Core KSP Mods

KSP ( Kerbal Space Program) is a great game, however the vanilla stock form of the game can be very frustrating, especially to new players.

One of the things most experienced players or streamers of the game will tell you is that there are a few mods that make playing KSP much much better. These are mods that by all rights probably should be stock. Each streamer's magic pick list is likely to vary slightly but what follows is mine:

 1. Kerbal Engineer Redux otherwise known as KER. Note that VOID or MechJeb can fill much of the same role for part of what this mod does. The key to this mod, and the reason it is so core to so many is that it provides information when building a rocket as well as in flight. Here are the things I think are the most important:

	 a) TWR: Thrust to weight ratio – This is the number that compared to the gravity of the selected celstial body shows your lift. So for example a perfect 1.0 means you will not go up at all, but could hover at that height. 1.4 is often considered the magic number for initial take off on Kerbin itself. Realize that as you burn fuel the weight of your rocket goes down but the thrust (if created by a solid rocket booster) will remain constant so that your TWR will actually go up as you lift off. In addition as you get further away from the gravity of a body the TWR will go up.

Many Engines have a better TWR in a vacuum so be aware that you need to think about the TWR once you are clear of the atmosphere as well.

A very low TWR once in orbit or between planets means a very long burn time to get yourself to a new orbit. This means that while you may have tons of delta-V (which we will talk about next) you likely will have multiple minute burns or longer in some extreme cases.

	 b) Delta-V: Change in velocity to be literal about it. This is the amount of change in vector that you can create. So for example if I am traveling relative to a rock at 100 m/s and I have 100 m/s delta-V I could zero my velocity relative to that rock. Now things like planets and moons are trickier as they have their own gravity which exerts a constant force you have to fight, plus in some cases you have to fight against or can use the thickness of the atmosphere to slow yourself down. This is what parachutes are really all about after all!

There are many delta-V charts on line and off the Kerbal forums. Study it, be aware that many of the inter-planetary ones rely on ideal transfer plans but the ones in early game that are the most important are for orbit around Kerbin and landing on the Mun or Minmus.
Be aware that the displayed delta-V likely will change dramatically as you go from thick soupy atmosphere of Kerbin to vacuum of space. Many engines are much more efficient in a vacuum, so if you can look at the stages, figure out what stage you will be out of the air and into the vacuum and then click on the atmo button to see what the values are for the later stages. A lot of this can be sort of eye-balled and learned as you go, but knowing these values without doing math on paper or using a spread sheet make things like KER priceless

	 c) In Flight Data: This mostly consists of things like how high your apo/peri are ( Your top and bottom orbital heights respectively) and how long to each of these. Getting into a good orbit really requires this information. While in KSP you /can/ get this information from the map screen to use it properly requires you to fly most of the time in the map screen, which to me really isn't that fun. When you can see this on your main flight screen and also see how much delta-V you have, your current speed and so on, it really is a much better game.

	 d) Landing Data: Without KER or another tool like it, you have no exact gauge on how high up you are, which is to say that while you have an altimeter it does not tell you the height above the ground but rather above 'sea level' which is rather useless when landing on the Mun or other body. In fact landing on 'land' on Kerbin it is pretty useless as well. You need to know the terrain height, and KER can provide this information. It can also give you a ball part figure on what is called suicide burn, which is the last moment you can burn at full thrust and hit zero at the moment you touch down to land (no, don't try this at home kiddies, it often doesn't take into account horizontal speed vectors or other things but can be a good rule of thumb to be sure you don't drop below this value).

 2. Kerbal Alarm Clock: This mod consists of a system for setting 'alarms' that pull you out of time warp either at a point before a node, a change in sphere of influence or another set point. While the game does have 'warp to' functions for some time, it is too easy to click on the wrong warp to thing and end up burning up or missing a node or the like. This helps avoid that kind of problem. While it is not required, it is a helpful mod and one that I don't like to play without.

 3. Precise Node: This mod lets you control a maneuver node without tugging on the little arrows in the map view. You can control exactly how much a node projects the burn by in which axis to the 0.01 in orders of magnitude up to 100. This lets you exactly set up your encounters with moons and planets making transferring between them much easier and letting you adjust things with much greater control. If you use the options and tell it to display more options in the settings you can make it so you can snap a node to the apo/peri or AN/DN (times when you most want to adjust your orbit inclination to match an object that is not in the same plane as you are orbital wise.

 4. Transfer Window Planner: This mod lets you plan and design a transfer window so that you can find the ideal time, path and delta-v for going from one planet to the next. While you can always brute force it and I actually rarely consult this mod in my actual careers, it really is something that I should do and that many think is vital. There are websites out there that can do this for you, but having the tool in game, especially with something like Precise Node with data you can just input and Kerbal Alarm Clock so you can ensure a proper timing of the burn you can get to other planets in a fraction of the time and cost in delta-V.

Here is where you can find these mods respectively. Note that for KER the 1.0.5 version is still 'not full release' and can not be found on Ckan (A mod repository tool some use), so for that you will need to go to github, get the output folder and put the KerbalEngineer folder from that in your game data folder.

Kerbal Engineer: https://github.com/CYBUTEK/KerbalEngineer
Kerbal Alarm Clock: https://kerbalstuff.com/mod/231/Kerbal%20Alarm%20Clock
Precise Node: https://blizzy.de/precise-node/download.html
Transfer Window Planner: https://kerbalstuff.com/mod/268/Transfer%20Window%20Planner

Each of these needs to be placed in the 'GameData' folder of your KSP game folder. Be sure not to put things in too far a sub folder and that you have the actual mod in the right place. For most it is easy enough to just put for example the KerbalEngineer folder inside the game data folder, but be sure you are putting the output sub folder in, as the other one is in fact the raw source code in the example of KER.

Hopefully this helps folks out in explaining the core mods, what the are, what they do and how to get them. Every other mod, be it part or game mechanic change is rather fun but not really required. However without these mods or something like them, the vanilla stock game can be a beast to get into and the learning curve and trial and error required can be outright painful. I hope the effort I've put into this can help those out there.