Kerbal Space Program has left Early Access. 1.0 comes packed with new features, optimizations, bugfixing, and tons more! Conquering Space Was Never This Easy!
User reviews:
Very Positive (639 reviews) - 93% of the 639 user reviews in the last 30 days are positive.
Overwhelmingly Positive (31,688 reviews) - 97% of the 31,688 user reviews for this game are positive.
Release Date: Apr 27, 2015

Sign in to add this item to your wishlist, follow it, or mark it as not interested

Buy Kerbal Space Program


Recent updates View all (35)

October 11

Kerbal Space Program update 1.2 “Loud and Clear” is now available!

Hello everyone!

Kerbals hit a milestone, they are now interconnected and they can hear you Loud and Clear! Let your imagination fly with new possibilities, build communication networks, control vehicles remotely and explore every inch of the Kerbol System in ways that weren’t possible before with this new update!

Kerbal Space program 1.2: Loud and Clear includes a broad range of improvements and features that will enrich the overall game experience, such as the introduction of CommNet and KerbNet, a rewrite of the Stability Assist System (SAS) that makes your launches more accurate and fuel efficient, an engine change from Unity 5.2 to 5.4, more tweakable options for many parts, a complete fuel system redesign, and much more!

Here are some of the highlights for this update:

Set up your own communications networks and have better control over your probes even when they cannot establish a direct connection. Link your probes back to Kerbin via an antenna to be completely autonomous and build relay networks for better science transmission!

Use satellites for reconnaissance purposes, scan the terrain below you, find biomes and anomalies, and place custom waypoints with a targeting interface.

Improved Fuelflow System
The Fuelflow system has been rewritten and now you have total control over how the fuel flows through your vessels!

Improved Wheels
The stability of Wheels has been greatly improved. Your rovers, wheeled vehicles will now turn and handle smoothly, making the overall driving experience more pleasant. Aircraft are also more stable, and all wheels have realistic load limits.

You can find the complete changelog here.

Kerbal Space Program 1.2 Loud and Clear is now available on the KSP Store and on Steam, and will soon be available on other third party platforms.

228 comments Read more

September 13

Update 1.2 Pre-release is here!

Hello dear Kerbonauts!

Update 1.2 has finished its Experimentals phase and we’re excited to announce the launch of the Public Pre-release.

During Experimental testing a small team of experienced KSP players threw everything they’ve got at the game in order to help us catch as many bugs as possible, so that we could make the game as stable as it could be. Now we’re proud to say that’ve come to the point where we can finally release the open test build.

This ‘pre-release’ test build is for everyone to have a go before we officially released the update and you’ll be able to opt-in to get the Pre-release builds via the Steam betas, or, for the first time ever, through the KSP Store. Naturally, you’ll need own a copy the game beforehand in order to access these builds. This opt-in branch will run for a minimum of two full weeks before the release date of the final update (the final release date hasn’t been closed, so changes may occur).

To facilitate discussions of the Pre-release branch we’ll be opening up a temporary sub-forum for feedback. Additionally, a Pre-release project will be made available on the bug tracker to report bugs on.

Furthermore, we want to help the modding community by making the modding API public. Click this link and enjoy!

Finally, and as promised, you can get Porkjet’s awesome rocket parts package files here .

We’re almost there and we couldn’t be more excited. Stay tuned for updates and happy launchings!

366 comments Read more

About This Game

In KSP you must build a space-worthy craft, capable of flying its crew out into space without killing them. At your disposal is a collection of parts, which must be assembled to create a functional ship. Each part has its own function and will affect the way a ship flies (or doesn't). So strap yourself in, and get ready to try some Rocket Science!

The game offers three gameplay modes: Sandbox, in which you are free to build anything you can think of; Science Mode, which lets you perform Scientific experiments to advance the knowledge of Kerbalkind and further the available technology; and Career Mode, in which you must manage every aspect of your Space Program, including administration strategies, Crew Management, Reputation, as well as taking up Contracts to earn Funds and upgrade your Space Center Facilities (or repair them).

Add to this the ability to capture asteroids (a feature done in collaboration with NASA), Mining for resources out across the furthest reaches of the Solar System, Constructing Bases and Space Stations in and around other worlds; plus literally thousands of mods from a huge active modding community, all add up into the award-winning game that has taken the space sim genre by storm.

