The first 25 years of space exploration resulted in extraordinary technological achievements and quantum increases in the scientific understanding of our home, the planet Earth, and the solar system in which it resides. Communications, weather, and other Earth observational satellites affected, directly or indirectly, the lives of most of us. Man traveled to the Moon, explored its surface, and returned with samples of our nearest celestial neighbor. Unmanned spacecraft have explored our solar system from inside the orbit of Mercury out to the orbit of Pluto.
NASA's program of lunar and planetary exploration with unmanned spacecraft produced a flood of scientific information about the Moon and the planets Mercury, Venus, Mars, Jupiter, and Saturn, as well as the environment of interplanetary space. Some startling discoveries were made: a dust storm that completely covered Mars at the time Mariner 9 went into orbit around the planet cleared to reveal a huge crater and a canyon larger than any on Earth; chemical reactions caused the Viking lander's biological instruments to indicate active results that were not of biological origin; Voyager discovered a ring around Jupiter, active volcanoes on Jupiter's satellite Io, and the strange braided rings of Saturn.
Many challenging engineering problems had to be solved to make these missions possible. Three outstanding accomplishments in this area were: achieving the navigational precision necessary to send Mariner 10 from Venus to Mercury and Voyager 2 from Jupiter to Saturn and Uranus; achieving a soft landing on Mars, whose thin atmosphere required the use of a heat shield for atmosphere entry, a parachute for descent through the atmosphere, and rocket motors for the final touchdown; and transmitting color television pictures of Saturn back to Earth from over 1 billion miles away with only 20 watts of power, the amount used by a refrigerator bulb.
The story of the development of these autonomous exploring machines and the missions they accomplished is one of outstanding engineering and scientific achievements. There were heartbreaking failures, great successes, and some brilliant technological detective work during both the development and flights of the spacecraft. It is also a story of organizations, people, personalities, politics, and outstanding dedication; there are many different perceptions of the relative importance of these factors and the roles they played in the achievements of the golden era of solar system exploration. This is the case not only for people who only observed the program from the outside but also for people who were an integral part of the enterprise.
It is not a history. Many of the events discussed are history, but this account is far from complete and coherent. On the other hand, it contains no fiction that I am aware of, and all of the characters, places, and incidents are real-at least as I saw reality. The accounts are largely personal and are therefore limited to my viewpoint or to the views of acquaintances who shared their experiences with me.
It is not a scientific report, although it is an attempt to share some exciting technical aspects of space flight with persons who are keenly interested' including those who have little formal training in technical subjects. I hope the book will also be enjoyed by those who are technically trained, especially those who understand the difficulties of explaining complex space missions and machines.
Although the subject of the book is automated lunar and planetary spacecraft, there are many references to people, and many accounts are written in the first person. It is not, however, an autobiography or biography of a person or a spacecraft. The people, machines, and incidents are blended in an informal manner, in the hope that the interactive processes involved in creating and deploying spacecraft will be viewed in perspective.
I hope you will accept the book as an account of the men, machines, and events as one person saw them, and that you will forgive oversights of deserving people and shortcomings of technical explanations and accounts. The effort will have been worthwhile if enjoyment is realized from revisiting the era when exploring machines reached out to other worlds as peaceful envoys of inquisitive, creative man.
