Freeman Dyson is the kind of 90 year old we could all aspire to be. Agile, articulate, funny, razor sharp, he seems to go instantly to the heart of any topic, and his topics are many. At Tuesday morning’s opening session at the Arthur C. Clarke Center for the Human Imagination, Dyson laid out his closely reasoned guesses about humanity’s activities in space in both near and long term timescales. For next 50 years or so, the economics and politics and space will dictate small, inexpensive, increasingly miniaturized spacecraft on missions to explore, map, and generally sort out the solar system, locate a greater percentage of the small, undiscovered bodies of the solar system rich in ice and scarce metals or posing a threat. Not much human exploration and no colonization.
But in the far term, in 2100 and beyond, Dyson thinks we may see cheap human missions all over solar system, gradually moving out to Kuiper belt objects. Advanced bioengineering will create plants especially equipped to thrive in space, resisting both intense solar radiation and the cold. Plants will grow greenhouses around themselves like a turtle growing a shell, and concentrate sunlight to harvest its energy even in the outer solar system. Dyson envisions “eggs”, small containers containing seeds, spores, soil, all the microbes needed for a healthy biosphere, that could be scattered among the lifeless worlds large and small, of this and other solar systems, readying them for eventual use by humans.
In discussing the rapidly growing catalog of extrasolar planets, he suggested a method by which to detect planets around white dwarf stars: planets which have so far resisted discovery. White dwarfs are about the size of the Earth. So any Earth-sized planets around the white dwarfs might line up exactly between us and the star, producing an easily noticeable eclipse. Only a few percent will by chance be lined up so perfectly, but look at enough white dwarfs and there will be some. Patient amateurs with medium-sized telescopes could observe the change in the star’s brightness, in a much simpler application of the same method used by NASA’s wonderfully successful Kepler Space Telescope. (And let us pause for a moment to say a word of thanks to the disabled Kepler Telescope and all who operate it, and send our best hopes that their wizard engineers will find a way to return it to service)
Dyson also spared a thought for science fiction and his countryman Clarke, recalling how impressed he was by one of Sir Arthur’s earliest stories Rescue Party, as a positive and optimistic vision of the Galaxy and humanity’s future in it.
I could have listened to Freeman Dyson all day, but there were other excellent speakers as well. Here were some of the highlights:
Futurist Peter Schwartz from the Long Now Foundation analyzed various scenarios ranging from no presence in space at all, “Stuck in the Mud,” to active interstellar exploration including contact with aliens. He laid out three possible motives for the enormous effort and expense of star travel: In “God’s Galaxy” fiercely religious and overpopulated globe might feel zealously impelled to spread their faith and faithful to the stars—to achieve a world where everyone is the same religion perhaps.
If the world goes more or less as it’s going, ecological or other catastrophe might warrant interstellar migration to save a remnant of the race from a dying Earth.
Thinking more cheerfully, in a low-population, wealthy future Earth, “Trillionaires in Space” might carry their own flag and name to the stars for personal prestige, ambition, or some idealistic beliefs (which may lead us back to “God’s Galaxy”). Many motives might drive us to climb to the stars. None know now what they will be.
Robert Zubrin, well known for his strong advocacy for the exploration of Mars, expressed an optimistic vision of a future in space. Helium-3 is the biggest energy resource in the solar system, used as fuel for spaceship engines. Most of it is out in the atmospheres of the gas giant planets. Collecting it and bringing it to where it is needed might be the Big Energy of the future, with Jupiter a kind of interplanetary Persian Gulf. He concluded his talk with the bold assertion, “We are living at the beginning of history not the end of it”.
Geoff Landis explained why he calls nuclear rockets the potential “work horse of the solar system”. In the 1970s NASA had a nuclear propulsion system called NERVA that was tested but never used. Landis made the case for the value of that propulsion method. Interestingly, as Soviet space archives became accessible, a parallel program was revealed. To my eye the weirdly twisted design of the Soviet fuel rods were oddly distinct from the shapes of their strictly linear NASA counterparts, echoing the way Soviet spacecraft have a noticeably different design concept from NASA’s.
Science fiction author Neal Stephenson described his project to design a 20-kilometer-high tower, far higher than the current world record of 800 meters for a building’s height. Working with a team comprised of a professor of structural engineering, an expert in wind loads and drag, and CAD architect/designers, this ambitious project is a fascinating challenge in engineering. The steel requirements alone would consume a substantial chunk of the world’s annual steel production. The base occupies an area the size of a small city. Holding itself up is difficult, especially when the jet stream winds can hit 300 mph.
What does this have to do with starships, one might ask? It’s a futuristic project of comparable complexity, cost and scale, perhaps easier for most people to visualize when contemplating the effort involved in making a starship. And one significant use for the tower would be to launch spacecraft from a platform on top, already above the first 20 km of atmosphere, the densest part for a rocket to punch through. You could haul the rocket up on a big elevator and launch it from the top with relative ease. And someday a geosynchronous space elevator could drop a 22,000-mile cable and hook it to the top of the tower. This so-called “space elevator” provides perhaps a long-term solution for the problem of cleanly and cheaply way of moving people and heavy freight into space. Arthur C. Clarke described a space elevator in great detail in his novel The Fountains of Paradise. That’s unlikely to happen anytime soon. Meanwhile, the tower will no doubt become the ultimate spot for extreme base-jumping.
Back in the present century, we heard from Patti Grace Smith, who served as Associate Administrator for Commercial Space Transportation for the Federal Aviation Administration (FAA), U.S. Department of Transportation, responsible for regulating the U.S. commercial space transportation industry. She outlined the current activities of entrepreneurs who are vying to take cargo, astronauts, or tourists on orbital or sub-orbital journeys. Her job was not as much fun as designing starship engines or base-jumping from 20 km.
She had to deal with issues like: is a hybrid spacecraft (part rocket, part airplane) under the jurisdiction of the Federal Aviation Agency or other agencies? How much indemnification should the government offer private companies against the inevitable insurance claims that will accompany private tours to orbit?
When the discussion is about the regulatory environment and lawsuits, you know that you have left the realm of science fiction and bumped into cold, hard reality. But a mere fifty years ago the notion of taking paying passengers for space jaunts was just as much science fiction as starships and 20-kilometer towers are today.
Many of today’s topics appear as essays or stories in the Starship Century book, debuted at the conference. It’s not on sale in bookstores yet, but it can be ordered at starshipcentury.com.
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