What should we do if we ever learn that our species is endangered? Im just back from the 100 Year Starship Symposium, which considered matters like this in light of the fact that asteroids crossing Earths orbit are not uncommon. It may well have been one of these that caused the extinction of the dinosaurs some 65 million years ago. At the symposium in Houston, one speaker outlined plans from a group called Space Colony Earth to create archives of human information and even human DNA in the event of just this kind of future catastrophe.
Science fiction? Many of those at the symposium, the first gathering since the Defense Advanced Research Projects Agency awarded a grant to study these matters last year, advocate taking the big picture, which includes space and the possibility of a backup plan for the human race. Just how that would be done is the subject of controversy, but the purpose of the 100 Year Starship organization ( www.100yss.org) is to take seriously the idea of studying the huge challenge of interstellar flight for centuries if need be until one day it is achieved.
This is high-tech pushed to the max. The nearest star system, Alpha Centauri, is 4.3 light years away. If one of our Voyager spacecraft were pointed at it, the journey would take 75,000 years, and Voyager, at 17 kilometers per second or so, is at the edge of what we can accomplish today. We dont know whether the three stars composing the Alpha Centauri system (and particularly the two Sun-like stars Centauri A and B) have planets or not, but three separate investigations are in progress to answer that question, and we should know for sure within a year or two.
Make no mistake, the idea of interstellar flight demands a near-term infrastructure right here in the solar system. Ive been arguing for years that the need to change the trajectory of a problematic asteroid to avoid a collision should drive us to develop the needed technologies to move around the solar system fast. At the symposium, ideas flew about how that could be achieved, new propulsion systems and tuned-up older ones that might make it possible to defend ourselves if necessary. Such an infrastructure could develop the tools we need to press further out, step by step, to the cometary cloud surrounding our sun, and then beyond.
If such advanced work seems remote from daily concerns, realize that the kind of advances a starship would demand would propel dramatic changes here on Earth. Learning how to maintain a closed ecology for long-term survival in space will teach us dramatic lessons about the environment and how to preserve it. Generating the huge energies involved to propel a payload to these speeds will create breakthroughs that will dramatically alter our production of energy.
A long trip
Thinking about issues like these can be a liberating as well as a humbling experience. If we ever do mount a true interstellar expedition, it would be the greatest engineering and scientific challenge ever faced by the human race. Three separate calculations of the energies involved have found that it may be up to two centuries before the world energy output is high enough to allow a mission at a reasonable fraction of the total energy supply. Even at a 10th of lightspeed, far more than we can achieve today, the trip to the nearest star would take over four decades.
Why think of these matters if they are so long-term? Because we have to get out of the habit of looking only to the next quarterly return and start thinking in terms of where were going. The fledgling work on these matters is in the eyes of many of its participants a gift to our great-grandchildren. None of us will ever see an interstellar mission launched, but we can hope our descendants will as a result of this ongoing work, now completely out of DARPAs hands and dependent upon philanthropy in moving forward. Call it an insurance policy for the species, one that recalls the words of Lao Tzu: You achieve the great thing through a series of small steps.
Paul A. Gilster is the author of several books on technology. Reach him at firstname.lastname@example.org.