[1.x+] Community Resource Pack

[regex]

To amend an earlier post:

I have standardized densities for all Real Fuels (that don't require consensus) to either liquid at boiling point for cryogenics or density at STP (1atm, 0C) for non-cryogenics. This means i must revise my advocacy for the density of Liquid Ammonia to 681.9 kg/m³ for consistency. Northstar makes a good case but I feel this is the better choice since literally everything else I've adjusted has gone this way.

Edited March 13, 2015 by regex

[Northstar1989]

To amend an earlier post:

I have standardized densities for all Real Fuels (that don't require consensus) to either liquid at boiling point for cryogenics or density at STP (1atm, 0C) for non-cryogenics. This means i must revise my advocacy for the density of Liquid Ammonia to 681.9 kg/m³ for consistency. Northstar makes a good case but I feel this is the better choice since literally everything else I've adjusted has gone this way.

Regex, that density is too low even for Ammonia at boiling-point. The density at boiling-point is 682.78 kg/m³, not 681.9 kg/m³.

But, once again, the ambient temperature of Low Earth Orbit is -40 C. The ambient temperature of deep space is below -80 C (colder than the freezing-point of Ammonia, so you're already going to want to heat it to keep it liquid- but preferably as little as possible...) The boiling-point of other cryogenics you would want to store it alongside is much lower still (-182.96 C for LOX, for example). Why would you ever want to store Ammonia at -34 C when you could get a higher density and reduce heating-requirements by storing in at -40 or -50 C?

Using the density at -34 C instead of the density at -40 C (which I posted here) makes even less sense from an immersion perspective because when you right-click on a fuel tank in the context menu, it normally shows an ambient temperature of -40 C in Low Kerbin Orbit, and a fuel tank temperature to match. You would need to implement some sort of active-heating module for Ammonia storage in order for using the temperature at -34 C to be realistic- and why would you ever do that when it would just be extra mass/complexity in order to reduce the density of a resource and increase its rate of boil-off?

If a convention doesn't make sense, abandon it. As long as there are notes in the CRP document as to the temperature and pressure we assumed for the resource, it should make sense to future modders.

Also, if you change all cryogenics to their boiling point, you would need to reduce the density of LOX from the currently-used 1141.00 kg/m³ to 187.07 kg/m³ (the density of LOX at 1 atm and -183 C, yeah LOX density declines extremely rapidly as you approach its boiling-point).

Are you sure you want to stick with using the boiling-point of cryogenics at 1 atm pressure? (don't forget, boiling-point goes up at higher pressures) That's an enormous (almost 10-fold) nerf to the density of LOX from what you've previously been using in RealFuels if you stick with that...

Regards,

Northstar

- - - Updated - - -

Also, speaking of the most practical/sensible densities for different resources, the density of LH₂ needs to be increased to 70.99 kg/m³ from 70.85 kg/m³ (the density at 20 K - according to Wikipedia you need to cool it to at least 20 K to prevent rapid evaporation, even if the triple-point is 33 K).

Edited March 14, 2015 by Northstar1989

[RoverDude]

@Northstar - nothing personal, but at this stage of the game we're not going to quibble over a difference of 0.00000014 per unit for LqdHydrogen. That's a rounding error (Also, NFT is the curator for that resource, and I doubt Nertea plans on changing it's density).

Some of the densities being argued here are miniscule, to the point where I trust the mod curators (i.e. Regex and FreeThinker) to just stick a number in for their relevant mods (and both have already been given write access to the CRP working doc.

At this juncture, the thread needs to turn to conflict resolution between curators, and leave any debate on an individual mod's resources that they curate to their own thread. That way you can have an in depth discussion on the topic, and the curator (i.e. Regex/NathanKell) can come to this thread to advocate the change (at which point, I expect the rest of us would just say 'yes' unless there's a serious game-breaking issue).

