Last 50 years of Space Missions on 1 Map

I came across a great picture on digg.com that originally appeared on the National Geographic site. It is a map of the solar system with individual lines representing a past space mission.

View the photo at either:

http://books.nationalgeographic.com/map/map-day/index

or

http://www.flickr.com/photos/adamcrowe/4002050596/sizes/o/