Tau Zero's founding architect brings news of a recent European Union meeting that included starships and their implications on the agenda. Here's hoping that while he was there he also had the chance to sample some of those fabulous Belgian ales... by Marc Millis The European Union recently held a conference to collect information to plan for the coming decades of science and technology priorities. This included the theme of international collaboration and the implications for all humanity across the globe. As a part of this conference, the EU organizers invited Mae Jemison of the 100 Year Starship organization to chair a session about interstellar flight. Mae rounded up a suite of speakers including Buzz Aldrin (a genuine space celebrity), Jill Tarter (SETI), Lou Friedman (solar sail advocate and former Planetary Society director), Kathryn Denning (space anthropologist), Pam Contag (microbiologist), Marc Millis (propulsion physicist), and about half-dozen more. Image: Outside the...
Into the Orion Arm
Although we have little observational data to go on, the existence of the Oort Cloud simply makes sense. We see new comets coming into the inner system that are breaking up as they approach the Sun, obviously not candidates for long survival. There has to be a source containing billions of comets to account for those we do see. The Kuiper Belt is stuffed with what we can call 'iceteroids,' all moving more or less along the plane of the ecliptic until, well beyond the Kuiper Belt itself at about 10,000 AU, the disk shaped belt of material spreads into the spherical Oort Cloud. A nudge from a rogue planet or passing star is enough to produce the velocity change to send a comet inward. We've been looking this week at possible human uses for cometary objects, including the fact that they're rich in water but also nitrogen and carbon wrapped up in interesting organic compounds. From the standpoint of resource extraction, we also find interesting elements like silicon, sulfur, nickel,...
Life Among the Comets
It's hard to imagine a sane human being who would choose to live in the Oort Cloud, on a colony world where the outside temperature is in the single digits Kelvin and small bands of maybe 25 each would tend to the problems of energy production and resource extraction. Human contact beyond this would be sporadic, though Richard Terra makes the case (in "Islands in the Sky," an Analog article I referenced yesterday) that a larger community dispersed through nearby settlements would meet regularly to ensure genetic diversity and relieve isolation. History tells us that people do all kinds of inexplicable things, and perhaps a small number of adventurers, outcasts, zealots and other dissidents would find a home here. But given the abundant resources closer to the inner system, I'm more inclined to look at the Oort Cloud as a source of raw materials for colonies on the move between stars. These would be generation ships moving perhaps no faster than Voyager 1 moves now, about 17...
Into the Oort Cloud: A Cometary Civilization?
Jules Verne once had the notion of a comet grazing the Earth and carrying off a number of astounded people, whose adventures comprise the plot of the 1877 novel Off on a Comet. It's a great yarn that was chosen by Hugo Gernsback to be reprinted as a serial in the first issues of his new magazine Amazing Stories back in 1926, but with a diameter of 2300 kilometers, Verne's comet was much larger than anything we've actually observed. Comets tend to be small but they make up for it in volume, with an estimated 100 billion to several trillion thought to exist in the Oort Cloud. All that adds up to a total mass of several times the Earth's. Of course, coming up with mass estimates is, as with so much else about the Oort Cloud, a tricky business. Paul R. Weissman noted a probable error of about one order of magnitude when he produced the above estimate in 1983. What we are safe in saying is something that has caught Freeman Dyson's attention: While most of the mass and volume in the galaxy...
The British Interplanetary Society at 80 Years: Part II
by Kelvin F. Long The chief editor of the Journal of the British Interplanetary Society here offers part II of his article on the Society's history. If there is one BIS project that captures the imagination above all others, it's surely Project Daedalus, the ambitious attempt to design a spacecraft capable of reaching a nearby star within 50 years. But the motivations for Daedalus were wide-ranging and the conclusions of the study may surprise you. The success of the design effort showed us what was possible with the technology of its time, while subsequent studies like Project Icarus upgrade the vessel and take us that much closer to what may one day be a working craft. Les Shepherd took things to new heights with the publication of his seminal 1952 paper "Interstellar Flight". This was the first paper ever to properly address the physics and engineering issues associated with sending a probe to another star and it is what I regard as the beginning of interstellar studies as a...
