The 100-Year Starship Symposium—A Historic Meeting?

T he 100-Year Starship Study Symposium was held in Orlando, Florida, from September 30 to October 2, 2011. The symposium was public and drew in 699 attendees from various disciplines, ages, and backgrounds. The attendees were highly motivated, as many of them, if not most, paid the associated travel costs from their own private funds. The objective of the meeting was to provide inspiration for the next generations and seed research that would enable interstellar flight in a time frame of roughly 100 years. The meeting was also convened to provide additional information and insights on a request by the Defense Advanced Research Projects Agency (DARPA) and NASA for proposals of a business concept that would bring the 100-Year Starship organization into existence. An award will be offered to cover start-up costs and provide some initial intellectual property. If the funded business entity is successful and eventually succeeds in building a starship that takes humanity to the next solar system, this meeting may be remembered as the starting point.

The meeting was opened with statements by the main organizers: David L. Neyland, DARPA's Director of the Tactical Technology Office; and Pete Worden, Director of the NASA Ames Research Center. In his opening remarks, David Neyland emphasized the benefits of the anticipated research to the military, while Pete Worden elaborated on the three pillars of astrobiology and asserted that the anticipated research would address the third pillar: the future of life. The meeting included two keynote addresses. Keynote speaker Ariel Waldman addressed how space exploration could be made accessible to everyone via internet resources and other educational tools, while speaker George Whitesides, President and CEO of Virgin Galactic, emphasized the need to develop toward a society of exploration and the idea that partnerships comprised of government and private concerns are essential to the advancement of humanity into space.

The breakout session included the topical themes of Time and Distance Solutions; Biology and Space Medicine; Destinations; Habitats and Environmental Science; Education; Social, Economic, and Legal Considerations; Communication of the Vision; Philosophical and Religious Considerations; and Demonstrations (for a complete agenda of the meeting, please see http://www.100yss.org/agenda.html). These breakout sessions included panels, which were also used to wrap up the meeting on the last day with a panel of the chairs from the breakout sessions, an Organizations panel, and a Communicating the Vision panel. In addition, on each of the two evenings a Science Fiction Writers panel and a social program were convened.

The meeting provided a snapshot in time of where we stand on undertaking such a monumental task. One critical point identified was propulsion technology. Clearly, current chemical propulsion technology would not get humans to another solar system; the energy yield would simply be too low. Nuclear fission engines have been tested and could potentially yield about 7×10¹³ J/kg. Thus, they would make such an endeavor feasible, according to Richard Obousy. Fusion engines would be an order of magnitude better, and matter-antimatter engines would yield three orders of magnitude more energy than fission engines. However, too little antimatter is currently produced by particle accelerators to make this approach feasible at present. Solar sails would provide a promising way for long-distance space travel as well, especially if they were to be combined with a beamed energy approach. And sorry, Star Trek fans, but warp drive and any travel faster than light speed remain in the realm of science fiction, at least for now.

Any of these propulsion technologies aims for a speed of about 10% of light velocity (c), which appears realistic to achieve. Nevertheless, even this velocity would make traveling to a planet such as the potentially habitable super-Earth planet Gliese 581d (at a distance of 20.4 light years) a voyage that would take an excess of 100 years. Ian Crawford suggested restricting the travel distance to 15 light years in order to reach the target star within 100 years after launch. This would leave about 38 solar systems as potential targets, and in some of them we will likely detect habitable planets in the coming years, based on a recent estimate that at least 30% of main sequence stars host terrestrial planets, and even that many gas giant planets might be orbited by habitable moons. In fact, the discovery of a nearby habitable planet, especially an Earth-like world with spectral signatures indicative of life, would provide an enormous motivational boost for such a starship mission.

However, even if the target were the closest star system, Alpha Centauri, which likely does not host any planets, the time to reach it would last several generations. And let's not forget that the objective would not be to fly by the target star at a velocity of 0.1 c but to stop and explore a potentially habitable world. The people who would embark on this voyage would not be those who would reach the destination. To visualize the challenge, we have to realize that Alpha Centauri is 272,000 AU (astronomical units) from Earth (4.3 light years), which means that the current location of the Voyager 1 probe is now analogous to having traveled 1 mile (1.6 km) on a trip from Orlando (the site of the meeting) to Los Angeles.