Key Features

  • The Vehicle Assembly Building and the Space Plane Hangar allows players to build spacecraft out of any imaginable combination of parts.
  • Fully-fledged, Physics-based Space Flight Simulation ensures everything will fly (and crash) as it should.
  • Take your Kerbal crew out of the ship and do Extra Vehicular Activities.
  • Fly out to Moons and other Planets.
  • Procedural Terrain delivers detailed terrain at a vast scale. The Kerbal Planet is 600km in radius!
  • Mod-enabled, allows players to create new content and modify the game.
  • Ship systems. Keep an eye out for engine temperatures and fuel levels, and try not to explode.
  • Build ships with multiple stages, and jettison parts away as they burn out.
  • Full control over the ship’s setup allows for complex ships and advanced functionality.
  • Dock spacecraft together to build Space Stations, Massive Starships, or even surface bases on other worlds.
  • Manage your crewmembers, hire them, and send them out into space and make them into heroes.
  • Research and Develop new technologies to advance your Space Program.
  • Take on Missions to attract interest in your Space Program.
  • Discover new worlds and expand the scientific knowledge of Kerbalkind.
  • Extract valuable resources from all over the solar system.
  • And a whole lot more!

System Requirements

Mac OS X
SteamOS + Linux
    • OS:Windows Vista or 7
    • Processor:Core 2 Duo
    • Memory:3GB RAM
    • Graphics:SM3 512MB VRAM
    • Hard Drive:4 GB HD space
    • OS:Windows 8 or 10 64 bit
    • Processor:Core i5
    • Memory:4 GB RAM
    • Graphics:SM4 1GB VRAM
    • Hard Drive:6 GB HD space
    • OS:Mountain Lion (10.8)
    • Processor:Intel
    • Memory:3 GB RAM
    • Graphics:SM3 512MB VRAM
    • Hard Drive:4 GB HD space
    • OS:El Capitan (10.13)
    • Processor:Intel Core i5
    • Memory:4 GB RAM
    • Graphics:SM4 1GB VRAM
    • Hard Drive:6 GB HD space
    • OS: Linux (Most distros should work)
    • Processor: Core 2 Duo
    • Memory: 3 GB RAM
    • Hard Disk Space: 4 GB HD space
    • Video Card: SM3 512MB VRAM
    • OS:Ubuntu 14.04
    • Processor:Core i5
    • Memory:4 GB RAM
    • Graphics:SM4 1GB VRAM
    • Hard Drive:6 GB HD space
Customer reviews
Customer Review system updated Sept. 2016! Learn more
Very Positive (639 reviews)
Overwhelmingly Positive (31,688 reviews)
Review Type

Purchase Type


Display As:

(what is this?)
25,229 reviews match the filters above ( Overwhelmingly Positive)
Most Helpful Reviews  In the past 30 days
226 of 265 people (85%) found this review helpful
226 people found this review funny
1,431.8 hrs on record
Posted: September 28
Just remember to eat and drink occasionally.
Was this review helpful? Yes No Funny
93 of 96 people (97%) found this review helpful
5 people found this review funny
469.6 hrs on record
Posted: September 25
Kerbal Space Program, at least to me is the king of simulation games. While I play numerous others (such as Farming Simulator) they don’t seem to hit every mark in that field. KSP, while challenging at first is the one that throws everything that happens in reality at the player, and force them to deal with it. While a game like Farming Sim only really requires you to keep an eye on fuel or some crops, KSP requires that you maintain a healthy supply of necessities ranging from fuel and electricity, to a satellite connection back home. But the part of the game that truly shines is the feeling you get when you first land on the Mun. A friend who gave the game a shot said
“it was just...pride. So many Kerbals died in previous attempts, and I finally made it.”

While the game is difficult, I can’t stop asking people to try it. To me, it’s the perfect “life isn’t about the destination, but the journey” and I think this game captures that perfectly.
Was this review helpful? Yes No Funny
19 of 21 people (90%) found this review helpful
2 people found this review funny
119.6 hrs on record
Posted: September 25
If you have even a remote interest in space and space travel, buy this game. Seriously. It's worth it.

There's a learning curve but when you learn how to play, it's very satisfying and rewarding completing contracts and exploring the solar system.

There's a huge modding community as well so you can make the experience even better with Realism Overhaul & Real Solar System to get as close to real life rocket ships as possible. (+hundreds of other mods like SpaceX rockets and other real life rockets and engines and graphic improvement mods.)