[regex]

Northstar, sorry, but given that we don't have elastic densities in KSP it makes sense to me to stick to conventions, regardless of how unimmersive you may find them. I suggest ModuleManager, if possible, if the values given do not work for you. Regarding the boiling point, the convention I have seen throughout documents on the web is that the density for cryogenics is as a liquid at the boiling point, not as a gas at the boiling point. Apparently the transition to a gas has not taken place when calculated. I'm no chemist, but this definition makes sense to me, and many sources use this convention, and LOX ends up with 1141kg/m3 in this state. If you'd like to discuss this further you can PM me (and I will entertain no more debate on this subject in this thread) but I'm pretty firm on the value I'll advocate for given that the convention works for everything else. This is especially important to me for anyone else who wants to add resources that might be of interest to the Realism Overhaul suite of mods.

RoverDude, aside from Liquid Ammonia, the only other resource I'm concerned with is gaseous Methane (no hurry, no rush, just making note). I'm assuming Liquid Ammonia density is something FreeThinker and I will need to hash out.

Edited March 14, 2015 by regex

[RoverDude]

Yep let me go find that. Was that for KSPI or for you? Just so I know where to put it in the doc.

[regex]

Yep let me go find that. Was that for KSPI or for you? Just so I know where to put it in the doc.

For gaseous methane you can put it under RF if you want, I don't recall anyone but you and I having an interest in it at this time.

[FreeThinker]

Well, it's also a kind of intermediate gas when you harvest it from an atmosphere. For example, at Titan, your supposed to scoop methane directly from it's atmosphere. Which makes me wonder if you could fly around with a modified jetengine using Oxigen as a fuel and retrieve the Methane from the atmosphere.

[Northstar1989]

Northstar, sorry, but given that we don't have elastic densities in KSP it makes sense to me to stick to conventions, regardless of how unimmersive you may find them. I suggest ModuleManager, if possible, if the values given do not work for you. Regarding the boiling point, the convention I have seen throughout documents on the web is that the density for cryogenics is as a liquid at the boiling point, not as a gas at the boiling point. Apparently the transition to a gas has not taken place when calculated. I'm no chemist, but this definition makes sense to me, and many sources use this convention, and LOX ends up with 1141kg/m3 in this state. If you'd like to discuss this further you can PM me (and I will entertain no more debate on this subject in this thread) but I'm pretty firm on the value I'll advocate for given that the convention works for everything else. This is especially important to me for anyone else who wants to add resources that might be of interest to the Realism Overhaul suite of mods.

Regex, the values I suggested were based on realism considerations. You don't store cryogenics at their boiling-point in real life, you store them at substantially colder temperatures to reduce evaporation and increase density (see the Wikipedia article on Liquid hydrogen, for instance- you store at at 20 K even though it boils as 33 K in order to prevent it from rapidly evaporating...) Cryogenic densities are often listed at boiling-point simply for convenience: because the temperature will tend to stall at that point while additional heat-input goes into overcoming the Enthalpy of Vaporization- making the precise temperature+density combination easier to measure...

And the density of 187.07 kg/m³ is for LOX in liquid form at its boiling-point. Once it actually boils its density falls to around 4 kg/m³.

Also, why do you insist on treating me as if I have no place in this discussion? I have just as much right to be here as you do- I help develop KSP-Interstellar Extended in the same way that you help develop RealFuels. I'm newer at modding to be sure, but I've definitively taken the leap from "player" to "modder" and and am learning all I can to make myself more capable and useful in this regard...

RoverDude, aside from Liquid Ammonia, the only other resource I'm concerned with is gaseous Methane (no hurry, no rush, just making note). I'm assuming Liquid Ammonia density is something FreeThinker and I will need to hash out.

Indeed. Liquid Ammonia is a resource also used by KSP-Interstellar. And a rather important one for the mod at that (it is used for Thermal Rocekts, Electric Thrusters, and ISRU production of Monopropellant- to name just its most important uses...) Which is why I suggest we actually go with a density at least equal to its density at -40 C (the ambient temperature in Low Earth/Kerbin Orbit), as we already use densities for other resources that are not equal to their densities at their boiling-points (LOX, for example. As I pointed out before, Liquid Oxygen reaches densities of less than 200 kg/m³ before it officially boils...)

- - - Updated - - -

Which makes me wonder if you could fly around with a modified jetengine using Oxigen as a fuel and retrieve the Methane from the atmosphere.

