Kerbin

Kerbin is the home planet of the Kerbals, the location of the Space Center, and the main focus of Kerbal Space Program. It is the Earth analog for the game. It has two moons, named Mun and Minmus.

Kerbin is the third planet in orbit around the star Kerbol. It is the third largest planet (after Jool and Eve) and the fourth largest celestial object around Kerbol (with Tylo, a moon of Jool, being slightly larger).

Reaching a stable orbit around Kerbin is one of the first milestones a player might achieve in the game. Achieving such an orbit with a fuel-optimal ascent requires a delta-V of approximately 4.45 to 4.7 km/s. For many interplanetary missions, this represents over half of the flight's total delta-V requirement. (This is also true of Earth-based interplanetary spaceflights, leading one observer to remark that "If you can get your ship into orbit, you're halfway to anywhere.")

Topography

Topographical image of Kerbin. Kerbin has a roughly equal distribution of surface liquid water and solid land, with polar icecaps and scattered deserts. There are mountains exceeding 3 km in height, with the tallest peak being at least 3750 m in altitude.

Atmosphere

Kerbin's atmosphere contains oxygen and extends to roughly 69,078 meters. Its atmosphere becomes exponentially less dense as altitude increases (with a scale height of 5 km). In general, the atmospheric pressure and density on Kerbin, at an altitude expressed in meters, are:

$p_{k}=e^{-altitude/5000}$

$d_{k}=1.2223\ p_{k}$ (expressed in kg/m³)

Orbits

Geosynchronous orbit is achieved at an altitude of 0.00 m (1008.9 m/s). A semi-synchronous orbit with an orbital period of 1/2 of Kerbal (3 hours or 10800 seconds) is achieved at an altitude of 0.00 m with an orbital velocity of 0.00 m/s.

Interplanetary Travel

From the lowest stable orbit around Kerbin (70 km), the amount of delta-V needed to reach the orbits of other celestials is as follows:

Body	Delta-V
Mun	~860 m/s
Minmus	~930 m/s
Eve	~1033 m/s
Duna	~1060 m/s
Moho	~1676 m/s
Jool	~1915 m/s

Reference Frames

	Paid (0.17)	Demo (0.13.3)
Rotational/Inertial transition	100,000 m	70,000 m
Warp	Minimum Altitude
1x	Any
2x	n/a	0 m
5x	69,078 m (above the atmosphere)
10x	69,078 m (above the atmosphere)
50x	69,078 m	150,000 m
100x	120,000 m	300,000 m
1,000x	240,000 m	600,000 m
10,000x	480,000 m	1,200,000 m
100,000x	600,000 m	n/a

Gallery

• NJ6qJ.jpg

  A projection map of Kerbin, as of 0.14.1 and before (including the demo).

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  An accurate full-colour projection map of Kerbin as of 0.14.2 and above.

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  The second launch site (currently unused).

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  Kerbin, Mun and Minmus.

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  A topographic heightmap of Kerbin made with the ISA MapSat plugin

Changes

0.17

• Improved atmosphere visuals.

0.15

• Minmus added.

0.14.2

• Much more varied and taller terrain added. Prior to this, some mountain ranges exceeded 600 m in height, but the tallest point was at an altitude of approximately 900 m.

0.12

• Mun added.

0.11

• Terrain overhaul, oceans became wet.

0.10.1

• Atmosphere extended from ~34,500 m to ~69,000 m.

?

• Initial Release