Humans have used tools since our species arose hundreds of thousands of years ago. But our ability to send specialized tools, robotic spacecraft, into the heavens and leave our mark on the cosmos has spanned only the last 60 years. This book is a chronicle of our attempts to send these robotic travelers beyond Earth orbit, to the Moon, to other planets and their moons, to the Sun, to comets, to minor planets, to dwarf planets, and ultimately beyond...