Escape Velocity Clarification

[Djsnowboy267]

I feel kind of stupid, but is escape velocity the speed required to orbit, or leave the body. I tried to look it up but all I found was the "speed required to leave a body and negate its gravity." However, I was looking at a Delta V chart, and it is 8,600 m/s Delta V to orbit. I'm pretty confused here.

Edited September 29, 2013 by Djsnowboy267

[Mr Shifty]

Escape velocity is the velocity required to escape orbit. It's dependent on altitude. As your speed increases in an orbit, the orbit gets more and more elliptical until it "breaks open" at the apoapsis and becomes hyperbolic. That speed at which the orbit stops being elliptical is escape velocity. Escape velocity at Kerbin's surface is about 3500 m/s.

[-Velocity-]

Very simply put, it's the velocity beyond which any object shot straight up will never come back down. It is dependent on radius from the center of mass (aka, altitude), and it IGNORES ATMOSPHERIC EFFECTS. You have to be slower than the escape velocity to be in orbit around an object.

[Djsnowboy267]

Thanks guys, that's what I had thought. Now I don't feel like an idiot every time I read something about escape velocity!

[lajoswinkler]

If you want to orbit Earth, you need first cosmic velocity. To escape Earth, second cosmic velocity. To escape Solar system, third cosmic velocity. To escape Milky Way, fourth cosmic velocity.