Help me find the mods...

[OmegaAlbert]

Hi... I'm looking forward to playing with realistic mods (in terms of mechanics not graphics)
Help me please find interesting mods...

[Pehvbot]

RP-1/RealismOverhaul is the gold standard  and combines most of the other realism mods available.

What types of mods are you interested in.  E.g. life support, part failure, fuel types, contracts, etc?

[Llamageddon]

I've not actually tried a game modded heavily for realism yet, but there are a few mods I've noticed recently and made note of for when I do. Right now, the only realism related mod I used is USI Life Support, specifically because by default it is probably one of the most forgiving life support mods. I mention it because it is also the easiest I've found to customise, from extremely forgiving, to brutally cruel levels of difficulty. It is quite limited in what it considers life support, compared to others, though. And if I do upgrade my life support mods, I am completely on the fence when it comes to a lot of interesting sounding options out there.

To answer your question, regarding life support, here are some that have caught my eye, in no particular order or preference:

• USI Life Support - Already mentioned and linked to above.
• TAC Life Support - Seems like it has quite a robust life support simulation, with a reasonably high difficulty level, but also quite customisable.
• IFI Life Support - Not looked into this much, but made note of purely because linuxgurugamer who has adopted and updated this mod, has yet to disappoint me in terms of quality and stability of their work, and seems to choose quality candidates to adopt and update.
• Kerbalism - This seems to be one of the most in depth life support mods out there, but actually covers "realism" in many more areas, quite comprehensively. It might even tick off most items on your realism checklist. For this reason, the mod recommends taking care and checking for compatibility problems with other mods, but as a counterpoint, seems to have very good compatibility and integration with mods that it does work well with - including Realism Overhaul that @Pehvbot mentioned above. I like the look of this, but suspect those compatibility issues might cause problems with some other mods I would have difficulty giving up.

As I said before, no particular preference from me, but it sounds like you would be interested in looking up all/any of the mods mentioned above.

I may as well mention those other mods I've bookmarked for a future realism playthrough. One of the reasons I've made note of these is that they seem to be currently working will with the latest versions of KSP, and have some new-ish/original ideas, or promising ongoing development. Like the rest of this post, this is entirely subjective, and I haven't actually extensively tried them out recently, but as with the life support mods I mentioned, I expect they might interest you as references/guidance for your own research of what you might be after:

• Kerbal Health - Somehow, this had not been on my radar until very recently. Seems to fill a bit of a niche or bridge a gap between some of the other realism mods. For the more literal/traditional "health" aspect, it makes use of a health bar system, which seems to be a bit more comprehensively/rationally integrated than with some other mods I've looked at in the past. On the less stereotypical side of its health remit, it simulates kerbal stress/comfort, and particularly of interest to me, how ship design and mission scope and length needs to be factored in with regard to this.
• Kerbal Launch Failure - Pretty self-explanatory and I think it also features possible catastrophic failures, to complement emergency escape, snd other related systems.
• Dang It! Continued - Part Failures, adds a % chance for random part failures, taking into account how much those parts are being used.
• Custom Barn Kit - Really a dependency for other realism mods relating to administration, costs, science and other things related to the KSC. I mention it specifically because it allows you to customise all these values for yourself if you don't mind tweaking config files. (Used in my current mod setup)
• Contract Configurator - Similar to Barn Kit but for contracts specifically, at the most basic level lets you individually disable vanilla contract types.
• Various contract packs - Probably better to search for yourself, there are a lot, and caution is advised as many are outdated or have bugs, not all are realism related, but quite a few are an improvement on the vanilla equivalents, in terms of realism. To get you started, I recommend searching for "Contract Pack" plus "Research", "Bases and Stations", "Exploration Plus", "Kerbal Academy". (Used in current setup)
• History of Spaceflight - This is the one contracts pack I will mention directly, as it seems particularly relevant to your question, It tries emulate what the title suggest, via contracts, and is also compatible with some part mods that offer analogues to rockets that were traditionally designed and built during the space race, which may also be of interest to you and are linked on that mod's forum post.
• Komplexity - Adds ten building upgrade levels to facilities instead of three, and is quite well-balanced, but also easily customisable using with Barn Kit. Might need tweaking when adding some mods related to building upgrades, to avoid inconsistencies in this regard. (Used in current setup)
• Strategia - A complete overhaul of the game's current strategy system, though not ultra-realistic, is a big improvement in this regard over vanilla. I find it compliments a more realistic selection of mission packs, too. (Used in current setup)
• Outer Planets Mod - Adds analogues to the planets from our solar system that are "missing" in KSP. It massively expands the scope of the vanilla system without completely making the game unplayable with most conventional mods, or requiring things that are arguably not realistic, such as wormholes and FTL travel. (Used in current setup)
• Remote Tech - Ups the difficulty, but adds a lot a realism, to the games' current remote control/CommNet system, also pairs well with the most realism focussed mission packs I do regularly use.
• CommNet Relays - Works well with Remote Tech, and I am particularly impressed with, given the limitations of the mission system, it sets such complex, yet functional objectives to achieve its remit. It rewards you for setting up uninterrupted relays for comms from and to other bodies and specific locations. Trying to set up 3-4 relay satellites in a perfectly stable orbit for unbroken comms, indefinitely, is practically impossible in the long run without some mods to help with things like resonant orbits, but if you like a realism related challenge, it's fun trying, and certainly possible to eyeball it to last for a hundred years or more, with a bit of skill and planning.
• Near Future Mod Series - This might not fit your criteria of realism but seems worth a mention. Adds a lot of theoretical technology and parts to the game, without drifting too far into the realm of science fiction. I think it does a great job of both adding a lot of new possibilities without completely overwhelming your parts list, but also, limiting its scope to concepts that are generally agreed to be both plausible and practical, have demonstrated proof of concept, or have just not been used yet or given the go ahead for funding of development programs. Often essential for use with mods that expand the scale of the Kerbol system, but adds a lot to the late-game experience, regardless.

