OhioBob

Surprises like these are good things, it keeps us having to alter our plans and designs. I can see how at first observation you would think that Tarsiss, with half the atmospheric pressure, would be a tougher place to fly than Niven. But since Tarsiss is so cold, its air is actually denser than Niven's. And as you say, the biggest difference is really in the gravity, where Niven has nearly three times the surface gravity of Tarsiss. A big part of the reason for that is because Tarsiss is an icy body with a much lower density than Niven. That's one of the things I think I'm going to like about this mod, it has a lot of variation and different challenges to overcome.

I would love to have the ability to customize the game calendar, including both length of day and number of days in a year. From my observations it appears that the game calendar is hardcoded to 426 days of 6-hours duration (or the alternate Earth calendar of 365 24-hour days). This means that for any mod that alters the rotation and/or orbital periods of the home world, the calendar is out of sync with the astronomical movements of the planet. I think it would be a fine addition to have a plugin that allows customization of the calendar so that game time keeping can be made to match the periods of a modified planet. This would give mod developers greater flexibility to experiment with alternate home worlds and would enhance the realism of their mods. I would happily write this mod myself if I had the ability, but alas I do not. I therefore appeal to the KSP mod community. If there is anyone willing and capable of producing such a mod, I would be very grateful.

Yes, I'm aware it can toggle between the Kerbin calendar and the Earth calendar. That does give me hope that other settings are possible. I'm planning to make a request for a mod in the Add-on Discussion section. Hopefully there is somebody out there who is willing to write a plug-in for it. I think that would be a really nice addition. (edit) I posted a request. Hopefully somebody will show some interest.

I'm making progress on the rest of it. I think that by the end of tomorrow I'll have everything except the descent/ascent dV for atmospheric bodies. Figuring out the dV for bodies with atmospheres will probably be a pain in the neck.

In that case, I'm certainly not going to demand that the star remains a G-type. For GPP stand alone, that's another story. If you want to change the star type for GN, then I'm OK with that as long as no one else objects.

Someone should write a mod for that. I would if I could, but it's beyond my ability (I'm only good at editing cfgs). I tried some experiments and found the calendar is hardcoded to 426 6-hour days. I think it would be great if we could (1) change the length of a day, and (2) change the number of days in a year. That way we could have a customized calendar to match the rotation and orbit periods of any planet we wanted.

Oh yes, I agree, let's not change GPP as a stand-alone product. I like it just as it is. I was talking about if we wanted to change the cfgs for use in GN. If we change the star type, it would be pretty easy to re-compute and change the semimajor axes (only the planets would change, no need to change the moons). To be honest, this is the first I've heard of GN. I'm now starting to understand just what it is. If no one really cares much about realism, then we could leave the semimajor axes just as they are and not worry about it.

It is vital that all the planets maintain their current temperatures. There is just way too much riding on that to change it at this point. For example, all the atmospheric models are dependent on temperature. Also the existence and location of lakes on Niven and Augustus are determined based on temperature. We can change the star type, but I'd want to change the planets' semimajor axes to maintain the solar irradiance at current values. That should be pretty easy to do. Once we decide on a star type, I can compute the star's properties and then move the planets closer or farther away as applicable (closer if we go with K-type). That will change all the planets' orbital periods, but their temperatures, atmospheres, and habitability would remain the same.

We decided early on to make GPP's home planet a near identical twin to Kerbin. We also had to give is an orbital period of 426 days to match the built-in calendar. Given those restraints, the sun ended up having to be G-type star. Changing the star type would have moved the habitable zone either closer to or farther away. That would have messed with the orbital period so we would be out of sync with the calendar. We didn't want that. From all that I can tell, the calendar is hardwired to 426 days. Do you know how to change that? I wished it were linked to the orbital period of the home world, but from my experiments I found that that isn't the case. If we could change the number of days in the calendar year, that would open up more possibilities to move home worlds around and use different class stars.

I estimated it closer to about a G6. @Sigma88, I'm the one who sized GPP's sun. I actually went out of my way to make certain that it's properties were in line with the normal mass-luminosity-radius relationships for main sequence stars. The following post describes Ciro's properties in quite a bit of detail.

Doing what you describe should have worked, but clearly there is an error in there somewhere. Your dossier shows Tellumo's mass as 1.435, but it should be over 5. I didn't check all the bodies, but the ones that I did were all wrong as well. You better check your formula, or perhaps something got corrupted in my spreadsheet. By the way, if you measure it in Gael masses rather than Kerbin masses, the formula I gave you earlier becomes, m = g * r2 / 360000 The denominator is simply g*r2 for the body in whose masses you are measuring the other bodies. As you know, in KSP 1.2.1 they changed Kerbin's mass a little so it is no longer exactly 1 g. So we have, for Gael, 1 * 6002 = 360000 for Kerbin, 1.00034160493135 * 6002 = 360123 I'll leave the decision about including science multiplier and altitude thresholds to you and Galileo. I think that is information that some people might find useful, but I also like the actions shots. Do you know where to find that data in the .cfg files?

