Kerbin

The 3rd planet of the Kerbol System after Moho and Eve. Home to the green men known as "Kerbals." Kerbin is 600 kilometers in radius with a breathable atmosphere in 70 kilometers in height making it the 3rd largest celestial body in the Kerbol system. Kerbin has two moons; The Mün and Minmus.

If you reach low Kerbin orbit, you are halfway to anywhere.