Sounds like quite an exciting way to fly.

Regards,

Northstar

Edited March 14, 2015 by Northstar1989

[RoverDude]

For gaseous methane you can put it under RF if you want, I don't recall anyone but you and I having an interest in it at this time.

Done. Would this be something we want to add to atmospheres as a potential element? Fairly trivial to do the config for it.

Well, it's also a kind of intermediate gas when you harvest it from an atmosphere. For example, at Titan, your supposed to scoop methane directly from it's atmosphere. Which makes me wonder if you could fly around with a modified jetengine using Oxigen as a fuel and retrieve the Methane from the atmosphere.

I recall someone talking about that in a thread somewhere, though I think the reference was into hydrogen not methane

[regex]

Well, it's also a kind of intermediate gas when you harvest it from an atmosphere.

Yeah, that was the idea.

And the density of 187.07 kg/m³ is for LOX in liquid form at its boiling-point.

That's interesting because every reference I've seen said the density of oxygen's liquid phase was 1142kg/m3 at the boiling point. If that's simply a convenience that chemists use then it's a strange way of doing things, but it seems to work for them and it's a useful reference point by which to list the resource in the game since everyone who wants to add a resource has a common, easily referenced, and easily found point around which to do so. It's a moot point anyway since we've always used the liquid phase density at boiling point (1142) for the game.

Also, why do you insist on treating me as if I have no place in this discussion?

Excuse me, I mistook your role here.

Which is why I suggest we actually go with a density at least equal to its density at -40 C (the ambient temperature in Low Earth/Kerbin Orbit)

I'll accept that density for Real Fuels.

Done. Would this be something we want to add to atmospheres as a potential element? Fairly trivial to do the config for it.

Yeah, I've looked into the configs there. It's specifically for Martian ISRU (on a spacecraft scale rather than industrial scale), although you could use it elsewhere since it seems to be a fairly common atmospheric resource. Edited March 14, 2015 by regex

[FreeThinker]

A quick question: I want to give Fluorine a cost but I'm not sure how to put it in the table. According to this source, Fluorine Cost, pure: $190 per 100g. How to translate this into a CRP cost?

[regex]

How to translate this into a CRP cost?

When I did the RF resources I assumed LiquidFuel was Kerosene and translated all the costs from there. Not sure about other's methodology.

[Starwaster]

Yeah, that was the idea.

That's interesting because every reference I've seen said the density of oxygen's liquid phase was 1142kg/m3 at the boiling point. If that's simply a convenience that chemists use then it's a strange way of doing things, but it seems to work for them and it's a useful reference point by which to list the resource in the game since everyone who wants to add a resource has a common, easily referenced, and easily found point around which to do so. It's a moot point anyway since we've always used the liquid phase density at boiling point (1142) for the game.

WOW, yeah no. Definitely don't go lowering LOX storage density. That would be a huge mistake. If you need good references, look at the shuttle's external tank or the Saturn V. There's a huge amount of data on both volume and mass for LOX and LH2 there. A density of 187 would make both of those vehicles impossible to recreate here.

A quick question: I want to give Fluorine a cost but I'm not sure how to put it in the table. According to this source, Fluorine Cost, pure: $190 per 100g. How to translate this into a CRP cost?

RF assigned a value of $1000 to the KSP monetary unity.

the field you want is unitCost and it's per volume unit. Once you know what storage density you're assigning it, per volume unit calculate your cost from there and divide by 1000.

Edited March 15, 2015 by Starwaster

[RoverDude]

FreeThinker/RegEx/Nertea,

I've added a new column to the CRP working document so you can note which resources are done. IMO given the amount of work some of us have to do to get our stuff for 1.0 sorted, we should get a fork stuck in these sooner rather than later.

As you sort out costs, etc. please change 'COMPLETE' to 'YES'.

Time table wise, let's shoot for a week from today (3/22). At that point, the bus is going to be leaving, and anything not complete will be dropped till the next version, or I'll just stick a number in it and call it a day. Otherwise, I expect we can spend months fiddling with the numbers, which completely defeats the purpose

[regex]

WOW, yeah no. Definitely don't go lowering LOX storage density.