@JadeOfMaar, I've looked at your planet dossiers and they look beautiful. However, there is something wrong in the way you computed the masses. One quick way to compute the mass of a body is, m = g * r2 / 360123 where m = mass in Kerbin masses, g = surface gravity in g, and r = planet radius in km. For example, the mass of Tellumo is, m = 1.9 * 10002 / 360123 = 5.276 Kerbin masses.

To use Realistic Atmospheres with KSP version 1.2.1, please be sure to update to Kopernicus 1.2.1-1.

@Jiraiyah, the following post includes all the updated properties: Note that the surface gravities (measured in g) haven't changed, so as long as you use go = 9.80665 m/s2 to compute the gravitational parameters, you should be good (at least I hope that's the case). The one exception is Ciro, whose surface gravity is now 25.8088134072288 g.

I've got all that figured out already.

Ah, I forgot about the dV map. I've got a start on it but there is still much to do (what I've do so far is just the easy part). @ProtoJeb21, yes, that is probably something you could help with. I don't have time to discuss it now, but perhaps tomorrow. I'm sure I can complete it myself but if there is anything you can do to help expedite the process, it would be helpful. Have ever done one before? I'm using an existing one as a guide and I've tried to back-engineer some of the numbers, but I'm not always coming up with the same values. Even if you don't do any of the math, just being available to answer some questions might help.

As for me, I think I have it covered. My part in this mod was to set all the physical, orbital, and atmospheric parameters for the celestial bodies. I've got all that in a spreadsheet, so it's actually easy to change things. Thanks for the offer though. I can't speak for the other guys.

Ciro is actually quite a bit different from the stock sun. Main sequence stars follow specific mass-luminosity-radius relationships. The stock sun really doesn't follow these relationships, most specifically its radius (which is way too big). I tried to make Ciro much more lifelike by making sure its physical characteristics were consistent with real life stars (accounting, of course, for the fact that celestial bodies in KSP are scaled down by factors of 0.1 radius and 0.01 mass). I also had to make sure that Gael received the correct amount of illumination (1360 W/m2) while maintaining an orbital period of 426 days (to match the built-in calendar). So Ciro had to have the right mass and luminosity and Gael had to be the right distance away to produce the right conditions, while at the same time the standard stellar mass-luminosity-radius relationships had to be preserved. Through iteration I was able derived Ciro's properties and Gael's semimajor axis to make sure that everything was internally consistent and lifelike. With the new go value I'm going to have to reproduce those computation (fortunately I still have the spreadsheet). It's likely Ciro's properties and Gael's semimajor axis may change a little bit, but I'm sure the change will be so small that no one will really notice a difference. Below are the differences between the stock sun and Ciro's current properties (which might change a little). (UPDATE) We've decided to factor Ciro's surface gravity to account for the KSP 1.2 change in the value of go. This keeps Ciro's other physical properties the same, while also maintaining the orbital parameters of the planets. This change is reflected in properties given below. Sun (Kerbol) Radius = 261,600 km Mass = 1.757E+28 kg Gravitational parameter = 1.172E+18 m3/s2 Surface gravity = 1.74685 g Luminosity = 5.672E+25 W (based on given radius and temperature), 3.161E+24 W (based on solar constant at Kerbin) Effective temperature = 5840 K (given), 2837 K (based on radius and solar constant at Kerbin) Spectral class = presumed G type, but too many inconsistencies to tell from physical properties Ciro Radius = 70,980 km Mass = 1.911E+28 kg Gravitational parameter = 1.275E+18 m3/s2 Surface gravity = 25.808813 g Luminosity = 3.342E+24 W Effective temperature = 5524 K Spectral class = about G6 If we factor Ciro up to life-sized dimensions, it's has a slightly larger radius than our own sun, but is less massive and less luminous. A life-sized Ciro has 1.02 solar radii, 0.96 solar masses, and 0.87 solar luminosities. (edit) Note that the information panel in the Tracking Station is currently showing Ciro's temperature as 5840 K. This is because temperature falls under the atmosphere node, and Ciro's atmosphere node is disabled because it is generating a visual artifact around the sun (personally, I find the artifact only mildly annoying). Therefore the atmospheric properties are defaulting to those of the template, which is the stock sun with a temperature of 5840 K.

The only reason I was using 9.81 previously was because that was internal to KSP. It always should have been 9.80665, I'm glad Squad has now changed it. Your spreadsheet should now use 9.80665. Once I've updated everything, I can help you make sure that your spreadsheets include all the correct numbers. Right now I'm not entirely sure what will change. I just have to rework everything and figure it out.

