Without mods, Kerbal Space Program is already an amazing accomplishment—a deep, rewarding sim that captures the majesty and challenge of going to space. In 2015 we gave it our highest recommendation, and since then it's appeared in both our staff’s and our readers’ top 100 lists. Kerbal Space Program sticks around because it is everything that makes PC gaming great: freedom, creativity, flexibility, and mods. Naturally, mods make it better. The best mods for Kerbal Space Program add new ships, new parts, and small touches to keep Kerbal fun and fresh after a hundred hours of rocket science.
Whether you’re looking for a flyable Enterprise, a recreation of NASA’s Apollo rockets or the International Space Station, the KSP community has been getting it done for ages now. Out of all of the fine work available, these are our favorite mods for Kerbal Space Program.
Comprehensive Kerbal Archive Network (CKAN)
Get it: Kerbal Space Program forums
Don’t forget: Add Module Manager, a mod that helps other mods play well together.
The first mod on the list isn’t really a mod, it’s a program. CKAN is an open-source, community-supported mod manager. Though KSP’s mod community has moved around a lot: for a while it was officially based out of the now-defunct Curse.com, most of the biggest mods still live on the game’s official forums, and still others live on SpaceDock. With so many mod sources out there, CKAN aggregates modders’ submitted files and cross-references them, making sure that every mod is up to date, installing/uninstalling instantly, and warning you if mods are incompatible with each other. If a modder has recommended other mods to go along with theirs, CKAN asks if you’d like to install them at the same time. It’s a gorgeous piece of work, and it’s more essential the more mods you add.
To add a mod using CKAN, just start typing the name. There may be a few mods only hosted on Curse or SpaceDock, but almost all of them are included in CKAN.
Immersion mods
Some of my favorite mods are the most useless. Check out these mods if you want a more beautiful, immersive game.
Chatterer
Get it: Forums
Don’t forget: Quindar tone volume can be adjusted if they’re too beepy.
In space, no one can hear you scream unless you hold down the push-to-talk button. Chatterer took real-life audio from the Apollo 11 missions, scrambled it up a bit, and chopped it into audio files that play in the background of your missions. Combined with some well-placed Quindar tones, this mod gives the impression of a bustling, chaotic mission control center buzzing with messages and cross-talk. Floating weightless in the black of space feels more real with mission control talking in your ear.
Hullcam VDS
Get it: Forums
Don’t forget: Pressing [-] cycles through all available cameras.
The Apollo missions happened before we discovered the joy of strapping a GoPro to everything, but Kerbals are much more advanced. The Hullcam VDS mod adds a variety of attachable cameras so you can watch your missions from the side of a rocket or from inside an engine housing. Launching with a down-facing hull camera lends flights a certain SpaceX kind of feel. The mod also adds a Hubble-style space telescope you can use to creep on distant planets.
Collision FX
Get it: Forums
Don’t forget: Sparks kick up a soft, soothing light for nighttime crashes.
Making crashes and screw-ups look nicer might be the most “Kerbal” thing imaginable. Collision FX adds sparks, smoke, screeching tires, ploughing dirt, and plumes of snow—depending on the ground you’re crashing into. They’ve been working on it for years, and that’s why the newest version throws up soil that matches the regolith you’re slamming into. That’s quality!
Collision FX also adds an adorable little “oof” noise for when Kerbals fly into something solid during EVAs.
RealPlume
Get it: Forums
Don’t forget: RealPlume is packaged to include SmokeScreen, a mod that lets you tweak and customize engine effects.
For all the many times that my Kerbals have died in a big ball of smoke and flame, I’ve always thought to myself: that smoke could be smokier. RealPlume completely reworks the exhaust and plume effects for KSP’s rocket engines (and quite a lot of the mod pack engines, too!). You spend a lot of time in KSP watching engines burn, after all, so why not make it look great?
PlanetShine
Get it: Forums
Don’t forget: Orbiting a planet with a colorful atmosphere reflects that color onto your ship.
