Ive heard that the escape velocity of a body is the same as the maximum velocity that can be achieved from gravitational acceleration from the same body. Like say it requires a spacecraft to be moving at about 11 km/sec to escape earths gravity, and we isolated the earth and spacecraft, so that the only force acting on the spacecraft is earths gravity. Then if the spacecraft was placed stationary any distance from the earth, the maximum velocity it could ever achieve is 11 km/sec. Is this correct, and if so why? Would it be incorrect in the example above, but correct in the real world because of other more powerful gravitational forces, such as the suns, countering acceleration due to earths gravity till the spacecraft is very near earth, or near enough for earths gravity to become dominant? Thx in advance for any clarification.