The British Interplanetary Society at 80 Years
by Kelvin F.Long Centauri Dreams readers will know Kelvin Long as the Chief Editor for the Journal of the British Interplanetary Society, but the résumé hardly stops there. He is also the Deputy Chair of the BIS Technical Committee and a member of the governing council. Long is the co-founder of Project Icarus, co-founder of the non-profit Icarus Interstellar (formerly serving as the Vice President European Operations) and is the co-founder of the pending Institute for Interstellar Studies. He is the managing Director of the aerospace company Stellar Engines Ltd. Here Kelvin begins a two-part article (to be completed on Monday) highlighting the British Interplanetary Society and its numerous contributions to spaceflight concepts both interplanetary and interstellar. Liverpool is a unique location in British history. Not just because of the Beatles or Olaf Stapledon, but because this is where the British Interplanetary Society (BIS) was founded in 1933 by a Cheshire-born...
Voyager: Looking Backward and Forward
The Voyager spacecraft have run into their share of problems as they move toward true interstellar space, but on the whole their continued operations have been a testament to what well designed equipment can do. Voyager 2's camera platform locked for a time not long after the Saturn flyby but controllers were able to restore the system by experimenting with similar actuators on Earth. Three years ago the craft began having data problems resulting from a flipped bit in an onboard computer but a reset from Earth corrected the fault. Even the failure of the primary radio receiver not long after launch was resolved by the use of the onboard backup. Obviously both craft are living on borrowed time as the power output of their radioisotope thermoelectric generators (RTGs) continues to decline, but we should still be getting signals for another decade or so. With the Voyagers now on what is designated their 'interstellar mission,' it's pleasing to note that Alpha Centauri is the guide star...
Keeping the Probe Alive
Talking about issues of long-term maintenance and repair, as we have been for the past two days, raises the question of what we mean by 'self-healing.' As some commenters have noted, the recent Caltech work on computer chips that can recover from damage isn't really healing at all. Caltech's researchers zap the chip with a laser, but there is no frantic nanobot repair activity that follows. What happens instead is that sensors on the chip detect the drop in performance and go to work to route around the damage so the system as a whole can keep performing. So the analogy with biological systems is far-fetched, and we might think instead of Internet traffic routing around localized disruptions. It's still tremendously useful because CMOS (complementary metal-oxide-semiconductor) chips can start acting flaky depending on factors like temperature and power variations. Problems deep inside a chip generally force us to replace an entire piece of equipment -- think cell phones -- whereas a...
Autonomy and the Interstellar Probe
Yesterday's thoughts on self-repairing chips, as demonstrated by recent work at Caltech, inevitably called Project Daedalus to mind. The span between the creation of the Daedalus design in the 1970s and today covers the development of the personal computer and the emergence of global networking, so it's understandable that the way we view autonomy has changed. Self-repair is also a reminder that a re-design like Project Icarus is a good way to move the ball forward. Imagine a series of design iterations each about 35 years apart, each upgrading the original with current technology, until a working craft is feasible. My copy of the Project Daedalus Final Report is spread all over my desk this morning, the result of a marathon copying session at a nearby university library many years ago. These days you can skip the copy machine and buy directly from the British Interplanetary Society, where a new edition that includes a post-project review by Alan Bond and Tony Martin is available....
Self-Healing Circuits for Deep Space
Computer failures can happen any time, but it's been so long since I've had a hard disk failure that I rarely worry about such problems. Part of my relaxed stance has to do with backups, which I always keep in triplicate, so when I discovered Friday afternoon that one of my hard disks had failed -- quickly and catastrophically -- it was more of a nuisance than anything else. It meant taking out the old disk, going out to buy a new one and installing same, and then loading an operating system on it. Because I do 90 percent of my work in Linux, I opted for Linux Mint as a change of pace from Ubuntu, making it the tenth version of Linux I've used over the years. My weekend was mildly affected, but the new disk went in swiftly and the operating system load went without incident, so I was still able to get to two concerts, one of them an absolutely brilliant handling of Elgar's 'Enigma Variations,' and to see the new Tommy Lee Jones movie 'Emperor.' Hardware failures in the midst of an...
