Planetary Missions of the 20th Century*

Among of the highlights of the 20^th century were flights of spacecraft to other bodies of the Solar System. This paper describes briefly the missions attempted, their goals, and fate. Information is presented in five tables on the missions launched, their goals, mission designations, dates, discoveries when successful, and what happened if they failed. More detailed explanations are given in the accompanying text. It is shown how this enterprise developed and evolved step by step from a politically driven competition to intense scientific investigations and international cooperation. Initially, only the USA and USSR sent missions to the Moon and planets. Europe and Japan joined later. The USSR carried out significant research in Solar System exploration until the end of the 1980s. The Russian Federation no longer supports robotic planetary exploration for economic reasons, and it remains to be seen whether the invaluable Russian experience in planetary space flight will be lost. Collaboration between Russian and other national space agencies may be a solution.     

Lunar and Planetary Robotic Exploration Missions in the 20th Century

The prospect of traveling to the planets was science fiction at the beginning of the 20th Century and science fact at its end. The space age was born of the Cold War in the 1950s and throughout most of the remainder of the century it provided not just an adventure in the exploration of space but a suspenseful drama as the US and USSR competed to be first and best. It is a tale of patience to overcome obstacles, courage to try the previously impossible and persistence to overcome failure, a tale of both fantastic accomplishment and debilitating loss. We briefly describe the history of robotic lunar and planetary exploration in the 20th Century, the missions attempted, their goals and their fate. We describe how this enterprise developed and evolved step by step from a politically driven competition to intense scientific investigations and international cooperation. This revised version was published online in August 2006 with corrections to the Cover Date.