Questions Not Worth Their Own Thread: C# Edition

[Pedroig]

Have to ask, there are Troops actually aboard said ship?

Asking from experience...

[Kaiser]

Have to ask, there are Troops actually aboard said ship?

Asking from experience...

Yes yes there were troops aboard 

I figured out the issue, I had to create a colony before, Jesus Christ.

[vorpal+5]

Thank you all for the answers to my questions, it was quite informative. 

[skoormit]

Does anyone know the calculation for the current base temperature of a system body?
I suspect it's a simple matter of star brightness and current distance from star.

Prior to eccentric orbits, the base temperature of a body never varied, so I could just use the value of FCT_SystemBody.BaseTemperature.
But that value seems not to vary over time.

[Pedroig]

Does anyone know the calculation for the current base temperature of a system body?
I suspect it's a simple matter of star brightness and current distance from star.

Prior to eccentric orbits, the base temperature of a body never varied, so I could just use the value of FCT_SystemBody.BaseTemperature.
But that value seems not to vary over time.

well there is this:  https://www.astro.princeton.edu/~strauss/FRS113/writeup3/ but I"m not sure it is quite that complex in game.

Factors (in real world):

Star Radiation Strength
Distance from Star
Rotation of body
Atmosphere
Albedo
Stefan-Boltzmann Constant

[vorpal+5]

I'm scratching my head as to why my Jump Stabilisation Ship is tracted at a meager 342 km/s. Is there a penalty at some point if the masses of the two ships are vastly different? 
My Tug is 10,000 tons and has a speed of 2400 km/s. My Bïfrost JSS has a base speed of 333 km/s. So what gives? 

Code: [Select]

TG-01 Sheperd 001  (Sheperd class Tug)      10 000 tons       114 Crew       360.5 BP       TCS 200    TH 480    EM 0
2400 km/s      Armour 1-41       Shields 0-0       HTK 47      Sensors 5/0/0/0      DCR 1-1      PPV 0
MSP 132    Max Repair 100 MSP
Tractor Beam     
Lieutenant Commander    Control Rating 1   BRG   
Intended Deployment Time: 3 months   
● Recreation Room-25    ● Library-25    2x ● Escape Pod-5    ● Security hardpoint-5   

Honeywell Aero Nuclear Thermal Engine C80 (6)    Power 480    Fuel Use 10.06%    Signature 80    Explosion 5%
Fuel Capacity 850 000 Litres    Range 152.1 billion km (733 days at full power)
Refuelling Capability: 50 000 litres per hour     Complete Refuel 17 hours

Silas-Nein Small Thermal Sensor 1-5 (1)     Sensitivity 5     Detect Sig Strength 1000:  17.7m km

This design is classed as a Commercial Vessel for maintenance purposes
This design is classed as a Tug for auto-assignment purposes


Code: [Select]

JSS-01 Bifröst 001  (Bifröst class Jump Stabilisation Station)      60 000 tons       197 Crew       1 384.8 BP       TCS 1 200    TH 400    EM 0
333 km/s      Armour 1-136       Shields 0-0       HTK 52      Sensors 5/0/0/0      DCR 1-0      PPV 0
MSP 24    Max Repair 1 000 MSP
Commander    Control Rating 2   BRG   AUX   
Intended Deployment Time: 3 months   
Jump Point Stabilisation: 180 days
● Large Crew Lounge-100    ● Onboard Hospital-50    ● Recreation Room-25    2x ● Security hardpoint-5    9x ● Escape Pod-5    3x ● Medium Hydroponics-50    ● Promenade-50    ● Fitness Center-50    ● Library-25    ● Small Armory-5   

Honeywell Aero Nuclear Thermal Engine C80 (5)    Power 400    Fuel Use 10.06%    Signature 80    Explosion 5%
Fuel Capacity 1 400 000 Litres    Range 41.7 billion km (1449 days at full power)
Refuelling Capability: 50 000 litres per hour     Complete Refuel 28 hours

Silas-Nein Small Thermal Sensor 1-5 (1)     Sensitivity 5     Detect Sig Strength 1000:  17.7m km

This design is classed as a Commercial Vessel for maintenance purposes
This design is classed as a Stabilisation Ship for auto-assignment purposes


[skoormit]

Factors (in real world):

Star Radiation Strength
Distance from Star
Rotation of body
Atmosphere
Albedo
Stefan-Boltzmann Constant

In Aurora, the atmosphere and albedo are not part of the calculation for base temp. They are part of the calculation of surface temp.

I don't think the Stefan-Boltzmann constant is part of Aurora's model.

[nuclearslurpee]

I'm scratching my head as to why my Jump Stabilisation Ship is tracted at a meager 342 km/s. Is there a penalty at some point if the masses of the two ships are vastly different? 
My Tug is 10,000 tons and has a speed of 2400 km/s. My Bïfrost JSS has a base speed of 333 km/s. So what gives? 

There are two important rules here:

• A ship under tow does not contribute its own engine power to the speed of the fleet.
• The speed of a tug plus a ship under tow is determined by the tug's engine power and the total mass of both the tug and the towed ship.

Given this, you have a total of 480 engine power on the tug, and a total of 70,000 tons (tug 10,000 + station 60,000) or 1,400 HS. 480 EP / 1,400 HS * 1,000 = 342 km/s, so the numbers check out correctly.

[vorpal+5]

Darn. I thought that the towed ship would be able to fire its engines. Thanks.

[pedter]

Does anyone know the calculation for the current base temperature of a system body?
I suspect it's a simple matter of star brightness and current distance from star.

