You can buy a DRM-free version directly from Private Division .
If you are writing a regarding this specific version or the distribution of KSP, note that v1.12.3.031 was the final major "Grand Slam" update for the original game. It introduced features like the "Rotating Calendar" and various final bug fixes before the developers shifted focus to KSP 2. Using pirated versions for development or modding is generally discouraged as it can lead to version mismatches and instability in your projects. Kerbal Space Program Free Download (v1.12.3.031...
Websites offering free downloads of paid games like Kerbal Space Program (KSP) are often used to distribute . Specifically: You can buy a DRM-free version directly from
Provides a DRM-free version that you can back up and play offline. The "Develop Paper" Context Using pirated versions for development or modding is
Occasionally offers games for free as part of their weekly promotions (KSP has been free there in the past).
If you want to play Kerbal Space Program safely and support the developers, you should use official storefronts: Often features deep discounts during seasonal sales.