile and increase its damage.

2400 MJ Railgun
Muzzle Energy: 2400 MJ     Muzzle Velocity 69,282 m/s    Cooldown Period: 24 seconds
Power Requirement per shot: 6,857 MJ    Energy Efficiency: 35%
Mass Ratio: 200k    Energy Efficiency Penalty: 0%
Railgun Size: 200 tons    Surface Area: 165.4    Projectile Mass: 1 kg
Cost: 24    Crew: 20    HTK: 2
Materials Required: 24x Vendarite
Development Cost for Project: 240RP

Now lets look at two options for doubling the size of the railgun to 400 tons. The first has the same 1kg projectile size and the second has a 2kg projectile. Both will inflict the same damage and both take 30 seconds to cooldown, because their surface area to volume ratio has decreased. The former has increased the muzzle velocity to almost 100 km/s but at the expense of reducing energy efficiency to 17.5% and therefore requiring 27,429 MJ per shot. The second has the same 70 km/s muzzle velocity as the 200 ton version and requires 13,714 MJ per shot. BTW, you may be thinking why bother with a 400 ton 4800 MJ railgun and instead have two 200 ton 2400 MJ railguns. I'll explain that when I describe the new shield generators.

4800 MJ Railgun - 1kg
Muzzle Energy: 4800 MJ     Muzzle Velocity 97,979 m/s    Cooldown Period: 30 seconds
Power Requirement per shot: 27,429 MJ    Energy Efficiency: 17.5%
Mass Ratio: 400k    Energy Efficiency Penalty: 100%
Railgun Size: 400 tons    Surface Area: 262.5    Projectile Mass: 1 kg
Cost: 48    Crew: 40    HTK: 4
Materials Required: 48x Vendarite
Development Cost for Project: 480RP

4800 MJ Railgun - 2kg
Muzzle Energy: 4800 MJ     Muzzle Velocity 69,282 m/s    Cooldown Period: 30 seconds
Power Requirement per shot: 13,714 MJ    Energy Efficiency: 35%
Mass Ratio: 200k    Energy Efficiency Penalty: 0%
Railgun Size: 400 tons    Surface Area: 262.5    Projectile Mass: 2 kg
Cost: 48    Crew: 40    HTK: 4
Materials Required: 48x Vendarite
Development Cost for Project: 480RP

Here is a third option using a 1.5kg projectile, which is a compromise between the other two. Bear in mind these are just the options for two different sizes at one tech level. You will be able to create a lot of different designs, of different sizes, even at just one technology level. With multiple tech lines involved, there are many possibilities for railgun design.

4800 MJ Railgun - 1.5kg
Muzzle Energy: 4800 MJ     Muzzle Velocity 80,000 m/s    Cooldown Period: 30 seconds
Power Requirement per shot: 18,240 MJ    Energy Efficiency: 26.32%
Mass Ratio: 266k    Energy Efficiency Penalty: 33%
Railgun Size: 400 tons    Surface Area: 262.5    Projectile Mass: 1.5 kg
Cost: 48    Crew: 40    HTK: 4
Materials Required: 48x Vendarite
Development Cost for Project: 480RP

I haven't worked through fire control yet for railguns but at the moment I am leaning toward tracking each projectile as if it were a missile with no maneuvering ability and checking if it occupies the same space as the target (or anything else that gets in the way) at the same time. If that is the case, there will be more chance of it intersecting a ship with shields than the same size ship without shields (see next post for shields). The actual firing of the projectile will be based on the course, velocity and acceleration rate of the target ship and an estimate of where it will be when the projectile arrives. Of course that means the best defence is small, random fluctuations in acceleration and heading. I need to get into the numbers to see how realistic this will be. Of course, a stationary target will make things much easier.

Steve

[Steve Walmsley (OP)]

Shield Generators

Shields have changed for Newtonian Aurora. There are three parameters in the design window.

Maximum Shield Energy Per Ton: This parameter is rated in Megajoules (MJ) and the tech line starts at 25 MJ per ton. This is the maximum shield energy that can be sustained by the shield generator. So if the Maximum Shield Energy Per Ton was 100 MJ and the generator was 50 tons, it could sustain a shield energy of 5000 MJ.