I'm ... not entirely sure where you got the idea that I/we were going to do that but, okay, I won't go lowering the density of LOX...

I've added a new column to the CRP working document so you can note which resources are done.

Time table wise, let's shoot for a week from today (3/22).

Thanks, will do and sounds good. Also, thanks for moving the solids up into the main mass of fuels (tripped me up for a second ); that's something we've wanted for a while but never got around to.

[FreeThinker]

RF assigned a value of $1000 to the KSP monetary unity.

the field you want is unitCost and it's per volume unit. Once you know what storage density you're assigning it, per volume unit calculate your cost from there and divide by 1000.

Sorry, it's still not clear. The Density of Fluoride is 1.7696 kg/M3 (STP) with 1 unit/L and 1kg cost 1900 $, now how much is the CRP cost for Fluoride?

Edited March 15, 2015 by FreeThinker

[NathanKell]

1.7696/1000 = 0.0017696 kg/liter * 1900 = 3.36224 $ / liter. Assuming the $1900 is in 1965 dollars, that means a unitCost of 0.00336224

That said, please, please don't use RF costs in CRP. They are completely, completely orthogonal to any kind of "stock-balanced" costing. They're for use with RP-0, where we give all real parts and real resources real costs.

Starwaster: regex wasn't proposing that, not sure why you thought he was.

[RoverDude]

Any reason why not tho? How 'off' are RF costs compared to stock? (Esp given that a lot of CRP bits are based on real world costs)

[regex]

Any reason why not tho? How 'off' are RF costs compared to stock? (Esp given that a lot of CRP bits are based on real world costs)

RF Fuels get their costs largely from Encyclopedia Astronautica, which uses 1960's prices. I've just used those costs in the sheet, so they are likely quite a bit lower than costs nowadays due to inflation and such.

[Nertea]

I calculated the rough cost of 1 L of kerosene to be 0.92 USD. As stock LF is 0.8 funds per 5L (0.16 per 1L), that's a ratio of 0.173.

So find the cost of 1L of a resource in USD, multiply by 0.173 to get the KSP cost. Make sense? Maybe not, someone should check my math.

I'll be back on the 21st, will revise my costs then.

[Starwaster]

I'm ... not entirely sure where you got the idea that I/we were going to do that but, okay, I won't go lowering the density of LOX...

Starwaster: regex wasn't proposing that, not sure why you thought he was.

And I'm not sure why either of you think I thought he was. Regex clearly indicated he didn't think it was appropriate to do so and I'm agreeing with that and pointing to some relevant reference material....

[regex]

And I'm not sure why either of you think I thought he was.

Probably because the entire conversation up to that point was about NOT changing the density but rather the definition of "boiling point" in regards to the phase of a chemical determining the density of that chemical. Basically two people were being pedantic and then someone else came in and agreed that nothing should change, even though we all agreed that change wasn't going to happen in the first place. Chalk it up to confusion.

Anyway...

[Northstar1989]

WOW, yeah no. Definitely don't go lowering LOX storage density. That would be a huge mistake. If you need good references, look at the shuttle's external tank or the Saturn V. There's a huge amount of data on both volume and mass for LOX and LH2 there. A density of 187 would make both of those vehicles impossible to recreate here.

@Regex, Starwaster (although I believe Starwaster has me on his "ignore" list- thus why he didn't know where the discussion of LOX density came from)

I thought this was very clear. Those tanks weren't at the boiling-point of LOX. No rocket scientist in their right mind would store LOX at exactly its boiling-point due to its much lower density at this temperature... You store it at a dozen or so degrees (or a significant pressure-margin) colder than this in order to effect a more complete phase-transition from gas to liquid form...

LOX has a density of 187.07 kg/m³ at its boiling-point at 1 barr pressure (-183 C). It had a destiny of 1142 kg/m³ at the temperatures and pressures it was stored on the Saturn V or Shuttle External Fuel Tank- as both vehicles stored it at significantly lower temperatures and higher pressures (pressure has almost no effect on density most of the time- but when it is used to effect a phase-transition... The thing about LOX is that it basically has a very gradual phase-transition: that is its thermodynamic behavior is significantly different at slightly lower temperatures or higher pressures than its boiling-point than right at it, leading to a large difference in density...)

