# Earth escape velocity using R_E

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vCalc.Earth escape velocity using R_E
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This equation computes the escape speed required to break the pull of Earth's gravity for an object at the input orbit radius, r. The answer is in units of kilometers per second .  As a fundamental example, escape velocity from the surface of the planet Earth (Orbital Radius = Earth Radius) is around 11.2 km/sec.

This equation uses the mean spherical radius of the Earth and the input value is the orbital radius, the distance between the escaping object and the center of the Earth's mass.

# Notes

This equation is based on a spherical earth model.

The energy of a parabolic trajectory is has the minimum energy required to escape Earth's gravitational attraction.  We can compute the escape velocity of any object at a distance r =(R_(o+) + h) by making energy equal to zero and solving for velocity.