Seriously, this is one of the best games I've ever played. The development team (SQUAD) is very active and transparent with the community.
Was this review helpful? Yes No Funny
12 of 14 people (86%) found this review helpful
1 person found this review funny
231.8 hrs on record
Posted: September 23
This game is pretty perfect. Don't buy it if you expect a story or an immersive career mode. Do buy it if you want to spend hundreds of hours building realistic-style rockets and trying to fly to the Mun, other planets and their moons, etc... and exploding spectacularly TONS of times.

A++ game
Was this review helpful? Yes No Funny
5 of 5 people (100%) found this review helpful
395.7 hrs on record
Posted: October 3
This is probably, my favorite game ever.
Its the only game that after a while I miss the ambiance, the music, the sounds and simply have to get back to.

I suck at it, its very hard to master (if its ever possible) but its simply great.

I could not recommend it more
Was this review helpful? Yes No Funny
4 of 4 people (100%) found this review helpful
1 person found this review funny
178.2 hrs on record
Posted: September 25
This game is amazing. There was a bit of a learning curve to figuring out the specifications needed for a space ship to reach its target, but with a little reasearch on orbital mechanics and rocket design, designing rockets became easier. It's such a satisfying feeling when you finally acomplish missions that took hours of hard work, I've even had to pull out the old pen, paper and FE approved calculator a few times while playing this game.
Was this review helpful? Yes No Funny
4 of 4 people (100%) found this review helpful
1 person found this review funny
257.3 hrs on record
Posted: September 25
Ok, first step... Build rocket, watch it explode.
Second Step: Build rocket again, launch it, then watch it dive bomb into the ground/water/mountain....
Third Step: Build rocket again, launch it, make it to the upper atmosphere and discover you didn't bring enough fuel....
Fourth: Build rocket again, add more fuel, launch, and finally get it into orbit.....
Fifth Step: Pass out from high blood pressure attack from actually getting into orbit and finding out you don't have enough fuel to return to the planet....

Sixth Step: Look at the clock and discover you forgot to go to work, feed the cat, ect.
Seveth Step: Return to step 1.

Bloody love this game! I acutally have more hours than posted, as I play this game on my laptop while on the road, usually at night so that I'm all stressed out.

Now the Cons:

[ ] Steep learning curve, unless you have high understanding of physic's, math, your already an Astronaut.
[ ] An i5 Intel CPU (or AMD equal) or better recommended
[ ] Lots of memory and graphics memory
Was this review helpful? Yes No Funny
21 of 37 people (57%) found this review helpful
42 people found this review funny
406.4 hrs on record
Posted: September 23
After over 300 hours ofplaying, this game crashes the most on my computer. I just recently had a game crash, and the window that said "KSP.exe has crashed" had crashed, then the window that said that last window crashed, then crashes.
Would crash again
Was this review helpful? Yes No Funny
3 of 3 people (100%) found this review helpful
5 people found this review funny
509.9 hrs on record
Posted: September 30
You ever wonder what people mean when they say "It's not rocket science"?

Wonder no more.

This game is all about rocket science. Put in about 500 hours and when someone says "its not rocket science" to you, you can retort with "i know rocket science and im about to show you how much Delta V it takes to crush your kerbals with my boot."
Was this review helpful? Yes No Funny
3 of 3 people (100%) found this review helpful
2 people found this review funny
50.9 hrs on record
Posted: October 13
I crashed on the Mün, wrecking my ship, but the crew survived. I mounted a rescue mission, but they crashed too. They live there now.
Was this review helpful? Yes No Funny
Recently Posted
66.5 hrs
Posted: October 23
This is my first review of any game on Steam so, the short version is: BUY THIS GAME if you can because it is awesome and you'll have tons of hours of fun.

Now, for the long version...

Although I highly recommend this game, I must first start with the main negative aspects, which could make you refuse to buy it.

First of all, it is a highly scientific game, which will require of you hours and hours of watching youtube videos of other people explaining what is what in this game. The in-game tutorials aren't very helpful (at least for me), too short and barely scratch the surface. Luckily, the community is extraordinary and you will find a lot of help in many places. You will need to learn a lot of physics and other aerospace stuff to understand the game, which in its essence is cool but for many, a game is a reason to relax, not to learn complicated things. So, you will have to do a lot of research before you can play the game well. Its tutorials aren't going to help you very much.

Second, it is quite buggy even now, in 1.2. Especially if you use mods, it will crash to desktop a lot of times so save often. And even though it doesn't look much, the graphics require a good PC. But played stock, 4 GB of RAM are plenty.

Now, for the good part.

