Kerbal Space Program Steam

NOTICE: Activation key must
be used on a valid Steam account. Requires an internet
connection.

In Kerbal Space Program,
take charge of the space program for the alien race known as the
Kerbals. You have access to an array of parts to assemble
fully-functional spacecraft that flies (or doesn’t) based on
realistic aerodynamic and orbital physics. Launch your Kerbal crew
into orbit and beyond (while keeping them alive) to explore moons
and planets in the Kerbol solar system, constructing bases and
space stations to expand the reach of your expedition.

Kerbal Space Program
features three gameplay modes. In Science Mode, perform space
experiments to unlock new technology and advance the knowledge of
Kerbalkind. In Career Mode, oversee every aspect of the space
program, including construction, strategy, funding, upgrades, and
more. In Sandbox, you are free to build any spacecraft you can
think of, with all parts and technology in the game.

• Build spaceships, rockets, and vehicles using any imaginable
  combination of parts, each with their own function that will affect
  the way your spacecraft behaves.
• Take full control over your ship’s setup to execute complex
  flight maneuvers.
• Manage your Kerbal crewmembers, including hiring, training, and
  sending them into space to become heroes.
• Discover a whole star system with unique moons and planets,
  exploring detailed terrain at a vast scale.
• Send your Kerbal crew outside their ships for “extra-vehicular”
  activities.
• Dock spacecraft together to construct space stations, massive
  starships, and surface bases on new planets.
• Use satellites to scan terrain and find biomes and other
  anomalies.
• Set up communications networks to communicate between your
  spacecraft and Kerbal Space Center.
• Research and develop new technologies to extract valuable
  information and resources from all over the solar system, and much
  more!
• Try out the many mods created by the Kerbal Space Program
  community!

System requirements