I wrote this book because I wanted to learn more about interstel lar flight. Not the Star Trek notion of tearing around the Galaxy in a huge spaceship-that was obviously beyond existing tech nology-but a more realistic mission. In 1989 I had videotaped Voyager 2's encounter with Neptune and watched the drama of robotic exploration over and over again. I started to wonder whether we could do something similar with Alpha Centauri, the nearest star to the Sun. Everyone seemed to agree that manned flight to the stars was out of the question, if not permanently then for the indefinitely foreseeable future. But surely we could do something with robotics. And if we could figure out a theoretical way to do it, how far were we from the actual technology that would make it happen? In other words, what was the state of our interstellar technology today, those concepts and systems that might translate into a Voyager to the stars? Finding answers meant talking to people inside and outside of NASA. I was surprised to learn that there is a large literature of interstellar flight. Nobody knows for sure how to propel a space craft fast enough to make the interstellar crossing within a time scale that would fit the conventional idea of a mission, but there are candidate systems that are under active investigation. Some of this effort begins with small systems that we'll use near the Earth and later hope to extend to deep space missions."

Why, today, would anyone undertake a plan to launch a spacecraft some 30 years in the future, and on a journey that would take some 40 years to complete? Paul Gilster investigates the science, and the spirit, of the NASA and JPL researchers who are actually at work on just such a project.

From the reviews:

"Gilster introduces the challenges of imagining and planning interstellar exploration by leading readers through the difficulties of reaching and exploring the nearest bright star, Alpha Centauri. Seeded by ideas and concepts of the late Robert Forward, the narrative is framed as a learning process undertaken simultaneously by writer and reader. Although Alpha Centauri is astronomically nearby, a postulated trip by robot spacecraft, followed by manned exploration, would take 50 to 1,000 years, depending on the type of spacecraft propulsion used. Various methods for interstellar travel are introduced and discussed, including solar sails that use the power of starlight, nuclear fusion, antimatter hybrid systems, and beamed laser propulsion. One challenge is to get there in a reasonable time so that funding support, public interest, and events on Earth will not divert attention from the mission. Another challenge is timing the mission relative to available technology, because with better technology it might be possible to send a later robot on the same mission in less time. The book has no figures, tables, or illustrations but does include 30 pages of notes and an adequate 14-page index. Though the concepts presented are often fanciful, this book will appeal to readers who wonder about the future of exploration beyond the solar system. Summing Up: Highly recommended. Generalreaders; professionals." (W. E. Howard III, CHOICE, March 2005)