OhioBob

It sounds like you really don't need to change anything. But if you did, couldn't you just copy the drag cubes of the stock tanks in PartDatabase.cfg* and add them to Porkjet's cfgs. I think KSP would then use those drag cubes rather than generating new ones. * Of course you would need to use PartDatabase.cfg from an KSP installation that doesn't include any tank modifications.

The ISP of liquid fueled engines in KSP are reasonably close to real life. Not perfect but in the ballpark. Solid fueled boosters are well below real life ISP (about 80%). If we compare the thrusts of the "Making History" engines to the real life engines on which they are based, the KSP engines are about 20-30% as powerful. The exception is the Wolfhound. Of course this make sense because everything in KSP is scaled down. The generally excepted rule in KSP is that dimensionally rocket parts are at about a 0.625 scale compared to real life parts (1:1.6). Since volume/mass scales by the cube, we have 0.625^3 = 0.244. And since thrust should scale with mass, this means thrusts should be about 24.4% of real life, which agrees nicely with the MH parts.

@StarStreak2109, Sigma Dimensions hasn't released a KSP 1.4.x. compatible version. That may be your problem. Does it work without Sigma Dimensions?

If you're getting that error then it is likely either a bad installation or a bad mod. Can't help you without more information. What are you trying to run that needs Koperniucs? What versions or everything are you using? A screenshot of your GameData folder would be a big help.

While that fits with your criteria, it fails to meet some of the other physical properties known to exist in KSP. Liquid ammonia and nitrogen tetroxide have densities of 0.68 and 1.45 kg/l respectively. And I estimate an ideal mixture ratio of about 1.9. None of that is very close to the KSP values. Let's face it, there's really no real life equivalent to liquid fuel and oxidizer in KSP. We might get close to matching one group of properties, but then something else won't match. And I really don't think there is any reason we must assume that "liquid fuel" is always the same stuff. "Liquid fuel tanks" and "fuel tanks" could contain different fuels.

Just to be clear, I was commenting about the hypothetical use of NTRs in real life, not in KSP. Since we were talking about the pros and cons of different fuels, I assumed we were talking about real life. Much of our conversation has no application in KSP. That being said, there's probably a Δv threshold in KSP as well, below which NTRs are not economical, and above which they are. However, I've never made any attempt to figure out what it is.

I haven't played 3.2x, but I have 2.5x. From that experience, I estimated the launch delta-v for Kerbin is about 4700 m/s at 2.5x. Using the mathematical method we get, 3200*SQRT(2.5) = 5060 m/s. So you can see there's quite a bit of difference. At 3.2x I'm guessing it can probably be done for 5700 m/s or less.

Something else that hasn't been mentioned in the discussion of NTRs is how much delta-v is needed. Because of the cost and complexity of an NTR, they are just not worth it unless we need to deliver a large amount of delta-v. For instance, @AeroGav compared an ammonia NTR to storable chemical propellants (e.g. nitrogen tetroxide and MMH). If we need 10 km/s Δv, then I think there is no question the ammonia NTR will outperform the chemical rocket. But if we need only 3 km/s Δv, then they are about equal in terms of the total overall mass; and the chemical rocket is undoubtedly much less expensive.

Most likely, yes. The possibility of sooting is my greatest concern with any carbon containing compound. Particularly in an NTR where we're just breaking the compound down into constituent parts and not burning it. In a chemical engine most of the carbon will combine with oxygen to form CO or CO2. In an NTR it will be free carbon. But the person I quoted mentioned methane, and if we compare it strictly on a performance basis, I think it ranks second to hydrogen. I'm not quoting any source. I'm the source of the information I posted. I based my calculations on a temperature of 2500 K. That's not what the person I quoted was talking about. He was making comparisons to a hydrogen NTR and LOX/LH2.

This method should be spot on for things for things like interplanetary transfers. For launch delta-v, however, it over estimates the delta-v required. This is because the planet scales up more than the atmosphere. For example, for the 3.2x rescale, the atmosphere is only 1.4x as tall. Therefore, proportionate to the planet, we don't have to launch into as high an orbit. Nonetheless, the described method is a good start and should give a safe value. You can always adjust the number down later as you gain experience.

According to my calculations, the next best NTR fuel after hydrogen is methane or propane. There's a considerable drop in ISP vs. hydrogen, but it's still better than any chemical propellants. And the density is so much better than hydrogen that, when we take tank size into consideration, the overall mass of an NTR rocket using methane is about the same as a hydrogen NTR. After that I think MMH or UDMH is next in line, though they have only marginally better performance than LOX/LH2 chemical rockets. These fuels have the advantage of high density and storability. Pentaborane is another fuel I looked at that has performance just a bit below MMH and UDMH. I found ammonia to be actually a little worse than LOX/LH2 chemical rockets. It ranked very low on this list of fuels I tested. Helium sounds promising based on its low molecular weight, but I found it to be a pretty poor NTR propellant. Its ISP is not as good as one might think because of its high specific heat ratio. And only hydrogen has a lower density. Also its boiling point is darn near absolute zero.