Shield Generation Rate: This is the rate in MJ/s per ton at which the shields can draw energy from the ship's homopolar generators (HPG) to replenish shield energy. The tech line starts at 0.1 MJ/s. For example, if this tech was 0.25 MJ/s, a 50 ton shield generator could replenish shield energy at 12.5 MJ/s.

Shield Generator Size: Between 10 and 500 tons. Each 10 ton increment adds a 1% bonus to maximum shield energy, on the basis that the larger installations are more efficient. So a 50 ton generator would have a 5% bonus.

Here is an example 200 ton shield generator using Maximum Shield Energy Per Ton = 100 MJ and Shield Generation Rate = 0.25 MJ/s

5250 MJ Shield Generator
Maximum Shield Strength: 5,250 MJ
Maximum Recharge Rate: 12.5 MJ/s    Minimum Recharge Time: 420 seconds
Cost: 10.5    Crew: 3     HTK: 1
Materials Required: 10.5x Corbomite
Development Cost for Project: 1050RP

Multiple shield generators can be added to a ship, although they must be all of the same type. The Maximum Shield Strength of the ship is equal to their combined strength and is the total amount of incoming energy (damage) that the shields can withstand. However, as well as a maximum overall strength, a ship has a Maximum Point Strength for its shields as well. This is the maximum damage than can be absorbed from a single hit from a railgun or beam weapon. This depends on a combination of the size of the ship and the overall strength of the shields. The shields are assumed to encompass a spherical volume that has twice the radius of the spherical volume of the ship. In other words, if the ship is a 40 meter sphere, the shields are a sphere with an 80 meter diameter. For the purposes of shields (and armour), every ship is assumed to be a sphere, even if for RP reasons they are described as different shapes.

The point strength of the shields is equal to their maximum strength divided by the (surface area of the shields in m2/10). For example, the ship below is 4620 tons (ignore the EM Signature and beam fire control stats as they are placeholders). The total strength of the shields is 72,000 MJ and the surface area of the shields is 395.4. Therefore the point strength is 72,000 / 39.54 = 1820.94, rounded up to 1821 MJ. So the shields will absorb incoming fire, reducing their own strength by an equivalent amount in the process, but any hit above their point strength will only be reduced by that point strength. For example:

If the ship below was hit by a 1000 MJ railgun shot, its shields would absorb 1000 MJ and be reduced to 71000 MJ and no damage would penetrate.
If the ship below was hit by a 2400 MJ railgun shot, its shields would absorb 1821 MJ and be reduced to 70179 MJ. The other 579 MJ would be resolved against the armour
If the ship below was hit by a 4800 MJ railgun shot, its shields would absorb 1821 MJ and be reduced to 70179 MJ. The other 2979 MJ would be resolved against the armour

Resolution class Destroyer    3,620 tons standard     4,620 tons full load     161 Crew     886.5 BP
Armour 3-24     Sensors 1/20/0/0     Damage Control Rating 1     PPV 12
Maint Life 1.91 Years     MSP 120    AFR 170%    IFR 2.4%    1YR 43    5YR 639    Max Repair 100 MSP
Active Signature 92.4    Thermal Signature 225    EM Signature 10000/2160000

Rolls Royce 7500 KN Ion Drive (3)    Total Power 22.5 MN    Fuel Use 299.2 litres per hour   Exp 10%
Full Load Acceleration  4.87 mp/s (0.5G)    Hourly Acceleration 17.53 km/s    Daily Acceleration 420.78 km/s
Standard Acceleration  6.22 mp/s (0.63G)    Hourly Acceleration 22.38 km/s    Daily Acceleration 537.02 km/s
Fuel Capacity 1,000,000 Litres    Delta-V Budget (Full Load) 66,046 km/s    Full Burn Duration 139.2 days

24 GJ Shield Generator (3)     Max Strength: 72 GJ    Max Point Strength: 1821 MJ    Recharge Rate: 150 MJ/s
690 MW Stellarator Fusion Reactor (2)     Total Power Output: 1380 MW    Exp 10%
11 GJ Homopolar Generator (3)     Total Power Storage: 33,000 MJ    Recharge Time: 24 seconds