Biological Evolution in Interstellar Human Migration
Centauri Dreams is happy to welcome Dr. Cameron M. Smith, a prehistorian at Portland State University's Department of Anthropology in Portland, OR, with an essay that is the capstone of this week's worldship theme. Dr. Smith began his career excavating million-year-old stone tools in Africa and today combines his archaeological interests with a consideration of human evolution and space colonization. He is applying this interest in his collaboration with the scientists at Icarus Interstellar's Project Hyperion, a reference study for an interstellar craft capable of voyaging to a distant star. Recently Dr. Smith presented a paper at the NASA/DARPA '100 Year Starship Study' conference in Houston, Texas. His recent popular science publications in this field include "Starship Humanity" (Scientific American 2013) and the book Emigrating Beyond Earth: Human Adaptation and Space Colonization (Springer-Praxis, 2013). We can look forward to a follow-up article to this one in coming weeks. by...
Habitable Zone Planets: Upping the Numbers
Whether we're planning to go to the stars on a worldship or with faster transportation, the choice of targets is still evolving, and will be for some time. Indeed, events are moving almost faster than I can keep up with them. It was in early February that Courtney Dressing and David Charbonneau (Harvard-Smithsonian Center for Astrophysics) presented results of their study of 3897 dwarf stars with temperatures cooler than 4000 K, revising their temperatures downward and reducing their size by 31 percent. The scientists culled the stars from the Kepler catalog, and their revisions had the effect of lowering the size of the 95 detected planets in their data. They went on to deduce that about 15 percent of all red dwarf stars have an Earth-sized planet in the habitable zone. [PG note: The 15% figure is a revised estimate that I've just learned about from Ravi kumar Kopparapu. Dressing and Charbonneau call attention to this change at the end of their paper. See citation below]. That would...
Life Aboard the Worldship
Konstantin Tsiolkovsky is the first person I know of to talk about worldships and their ramifications, which he did in an essay originally published in 1928. "The Future of Earth and Mankind" was the rocket pioneer's take on the need for enormous ships that could reach the stars in journeys taking thousands of years. The notion percolated quickly through science fiction, and by 1940 we have Don Wilcox's "The Voyage that Lasted 600 Years," which ran in Amazing Stories. Wilcox, who taught creative writing at Northwestern University, imagined a ship's captain who, though kept in hibernation, wakes up every 100 years to check on his ship, watching the gradual degeneration of the successive generations of the crew. It's a bleak take on worldship travel that has often been echoed in later science fiction. But would a worldship actually be this horrific, a cruise from hell that lasted entire lifetimes? See Ken MacLeod's Learning the World: A Novel of First Contact (2005) for the worldship...
Space Habitats and Nearby Resources
If humans go out into the Solar System and beyond drawing on the resources they find along the way, they don't necessarily have to do it on worldships of the kind we talked about yesterday. But it's a reasonable assumption that creating large space habitats would make engineering projects in deep space easier to implement, housing workers and providing a base for operations. Ken Roy presented ideas about habitats in the Kuiper Belt at Huntsville, including the possibility of a large colony being created inside objects like Pluto. If we choose to go that route, we'll have the kind of space expertise to create artificial objects similar to worldships to help ourselves along. Of course, we hardly need to limit ourselves to the Kuiper Belt for this kind of thinking. Whatever the design of the ships we use, we can also consider expansion into the vast cometary resources of the Oort Cloud and any other objects that may lurk there, including so-called rogue planets. For years we've kicked...
Toward a Space-Based Civilization
The assumptions we bring to interstellar flight shape the futures we can imagine. It's useful, then, to question those assumptions at every turn, particularly the one that says the reason we will go to the stars is to find other planets like the Earth. The thought is natural enough, and it's built into the exoplanet enterprise, for the one thing we get excited about more than any other is the prospect of finding small, rocky worlds at about Earth's distance from a Sun-like star. This is what Kepler is all about. From an astrobiological perspective, this focus makes sense, as we want to know whether there is other life -- particularly intelligent life -- in the universe. But interstellar expansion may not involve terrestrial-class worlds at all, though they would still remain the subject of intense study. Let's assume for a moment that a future human civilization expands to the stars in worldships that take hundreds or even thousands of years to reach their destination. The occupants...
