Kerbal Space Program: Stellar Expansions

Mods that extend and redefine KSP

Posted by Wisq on December 27, 2014

Having introduced Kerbal Space Program, and discussed some realism and user interface mods, it’s time to get to the “meat” of Kerbal modding: the mods that add new stuff.

In this final part of my KSP mod round-up, I’ll be talking about mods that actually extend gameplay and let you do new things. From Science to parachutes to colonisation to even building ships off-world, these mods can completely redefine your Kerbal experience.

This is a pretty long one, but I’m just going to power through it, because I want to get on to some actual gameplay! To help, here’s an index:

You can hover over each one for a short description, or you can just read on for the complete list.

DMagic Orbital Science

In stock KSP, the methods of gathering Science tend to be strongly biased towards manned sample-return missions. Crew reports, EVA reports, and surface samples all require crew, and you typically only get 30% or 40% if you transmit experiment results rather than bringing them home (even if that doesn’t really make sense for most of them).

DMagic Orbital Science doesn’t change any of the existing science tools, but it adds a lot more, all strongly based on real-life science and existing probe tools.

Examples include the Radio and Plasma Wave Science (RPWS) instrument (based on the Cassini probe) that measures radio and plasma fields in space to learn about planetary magnetic fields and the solar wind, or the Laser Ablation Spectroscopy unit (based on Curiosity’s ChemCam module) which fires lasers at soil and measures the chemical composition of the vaporised dust.

DMagic Orbital Science

Most of these tools can also transmit their data at full value, then go on to collect more — although some (like the Solar Particle Collector) do limit how many samples you can take and require returning for full value.

Also, several tools have extensive writeups in the DMagic mod release thread, which are well worth a read if you’re wondering how the instrument actually works. Between these descriptions and the actual science reports these instruments produce, this is probably the most educational KSP mod out there.

Of course, with all these new experiments to run, you can now get more science and unlock things faster than in stock. Whether that’s a good thing or not is up to you, but personally, I appreciate having more ways to collect science, especially via the more realistic unmanned-probe approach.

Note that all the DMagic instruments also come with Universal Storage wedge versions. These are included directly in the DMagic mod, so you don’t need to install anything extra.

Kerbal Attachment System

Ever had a rocket run out of fuel and wish you could call a tow truck or get a refuel? Or maybe you made a space station but forgot to put any lights on it?

If so, Kerbal Attachment System (“KAS”) is the mod for you. It allows Kerbals to EVA and attach/detach various things to ships, store and retrieve things from containers, and connect ships together using winches, pipes, and even grappling hooks.

Kerbal Attachment System

Kerbals now have some rudimentary ability to detach and pick up smaller items like lights, antennae, solar panels, RTGs, etc. They can carry these items on their back, then attach them at a point of your choosing. You can also mount containers on your ships to store or retrieve these small items, and pre-fill them with components in the ship editor. And then during EVA, you can take or store things in them, or even detach and carry the containers themselves.

With a winch or pipe between ships, you can tow ships along or keep them from drifting apart. You can also optionally dock them together to form a single ship, allowing you to transfer resources and crew between them. I’ve even had the opportunity to tow a 300-tonne asteroid using multiple winch cables!

KAS also provides this general “grab and carry stuff” framework for other mods, and some of them make use of it when available. For example, Universal Storage wedges can be removed and reinstalled using KAS. And if you install the Universal Storage KAS pack, you also get a KAS Storage wedge that acts like an inline container.


If you’ve ever wished for a simple flat map of a planet, or wanted to know where all the biomes are so you can squeeze out that last bit of science, then you need SCANsat.

SCANsat – big map

By attaching one of the scanning tools to a ship and then flying over the surface of the planet or moon, you can slowly fill in a map of the entire surface. Different instruments will fill in different map layers, such as surface topology or biomes, and are designed to operate at different scanning altitudes.

Background scanning is supported, meaning you can put a satellite in a polar orbit and leave it there, slowly scanning the entire planet, while you do other missions. And, once you’re done, you can analyse the data and transmit it back home for a small bit of Science.