Good, I'm glad changing the dossier images is not a big issue (I was worried about that). I should have the tables of properties updated later today. I think a lot more of the numbers are going to change than what I originally thought. Sorry about that. I too like the subtle differences between Gael and Kerbin. I'm glad they're very similar so that it's easy to make the switch from Stock to GPP, but they're not the same planet so I welcome small differences. I also think the change in the location and orientation of KSC has a far greater impact on gameplay than any small physical differences between the planets.

Changing both go and surface gravity is what Squad has done with stock KSP (versions 1.2 and 1.2.1 respectively). But that's a game that's been out for years and has been played by thousands of people. Users have gotten use to certain values that Squad apparently wanted to keep in place. GPP is a new mod still in development that hasn't seen wide circulation yet. So to what are we being 100% accurate? To so made up numbers that we have the freedom to change at will? It's true that things like geosynchronous distances are a smidgeon different now than they were when we started out in KSP 1.1.3, but that doesn't mean either value is better than the other. The difference is insignificant and it will have virtually no affect on gameplay. I just know that when I look at the info panel in the Tracking Station I'd rather see that Gael's gravity equals 1 g then see that it equals 1.00034160493135 g. The difference that makes in the geosynchronous distance is less than 400 meters.

I had missed the fact that the value of go (standard gravity) was changed in 1.2. In prior versions go = 9.81 m/s2, but now they've made it the correct value of go = 9.80655 m/s2. Since the gravitational parameter is computed internally from surface gravity (measured in gees) and the value of go, all the gravitational parameters in the game changed. This changed things like orbital periods, spheres of influence, geosynchronous distances, etc. In order to keep gravitational parameters the same as they were prior to 1.2, in version 1.2.1 they have changed all the surface gravities by a factor of 9.81/9.80665 to cancel out the effect of the prior change. Take Kerbin for instance, prior to version 1.2 it had a surface gravity of 1 g, where 1 g was defined as 9.81 m/s2. Therefore its gravitational parameter was, μ = 9.81 * 1 * 6000002 = 3.5316E+12 m3/s2 Now they've redefined 1 g to be equal to 9.80665 m/s2, but they've made Kerbin's surface gravity equal to, 9.81/9.80665 = 1.00034160493135 g. Therefore Kerbin gravitational parameter is now the same as it was prior to version 1.2, μ = 9.80665 * 1.00034160493135 * 6000002 = 3.5316E+12 m3/s2 Therefore things like orbital periods, spheres of influence, geosynchronous distances, etc. have returned to their pre-1.2 values. Note that they also changed the value of the gravitational constant from G = 6.674E-11 Nm2/kg2 prior to v1.2, to G = 6.67408E-11 Nm2/kg2 now. That will change the masses of the celestial bodies, but I don't think mass is really used directly in any significant calculations. I think this is likely more of a cosmetic change (i.e. mass is shown in the info box in the Tracking Station). What implications does this have for GPP? Since we're still in beta and GPP has only been played by a small number of testers, I certainly see no reason to apply a patch to force everything to return to their pre-1.2 values. So the gravitational parameters are 0.034% smaller than we initially thought they were, big deal. I say leave everything as is. However, this will change some of the values in my tables of properties, which I'll have to revise. And for @JadeOfMaar, this means you'll likely will have to make some revisions to your celestial body dossiers (I'll have revised numbers later). @Galileo, there will also be some small changes to at least a couple planet cfgs. For instance, right now I can tell you that the rotational periods of Icarus and Gratian will have to change. I can't think of any other cfg changes at the moment, but if I do, I while certainly let you know. @Jiraiyah, I think your spreadsheets might be OK provided you change 9.81 to 9.80665 in your equations (we can check later to see if any other unforeseen errors have crept in). The only planet for which I can see possibly changing the surface gravity is Gael. As far as it's physically properties are concerned, we've made Gael an identical twin of Kerbin. If we want to keep Gael an identical twin, we would need to change its surface gravity to 1.00034160493135 g. My personal opinion, screw it, leave Gael's gravity at 1 g (9.80665 m/s2). Gael is not Kerbin, so if it differs a little bit, I'm OK with it. There are already some small differences between Gael and Kerbin regardless of what we do, for instance, the sphere of influence distance. This is not because of any difference in the physical properties of Gael and Kerbin, but because of differences between Ciro and Kerbol. Also Gael is a little farther from Ciro than Kerbin is from Kerbol. Since there are already a few small differences, I don't think it's a big deal to add a few more. Opinions, comments?

Those newer versions aren't working for me either, but then I've had a whole lot of weirdness going with my installation (you may have read some of the discussion in the Kopernicus thread). I just noticed that KSP 1.2.1 is now available; I'm downloading it now. I'm going to delete all my old installations and start fresh. Maybe that will clear up my problems.

Nope. Never heard of that before. I had to look it up. Now I get it.

Yep, that's as equally random and irrelevant as my selection.