Centauri Dreams: Imagining and Planning Interstellar Exploration

by Paul Gilster

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.

Genres: Science, Space, Technology, Nonfiction, Astronomy, Physics

317 pages, Hardcover

First published October 8, 2004

Reviews

[Jacob · Rating 4 out of 5]

Space is big. No, really, space is effing big. If you ever wondered just how effing big space is, let’s shrink the distances a moment: if the sun was the size of a grain of salt (making the earth thousands of times tinier still) the next three grains of salt, in the Alpha Centauri system, would still be seven miles away.

Get it? Got it? Properly awed, mind boggled, all that stuff? Good. That should tell you what NASA has to deal with. We’ve only been zooming around the solar system for a few decades, really. It still takes years just to send probes to the outer planets (New Horizons won’t reach Pluto until 2015), we still haven’t gone back to the Moon (much less Mars), and that oh-so-awesome manned Venus flyby mission never happened. So it’s easy to get impatient. We still measure travel distances in terms of astronomical units (AU, the average Earth-sun distance, roughly 93 million miles); thinking in terms of light-years will be even trickier.

Enter Paul Gilster. Gilster, who also publishes the fascinating Centauri Dreams blog, wants to know what needs to be done, now, that will help us launch efficient and independent robotic probes (and, later, manned ships) sometime within the next few decades that can conceivably travel to the Alpha Centauri system (or beyond) within a few centuries--but hopefully less time than that. It won’t be easy. Liquid fuel rockets are a joke and nuclear power isn’t such a good idea anymore, but antimatter engines, solar sails, lasers and fusion--don’t ask me to explain them, but those are promising. Just how promising is what Gilster set out to find in this book, traveling across the country to various think tanks, laboratories, and NASA-funded research centers that are all working on the latest technologies (and some theoretical ones) that could someday do the job. Obviously we have to think long-term, as even some of the methods we explore today could be rendered obsolete in ten or twenty years, while the technology we need to explore most (think nanotechnology) is still in very early stages. And even then, getting a probe to the next star isn’t the only big step: getting a probe there that can think for itself without relying on messages from a far-away Earth is just as important.

All heavy stuff (I’m still trying to wrap my head around antimatter as a fuel source), but vital and necessary reading for anyone interested in the far future of space exploration. It’s disappointing to occupy this point in history, when the last big leaps happened years ago and the next ones are decades away (and none of us will ever get to live on Mars), but we can’t expect to get anywhere if we wait for other people to do the work for us. There’s a lot of work to do.

But I still recommend keeping a towel around, just in case.

[Filipe · Rating 4 out of 5]

What a dream. Fascinating look into the possibilities of science and space exploration of the future and what's being done now to move towards that future. Sure, it's a long time away before we truly reach the stars, but to get somewhere, one must first begin the journey and this book explores some of the possible technologies and ways we might touch the farther reaches of our galaxy.

[Muhammad al-Khwarizmi · Rating 3 out of 5]

I largely benefited from this but the author (perhaps necessarily) is just very fast and loose with details in many areas, making for slow and difficult reading. I ultimately quit about 70% of the way through, here, emphasis on the straw that broke the camel's back mine:

Out at the end of the theoretical limb, wormholes could conceivably be constructed, in Robert Forward fashion, by creating vast engineering projects like a ring of ultradense matter the size of Earth's orbit around the sun. Such a wormhole would open into what Forward called a "hyperuniverse," where spacetime exhibits different properties than our normal spacetime. Two such rings, each opening into such a hyperuniverse, might conceivably be connected if each were spun to speeds close to that of light and charged with massive voltages.

What the fuck? Why are these factors in particular necessary, rather than some other ones? You never find out.

[Prabhat Gusain · Rating 5 out of 5]

Of antimatter drives, fusion runways, ramjets, solar sails, wormholes, dyson probes and other wild possibilities of interstellar travel to plan a journey to our nearest neighbor star. Alpha Centauri is the next giant leap for humanity after Mars and we must plan well in advance. The big question, however, is to build and operate an interstellar exploration with a travel time of less than the creator's lifetime. What if the spaceship could build and evolve itself in space? What if a fraction of lightspeed travel is attainable with continuously accelerating probes? What if the Fermi Paradox leaves us all alone in our endeavors? Centauri Dreams intrigues the reader with such pertinent existential and scientific questions and more. Interstellar exploration is the next big celebration for the space faring humans, awaiting to be created or discovered.

[Jim · Rating 3 out of 5]

I found this book a bit depressing. It spoke of various ways that NASA and other organizations are considering for sending a probe to nearby stars but mostly it talked about how incredibly difficult, time-consuming and expensive such an undertaking would be. I grew up with Sputnik and the Apollo program and thought back then that manned flights to Mars and robot probes to the stars were just around the corner. While the trip to Mars is still a possibility, even the launch of a probe to the nearest star is not going to happen in my lifetime and probably not in the lifetime of my
children. Like I said, depressing.

[Matthew · Rating 5 out of 5]

I give this one 5 stars, because I'm not aware of anyone else to devote an entire book solely to this subject. Still in the years since. If you're interested in the engineering, physics, and economical needs that would be required, as well as the various approaches and methods to accomplish this feat, then this is your book. Be prepared to sit in and study interstellar travel.

[Daniel Franco · Rating 4 out of 5]

A vision into interestellar exploration with a technological approach, a bit out of date regarding some of the technologies but we keep stuck at same dead ends, worth reading

[Paul Norman · Rating 5 out of 5]

This was hugely inspiring to me. A near perfect and simplistic explanation of space travel.

[Ushan · Rating 2 out of 5]

Speculations on sending a probe to Alpha Centauri and having it radio a report back to Earth; an homage to the late hard science fiction writer Robert Forward. Note that we still cannot generate electricity using inertial confinement fusion on Earth after decades of research and billions of dollars in investment; powering a starship with it is pure fantasy.

[Asrik · Rating 4 out of 5]

Wow.

I've thought for years that I should have been born 100 years from now, when space is (theoretically) more open to exploration. When I read this book, I can see it. I can dream about interstellar missions and think about the science and different propulsion technologies.

So cool.

[Jeffrey McKinley · Rating 4 out of 5]

(read 12/26/2012) A fascinating look at the various methods of space travel being proposed for the future. The book demonstrates just how difficult such a feat will be, yet introduces the men and women who pursue this dream with dogged determination.

[Brian Rast · Rating 5 out of 5]

An excellent book that recognizes the strength of imagination and the future success we'll have exploring the extra-solar planets discovered by our Kepler space telescope.

[Martin Böhler · Rating 3 out of 5]

[Tony Goins · Rating 4 out of 5]

A great overview of the state of the science. Written in 2004, so it's a little dated - BUT NOT AS DATED AS IT SHOULD BE.