The version you are looking for, Kerbal Space Program (KSP) 0.25.0.642, was released on October 7, 2014. This update, titled "Economic Boom," introduced iconic features like destructible buildings, the Administration Facility, and spaceplane parts.
If you own KSP on Steam, you cannot normally download old betas, but Steam’s console allows it for users with knowledge: Kerbal Space Program -KSP- 0.25.0.642 download for computer
: A comprehensive menu allows you to fine-tune your experience. Options include enabling permanent Kerbal death, adjusting resource rewards, and toggling facility destruction. New Department Leads The version you are looking for, Kerbal Space
If you have a legitimate license for KSP, you can typically access older versions through these official channels: Steam (Beta Tab): Right-click Kerbal Space Program in your Steam Library. Select Properties > Betas. installation is manual:
This report details the specifics of Kerbal Space Program (KSP) version 0.25.0.642. This version represents a specific milestone in the early development history of the game, often associated with the "Demo" builds or the early "ARM" (Asteroid Redirect Mission) update era. Due to its age (released circa 2014), this version is no longer officially supported or sold on modern storefronts like Steam or the Private Division store. Acquiring it requires navigating legacy archives.
Version 0.25 was often listed here as part of the archived installers. Key Features of Version 0.25.0.642
Since this is a pre-Steam "KSP Store" era version, installation is manual: