Realism Overhaul Discussion Thread

[gemini4]

I know I asked this before and didn't get a reply, but I still want to know: Could there be a config for fuel cells that allows them to use HTP as an input resource? I've done some research just to make sure, and I can't see a reason why HTP couldn't be used as an input resource for a fuel cell. It has several advantages over the LOX/LH2 combination available now, not least its storable, as opposed to cryogenic, nature. It would also provide both water and oxygen, in addition to power, in its energetic decomposition. Thus, I think the addition of an HTP config to fuel cells would make them far more useful, especially in the early to mid-game, when they well outperform the available solar panels. As they can only be used with LOX/LH2 right now, however, I find myself using batteries instead for the early game because the boiloff is so limiting. I'd really like to know if we could see this configuration for fuel cells in a future update, and if there would be differences in power generation, etc. that we should expect. Thank you so much for your response. 

[Nightside]

Hey Overhaulers,

What should I consider when creating a realistic engine capable of multiple restarts.  I know many 2nd stages are capable of 2 burns, what are the limitations of giving a motor more restart capacity?

[Carraux]

20 hours ago, Phineas Freak said:

Source for that? AFAIK Saturn V only used propellants from GSE to start the gas generator for the turbopump. Is it possible to push the required amount of propellants via the GSE?

You are right, external propellant were only used to start the gas generator and to operate as a lubricant and as hydraulic working fluid for the engine. And this was RJ-1, not RP-1. One small letter, but such a big difference. I should have read the operations manual more carefully. Sorry.

[Phineas Freak]

@Carraux no problem, i also thought that i missed something! These discussions are the best way to learn new things.

@gemini4 i also found some research papers but nothing solid. Probably that is the reason why nobody has written an alternate fuel cell config. You could try and create one though.

@Nightside it is not the ignition count per se. Usually it is limited by the ignitor used (some are self - consuming meaning that you can carry/have only so much), the construction of the engine (materials and cooling limiting the overall burn time) and the propellant pressurization. On that end, TestFlight can be a much better balance point than just specifying an arbitary ignition count.

The XLR-81 engine used on the Agena upper stage is a nice example of a pressure - fed pump - fed hypergolic engine that started with a single ignition and reached the capability of "infinite" restarts due to the advancements of Rocket Science^TM.

Edited July 24, 2016 by Phineas Freak

[NathanKell]

Yep, no reason we can't have an HTP fuel cell, but AIUI the code it'd need to be a different part, there's no modular configs for them.

 

On pumps: yeah, I think in practice rockets start off internal supplies. In that way, I rather erred in allowing clamps to pump during startup.

 

@Phineas Freak Sorry to play pedant, but the XLR81 is pump fed. Were you thinking of the AJ10-37/42/101 which was modified to allow restarts in 104D? You're right though that the first model of XLR81 was non-restartable and the -B/D gained a restart (and the 8247 for GATV gained >15) due to advancements and in the case of the 8247 a decently significant redesign of the ignition system.

[Phineas Freak]

@NathanKell frack, i wrote pressure instead of pump...but now that you mentioned it, the AJ10 is another excellent example! Shame on me that i forgot that legendary engine.

[Sol Invictus]

May I ask why Realism Overhaul does not recommend Persistent Rotation and/or Orbital Decay?

Edited July 25, 2016 by Sol Invictus

[leudaimon]

@Sol Invictus PersistentRotation is actually recommended in CKAN, probably just forgotten in the OP. No idea about Orbital Decay, but I would guess it's because it's new and probably not stable/compatible enough.

[NathanKell]

I had heard Orbital Decay did not work right in RSS these days.

If Persistent Rotation is missing from the RO OP that's a mistake.

[gemini4]

I tried Orbital Decay in my most recent career file. It would cause arbitrary decay rates, as far as I can tell. I lifted a MK1 capsule and storable propulsion module into a 450km orbit, and it decayed in about 4 hours, while the less -dense, greater cross-section spent upper stage I had used for insertion stayed in orbit for a few months. Also, if uninstalled, all debris that had "decayed," and been destroyed by the mod, is still present, and crashes the game when attempting to delete it. This ended up clogging my tracking station window with scores of objects, none of which I could do anything about, and which I suspect, although I am not completely certain of the cause of the issue, reduced my frame rate in the tracking station window dramatically, and made it all but unusable for the rest of my save. I'm not sure if I'm the only one who has had these issues, however. 

Edited July 27, 2016 by gemini4

[h0yer]

On 27.7.2016 at 3:51 AM, gemini4 said:

I tried Orbital Decay in my most recent career file. It would cause arbitrary decay rates, as far as I can tell. I lifted a MK1 capsule and storable propulsion module into a 450km orbit, and it decayed in about 4 hours, while the less -dense, greater cross-section spent upper stage I had used for insertion stayed in orbit for a few months. Also, if uninstalled, all debris that had "decayed," and been destroyed by the mod, is still present, and crashes the game when attempting to delete it. This ended up clogging my tracking station window with scores of objects, none of which I could do anything about, and which I suspect, although I am not completely certain of the cause of the issue, reduced my frame rate in the tracking station window dramatically, and made it all but unusable for the rest of my save. I'm not sure if I'm the only one who has had these issues, however. 

