Editing Escape velocity

'''Escape Velocity''' is the minimum speed which a vessel or other object needs to travel in order to leave the vicinity of a planet or other large object. This speed depends on the mass of the planet, and the distance from its center. Because escape velocity depends on distance from the planet, it can have any value, but the most commonly quoted value for escape velocity is defined relative to the surface of the planet.

To be precise, a vessel travelling at escape velocity is on a [[Parabolic Orbit|parabolic orbit]], with an [[Eccentricity|eccentricity]] of 1.0 exactly. Vessels travelling slower travel along an [[Elliptical Orbit|elliptical orbit]], and vessels travelling faster travel along a [[Hyperbolic Orbit|hyperbolic orbit]]. 

Also, a vessel or other object dropped from infinitely far away with zero initial speed, will impact the planet at precisely the surface escape velocity.

Escape velocity is calclated using the following formula:

<math>v_{esc}=\sqrt{\frac{2GM}{r}}</math>

where

*<math>G</math> is Newton's universal gravitational constant, <math>6.67259\times10^{-11}\frac{\mbox{m}^3}{\mbox{kg}\cdot \mbox{s}^2}</math> in Orbiter (OrbiterAPI.h, line 39)
*<math>M</math> is the mass of the central object in kg (obtainable from the object's config file Mass= parameter)
*<math>r</math> is the radius of the central object in m (obtainable from the object's config file Size= parameter)

[[Category:Celestial mechanics]]
[[Category:Glossary]]