The voyage itself would add its own challenges on many fronts. The starship would not only have to provide the travelers with a place to survive but also to thrive, and it would have to provide as well for meaningful work, social intercourse, recreational activities, spiritual enlightenment, and much more. Many of the travelers would spend their whole lifetime in the starship. Conflicts in this kind of situation are inevitable when so many people are confined to a small space with limited resources. A governance system would have to be established, which would be flexible, democratic, and able to solve conflicts before they became critical issues. Since the starship would be multigenerational, reproduction would have to be feasible on that ship, which means that there would have to be some way to implement artificial gravity, a point brought up by Dan Buckland. We don't know at present whether 1g is needed for sexual reproduction as on Earth, and experiments would have to be conducted to discern the minimum implemented gravitational force needed. The artificial gravity could be created by having the ship, or at least part of it, rotate. Radiation is another concern, and the human load would have to be protected by thick shielding or possibly by sending the travelers within an asteroid in which habitable areas would be contrived deep within the rock. Also, if the goal were to ensure the survival of the human species and potentially colonize some other planetary system, 250 people would be about the minimum to embark on the voyage in order to keep the population genetically diverse enough. This amount of people would require a starship at least the size of a typical aircraft carrier.

Because of these difficulties, some of the presenters suggested having a fully robotic starship without a human component. That starship could be of a diminutive size (such as the size of a soda can) if advances in nanotechnology were to allow. However, most of the attendees seemed to be set on a human mission, mostly because of the single point failure possibility of Earth—meaning that some natural catastrophe could threaten the survival of the human civilization or Earth itself. However, if this is the main driving force, a colonization of Mars prior to sending a starship to another solar system would make more sense, as advocated by the author of this forum article. A thorough exploration of our Solar System along with a continued search for a second genesis of life prior to a long-distance mission was also suggested by Jill Tarter, which would better prepare starship voyagers for an encounter with extraterrestrial life on a habitable planet outside our Solar System.

One issue that was pointed out by several speakers was the anticipated singularity, the hypothetical future emergence of greater-than-human intelligence through technological means. Where might the evolution of the human species lead us over the course of 100 years? Will we be hybrids of humans and machines? Or might machines be smarter than we will be at that time? And as for the travelers on the starship, they would certainly develop a culture of their own, one that would be disjointed from Earth, given the time-delayed communications with their home planet.

On the upside, any discovered solutions to the many challenges for the 100-Year Starship Project—from the problem of extreme sustainability and long-distance communication to propulsion and radiation—would also be useful for many other space missions and applications on Earth. But how can we make the 100-Year Starship Project happen? The organization leading the endeavor would have to remain viable and efficient throughout many generations, and it would be overseen by many different people, some with stronger, some with weaker leadership qualities. Stewart Brand compared the task to building cathedrals in Europe during the Middle Ages, which took many generations to complete. Organizational parallels can be drawn with the Catholic Church and the British East India Trading Company, which also provide some clues as to how to finance an endeavor of such magnitude. One interesting suggestion was to issue bonds to the government, which would only be redeemable by the government when the 100-Year Starship Project has begun.

Even if only a significant subset of the population contributed a small amount of money to the project, it would add up to a large amount given the enormous stretch of time to finish the project. It would be crucial to keep the public excitement for space exploration high while the project was in progress. Harry Kloos emphasized how important it would be to communicate the vision and employ as many concepts and means as possible to inspire the public; from storytellers to movie makers and from utilizing computer games to documentaries. The layperson would have to feel a certain enthusiasm to be part of that vision, and people would need to feel personally connected to the 100-Year Starship Project for it to be realized.

The associated philosophy of space exploration should not be conquest but rather learning. As pointed out by Mae Jemison, many grand projects such as Columbus' voyage to the Americas received an initial no but eventually succeeded through persistence. Columbus successfully launched his ships to the New World and discovered America. James Webb fought for every dollar to get the Apollo missions launched, and he showed that it was possible to land humans on the Moon, which seemed all but impossible prior to 1969. How will we make a difference, and what will be our legacy? History will decide, but perhaps, just perhaps, this meeting will be remembered as the one when we decided to go to the stars.