April 2011 is the 50th anniversary of the first man in space, and the first complete orbit of the earth by a man in a spacecraft. Sixty Symbols uploaded a video explaining some things about orbiting spacecrafts. For me, this video, and a video from an older blog entry helped me understand what on earth is the "escape velocity". I always wondered, why a space shuttle must go that fast to escape from the gravitational force of the earth, is a simple "plane" could maintain a constant low speed and escape in space as well... The answer is much more complicated. I suggest you watch both videos, starting from the older post.