OK, this one is really useless. Even for this list. Still, I love PlanetShine because it exemplifies the obsessive attention to detail great modding communities thrive on. Here’s what it does: when a ship is in low orbit around a planet, the backside of the ship will be softly illuminated by the planet’s reflected atmospheric light. The mod plays well with Environmental Visual Enhancements, which adds nighttime city lights and cloud effects.
Kronal Vessel Viewer
Get it: Forums
Don’t forget: Distance between pieces in the exploded view can be adjusted, from huge gap to tiny sliver.
I love blueprints. I’m not an engineer or an architect, but I have a fascination with blueprints and technical drawings. Kronal Vessel Viewer adds a view window in the VAB for you to tinker with two-dimensional sketches of your huge Kerbal ships. Using the exploded view, it’s possible to get a schematic-style look at your most historically important missions. Just imagine: this view of your ship, the Get To The Mun Please Damn It All, will be in every young Kerbal’s history books in school.
New challenge mods
Kerbal Space Program is a hard, hard game because physics is impossible and the universe wants to squish your frail, pathetic spirit. If it’s not hard enough, though—if you want new ways to fail spectacularly—then these mods bring new punishments for the most advanced Kerbonauts.
SCANsat
Get it: Forums
Don’t forget: Pack plenty of solar panels; SCANsat readouts are not low-wattage.
Previous satellite mods focused on scanning and locating resources for pre-1.0 KSP. Now that resources and refineries are part of the vanilla game, SCANsat is the best precisely because it focuses on what satellites do best: exploration. With high-definition scans from a SCANsat satellite, players can target flat areas for safe landings, identify points of interest, and get a full understanding of a planet’s biomes worthy of research. Even the smallest bodies in the Kerbol system are enormous, so this mod is a great way of approaching that challenge.
Orbit Portal Technology Space Plane Parts
Get it: Forums
Don’t forget: Kerbal Aircraft Expansion is another excellent parts pack devoted to aircraft, but its best parts focus on exploring Kerbin itself.
There’s nothing quite as satisfying as a single-stage-to-orbit space plane that flies smooth and lifts heavy. Once you get your arms around the peculiar physics of KSP’s space planes, you’ll have a cheap, reusable shuttle system to bring supplies, Kerbals, and even space station modules to orbit. OPT’s excellent space plane parts pack dramatically expands the tools you have to get to orbit.
Dang It!
Get it: Forums
Don’t forget: Pairs so well with Entropy, a mod that causes wear and tear damage to all ships, that the two mods fell in love and decided to merge. Entropy is now an official part of Dang It!
This ingenious and mildly bowdlerized mod breaks stuff. Solar panels short out, engines misfire, fuel tanks start leaking, batteries fail. You can adjust how frequent and how catastrophic the failures, but the end result is that with Dang It!, even perfectly designed missions sometimes have hiccups. Luckily, your expertly trained Kerbals can perform an EVA and fix the problem, as long as you brought along a few spare parts.
For some players, this sounds like a hellish nightmare. I admit, though, that I find surviving a Kerbal version of Apollo 13 to be more than a little compelling. The alarm klaxon that sounds when a malfunction occurs will haunt my dreams for months.
Kerbal Construction Time
Get it: Forums
Don’t forget: You can “simulate” a ship to see how it flies without waiting for the actual construction time. Simulate a few times, then when you’re happy with it, build it for real.
One of the quirks of KSP is that it keeps track of time. Every second of spaceflight is added to the overall game clock, which tells the game where every planet and ship is in space. Time is paused while you tinker with design of a new ship, and only begins when you click “launch,” meaning every ship is built instantly. Kerbal Construction Time changes that. The more complex the ship, the longer it takes to build. Why bother? Realism is a part of it. It also forces you to plan ahead, designing and sending new ships into the construction pipeline weeks or months before you’re ready to launch. If you’re building a space station in orbit, for example, you either need the cash to build multiple ships at once or you need to plan for the first module to orbit for a few months before the second module can join it.
