Players may also set challenges for each other on the game's forums, such as visiting all five moons of Jool (the in-game analogue of Jupiter), or use mods to test each other's aircraft in air combat tournaments. Missions (either player-set or assigned 'contracts') involve goals such as reaching a certain altitude, escaping the atmosphere, reaching a stable orbit, landing on a certain planetary body, rescuing stranded astronauts, capturing asteroids, and creating space stations and surface bases. Spacecraft maneuver 'nodes' can be plotted, timed, and executed, and objects can be selected and 'targeted' to facilitate flybys, rendezvous, and docking. To visualize vehicle trajectories, the player is provided a 'map' mode that displays the current vehicle's trajectory as well as that of celestial bodies and other spacecraft, as well as their orbital parameters. Provided it maintains sufficient thrust and fuel, a spacecraft can enter orbit or even travel to other celestial bodies. Players control flight with little assistance other than a Stability Assist System (SAS) to keep their rocket oriented. Constructed craft can be launched from the space center's launch pad or runway to accomplish various tasks while avoiding partial or catastrophic failure (such as lack of fuel or structural failure). From the space center players can build various vehicles such as rockets, aircraft, spaceplanes, and rovers from a provided set of components. The player administers a space program operated by Kerbals, a species of small green humanoids, who have constructed a spaceport on their home planet of Kerbin. In-game Kerbals, Valentina Kerman and Jebediah Kerman, standing on the launchpad Gameplay A rocket (preloaded ship 'Kerbal X') sitting on the launchpad with the Vehicle Assembly Building and Mun, Kerbin's nearest moon, in the background. A sequel, Kerbal Space Program 2, was released in Early Access on February 24, 2023. Two expansions for the game have been released as downloadable content: Making History in March 2018 and Breaking Ground in May 2019. An Enhanced Edition was released for Xbox One and PlayStation 4 in January 2018, and for PlayStation 5 and Xbox Series X/S in September 2021 by Private Division, a publishing subsidiary of Take-Two Interactive. In May 2017, Squad announced that the game had been 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. The game has garnered commendation from spaceflight industry figures such as NASA, ESA, science communicator Scott Manley, ULA CEO Tory Bruno, SpaceX CEO Elon Musk, and Rocket Lab CEO Peter Beck. Popular mods have received support and inclusion in the game by Squad. Kerbal Space Program has support for user-created mods that add new features.

The game was released out of beta on 27 April 2015. 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. The game features a realistic orbital physics engine, allowing for various real-life orbital maneuvers such as Hohmann transfer orbits and orbital rendezvous. In the game, players direct a nascent space program, staffed and crewed by green humanoid aliens known as 'Kerbals'. Kerbal Space Program ( KSP) is a space flight simulation video game developed by Mexican studio Squad for Linux, macOS, Windows, PlayStation 4, PlayStation 5, Xbox Series X/S and Xbox One.

Kerbal space program 1.0 ascent guide