I had the exact same issues. While OrbitalDecay might have been fixed in the meantime, those ghost-parts can be deleted manually, either by opening the persistence file and deleting the entire 'vessel' or using a save editor^^ I totally like OD, but it stopped decaying stuff all of a sudden, so out it went^^

PersistentRotation works like a charm, although RO/RP0 avionics system counterplays it's ability to hold attitude relative to the orbiting body in time acceleration mode, since (some) avionics get turned off and PR is dependant on an actively working SAS. MechJeb could use some integration on that part as well.

[Sol Invictus]

Thank you for all this information. I remember author of Orbital Decay, @Whitecat106, saying that it's compatible with RSS. I guess it's not then. It would be nice if Cat himself could clarify the situation.

Nonetheless, I have one more question. It's about unrealistic EVA fuel that is magically restored every time you return to your vehicle, even if there is no RCS fuel on board. Do I need to install EvaFuel in order to fix it, or did Realism Overhaul take care of it in some other way?

Edited July 31, 2016 by Sol Invictus

[h0yer]

5 hours ago, Sol Invictus said:

Thank you for all this information. I remember author of Orbital Decay, @Whitecat106, saying that it's compatible with RSS. I guess it's not then. It would be nice if Cat himself could clarify the situation.

Nonetheless, I have one more question. It's about unrealistic EVA fuel that is magically restored every time you return to your vehicle, even if there is no RCS fuel on board. Do I need to install EvaFuel in order to fix it, or did Realism Overhaul take care of it in some other way?

I might have put that a bit unfortunate, OrbitalDecay should right now work perfectly in a good RSS/RO Install. I merely lost the 'Slap The Kraken' game on my end, by trying too much funky stuff

 

[Whitecat106]

Hello everyone,

Orbital Decay should work fine, I have been using it in my own playthough with RSS and RO for quite some time, with the latest version and the latest RO install in KSP 1.1.3. If there are any obvious issues like orbits not decaying please do let me know in the Orbital Decay thread and/or the Github issue tracker here .

 

That being said the latest version will need some tweaking for an RO and RSS play through, within the WhitecatIndustries/Orbital Decay folder lies a folder for PluginData, within this there should be a settings.cfg file, within this the line

DecayDifficulty = 10 needs to be set to DecayDifficulty = 1, otherwise orbits will decay 10x as fast as real life.

 

The mod itself has been made to follow realistic formulas as much as possible and so should be well suited to a RSS-RO career, if anyone has any issues with non decaying orbits please do let me know as soon as possible so I can fix this and ensure compatibility with RSS-RO

Whitecat106

 

[Sir_Fanch]

18 hours ago, Whitecat106 said:

Orbital Decay should work fine

I second this, I've had some slight problems with it (certain test payloads not lasting quite as long as they did in real life, such as vanguard-1 which was more due to the way it maps surface area IIRC) but on the whole my test payloads have decayed at pretty close to the real life decay date, Whitecat has done fantastic work .

[h0yer]

Aye, as now stated in the OD thread, the game's "Orbital Drift Compensation" needs to be deactivated for OD to run properly, which I didn't.

I just thought to put the info here as well, since I got help from the other thread and other interested peeps might find it helpful.

 

Orbital Decay works perfectly as advertised

Thanks, Whitecat

(My Kraken turned into... a... beautiful butterfly^^)

[gemini4]

I also have some questions about RO's handling of solid rocket motors. I don't know if it's just me, but attempting to use many of the KW and FASA strap-on solids causes my rockets to roll during my pitch program. I think it's something to do with the nozzles, which are normally angled slightly away from the rocket body, but I'm not sure what. Even symmetrically attached motors cause rolls which can become nearly uncontrollable. In practice, this has often limited me to only a few solids with non-angled nozzles. I can't use the procedural solids either, as I've found through experimentation that they are inferior in almost every way to the solids already present through RO and mods. The procedural solids' ISP increase with tech level is quite balanced, in my opinion, but I think the fact that the case mass remains the same regardless of tech level, as far as I can tell, makes them second-rate compared to the late-generation solids with similar ISPs but much lower case masses. In addition, a procedural SRB costs far more than an existing solid motor of the same tech level. These disadvantages mean I find myself very rarely using procedural SRBs, which is a real shame. I would really appreciate it if you could address some of my concerns. Thank you.

 

Edit: I forgot to mention that the procedural SRBs also don't have thrust curves, which isn't a huge deal, but just a minor realism detail I wanted to address.

Edited August 1, 2016 by gemini4

[EliasDanger]

Out of curiosity, ever thought of making a realistic sound mod? Just occurred to me, in space sound waves have nothing to travel through so I shouldn't hear engine noise, decoupler noise, or anything. I'm sure that'd seem pretty dull, removing audio from the game...but hey this is supposed to be about realism!

[asmi]

11 hours ago, EliasDanger said:

Out of curiosity, ever thought of making a realistic sound mod? Just occurred to me, in space sound waves have nothing to travel through so I shouldn't hear engine noise, decoupler noise, or anything. I'm sure that'd seem pretty dull, removing audio from the game...but hey this is supposed to be about realism!

That depends on where the "ears" are so to speak. If they are inside the vessel, than sound waves travel through vessel structure with no problems (infact speed of sound in most metals is FAR higher than in air - we're talking like 20 times higher).

[asmi]

On 7/31/2016 at 10:11 AM, Whitecat106 said:

DecayDifficulty = 10 needs to be set to DecayDifficulty = 1, otherwise orbits will decay 10x as fast as real life.

Wow - I was really lucky I've come across this post. Can you please include this instruction somewhere where any user would be able to find it? Or better yet, set it up automatically (based on Kerbin/Earth radius for example)?

Anyways I've like to thank you for great mod! Thanks to you my orbital insertion stages to longer litter 200km circ orbits

[h0yer]

On 1.8.2016 at 11:54 PM, gemini4 said:

I also have some questions about RO's handling of solid rocket motors. I don't know if it's just me, but attempting to use many of the KW and FASA strap-on solids causes my rockets to roll during my pitch program. I think it's something to do with the nozzles, which are normally angled slightly away from the rocket body, but I'm not sure what. Even symmetrically attached motors cause rolls which can become nearly uncontrollable. In practice, this has often limited me to only a few solids with non-angled nozzles. I can't use the procedural solids either, as I've found through experimentation that they are inferior in almost every way to the solids already present through RO and mods. The procedural solids' ISP increase with tech level is quite balanced, in my opinion, but I think the fact that the case mass remains the same regardless of tech level, as far as I can tell, makes them second-rate compared to the late-generation solids with similar ISPs but much lower case masses. In addition, a procedural SRB costs far more than an existing solid motor of the same tech level. These disadvantages mean I find myself very rarely using procedural SRBs, which is a real shame. I would really appreciate it if you could address some of my concerns. Thank you.

 

Edit: I forgot to mention that the procedural SRBs also don't have thrust curves, which isn't a huge deal, but just a minor realism detail I wanted to address.

I once had similar issues, although mine came from not using the proper symmetry/angle-lock, which lead to the boosters beeing mounted slightly 'twisted' around their longitudinal axis, which gave the rockets a slight spin, during booster burn.

Most likely unrelated, but I had very strange rocket bahaviour with odd circular mirrored engine clusters, like three nozzles in a circle/triangle.

If you have RCS build aid installed, you can have a more precisely look where the momentum comes from, maybe their thrust transforms are somewhat off, hmm.

On 2.8.2016 at 7:39 AM, EliasDanger said:

Out of curiosity, ever thought of making a realistic sound mod? Just occurred to me, in space sound waves have nothing to travel through so I shouldn't hear engine noise, decoupler noise, or anything. I'm sure that'd seem pretty dull, removing audio from the game...but hey this is supposed to be about realism!

I think there already is exactly what you're looking for, not sure how well it runs momentarily, but I used the last stable setup for quite a while, awesome mod, especially if you are more the flyboy type and less rocket man

 

[Nightside]

On 7/31/2016 at 7:11 AM, Whitecat106 said:

Hello everyone,

Orbital Decay should work fine, I have been using it in my own playthough with RSS and RO for quite some time, with the latest version and the latest RO install in KSP 1.1.3. If there are any obvious issues like orbits not decaying please do let me know in the Orbital Decay thread and/or the Github issue tracker here .

 

That being said the latest version will need some tweaking for an RO and RSS play through, within the WhitecatIndustries/Orbital Decay folder lies a folder for PluginData, within this there should be a settings.cfg file, within this the line

DecayDifficulty = 10 needs to be set to DecayDifficulty = 1, otherwise orbits will decay 10x as fast as real life.

 

The mod itself has been made to follow realistic formulas as much as possible and so should be well suited to a RSS-RO career, if anyone has any issues with non decaying orbits please do let me know as soon as possible so I can fix this and ensure compatibility with RSS-RO

Whitecat106

 

@Whitecat106,

What about the "Realistic Decay" setting?

(I assume I would also want to turn 24-hour clock on as well).

[Sol Invictus]

@Nightside

quoting White Cat at his Orbital Decay thread:

Quote

This setting is depreciated and should have no effect to gameplay, it was added pre 1.2.0 as an option to allow realistic decay instead of the former stock model (which no longer is implemented and only applied to atmospheric drag), the only decay formula used now is one based on actual decay equations as of 1.3.0 +!

 

[Jovus]

How well does RO support the Near Future Technologies pack? I've heard conflicting things, all old, but I'd be interested in including NFT in my next run if it's compatible.

[Temeter]

59 minutes ago, Jovus said:

How well does RO support the Near Future Technologies pack? I've heard conflicting things, all old, but I'd be interested in including NFT in my next run if it's compatible.

It did in the past, but I think most configs are long outdated.

But even if it did, NFT doesn't really fit RO, and I wouldn't recommend it. IRL - and in technical documents for concepts - those engines are sometimes designed to fire for months, sometimes even years, again and again, because they are so incredibly weak. It's hardly viable in KSP at all.