Solar Sails: A Novel Approach to Interplanetary Travel

by Giovanni Vulpetti, Les Johnson, Gregory L. Matloff

The reality of sunlight-based sailing in space began in May 2010, and solar sail technology and science have continued to evolve rapidly through new space missions. Using the power of the Sun's light for regular travel propulsion will be the next major leap forward in our journey to other worlds. This book is the second edition of the fascinating explanation of solar sails, how they work and how they will be used in the exploration of space. Updated with 35% new material, this second edition includes three new chapters on missions operated by Japan and the US, as well as projects that are in progress. The remainder of the book describes the heritage of exploration in water-borne sailing ships and the evolution to space-vehicle propulsion; as well as nuclear, solar-electric, nuclear-electric and antimatter rocket devices. It also discusses various sail systems that may use either sunlight or solar wind, and the design, fabrication and steering challenges associated with solar sails. The first edition was met with overwhelmingly positive reviews, and deemed “a title that needs to be on your shelf if you’re seriously interested in the next step as we move beyond rocketry" ( Centauri Dreams , September 2008). Written with a mixed approach, this book appeals to both the general public as well as those with a more scientifically technical background.

301 pages, Paperback

First published July 23, 2008

About the author

Les Johnson is the co-author of three published popular science books, Living Off the Land in Space, Solar Sails, and Paradise Regained: The Regreening of Earth. His first science fiction novel, Back to the Moon, was published in December 2010 by Baen. Les is the Deputy Manager for NASAs Advanced Concepts Office at the Marshall Space Flight Center in Huntsville. He was technical consultant for the movie, Lost in Space. NPR, CNN, Fox News, The Science Channel and The Discovery Channel have all interviewed him. He appeared on the Discovery Science Channel in their Exodus Earth series and the "How to Build A Starship" episode of Michio Kaku's 2010 Discovery Science Channel Series "Physics of the Impossible. He was the Chief Scientist for the ProSEDS space experiment, twice received NASAs Exceptional Achievement Medal, and holds 3 space technology patents. He has numerous peer-reviewed publications and was published in Analog."

Reviews

[Jeff Greason · Rating 4 out of 5]

(This review applies only to the first edition)
The literature on solar photon sailing tends to be either very sparse on technical detail or very dense for the specialist. This book appears to fill a gap for the interested but non-expert audience, and in that, I think it succeeds.

The tone of the presentation changes from section to section -- at times appearing to be a survey of various technologies, at times appearing to be unashamed advocacy of the photon sailing alternative. Solar wind sailing is discussed and then dismissed rather abruptly -- after a long and good discussion of the physics of wind sailing on Earth, it is jarring to see little more than 'solar winds are variable and that is hard'. We have, after all, made good use of highly variable winds on terrestrial sailing for millenia.

Still a useful work and I look forward to the later edition.

[Gary · Rating 2 out of 5]

The concept of solar sailing is very interesting, but this book does contain flaws. It starts out very well, and gives descriptions of the intricacies of sailboats. Showing all of the different factors that go into sailing on the ocean, it then gives analogies to solar sailing (where the photons are analogous to the wind). This was all well-written and well-explained.

Unfortunately, the book then changes to a point of view that is so overly optimistic that it borders on science fiction. The authors describe solar sails and how they would theoretically work. The important thing to remember is that we still have no actual proof of concept. But this is almost entirely glossed over. There was a description of a mission from JAXA where a solar sail was deployed but didn't unfurl properly. This mission was considered a success by the authors, who then went on to state that if the sail had been deployed properly, it would have been even more successful. From an empirical standpoint, this is simply untrue. If the sail had been deployed properly and the spacecraft was able to be propelled merely from the impact of the photons on the solar sail, THEN it would be a great success. But there could be other factors with light not hitting the sails as evenly as predicted, the light not providing enough thrust as predicted, or too much space debris stopping an even flow of light for a solar sail to work. But all of this is completely ignored. The authors are 100% convinced that because it works on paper, there can be absolutely zero real life obstacles not accounted for in the equations.

Another huge problem comes with the equations themselves. The explanations of the equations are extremely inconsistent. The authors will explain what each variable stands for in a very basic physics equation such as F=ma. But when it comes to the complex equations for solar sails that include some variables created specifically for solar sails, the authors sometimes only explain what half of the variables stand for. Also, there are many times where an equation is supposed to show what is happening on a particular chart. But the equation is semi complicated and contains some calculus, while the chart can be used in kindergarten showing circles of orbits around the sun.

Overall, I was hoping to gain a lot more out of this book than I did.