DMagic Orbital Science: Probe and Rover Pack
Get it: Forums
Don’t forget: DMagic recommends several great mods to go with this one, the best of which is [x] Science, a mod that gives you a master checklist of the experiments you have and haven’t finished yet.
Depending on what contracts you take, you might be sending routine flights up and down around the same parts of space for a while. After you’ve gotten temperature (cold) and atmosphere (none) data back to KSP central, there’s not a lot more science to be done. This mod adds a ton of new experiments for your vehicles, including a soil moisture sensor and an x-ray diffraction analyzer. Get back to work!
SpaceY
Get it: Forums, CKAN
Don’t forget: A calculator in the VAB tells you how long your Kerbals will live with the provided supplies.
Sad, but true: NASA isn’t really in the inspiration business anymore. These days, all the exciting space stuff is happening at SpaceY, the privately held Kerbal space agency that bears no resemblance to privately managed space agencies here on Earth. All of your favorite SpaceY heavy lifter parts are ready to download and head to space.
Umbra Space Industries
Get it: GitHub
Don’t forget: Umbra’s most famous mod packs are Kolonization Systems and Life Support, a 1-2 punch combo that will definitely have you leaving hundreds of Kerbals to starve to death beneath the ruins of their failed colonies.
Unlike most one-off mods, the rocket scientists behind Umbra Space Industries have established a cottage industry of mod packs. They’ve got cranes and magnets in Konstruction!, submarines for charting alien oceanography in the USI Exploration Pack, and high-speed engines in Alcubierre Warp Drive.
Almost all of USI’s projects packs are modular, so you can take a few science gizmos here and a couple of engine couplings there as you like.
Near Future Technologies
Get it: Forums
Don’t forget: Near Future’s mods are basically just parts packs, so you still unlock them through the usual R&D programs. Keep farming those science points!
It’s easy to get carried away by the siren-song of sci-fi splendor: god damnit, I want warp drive and phasers and I want them now. The Near Future series of parts packs takes a more patient approach by bringing near-future sci-fi to KSP. There’s no teleportation, but there are highly refined nuclear reactors and advanced xenon engines. These mods won’t get you to Star Wars, but they will get you to The Martian.
Automation mods
KSP asks you to be a lot of things at once: administrator, engineer, pilot, scientist, micromanager. These mods automate some of these tasks, freeing you up to focus on other things.
Kerbal Attachment System
Get it: Forums
Don’t forget: You can use KAS to move modules outside of the VAB, so your Kerbals can make an EVA and rearrange drilling platforms or solar panels that aren’t pointed the right way.
I once built an entire Mun base using modular pieces designed to fit a mini-rover with a docking port. The mini-rover could drive under the modules, lift them off their struts, and drive them over to their final destination. It was a horrific pain in the ass.
Instead, use Kerbal Attachment System’s network of wires, winches, pulleys, and fuel lines to connect parts of your base without actually rearranging them. Drag a wire from a solar panel array over to your habitat to produce power, or pull a fuel line from your storage tanks to your rover to refuel.
MechJeb
Get it: GitHub
Don’t forget: If you really do think that MechJeb is cheating, try Kerbal Engineer. It gives you a ton of extra flight data so you can see all the information you need to fly perfect missions by hand.
By far the most famous and most popular KSP mod in existence is the mechanical Jebediah, or MechJeb. Allowing a computer autopilot to take over your piloting tasks is ideal for anyone with a solid flight plan and great engineering skills, but without the rock-steady hands it takes to carefully touch 80 tons of steel onto alien soil. MechJeb can do it all, from extra-planetary insertion burns to docking maneuvers.