SCANsat – small map

This mod doesn’t really have a huge impact on gameplay, but it does help add a sense of exploration. The maps themselves can also be useful for plotting future missions — particularly for finding flat places to land, or for determining a latitude and longitude to punch into MechJeb for a precise landing.


The RealChute mod is a reworking of the parachute system, offering tons of new options for parachute deployment. It comes in nosecone, radial, and even stack versions, and offers a much more comprehensive set of options for how to slow your craft down for landing.

Parachutes now come in three varieties — main, drogue, and drag. The main chutes are what you’d expect for slowing a craft down to touchdown speeds, but now the smaller drogue chutes can be used to help slow the craft down to a safer speed such that the main chutes don’t risk ripping off. Drag chutes can be used by planes to bleed off speed on the runway, and won’t auto-cut on touchdown like stock parachutes.


All RealChute parachutes are fully resizable and customisable with profiles, accessed using the “Action Group” mode in the editor. Parachutes can be set to auto-deploy at a particular altitude or pressure once manually armed, and can also be set to wait for a negative vertical velocity (i.e. only while descending). They also deploy more gradually than stock, spreading out the G forces and reducing the deployment shock, even under time acceleration.

If you’ve ever had trouble with the stock parachutes, give RealChute a go. Personally, I always feel a lot safer landing with a RealChute parachute.

EVA Parachutes

EVA Parachutes

Even RealChutes sometimes snap if you use them incorrectly. For those embarrassing moments where your command pod is hurtling to its doom, you need EVA Parachutes. This adds personal parachutes, giving your Kerbals an extra line of defence against unplanned lithobraking.

Personally, I also install the extra plugin file that gives all EVAed Kerbals a parachute at all times — when I’m zooming through the atmosphere, I don’t have the time or safety to open a parachute box and grab one! This has saved my Kerbals on several occasions, including one where I evacuated and safely parachuted all three Kerbals from a Mark 3 pod landing gone wrong.

Modular Kolonization System

If you’re using a life support mod such as TAC, you know that all manned missions will eventually run out of resources and must either be resupplied or come to an end. But what if there were a way to extend your resources, or even create a closed system that didn’t need resupplying?

The Modular Kolonization System mod (“MKS”), and the included Orbital version (“OKS”), does just that. It comes either in the form of several standalone modules that you can connect to each other via inflatable tubes on a planet’s surface, or in the form of orbital modules that you can dock to each other. Either way, it allows completed closed-loop recycling of all life support resources … eventually.

It’s worth noting that this isn’t a cheap “get out of life support free” card. Setting these systems up takes a lot of time and effort, even if you include some resources from Kerbin to get things started. Just setting up a greenhouse is going to involve a colony hub, an aeroponics module, several agricultural modules, a terraformer, some Kerbitats to house your Kerbals so you can collect their waste for compost, some starting materials to get things rolling, etc etc.

But the end result is something that really feels like a living, breathing colony. Or so I’m guessing, anyway. Truth be told, I’ve never actually gotten around to making an MKS/OKS colony (so no screenshots here, alas). But I’ve been watching this mod pretty closely, and I’m definitely planning on building some in my next game.

MKS also features some drills that you can use to extract various elements from planets, including ore, water, minerals, substrate, etc. These can be turned into various useful materials, whether you actually use the MKS structures or not. For example, with Universal Storage’s Elektron, you can break water apart into hydrogen and oxygen via electrolysis, just like on nuclear submarines or the International Space Station. This can cut down on your need for resupply missions, since between solar energy, water from drilling, and oxygen from electrolysis, you’ve covered all your life support needs except food.


TweakScale allows you to make almost any part larger or smaller. Want a giant ion engine? Go ahead! A probe-sized standard fuel tank? Why not! There’s a ton of possibilities.


If you’re concerned about balance, TweakScale does scale the mass and capacity of each part, and I’ve generally found that e.g. an array of engines is more efficient that just scaling an engine up. So far, I haven’t managed to produce anything that felt particularly imbalanced with it.

Infernal Robotics

Ever get the urge to replicate the Canadarm in KSP but had no idea how? Or maybe you’re a Transformers fan and want to make some space-faring battle robots? Infernal Robotics (“IR”) to the rescue!