It is a hugely entertaining and educating game. You will learn a lot about how hard was it for the early pioneers of NASA to get a hang of launching stuff into space. Of course it is far from reality, but you will get a pretty good idea of it. At least, you'll get closer to it than with any other simulator. You will have to start from scratch, learning how to launch a rocket, how to build a plane, how to take into account the center of weight vs center of lift stuff, you will deploy sattelites built by your own hands (click by click), you will visit other worlds, plot courses that require enough celestial mechanics knowledge on your part. Your way of thinking will CHANGE.

If you are passionate about astronomy, this is your game. If you are passionate about astrophysics, this is your game. If you love building stuff, being patient enough to see them explode then rethink them, if you love learning thousands of things about planes and rockets, THIS IS YOUR GAME.

There are many detailed reviews about the game, here on Steam and elsewhere. The game is worth every penny so try saving some cash or just buy it, plain and simple. I've spent 60+ hours on Steam and at least 100 before that on another version of the game. I've barely scratched the surface. It keeps me up at night, making me plan for my next contraption and my next launch. So...

WARNING: It is highly addictive! At least, if you're into this kind of games. I uninstalled it and reinstalled it at least 10-15 times but I keep getting back to it. It is by far the most interesting, challenging and rewarding game (all together) I've played in my life.

Now... If this hasn't convinced you to buy it, just read the other reviews on this page. I'm just a newbie, but others have more comprehensive opinions about the game that will convince you this game is worth the money. I've got mine from ♥♥♥ at half the price but if I have had the money, I would've payed the full price or double. It's a lot of work inside a very beautiful game.


As a final note: 95/100. Hard to learn, very hard to master, fun to play and addictive to discover its secrets. BUY IT.
Helpful? Yes No Funny
826.5 hrs
Posted: October 22
played it for hundreds of hours
Helpful? Yes No Funny
344.9 hrs
Posted: October 22
Anyone who writes a bad review of Kerbal Space Program is just plain lying.
Helpful? Yes No Funny
21.7 hrs
Posted: October 22
Helpful? Yes No Funny
88.2 hrs
Posted: October 22
All I can say is WOW! I bought this when it first came out, played for short time, decided it was cool, but too hard, then forgot about it. Recently, I noticed that I had downloaded an update through Steam. I decided to boot it up again and I'm glad I did. I am having an absolute blast with the career mode and I really like all the mods that are out there. It makes it "your game". 3...2...1...AWESOME!
Helpful? Yes No Funny
1.1 hrs
Posted: October 22
very gooooooooD!!!
Helpful? Yes No Funny
a bag full of puppies
76.2 hrs
Posted: October 22
Helpful? Yes No Funny
167.9 hrs
Posted: October 22



Pick your superlative and it still doesnt do KSP justice. The options on hand, the freedom of choice, the sheer audacity of it and it has REAL and PROPER physics, not crappy 3rd party rubbish that doesnt work or "faux" effects.

If you like space in any way, or if you like just blowing stuffs up, this game is a MUST have.

Personal rating for KSP - 9.5 / 10

Its that good.
Helpful? Yes No Funny
547.5 hrs
Posted: October 22
I'm one of the many fans of KSP, and it's essentially the only game that I play. Success at the game requires a significant knowledge about rocketry and orbital mechanics, and the game does make it possible to learn quite a bit of what you need to know. There is also a lot of support in the community (for example, the interplanetary travel calculator that shows the orientation in orbit needed to reach other planets). I've put quite a few hours into KSP and still have plenty of challenges left. Making it safely to another celestial body (a planet or a moon) feels like a significant challenge - it's very satisfying.
Helpful? Yes No Funny
30.4 hrs
Posted: October 22
Joke review: Took 18 hours to reach orbit, better then the 800 hour players.
Real review: Buy this game. Maybe on sale, maybe not, but if you like space, and sandbox, or just glitches, this game is for you. Lets start with sandbox;this is considered the main part of the game. This is pretty self explanitory, but I love to mix in game cheats in the mix (windows: alt+(fn/function if you have it)+ f12). Now science, at the time I have not touched, but I already know what it is. It is career, without money. Now career, is the real deal for veterans on normal. This game is the ultimate time waster, in a good way. Now the modding community, they have some GREAT things, but you have to drag and drop files yourself, but is honestly fast.

Gameplay 9/10
Story: N/A
Sound 6/10
Graphics: 8/10
FPS: 5/10

TLDR: Buy, buy, BUY! Big modding community, and fun in vanilla.
Helpful? Yes No Funny