Related mods not included above for "reasons":

• Real Solar System - Arguably you can't get more realistic than our actual solar system, but in terms of realism, I am put off for two reasons. Firstly I feel this is taking realism too far for me, I want realism within the setting of Kerbal Space Program, and feel this is taking the game too far from what it was actually envisioned to be. Secondly it expands the distances involved to such extremes, you need to very carefully think about what other mods you might be using with it. The game will just be completely broken without quite a few essential mods to compliment this, and with a lot of mods you might not have thought of that completely mess up the game with this installed as well. That being said, it's certainly one of the more impressive modding achievements, and at some point I plan to make a second modded version of the game, purely centred around this one, for a completely different KSP experience.
• RSS related realism mods - Similar to the previously mentioned RSS, these are such extreme overhauls in general, that you are locking yourself into a completely different modding ecosystem, which would invalidate many of the suggestions I made above. Again, not claiming these are in any way flawed or inferior, just with realism turned up to 11, you are playing with such fundamental alterations to the core game's design, that you need to re-evaluate your mod choices purely from that perspective.
• Other Parts Mods - These are not excluded because I think they are invalid choices for improved realism, or that I am biased towards the Near Future series (I thought I ought to include at least one example), but because there are so many to chose from, and preferences are inevitably very subjective. It's worth noting that if you try to add them all, your game initialisation can quickly exceed ten minutes (or even with just one or two of the larger ones), and this will also translate to much longer scene changes in the game. In this scenario, it can take a lot of work to get your parts list to a readable state, probably requiring a couple of utility mods just to manage this. Also, I think there are others who might post here who would be much more knowledgeable about this category of mods than me.
• Mods that have slipped my mind - There are so many out there, don't take this as a comprehensive or ultimate list of mods, even within the categories of those I have mentioned.

A long post, but I've been thinking about, and looking into this myself recently, so if nothing else, this will be quite a useful summary for me to check when I start my next game. As I hinted at, I'll probably re-read this and be slapping my forehead, thinking, "How could I have forgotten to mention that mod."

[Pehvbot]

Personally I would either dive straight into the deep end and use the CKAN express install of RP-1 -OR- start going through your list one mod at a time to see how you like it.  Just be sure to have only one life support mod and one failures mod installed at the same time, otherwise it things might go sideways.

My favorites are Kerbalism and Dang It but really, it's just about personal preferences.  History of Spaceflight + Kerbal Construction Time is a good combo and I like Strategia as well.

A few items on that list are really just support mods.  Contract Configurator and Custom Barn Kit don't really do anything by themselves but they are used by other mods.

Another option is to use my own Less Real Than Real(ism) + Less Real Kerbalism 

It uses the RP-1 tech tree, science, and contracts, plus crew training stuff but with a much more 'Kerbal' feel.   It works with both RSS and KSRSS and is pretty tolerant of other mods.  I made the mod specifically so I could play a fairly 'light' game since it only needs stock parts and Restock+ to be completely playable.  It pairs well with Near Future as well.

I wrote a failure mod (well technically it's and addon for another failure mod) called Less Real Test Flight specifically for LRTR but can certainly be used without LRTR as well. 

[Llamageddon]

Now you mention it, I might try out your Less real mods myself, to get a taste for that side of things, before jumping straight into the deep end with real solar system stuff.

5 minutes ago, Pehvbot said:

 

A few items on that list are really just support mods.  Contract Configurator and Custom Barn Kit don't really do anything by themselves but they are used by other mods.

 

This is a fair point, I added them as I have made a lot of custom tweaks in my current set up, but it was hardly straightforward compared to using a mod with a custom settings interface. On those grounds @OmegaAlbert might want to ignore them as individual mods; if they are a dependency, that mod will be doing the config for you, most likely.

[OmegaAlbert]

Wow... thansk geen guys!