Odin 4800 MJ Heavy Railgun (1)    Energy: 4,800MJ    Velocity: 69,282 m/s    Power Reqt: 13,714 MJ    Cooldown: 30 secs
Thor 2400 MJ Railgun (1)    Energy: 2,400MJ    Velocity: 69,282 m/s    Power Reqt: 6,857 MJ    Cooldown: 24 secs
Beam Fire Control (1)    Max Range: 192,000 km   TS: 4000 km/s     95 90 84 79 74 69 64 58 53 48

R100 Active Search Sensor (1)     GPS 10000     Range 100.0m km    Resolution 100   Power Reqt: 500 MW
EM20 Passive Sensor (1)     Sensitivity 20     Detect Sig Strength 1000:  20m km

This means that larger ships may have a greater total shield strength than their smaller opponent but may not necessarily have a greater point strength. Although given the reducing ratio of surface area to volume as ships become larger, larger ships will be more efficient in terms of point strength vs total strength. In a battle between two railgun-armed, shield protected ships, the ship that is able to penetrate the shields of its opponent more effectively is likely to prevail. In a sense, such a combat would resemble that of two WW1 dreadnoughts.

EDIT: One final point is that a ship with shields is easier to hit than one without because the shields are larger than the ship.

Steve

[wedgebert]

Will there be seperate to-hit checks for shields vs armor? 

For example, is it possible for my railgun to hit the enemy shields, pierce through due to overcoming the shield's maximum per-hit strength, but have the projectile physically miss the ship?

[Rastaman]

Interesting. That means the detailed ship can hit itself from a maximum range of about 270 000 km. The time it needs to move itself out of the way of a projectile, shields included, is 3.9 seconds. Will "tracking speed" have any relevance in Aurora FTL?

[jseah]

For example, if this parameter was 0.6 MJ/s and the railgun was 200 tons and 2400 MJ, the surface area would be 165.4, the dissipation rate would be 99.24 MJ per second and the total cooldown period would be 2400/99.24 = 24.18 seconds, rounded to 24 seconds.

Surely the efficiency of the railgun matters.  A more efficient but higher power railgun  that retains the same amount of energy as a less efficient lower power railgun would take the same amount of time to cool for the same tech and size. 

eg.
50% efficiency with 2000MJ per shot = 4000MJ draw
33% efficiency with 1000MJ per shot = 3000MJ draw

Both of them, with the same heat dissipation and the same size, ought to cool at the same rate since they both retain 2000MJ of energy. 

I suggest that the heat dissipation only applies to the portion of energy the railgun drew that did not go into the projectile. 


EDIT:
I forgot to add that this is awesome!  I look forward to seeing Newtonian Aurora!

Absolutely amazing detail. 

[jseah]

Here's a suggestion for railguns:

Have a railgun design for "special ammunition".  Basically, railgun assisted launches.  Can fire cargo bay stuff as well. 

Have a special design of railgun able to launch things.  Obviously this will have a much lower acceleration than normal railguns although they use the same calculations (the max accel a particular thing can withstand depends on what you're firing, might be a tech line?). 

It'll need to calculate the length of the railgun and the acceleration on the object. 
Thus, railguns could be "extended" in an additional field that increases mass but doesn't affect projectile and efficiency stats except by lowering acceleration by increasing the railgun's length.  Say 1 ton per 10 meters.  (and this likewise increases the area and thus the heat dissipation, a bit like adding mass for heat sinks)

Also, the railgun will have to be designed to launch that one thing only.  (mineral packets can be "one thing" for all combinations, and the mass driver-railgun will have a designed weight per packet)

Obviously, railgun length will have to be calculated for ship sizes.  Might want to check ship size and take the "calculated by weight" size or the railgun length, whichever is higher. 

Also obviously, this applies to rail assisted hangar launches, missile launches, mass drivers and "engine-less missile" weapons (laser warhead missile with no engine, fired from railgun).  Railgun launched escape pods... although why you would want that I have no idea. 
And if the recoil is ever calculated, a "railgun" drive might be possible. 

[UnLimiTeD]

A W E S O M E
Does that mean that Sensors can't be turned off?
Or that they always draw energy despite being shut down? (Electronics in active standby, so to say)

I also second the question if a Projectile can hit the shields but miss the ship.
I suppose minimum distance will be reduced massively?