Some purists insist that using MechJeb is “cheap” or “cheating.” To them, I say nonsense. MechJeb doesn’t let an underpowered rocket reach orbit, and it won’t give you infinite fuel. If designing missions sounds like more fun than flying them to you, there’s no shame whatsoever in handing the controls to an expert.... but since we couldn’t find an expert anywhere around here, we’re handing them to Jeb. Good luck.
Kerbal Alarm Clock
Get it: Forums
Don’t forget: You can set an alarm for ideal interplanetary launch windows, letting you fast-forward until it’s the right time of year for a trip to Duna.
Throughout most of KSP’s development, you had to simply fast-forward time and hope you didn’t rocket past your burn window. In those dark days, Kerbal Alarm Clock was born. Even though KSP has made it easier to hit your windows, the alarm clock is still essential. Set alarms for certain parts of your orbit, for other crafts passing nearby, for crossing orbits, and others. You can even tie into a strange alternate universe, a planet called “Earth,” and set alarms based on the local time.
Docking Port Alignment
Get it: Forums
Don’t forget: The target window is also viewable from the cockpit view, which means you can get the immersive experience of docking from the pilot’s chair. Stressful! Horrifying!
The navball in vanilla KSP is much-maligned, but I don’t think it deserves the flak it gets. It’s perfect for most purposes. Its biggest failure, to my mind, is docking guidance. Trying to line up a three-dimensional maneuver with a one-dimensional target? That’s silly business. Docking Port Alignment adds a pop-up window with four crosshairs. Point at the target, rotate into alignment, face perpendicular to the target, and get moving gently toward it, all with the same window.
It won’t dock for you like MechJeb, but it gives you all the information you need to nail it. I went from docking in a couple of minutes to under thirty seconds when I started using this mod.
For Science!
Get it: Forums
Don’t forget: If you have a scientist on board, one-use experiments will also automatically reset.
Of all the mods on this list, this one feels the most like cheating. For Science! is designed to remove the science grind by automating it. Simply taking a thermometer into the ocean will automatically record that reading and store it in the command module. Arming a plane with a few experiments and flying it across Kerbin will bring in a steady stream of new science points. No more guessing if you’re over a certain biome or trying to fly and press go on an experiment at the same time.
Multiplayer mods
For some, KSP’s greatest asset is its loneliness. For others, the only thing better than docking is docking with a friend. Vanilla KSP was supposed to one day support multiplayer, and the idea took off with the community. There are a few solid options available.
Telemachus
Get it: Forums
Don’t forget: Telemachus works (mostly), but it’s as ugly as the dark side of a Kerbal. Install Houston, a UI upgrade that plugs into Telemachus to make it a little prettier.
Telemachus is complicated and I am but a simple moron, but the basic gist is this: Telemachus pulls flight data out of KSP and puts it into a web browser. Using magic, presumably.
Why is that cool? Well, you can use it for a bunch of things. You can gather up tablets and old laptops and assemble yourself a mission control. You can send that browser link to a friend and share real-time data as you fly. Or, and here’s where it gets really fun, you can assemble a team to play as your mission control. One player plays as the pilot in cockpit view, and mission control works to tell her when to burn, how long, and where. Add some beer and a few explosions, and you’ve got yourself a party.
Dark Multiplayer
Get it: Dark Multiplayer site
Don’t forget: Your firewall may have some issues with sharing network access. Consult the DMP FAQ to figure out which ports to open.
Dark isn’t the original multiplayer mod, the one that got the entire Kerbosphere a-twitter when it first launched, but it is the best we have right now. By combining a lot of server options with more-stable-than-not netcode, Dark Multiplayer allows you to hook up with a friend, rendezvous in orbit, and start constructing that orbital science station.
The big hurdle for multiplayer is time warping: if I fast-forward two hours to catch up to my friend and she stays put, we’re now in two separate time lines with two versions of Kerbin at different points in orbit. Without getting into Doctor Who levels of timey wimey-ness, Dark Multiplayer allows for a single master to control time warping. This keeps everyone on the same timeline, preventing fourth-dimensional weirdness and Dalek attacks.
