Kerbal Space Program

Kerbal Space Program is a physics simulation game focused on aerospace. Players design their own vessels such as rockets, rovers, space stations, probes, planes, or even boats and can travel throughout the Kerbal solar system which includes planets and moons similar to our own. Players must face similar challenges to real world aerospace but the difficulty may be reduced such as making it easier to reach orbit, having no requirements for life support, or engine relights.

Construction

Vessels are constructed at the Kerbal Space Center on Kerbin using a catalog of parts which include command pods, fuel tanks, engines, wings, and structural elements. Additional electrical and coupling elements enable support for more complex vessels. The vessel editor resembles CAD or 3D modeller, and parts can contain properties and settings which can be changed both during construction and in-flight. During the simulation each part is a physics object which is attached with fixed but breakable joints to other parts. Care needs to be taken the forces exerted on the parts do not exceed the limits to keep the vessel intact.

Flight

Once a player has designed their vessel, they can launch it at the Kerbal Space Center on the launchpad or runway. Direct control inputs can be used and rudimentary stability controls can help prevent rotations or point in a pre-defined direction. Players also control the engine throttle and staging of the vessel to allow for shedding off of spent fuel tanks, to optimize their ability to reach orbit. Flight near the surface of Kerbin and other planets with atmosphere require planning around the atmosphere as spinning out of control or overheating can cause the vessel to break apart, dooming the mission.

Once out of the atmosphere, focus moves to gaining enough velocity over the body to remain in orbit.