Starbound: Interstellar Travel and the Limits of the Possible

by Ed Regis

This book is for anyone enthralled by the romantic dream of a voyage 'to the stars.' From our current viewpoint in the twenty-first century, crewed interstellar travel will be an exceptionally difficult undertaking. It will require building a spacecraft on a scale never before attempted, at vast cost, relying on unproven technologies. Yet somehow, through works of science fiction, TV and movies, the idea of human interstellar travel being easy or even inevitable has entered our popular consciousness. In this book, Ed Regis critically examines whether humankind is bound for distant stars, or if instead we are bound to our own star, for the indefinite future. How do we overcome the main challenge that even the nearest stars are unimaginably far away? He explores the proposed technologies and the many practical aspects of undertaking an interstellar journey, finishing with his reflections on whether such a journey should be planned for.

Genres: Science, Nonfiction

300 pages, Hardcover

Published January 30, 2025

About the author

Ed Regis holds a Ph.D. in philosophy from New York University and taught for many years at Howard University. He is now a full-time science writer, contributing to Scientific American, Harper's Magazine, Wired, Discover, and The New York Times, among other periodicals.

Reviews

[jedioffsidetrap · Rating 5 out of 5]

An indispensable essay laying out all the extremely real & incredibly difficult problems to overcome for humans to reach another star system. Grand space plans are almost completely aspirational rather than objectively looking at the hurdles (see Musk Mars colony). Rational, researched & practical like the Weinersmith’s A City on Mars.

I’m a lifelong spaceship sci-fi nerd so Regis’ conclusion is disappointing but he is addressing only interstellar travel— exploration within our solar system is more (more or less) feasible/justifiable. There’s the hope for me.

All sci-fi set in deep space has to make huge leaps of imagination to overcome the reality that a)the universe is inconceivably vast & humans achingly finite, and b)space wants to kill us. I have no problem assuming near impossible propulsion systems or hibernation techniques in order to live out the dream of space travel in sci-fi.

[Martyn Vaughan · Rating 3 out of 5]

This book is something of a disappointment at its hefty £25 price tag. The author is clearly not a fan of the concept of interstellar travel (which is of course a very unlikely prospect). However, he does little to examine the theoretical objections to the concept, concentrating on rehashing objections to various old plans for such travel, such as the British Daedalus, the American Orion and Bussard Ramjet. All three are very old ideas and have been thoroughly discredited long before this book came out. He finds it harder to reject the concept of the Generation Starship, aka the Interstellar Ark. Here he points out the problem of keeping systems working over centuries. I don't think many people have suggested such ships would be viable over millennia. Some of his objections are dealt with in my own novel about a Generation Starship - "Culmination Of Stars." A much better book on the topic which I recommend is "Interstellar Travel"by Dr. Sten Odenwald.

[Patrick Brennan · Rating 3 out of 5]

Competently written, and yet ...

I think he has a narrative direction he wants to take the book in, and he is dead set on the notion that interstellar travel per se is undoable, and not even worth doing.

Of course I agree with Regis that interstellar flight is far, far more difficult than popularly imagined, and is not something which is doable in the near future, probably not for many thousands of years hence, although robotic probes may be doable in hundreds of years. Still, I am slightly annoyed at his apparent attitude that the ideas in the book are impossible, period. I think he displays a colossal lack of imagination. For example, in discussing Robert Forward's proposal to use lasers to drive light sails, he takes Forward's estimate of the power requirement - 75,000 TW - as prima facie proof of its impossibility, since this is orders of magnitude more power than humanity currently produces. But Forward didn't write his article as a blueprint for a project, he wrote it as a exploration of what is conceptually possible, what is allowed by physical law, and certainly not as something which could be done in the next few years. Regis ignores this completely and dismisses the idea as absurd and impossible. This is what I mean by colossal lack of imagination.

[Jeff · Rating 4 out of 5]

Solid Look At Complexities Both Scientific And Ethical Regarding Interstellar Travel. This is exactly what the title says - a solid look at pretty well all aspects of the complexities of interstellar travel from both scientific and ethical directions, with discussions of the sheer distances involved, the various proposed types of habitation possibilities, propulsion technology, and seemingly every other conceivable facet of the topic at hand.

At 300 ish pages with just 11% or so of that being bibliography, the actual discussion is somewhat brief while still being comprehensive. Technical enough in both science and philosophy to underscore the key issues, yet informal enough to be easily followed along with by most readers. Indeed, the only real problem I had with the text was that 11% bibliography - it needed to be 50% ish larger, from what I've seen across my several years of reviewing advance review copies of nonfiction books, as I've done here.

Overall truly a fascinating book and a great primer for anyone even remotely interested in the complexities of actually achieving interstellar travel.

Very much recommended.

[Tim Moy · Rating 3 out of 5]

It's a decent summary of the history of dreams, research and skepticism on human interstellar travel but occasionally fails to fully interrogate its arguments.

For example it concludes that maintenance of a ship over a journey is impossible because "reliance on automatic repair systems does not solve the breakdown problem because such systems are physical apparatuses that are themselves subject to failure" without 1.) considering the duration such a system would need to remain active for 2.) not considering the "obvious" (although of course unfeasible with current technology) solution that maintenance could be carried out by self-replicating agents. Indeed in the limiting case where degradation is at a slow enough rate to be manually repaired by humans, humans are an example of such a system!

[Steve · Rating 5 out of 5]

I loved this book. I enjoyed Ed Regis’s writing style: clear, conversational and blunt. Regis does not hide his feelings when he discusses what are to him, ill-considered ideas. I found the writing clever and honest, with all the science (or lack thereof) well-explained. And exceptionally for me, I loved the excellent, balanced discussion of ethics and the philosophical aspects of interstellar travel. In addition, I am a big fan of science fiction, and as I read the book, I kept in mind all the genre shows and books I watched and read, making the book more personal to me. Thank you to Netgalley and Cambridge University Press for the advance reader copy.