Space research is one of the most evocative and challenging fields of human endeavour. In the half-century that has elapsed since the beginning of the space age, we have been exposed to wonders beyond the imagination of even the most visionary of science fiction writers. We have peered deep into the Universe and studied physics that we can never duplicate on the Earth. We have begun to understand our own Sun, and the flow of energy outward through the Solar System that is fundamental to our existence. Robotic agents have explored the planets in the Solar System and the environment of our own planet, the Earth