Stranger Than Fiction
Just what does it take to make a habitable world? Keith Cooper is editor of Astronomy Now, the British monthly whose first editor was the fabled Patrick Moore. An accomplished writer on astronautics and astronomy as well as a Centauri Dreams regular, Keith has recently become editor of Principium, the newsletter of the Institute for Interstellar Studies, whose third issue has just appeared. In this essay, Keith looks at our changing views of habitable zones in light of recent work, and takes us to two famous science fictional worlds where extreme climates challenge life but do not preclude it. How such worlds emerge and how life might cope on them are questions as timely as the latest exoplanet findings. by Keith Cooper Literally overnight, two habitable planets - tau Ceti f and HD 85512b - were rendered barren and lifeless. What was the cause of this cataclysm? A nearby supernova? Asteroid impacts? On the contrary, it was something far more mundane. A dozen light years away,...
SETI: The Artificial Transit Scenario
Among the many memorable things Freeman Dyson has said in a lifetime of research, one that stands out for me is relatively recent. “Look for what is detectable, not for what is probable.” This was Dyson speaking at a TED conference in Monterey, CA back in 2003, making the point that the universe continually surprises us, and by making too many assumptions about what we are looking for, we may miss unexpected things that can advance our understanding. Dyson has been thinking about this for a long time considering that it was way back in 1960 that he first suggested looking for the excess infrared radiation that might flag a distant Dyson sphere. I would call this an unorthodox approach to SETI in its day except that when he first came up with it, Dyson didn’t have a SETI effort to consider. It was only in the same year that Cornell’s Frank Drake began SETI observations at Green Bank, and a scant year before that that Philip Morrison and Giuseppe Cocconi published the seminal paper...
Into Europa’s Ocean
Europa continues to fascinate us with the possibility of a global ocean some 100 kilometers deep, a vast body containing two to three times the volume of all the liquid water on Earth. The big question has always been how thick the icy crust over this ocean might be, and we've looked closely at Richard Greenberg's analysis, which shows surface features he believes can only be explained by interactions between the surface and the water, making for a thin crust of ice. See Unmasking Europa: Of Ice and Controversy for more, and ponder the prospects of getting some kind of future probe through a thin ice layer to explore the potentially habitable domain below. Possible interactions between the surface and the ice are considered in a new paper by Mike Brown (Caltech) and Kevin Hand (JPL), one that makes the case that there are two ways of thinking about Europa. One is to see the Jovian moon purely as an ice shell upon which the bombardment of electrons and ions have created a chemical...
A Framework for Interstellar Flight
Those of us who are fascinated with interstellar travel would love to see a probe to another star launched within our lifetime. But maybe we're in the position of would be flyers in the 17th Century. They could see birds wheeling above them and speculate on how humans might create artificial wings, but powered flight was still centuries ahead. Let's hope that's not the case with interstellar flight, but in the absence of any way of knowing, let's continue to attack the foundational problems one by one in hopes of building up the needed technologies. Marc Millis, who ran NASA's Breakthrough Propulsion Physics project at the end of the 20th Century, always points out in his talks that picking this or that propulsion technology as the 'only' way to get to the stars is grossly premature. In a recent interview with the Australian Broadcasting Corporation's Antony Funnell, Millis joined physicist and science fiction writer Gregory Benford, Icarus Interstellar president Richard Obousy and...
Interstellar Ice Grains and Life’s Precursors
One of the first science fiction novels I ever read was The Black Cloud, by astrophysicist Fred Hoyle. I remember that one of my classmates had smuggled it into our grade school and soon we were passing it around covertly instead of reading whatever it was we had been assigned. In Hoyle's novel, scientists discover that the cloud, which approaches the Solar System and decelerates, may be a life-form with which they can communicate. My young self was utterly absorbed by this book and I suspect it will hold up well to re-reading. What brings The Black Cloud to mind is recent work using data from the Green Bank Telescope in West Virginia, where scientists have been studying an enormous gas cloud some 25,000 light years from Earth near the center of the Milky Way in the star forming region Sagittarius B2(N). This cloud is not, of course, behaving as entertainingly as Hoyle's, but it's offering up information about how interstellar molecules that are intermediate steps toward the final...