Kerbal Space Program is a space flight simulation video game developed and published by Squad for Microsoft Windows, macOS, Linux, PlayStation 4, and Xbox One. In the game, players direct a nascent space program, staffed and crewed by green humanoid aliens known as "Kerbals". The game features a realistic orbital physics engine, allowing for various real-life orbital maneuvers such as Hohmann transfer orbits and bi-elliptic transfer orbits.

The first public version was released digitally on Squad's Kerbal Space Program storefront on 24 June 2011, and joined Steam's early access program on 20 March 2013.[1] The game was released out of beta on 27 April 2015. Kerbal Space Program has support for user-created mods that add new features, and popular ones, such as those for resource mining and context-based missions, have received support and inclusion in the game by Squad.[2] People and agencies in the space industry have taken an interest in the game, including NASA [3][4] and the European Space Agency.[5]

In May 2017, Squad announced that the game was purchased by video game company Take-Two Interactive, who will help support Squad in keeping the console versions up-to-date alongside the personal computer versions. An Enhanced Edition was released on the Xbox One and PlayStation 4 in January 2018 by Private Division, a publishing subsidiary of Take-Two Interactive.[6] Two expansions for the game have been released as downloadable content: Making History in March 2018 and Breaking Ground in May 2019. A sequel, Kerbal Space Program 2, has been announced for a 2021 release.