This mod adds a ton of different ways to make things move. Hinges, telescoping multi-segmented pistons, rotating sockets, gantry rails for full 3D movement … if you can imagine making it on a robot, chances are you can make it with Infernal Robotics.

EVA Parachutes

I’ve used this for various things, but a good example is a moon lander (pictured above) that started out with the legs all curled up inside itself, then unfurled them once in space to create an extremely stable (if rather ugly) landing platform. I was able to land it on all kinds of crazy lunar terrain that would have caused any normal ship to topple.

Really, though, this is one of those mods where your imagination is the only limit. If you’ve played a lot of KSP before, you’re probably already thinking of some situations that would’ve been a lot easier if only you’d this sort of full robotic freedom available.

Kethane and Karbonite

Ever wanted to drill a moon for fuel instead of having to haul it up through Kerbin’s atmosphere? These mods let you do that.

Kethane and Karbonite are two different fuel-like substances that you can drill and extract from the ground of most planets and moons. Each can then be converted into most of the fuels available in the game — fuel, oxidiser, monopropellant, xenon for ion engines, and in some cases, even solid fuel for boosters.

The main difference between these two mods is that Kethane is finite while Karbonite is not. With Kethane, planets are divided into hex grids, and some grid tiles will have a finite amount of Kethane available (if any). If you try drilling anywhere else, you won’t find it, and if you drill a single tile too much, you’ll eventually run out. In theory, you can strip an entire moon of all its Kethane and be done with it.

Karbonite, on the other hand, is infinite, and is based on density. You can touchdown anywhere and drill for it, but unless you’ve hit a deposit, you’ll just get a slow trickle (if anything). The shape, location, and density of these deposits is specified by a planet-wide gradient map rather than coarse tiles. You can also collect Karbonite from oceans, or by flying through a gas giant atmosphere with a collector.

Scanning is also different in each mod. Kethane requires that you fly over each grid tile with a detector to determine how much Kethane it contains. Karbonite used to show “hotspots” with no scanning needed, but with the latest version, deposits are now by biome. You can either just fly over and watch the percentage on the scanner to learn what biomes have Karbonite in them, or you can install SCANsat and use your scanner to slowly compile a map of the exact shapes and densities of the deposits.

Note also that Karbonite (SCANsat-style) scanning works in the background, like SCANsat itself — but Kethane scanning does not, making it much more bothersome since you actually have to sit and watch the ship the whole time.

There’s also some more technical and political differences between the two. Karbonite was originally based on the Open Resource System — which (I gather) was created mainly to deal with the technical and licensing limits of Kethane — but it’s now migrated to the author’s new “Regolith” framework, which will support asteroid mining as well. Kethane hasn’t really changed much in a while, but it’s hard to say if that means it’s stagnant, or just mature.

Which mod you choose depends on your preferences and play style. If you’re setting up a large ground-based colony (particularly an MKS one) and you plan on harvesting a lot of fuel, you may want to go with Karbonite, because you don’t want to be sitting on tonnes of scrap when the Kethane wells go dry. If you hate the idea of infinite fuel mining and don’t mind babysitting your scanner probes, Kethane works fine. Personally, I prefer Karbonite, but both frameworks are popular enough that most add-on mods will support both of them.

Extraplanetary Launchpads

Of all the mods I’ve listed here, I think it’s safe to say that Extraplanetary Launchpads (“EPL”) has the most potential to change how you play KSP.

In a nutshell, EPL does what the title suggests: It lets you set up launchpads, runways, and orbital construction docks outside of Kerbin’s atmosphere. You can use these launchpads to build and launch ships — all you need is the equivalent mass of “RocketParts”. You can also recycle existing ships, recovering all of their resource contents and about 80% of their tonnage as parts.

Extraplanetary Launchpads — orbit

If that’s all it did, EPL would still be pretty revolutionary — now you could build giant space-faring ships that you would never be able to get into Kerbin orbit, without needing to build them up piece-by-piece with docking ports. You might have to launch dozens of supply missions to do it, but it would be quite doable.

But EPL goes one step further, and lets you mine planets for ore, then smelt that ore to metal, and finally convert that metal into rocketparts. If you build a surface base on an ore deposit, you can mine it and launch dozens of ships right from there — no atmosphere, and a much easier gravity well, particularly on small moons like Minmus. Add some Kethane or Karbonite and you can launch them all fully fuelled, too. And even if you’re running an orbital base instead, you just need to occasionally send a ship down to the surface to grab some ore and bring it back up.

Extraplanetary Launchpads — ground

EPL normally requires the Kethane mod to provide the framework for mining ore, but an EPL Regolith conversion mod is also available to have it use Karbonite’s Regolith framework instead. Just remember that, like Kethane/Karbonite themselves, your choice of mod will determine whether ore is found in finite discrete deposits or as infinite density gradients.

If you’re concerned about making the game too easy (especially with infinite Karbonite-style ore), note that this mod goes quite well with TAC Life Support. You need living, breathing Kerbals to actually build the ships, and those Kerbals require life support, which means that any EPL base is either going to be a temporary outpost or a big MKS investment. You’ll also probably be launching a lot of unmanned ships, since you can’t really spare Kerbals to pilot them, meaning RemoteTech can also add some challenge to that aspect.

EPL really unlocks a ton of potential. You could build a giant mothership that slowly travels the solar system, collecting ore and Kethane/Karbonite, and building specialised ships from its orbital dock. Or you could set up a base on one of Jool’s moons and explore the entire moon system without ever sending any more ships. Or you could just set up a colony somewhere and build an endless supply of rovers to explore the entire planet. The possibilities are almost endless.

Asteroid bases

When NASA announced their Asteroid Redirect Mission, the KSP devs decided to work together with NASA to replicate asteroid redirects in-game. Grabbing an asteroid and (say) pulling it into a near-Kerbin orbit is certainly fun and all, but they never really came up with a reason as to why you might want to do that.

The Asteroid Recycling Technologies (“ART”) mod addresses this, by letting you turn asteroids into a sort of floating fuel tank, and maybe getting a little actual fuel out of them too. The idea is that you hook up one or more “Jaw” units to the asteroid, which will drill into it and convert rock into rock dust. You can then either convert that rock dust into small amounts of fuel (or water, or etc.), or spit it out via a Mass Driver to act as an engine to help move the asteroid.

Asteroid Recycling Technologies

But whatever you decide to do with the rock dust, the end result is a bunch of empty space. That’s where the ART “Hatch” comes into play. You can attach them and (invisibly) inflate them inside the asteroid to provide space to store resources (such as fuel, Karbonite, etc.), or to provide crew housing. Although the mod only comes with a few resources, it’s fairly easy to add more — I added some basic life support in my Github fork.

I’ve just recently discovered that the Hangar mod seems to do roughly the same thing these days, but goes one step further: You can turn your hollowed-out asteroids into giant docking bays and store actual ships in them. The Hangar mod also offers a lot of other goodies — essentially, it’s all about storing ships inside other ships. I’ll definitely be checking this out on my next playthrough.

Note that one downside of asteroid bases is that they can get pretty laggy. I’ve heard that the claw you use to connect to an asteroid is a major source of that lag, meaning that attaching a bunch of base components — or ART hatches — gets dodgy pretty fast. Until this is fixed, I can’t really recommend trying to set up full-sized asteroid bases. But they still make good giant mobile resource tanks.

And that’s it!

… for now, anyway. There are a bunch of smaller mods I’ll be using in my next playthrough — over sixty mods in total — but these are either too small to really be worth mentioning, or else I’ve only just started using them so I can’t really give a proper description and review.

For a game that hasn’t even released yet, KSP has a pretty ridiculously amazing modding community. That’s a testament to how truly excellent developers Squad have been in supporting the mod scene and in designing their engine to support it — but also equally to how vibrant and supportive a community the players and modders have built around the game.

And of course, this mod list is constantly changing. I’m sure that if I revisit this mod list in a year, I’ll have a ton more mods to add, and probably several of the ones I’ve listed will be superseded by even better alternatives.

But for now, it’s time to stop modding and start playing! I’m currently doing a playthrough with over 80 mods installed, so if you’re interested in how all these mods play together, go take a look.

Happy KSPing!

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