Once again, I'm not making this up. I not only already provided calculated density-figures at different temperatures for LOX

, I also provided a link to the Thermodynamics Calculator I used to find them. You can check these figures for yourself. At 1 atm and -200 C you get a density of 1223 kg/m³. However at 1 atm and -183 C you get a density of 187.7 kg/m³. If you raise the pressure to 2 atm at -183 C you increase the density to 425.7 kg/m³ (you can much more easily effect the same more complete phase-transition by cooling the Oxygen a few degrees), but this is because you are effecting a more complete phase-transition not because you are compressing the liquid with pressure. If you raise the pressure to 2 atm at -200 C the density remains entirely unchanged at 1223 kg/m³ because the phase-transition is already complete.

Regards,

Northstar

P.S. I hope you won't interpret this as a re-visit of my faulty "compressible liquids with pressure" argument from ages back. It's not. What I'm referring to is effecting phase-transitions (or as the case may have it, more complete phase-transitions) to increase density- in the same manner you can drastically increase the density of a gas at room temperature if you pressurize it until it turns into a liquid. It's not that you're compressing the gas with pressure- it's that you're raising the boiling-point until the gas enters a liquid state (which is always much more dense than the gaseous state). The most mass-effective way to turn a gas into a liquid is always to cool rather than pressurize it...

Edited March 15, 2015 by Northstar1989

[RoverDude]

NorthStar - with all due respect, we need to let this bit go. We're past discussing densities for now, and focusing on getting the first cut taken care of. At that point, if there are any issues - and within that context, only between shared resources, and between two mods with a conflict, we'll bring it up.

Just need us to stay on task as time is limited, and we all have a lot of work to do.

- - - Updated - - -

Two side notes.

SpareParts (courtesy of DangIt!) is also moving to 1L units, so that's out of the way

BioMass is off the list due to lack of communication. In the interest of not stomping over their stuff, I'll move the USI mods to a 1L 'Organics' resource. LqdCO2 does not conflict already so we're good on that front.

[Northstar1989]

I'll accept that density for Real Fuels.

Regarding LqdAmmonia, the most sensible temperature/density would be -50 C and 1 atm (702.1 kg/m³), not -40 C and 1 atm (690.2 kg/m³). That is because at -50 C you only have to cool/insulate the Ammonia by 10 degrees in LEO, but have to heat it 30 degrees in interplanetary space (or orbit of a planet further out from the Sun) in order to maintain it at this temperature. If you stored it at -40 C your heating-requirements in deep space would become substantially greater as you would have to maintain a 40-degree temperature differential from ambient (through heating and insulation) not a 30-degree one...

At a lower temperature, LqdAmmonia is going to be denser. It's also going to be easier to store in the same rocket at LOX, Liquid Nitrogen, or LH₂ as the temperature-differential between the propellants (how much warmer the Ammonia is than everything else) will be reduced- thus requiring less insulation between the different fuel-tanks inside the rocket... Both of these are of course very, very, very good things for a rocket- as they save mass on fuel tanks and insulation... (as well as heating-equipment, like I discussed above)

You can find the Thermodynamics Calculator for Ammonia HERE.

Finally, the density of LqdMethane ought to be based off -180 C and 1 atm, not its boiling-point (as you store Methane in the same rocket as LOX and LH₂, both of which need to be kept substantially colder). This means its density should be 448.25 kg/m³. Once again, HERE is a link to the Thermodynamics Calculator used to find the density at -180 C. The currently-selected density is 448 kg/m³, so it looks like you guys actually took my advice on this one...

Long story short- using density at the boiling points of cryogenics does not make sense. At the very least you're going to get a 10-20% decrease in density vs. a lower temperature. With something like LOX the difference becomes much more drastic- nearly a 90% reduction in density when storing at its boiling-point instead of -200 C...

Regards,

Northstar