A Note on Interstellar Migration

From my guest blog at Paul Gilster's influential 'Centauri Dreams' website, concerning interstellar migration. Sound crazy? SCIENCE magazine's recent edition focuses on exoplanets, now being discovered monthly, highlighting 'habitability'. Why highlight habitability? Because those are the places we humans are going if we don't wipe ourselves out first. Today Earth had its 'hair parted' by a space rock that could have wiped out civilization had it struck our planet--and in galactic terms, it came close.

"Over the course of several generations, as on voyages to nearby stars with propulsion systems that are beginning to seem reasonable, interstellar voyaging is entirely possible from a genetic perspective, with two provisions. First, we will have to ensure the genetic health of the colonist population as it will be under strong founder effect. Gene therapies, carrying genes from Earth in the form of stored eggs and sperm, and even the artificial induction of mutations can all be used to mitigate such effects, but at some point it will cease to be desirable to keep ‘pushing’ a human Earth genome into interstellar space. This brings us to the second proviso, and that is that natural selection will in fact return as a significant concern in human evolution, particularly when the unknowns of new planetary environments are encountered (even if they are surveyed by reconnaissance vehicles first).

We should note that, in the currently-considered timelines and populations, according to what we know about human biology it is unlikely that humanity will undergo speciation in less than a few thousand years (Figure 1, lower right).

These lessons remind us that adaptation is a continual process of the adjustment of the genome to environmental conditions. In non-humans that evolve reactively, with no conscious effort, this equilibriating process is slow and uncentralized and results in many extinctions over time. In humanity, consciousness can be used to help proactively shape our evolution, but we must remember that the only way to stop evolution is by extinction. We should accept and learn from the fact that if things live, they evolve and adapt. We should plan our adaptation to space as students of evolution. We must internalize the truth that the nature of the universe is change, not fixity, and allow this truth to condition our plans for the human colonization of space."

Glove Remount

This morning I woke with an urge to go straight to work removing the old, bulky glove mounts and replace them with much slimmer mounts; I dressed, turned on the radio and set to it, feeling good to finally take the dive after a year of thinking about how to do this. Five hours later, I have one remount completed. Now for a bite to eat, then knock out the other one (which will be a little more complicated as it includes the suit pressure gauge)! In the lower photo you can see the larger mount removed, an inch greater in diameter than the new mount. I also now have four rather than two hose clamps employed, and I feel confident enough with this build to stake my life on it in the altitude chamber in Copenhagen this August. Once both gloves are remounted, I will work on seaming in a new integration with the suit's pressure restraint garment. Just one of close to 65 items on the To Do list -- there is no time to lose!

Fingertip Reinforcement

The fingertips of the gloves are fraying -- I've used the suit in over 30 pressure tests now, including underwater! -- so I'm painting on a rubberized fingertip coat. Easy enough. This is not meant to hold pressure, that's done by the blue gas-impermeable layer you see under the fraying cotton cover layer on the gloves in one of the photos above. This just reinforces the glove tips, and the stickiness of the rubber can add a little dexterity.

Vivaldi

It seems that Vivaldi flew down from space, delivered these goods, and then flew off, back to space!

Spanish Translation of my Scientific American feature

I'm always thrilled to be translated for a wider audience; recently my January 2013 feature on space colonization, for Scientific American has been translated for Investigacion y Ciencia, the Spain-based version of Scientific American. I've also recorded a podcast with Scientific American, which is available here, and my next item for them will be a report on this year's Mars Society meeting, where I will give a plenary address, and the 100 Year Starship Study conference in Houston, Texas.

Pressure Test

Another pressure test (actually, four) this weekend; thankfully we now have a reliable team of dedicated people aboard; I simply can't do this alone anymore. Photos show Nicholas Walleri working down a checklist, and his perspective of the tests, to the right and behind me. As in a flight, he has a webcam looking at me that can be used to help if we lose voice comms and have to go to hand signals. Also in the second photo is Ben Wilson, who has been in the suit twice now, and will, with me, next weekend spend several hours in the suit as we slay one last technical Dragon! Thanks, team! Photos by yet another Ben, Ben Robbins, and off-camera is Alexander Knapton, who has devised a great way to route the extra coolant hoses, which I will be sewing in tonight!

Larger-Gauge Bailout Breathing Gas Manifold

The small hoses for breathing gas were a bad idea, but they did get the systems proved out. Now I'm going to larger-gauge manifolds to match hoses; the photo shows today's rebuild of the bailout breathing gas manifold; the old, smaller one is held there for comparison. Easier breathing all around! Pressure test tomorrow, knocking out some of the 100 or so items on the pre-Copenhagen altitude chamber test!

Interstellar Migrant Population

Did some adjustments (see previous post); all of this came out of looking at these figures from the perspective of early human migrations, researched for my forthcoming Atlas of Human Prehistory! But Icarus Interstellar asked me to juggle them for their purposes. This'll go to either Journal of the British Interplanetary Society or Acta Astronautica (International Academy of Astronautics) for peer review :p

Estimation of a Viable Population for Multigenerational Interstellar Voyages

Cameron M. Smith
Department of Anthropology
Portland State University
17 May 2013
7,243 words
Late Draft Form; some figures to be added, but essential findings are secure.