Why shouldn't we use two types of shields? wouldn't those stats described just add up?
Also, will it be possible to specialize a Shield to be faster recharging, but less capacity, or the other way around? In essentially the same way that one could now specialize a ship to have massive weaponry fueled by batteries, but low endurance, or the other way around....

Suggestion/question: Given that projectiles are now calculated in the energy they contain, and Shields work on that principle as well, will hull strength change as well?
I always thought that quadrupling the HTK of Internal systems and the weapon damage, and multiplying armor thickness and amount by 2 would allow for more options, like large Mesons finally being better than small ones in some aspects.

But only now, in this gorgeous wet dream of strategy nerds, would it really make sense.
Will Armor strength be calculated in MJ as well?

Also, those systems described by various persons in this thread, of "Electric Armor"... will there be different armor types?
Essentially to allow stuff like a tank today, huge target, slow, expensive, but completely impervious to small projectiles.
On the other hand, those new systems described could allow for a lightweight, hard to hit ship that reduces the effect of one shot of ~(insert very high number here) MJ every 10 seconds to (insert very low number here), but would horribly fail in a hailstorm of railgun fire.

[Antagonist]

As for special ammunition, missiles is the most obvious.  A launch boost of 70km/s while not extreme would be welcome, though missiles I guess weigh a little more than 1kg so would propably be less under this system.  Would the railgun mass be worth it though for a 70km/s bonus instead of just carrying 70km/s worth more fuel?

As for faster charging shields versus higher capacity...

That shield specifies 12.5MJ/s recharge rate.  To recover from a 2400MJ hit (assuming all of it got absorbed) would take 192 seconds or 3.2 minutes.  Considering they fire every 24 seconds and it is likely there is more than just one firing, they will quickly destroy the shields if you rely on passive tanking.  A 100 MJ/s recharge is needed in order to recover from a single railgun's attacks firing at max rate, multiplied by several times for multiple railguns.

Now, would it be possible to increase your shield recharge rate by dumping your capacitor energy into it?  In this case it can be a trade-off between shields and weapons, but the much greater recharge rate would make tanking possible.  If implemented I can just imagine the ships with huge excess generators to take advantage of it, but I'm unsure whether it could be game-breaking.  Perhaps transferring to shields at a max rate and with a certain inefficiency?

[jseah]

The point penetration for shields is nice though.  It makes building lasers at max size worth it.  That is, if we were still playing normal Aurora. 

Capital ship weapons vs puny frigate weapons.  Instead of the forest of puny frigate weapons we see on capital ships now. 

Still, the way Aurora handles laser PD, I'd still end up using a one-size fits all 15cm dual role laser. 

[Mel Vixen]

Hmmm if shots that are fired are handled like objects i could build my own mjoelnir-Railgun (From the P&P "Justifiers"). Imagine it a giant size Kilometer long railgun somewhere in position a bit outside of the earthorbit say a lagrane point. Some scout-ships out on the rim of the system and all need is to take aim at a certain position. The problem is that i need to know there my target is going and i can let rain red hot death on the enemy. At big enough ranges i dont even need to worry about cooling down. The "artillery" is back on the battlefield.

Edit: Do wee need to take ammo with us for the Railguns? I mean even if thousand slugs for the railgun weight just a ton its would be interesting take on realism. 

[UnLimiTeD]

Ammo would certainly be nice, now that it's a true ballistic weapon.
Such a huge Artillery weapon would likely fail, at that distance the enemy could easily evade. More importantly, he could counterfire witht he smallest weapon available in his arsenal.^^

As for shields, I figured a modification that subsitutes generator power, aka force projection, for a hotwireing to the ships main batteries.
Btw, if shields not have an assigned size, would it, with very high tech, theoretically be possible to have a Shield Cruiser that flies ahead and covers the fleets advance for a minute?

Edit: Another question; How will shields handle Missiles?
I Imagine a nuclear blast should hit a larger portion of the shield, thus dealing more damage, but also being absorbed to a larger percentage?

[Rastaman]

Citing the above example of 2 destroyers fighting at a range of 270 000 km, a missile with 180 mp/s accel (360kN engine example) needs 28 minutes to cross the distance, as compared to the 4 seconds of the rail gun projectile. 28 minutes is some time to shoot down a missile with railguns. And point defense guns probably have a rate of fire above the listed ones.