From Kerbal Space Program Wiki
Revision as of 02:34, 8 June 2013 by Xom (talk | contribs) (Undo revision 18276 by Xom (talk))
Jump to: navigation, search


Kerbol (officially called the Sun, and also known as the Star) is the star at the center of the Kerbol System. It is known to be orbited by five planets: Moho, Eve, Kerbin, Duna and Jool and two dwarf planets Eeloo and Dres.

Compared to our own Sun, Kerbol is 113 times less massive and has a radius 3 times smaller. Kerbol is likely a K Class main sequence star based on its temperature, but it may also be an M class star based on its radius, or a G class star based on its luminosity.

Orbiting just above the surface gives an orbital period of 409.214 Minutes and a speed of 66.945 km/s.

Reference Frames

Time warp Minimum Altitude
5× 3 270 000 m
10× 3 270 000 m
50× 6 540 000 m
100× 13 080 000 m
1 000× 26 160 000 m
10 000× 52 320 000 m
100 000× 65 400 000 m

All Kerbol orbits are in an inertial reference frame. In the old demo, getting close enough to experience the lower maximum time warps results Deep Space Kraken attacks.


  • Between versions 0.7 and 0.10.1, Kerbol was a mere point of light in the skybox.
  • Kerbol gained gravity in 0.12.
  • It is still safe to drop below the 'surface' in 0.13.3, but a ship can break up from the extreme gravity gradients and/or shot outwards at large fractions of c.
  • Since 0.14, close encounters will result in a collision that destroys the ship and kills all crew members.
  • The current “surface” of Kerbol is an invisible, and likely, featureless plateau approximately 4500-4700 km above the nominal radius. There is no known way to land on it, as the Kraken makes all maneuvering difficult, and the gravity reduces the TWR of all engines below 1. One can attempt to place edited parts on the surface, but they bounce erratically at a few hundred to a few thousand m/s if they do not explode.
  • While Kerbol can be reached from Kerbin's orbit by using a Hohmann transfer orbit, a spacecraft doing so will require a ΔV of about 8 km/s to do so. The most efficient way to reach Kerbol from Kerbin's orbit is to use a bi-elliptic transfer. With a sufficiently-distant apoapsis, the required ΔV to sundive can be reduced to under 4 km/s, at the expense of drastically-increased flight time.
  • The name “Kerbol” was created by forum members and never appears in the game. Officially, the star is simply referred to as “the Sun”, though the lead developer did mention that the name could change once the need to differentiate it from other stars arises.
  • Kerbol's Sphere of Influence is infinite, which makes it impossible to escape its orbit and achieve gravitation-free flight.
  • Once the sun apoapsis reaches a certain point, it will always say it takes 68 years to reach. This is because times in Kerbal Space Program are limited to 232-1 seconds as a consequence of how numbers are handled.



  • Art pass.
  • Actual model added, new sprite/flare effect, size changed.
  • Added solid surface (featureless invisible plateau ~4500-4700 km above nominal radius).
  • Added Gravity, nominal radius of 65,400 km.
  • Made it possible to reach Kerbol.
  • Initial Release.