What is escape velocity? According to Wikipedia http://en.wikipedia.org/wiki/Earth Earth: Escape velocity: 11.186km/s? What does that mean? Does the projectile should be fired perpendicular with respect to the ground angle? According to this: According to this, can the projectile be fired in any direction (because it is speed not velocity) as long as its speed is 11.186 Km/s to escape earth? If (supposed Earth has no atmosphere) the projectile is fired parallely to the ground (tangent), what is its escape velocity? Thanks for any explanation.