If you do a fresh install with just the following, it works. But beyond that I can make no guarantees. KSP 1.4.2 Kopernicus 1.4.2-1 GPP 1.6.2.2 GPP_Textures 4.1.1 There are known issues with some of the optional and recommended mods. And since probably every GPP player uses at least some of those mods, we're not updating until everything is working. In the meantime, you can do whatever you want, but you're entirely on your own. Don't expect any support from the GPP devs if you're using KSP 1.4.x, and please don't make any bug reports.

Below is what we have in KSP. Densities are not known, but we do know that oxidizer and fuel have the same density. I computed an approximate density by estimating the volume of a Jumbo64 tank. Propellants Formula Density O/F Isp,sl (g/ml) Ratio (s) Oxidizer ? ≈0.98 1.22 ≈280 Liquid Fuel ? ≈0.98 And below are the propellants that I think come closest to matching the KSP properties. The mixture ratios and specific impulses are my own calculations (done years ago). Specific impulse is "ideal" and based on a combustion chamber pressure of 1000 psi (68 atm). Actual performance will be less; probably close to the 280s value used in KSP. One of the two hydrazine blends (Aerozine 50 or UH25) is probably most likely because they come reasonably close to matching both density and mixture ratio, and they have enough thermal stability to be used as an engine coolant. Hydrazine and MMH are not stable enough, therefore they aren't used in large regenerative cooled rocket engines. Propellants Formula Density O/F Isp,sl (g/ml) Ratio (s) Liquid oxygen LO2 1.141 0.74 303.2 Hydrazine N2H4 1.004 Propellants Formula Density O/F Isp,sl (g/ml) Ratio (s) Liquid oxygen LO2 1.141 1.15 299.6 Monomethyl hydrazine (MMH) CH3NHNH2 0.866 Propellants Formula Density O/F Isp,sl (g/ml) Ratio (s) Liquid oxygen LO2 1.141 1.38 297.4 Unsymmetrical dimethyl hydrazine (UDMH) (CH3)2NNH2 0.791 Propellants Formula Density O/F Isp,sl (g/ml) Ratio (s) Liquid oxygen LO2 1.141 1.06 299.9 Aerozine 50 50% UDMH + 50% hydrazine 0.885 Propellants Formula Density O/F Isp,sl (g/ml) Ratio (s) Liquid oxygen LO2 1.141 1.22 298.6 UH25 75% UDMH + 25% hydrazine 0.835

In KSP, liquid fuel and oxidizer have the same density, a mixture ratio of 1.22, and good specific impulse. Probably the thing that comes closest to matching those properties in real life is liquid oxygen and some derivative of hydrazine, or a hydrazine blend. Though that is not a combination used in any real life rockets.

Did you see the note that says, Will NOT work with KSP 1.4.

Just to elaborate a bit I what I said earlier. For any particular rocket, it is good practice to fly it on a trajectory and in a manner that will get it to orbit utilizing the least amount of propellant, i.e. the least amount of Δv. That just makes sense because you can then either use less propellant, or you have more propellant left over for subsequent maneuvers after getting to orbit. So if you have a rocket capable of getting to orbit using 3400 m/s ΔV, then that's what you should try to do. If it takes you 3500 m/s, then you are not flying the rocket as efficiently as it is capable of doing. My original point, however, is that lowering Δv should never be your goal when designing a rocket. In other words, let's say your last design could get to orbit using 3400 m/s. So now you say to yourself, I want to design a rocket that can get to orbit using 3300 m/s because that's going to be more efficiency. THAT IS AN INCORRECT WAY TO GO ABOUT IT. Efficiency of design is not about Δv. And if you design a launch vehicle to minimize Δv, you're probably going to end up with a bad design from an efficiency standpoint. You should design to maximum payload versus cost, and the heck with how much Δv it takes. If it takes 3500 m/s but gets a large payload to orbit cheaply, then it's a good design.

Yes. Transfer Window Planner uses the orbital elements in the planet's cfg file to compute the transfers. So it doesn't matter if the planets are stock or from a planet pack. TWP is going to do its thing the same either way.

@63Hayden, don't get too hung up on delta-v. Minimizing delta-v does not necessarily mean you are being efficient. Often a vehicle that is very good at getting to orbit using little delta-v is very poor in terms of cost efficiency or payload fraction. Being efficient is about getting the most payload to orbit using the least amount of rocket. Delta-v is irrelevant.