Prior to eccentric orbits, the base temperature of a body never varied, so I could just use the value of FCT_SystemBody.BaseTemperature.
But that value seems not to vary over time.

I'm good for this question; I had to derive it to match Aurora's model to get my body planner to work the way I wanted it to. It largely follows Pedroig's link and can be simplified even further for the values we have access to:

BaseTemp (K) = SysConst * L^0.25 / AU^0.5

L is the star's brightness measured in solar units; AU is the body's current distance in AU (works with eccentric orbits as a result). The system constant I didn't bother to break down further; it's value appears to be exactly 255 for all systems other than real Sol when plotted. Real Sol uses something between 255.13 and 255.3406815 (I've been too lazy to nail it down precisely) to determine base temperature. Rotation rate, atmosphere, and albedo are all modeled during the surface temperature calculation while the Stefan-Boltzmann constant is baked into the ~255 system constant.

Because the terraforming tab still uses 255 for its math even in Sol, bodies in Sol are slightly warmer than their listed terraformed values. This is most evident with the maximum periapsis temperature when they're located at periapsis. Venus was the first that I caught doing this as its temperature is the highest and least susceptible to hiding the error in rounding; see attached screenshot.

[skoormit]

BaseTemp (K) = SysConst * L^0.25 / AU^0.5

That. Is. Beautiful.

A million thanks!

[Steve Zax]

Darn. I thought that the towed ship would be able to fire its engines. Thanks.

I don't know if this (bug?) (exploit?) (intended action?) has been changed since 1.13, but the last time i played Aurora for more than 15 minutes, I made "tuglets" with only a tractor beam and sufficient crew and barracks to operate it, and used them between my actual tugs and the towed object. The mass of the "tuglet" is the only thing that contributes to the slowing of the tug, so they would go at a quite impressive speed.

[pedter]

Darn. I thought that the towed ship would be able to fire its engines. Thanks.

I don't know if this (bug?) (exploit?) (intended action?) has been changed since 1.13, but the last time i played Aurora for more than 15 minutes, I made "tuglets" with only a tractor beam and sufficient crew and barracks to operate it, and used them between my actual tugs and the towed object. The mass of the "tuglet" is the only thing that contributes to the slowing of the tug, so they would go at a quite impressive speed.

This is still alive and well in v2.5.1 - the velocity only takes into account the tug's engines, the tug's mass, and the mass of the singular vessel that the tug is directly connected to (ignoring anything further down the tug chain) so having a low-mass tractor pod between the tug and the true tugged target lets the tug perform exceptionally well by ignoring the bulk of the true tugged mass. I try to avoid it if I can but it's available.

[Steve Walmsley]

Does anyone know the calculation for the current base temperature of a system body?
I suspect it's a simple matter of star brightness and current distance from star.

Prior to eccentric orbits, the base temperature of a body never varied, so I could just use the value of FCT_SystemBody.BaseTemperature.
But that value seems not to vary over time.

I'm good for this question; I had to derive it to match Aurora's model to get my body planner to work the way I wanted it to. It largely follows Pedroig's link and can be simplified even further for the values we have access to:

BaseTemp (K) = SysConst * L^0.25 / AU^0.5

L is the star's brightness measured in solar units; AU is the body's current distance in AU (works with eccentric orbits as a result). The system constant I didn't bother to break down further; it's value appears to be exactly 255 for all systems other than real Sol when plotted. Real Sol uses something between 255.13 and 255.3406815 (I've been too lazy to nail it down precisely) to determine base temperature. Rotation rate, atmosphere, and albedo are all modeled during the surface temperature calculation while the Stefan-Boltzmann constant is baked into the ~255 system constant.

Because the terraforming tab still uses 255 for its math even in Sol, bodies in Sol are slightly warmer than their listed terraformed values. This is most evident with the maximum periapsis temperature when they're located at periapsis. Venus was the first that I caught doing this as its temperature is the highest and least susceptible to hiding the error in rounding; see attached screenshot.

Here is the code:

                    // base temperature
                    sb.BaseTemp = 255 / Math.Pow(sb.OrbitalDistance / Math.Pow(sb.ParentStar.Luminosity, 0.5), 0.5);
                    if (sb.BaseTemp < 4) sb.BaseTemp = 4;

The result is in Kelvin.

I decided to not to add the effects of other stars in the system. I have the necessary formulae, but it would be hard for players to visualise.

[pedter]

Here is the code:

                    // base temperature
                    sb.BaseTemp = 255 / Math.Pow(sb.OrbitalDistance / Math.Pow(sb.ParentStar.Luminosity, 0.5), 0.5);
                    if (sb.BaseTemp < 4) sb.BaseTemp = 4;

The result is in Kelvin.

I decided to not to add the effects of other stars in the system. I have the necessary formulae, but it would be hard for players to visualise.

Does the real Sol system use hard-coded base temperature values to better match reality in that case or is there something else afoot that's causing real Sol bodies to be ever-so-slightly warmer than they "should" be? When I plotted the hundreds of real Sol bodies, regression analysis spat out 255.3406815 with R²=1.000 (and it was the only system to do so) so I assume there's something exceptional in play.

It's not out of the question that the 4 Kelvin minimum is playing games with the data but Venus wouldn't be presenting the same problem if that was it (and other systems would've been showing something other than 255.000 as well)

I had briefly considered if other stars in a system would add a bit of temperature or not but discovered they did not as I checked them; thank you for saving me that headache