I've experienced this problem many times when attempting to aerocapture, just not at Tellumo but at other planets as well, including the stock ones. In my experience the vessel always flips just as it reaches the lowest point in its trajectory and is about ready to begin rising again. The only remedy that I've ever found is to simply start over with a higher periapsis. There seems to be a periapsis threshold below which the vessel become unstable. I usually only have the problem when aerocapturing/braking, where the vessel is doing a "skip". I don't recall having the problem during a landing when I'm coming in at a steeper angle, unless I just have a poorly designed and aerodynamically unstable vessel.

KSP 1.4.2 + EVE 1.4.0-1 + SVE 1.3.0.2 works fine for me. Don't know why y'all having problems.

It's my understanding the GPP generally works OK with 1.4.2 using the new Kopernicus, but there are problems with some of the other dependencies and optional mods. A plain vanilla GPP install will probably be fine, but as soon as you start adding other stuff, you could run into problems.

@enewmen, @Space Cowboy, @Space_Coyote, try it using the old 1.2.2-1 configs. Or use the Stock Visual Enhancements configs. I'm not sure if the former works, but I know the latter does.

That last part is something I've been meaning to bring up because I think it's important. We've been talking much about gravity and drag losses, but the trajectory we fly is extremely important too in how efficient our launch is. We want to fly as close to horizontal as the atmosphere and rocket design will permit. Let's consider the two extreme scenarios. For this I'm going to ignore drag and pretend that Kerbin has no atmosphere. This will allow us to see just what affect the trajectory has on delta-v. First, let's say we launch straight up into a trajectory that reaches an apoapsis of 80 km, then when we reach the apex, we accelerate horizontally to orbital velocity. To simplify the calculations, we'll assume that the delta-v is applied in instantaneous bursts. From sea level on Kerbin, we need to give our rocket a velocity of 1177 m/s to reach an apoapisis of 80 km. We when reach the apex, we have to go from zero to orbital velocity, a delta-v of 2279 m/s. So adding it together, we have a total of 3456 m/s. That's the worst case. New let's look at the best case. The most efficient thing we can do is launch horizontally right off the pad (hoping there's no mountains in the way) and perform a Hohmann transfer to orbit. This takes a delta-v of 2501 m/s off the launch. But by the time we coast around to the 80 km apoapsis on the opposite side of the planet, it takes only 72 m/s to circularize the orbit. That's a total delta-v of only 2573 m/s, which is far more efficient than the first scenario. In reality we fly a trajectory that is somewhere in between these extremes. We have to launch our rocket initially upward to get above the thickest part of the atmosphere, and then transition to horizontal. The faster we can transition to horizontal, the more efficient the trajectory will be. I tend to measure the efficiency of my trajectory by the magnitude of the apoapsis burn needed to finalize the orbit. If I can keep the burn down to about 100 m/s or less, I'm happy. On the other hand, if I have to make an apoapsis burn of, say, 300 m/s or more, then I'm unhappy. If I have to make that great of a burn, then I know I lofted the rocket into too steep of an arc and reached apoapsis too soon. Maybe I'm just really bad at flying high TWR rockets, but I find it much more difficult to fly a good trajectory with a high TWR rocket. We can't pitch over right off the launch pad or else the drag losses will kill us, so we have to gain some altitude first. While we're gaining that altitude, the high TWR rocket is gaining more speed than the low TWR rocket. And a high-speed rocket is more difficult to turn because the wind moving over its surface resists the turn. As a result of this, I just can't flatten out the trajectory of a high TWR rocket enough. I always end up in highly lofted a trajectory with a large apoapsis burn. So while I've saved on gravity losses, I've given it back on the poor trajectory and greater drag losses. This is one of the reasons why I favor low TWR rockets (I typically like about 1.3-1.4). I find them much more controllable during launch. I can pitch the rocket over and just slowly push the apoapsis higher and higher. I try to keep the "time to apoapsis" at around a minute or so while ascending. By keeping the apoapsis just a short distance ahead, we're flattening out the trajectory. If we let the apoapsis get away from us, we'll end up in a steep arc (which is what typically happens to me with high TWR rockets). As we gain altitude and near the end of the burn, the apoapsis will rapidly move far out ahead of us and wrap around the planet, but that's OK. If we have to travel 1/4 of the way around the planet before performing the apoapsis burn, that's good. It means we've come a little closer to the ideal Hohmann transfer.

Are you sure the problem isn't with something else that uses Kopernicus? What happens when you remove everything but Kopernicus?

They work for me.