ABSTRACT

"Designing interstellar starships for human migration to exoplanets requires establishing the starship population, which determines many variables including overall design, architecture, mass and propulsion. I review the central issues of population genetics (effects of mutation, migration, selection and drift) and demographics (population size, age, and sex structure on departure) for human populations on such voyages, specifically referencing a roughly 5-generation (c.150-year) voyage currently in the realm of thought among the Icarus Interstellar research group. I present several formulae as well as concrete numbers that can be used to help determine populations that could survive such journeys in good health. I describe why previously-proposed multigenerational voyage populations, on the order of a few hundred individuals, are significantly too low to consider based on current understanding of human genetic variation and general patterns in vertebrate population dynamics. Population genetics theory, calculations and computer modeling determine that a properly-screened and age- and sex-structured total population (Nc) of anywhere from roughly 14,000 to 44,000 people would be entirely sufficient to survive such journeys in good health. A safe and well-considered figure is 40,000 people. This ‘IMP’ or Interstellar Migrant Population, would be composed of an effective population [Ne] of 23,400 reproductive males and females, the rest being pre- or post reproductive individuals. This number would maintain good health over five generations despite (a) increased inbreeding resulting from a relatively small human population, (b) depressed genetic diversity due to the founder effect, (c) demographic change through time and (d) expectation of at least one severe population catastrophe over the 5-generation voyage."

Interstellar Migration Ship Population

The numbers are looking good right now -- let's see in a few days :) I started with looking at Minimum Viable Populations for ancient hominins--critical for the Atlas of Human Prehistory that I'm working on (Fall '14!)--then converted some of that information for Project Hyperion, an international collaboration of scientists working on giving humanity the option to voyage to exoplanets by the end of this century. The population genetics translate, though there are some significant differences to be wrestled with. Abstract for this year's NASA / DARPA / 100YSS paper in Houston!

"In this study I model the population genetics of five human generations, each of 30 years, for a total of 150 years, according to the broad goals of Icarus Interstellar's Project Hyperion, scaled to reach an exoplanet within 150 years at just over .03 light speed. I adjust population figures to account for various likelihoods of large-scale disaster, which we should expec...t on a voyage of such a duration. I conclude with an estimate of Nc, or total population of the first generation of interstellar migrants (of a certain age- and sex-structure), to be well capable of sustaining founder-, drift- and inbreeding-effect to range from 18,000 to 60,000, depending on the safety factor employed. Roughly averaging these, we should plan for the first 5-generation interstellar starship population to be of 40,000 people, roughly the size of 10-20 oceangoing cruise ships. Such a population could sustain founder-, drift-, and inbreeding-effects and significant disaster. Based on modern, genomics-informed population genetics, this figure helps to determine many engineering issues, including starship architecture, mass and propulsion."

Piracy!

English buccaneer Bartholomew Sharp, on capturing a Spanish vessel off Ecuador in 1681:

"[we captured also] a great Booke full of Sea-Charts and Maps, containing a very accurate an exact description of all the Ports, Soundings, Creeks, Rivers, Capes and Coasts belonging to the South Sea, and all the Navigations usually performed by the Spaniards in that Ocean...[the Spaniards tried to throw the chart book into the Ocean and]...{they} cried when I got the Booke."

Snow Shoes

Olaus Magnus describing his journeys to Norway and other 'Northern Lands' as early as 1510;

"On the frontier of Sweden and Norway there are lofty mountains called Dovre-fjell and others like them, which in wintertime are covered in such dense, deep snow that it is quite impossible for travellers to find a firm route over them in the usual way. Yet, to overcome a difficulty of this sort (by their ingenuity) and skilfully lighten their loads, the traders of those parts fasten to their own and their horses' feet wickerwork shoes, or light, broad half-circles of cork or lime bark and, even though they are weighed down with a heavy burden, tread the ridges of snow without fear of sinking...at night, when the moon gives a brilliant light...by the reflection of the white surface, the shimmering brightness illuminates the elevated and sloping snowfields, so that they may pick out from far off the mountain precipices and harmful beasts that have to be avoided...A still greater danger overhangs travelers among mountains that are full of caves, for through the concentration of tiny snowflakes there one can observe the blasts and gusts of wind roused to such violence in those places that, unless they bring along shovels or ice picks with which to clear the way, they have hardly any hope of emerging from mountains so high and valleys so deep."

Bulky Fittings

I'm replacing all plastic fittings with metal; the problem is that without custom fittings the assemblies--like this suit automatic overpressure dump valve (silver cap on pipe extending right) and the manual dump valve (black knob)are very bulky, obviously not suitable for flying, only for testing. But the testing is done! It's time to build the flying system! So I need access to a few lower-profile fittings; working on assembling them this coming week, knocking off items on the 48-point To Do list with a laser focus on a good test this summer in Copenhagen.

Multi-Planet Species

Off to give a talk tomorrow on not the human past, but the human future. We buy life insurance -- why not species insurance? The cost of that is the cost of making our species at least a two-planet species...but even that (e.g. Mars) is a 'close-in' perspective. Ultimately, as HG Wells wrote, for human survival, 'it's all the universe, or nothing.' Stay on Earth and we're cooked; ask any geologist or palaeontologist. So we must go to the stars and their planets; like any child, we must move away from home -- a project I'm working with on at three levels:

1 / FAR OUT= working with the research group Icarus Interstellar, specifically Project Hyperion, to provide humanity with the option to voyage to distant planets by the end of this century (they're doing propulsion physic; I'm working on the population genetics).

2 / CLOSER IN = working with the Mars Society on human settlements on Mars, as a stepping-stone to interstellar voyaging.

3 / EVEN CLOSER IN = working on life-support systems, specifically the space suit & life-support machinery for Copenhagen Suborbitals' private space-access project.

And spreading humanity universally is not an escape from Earth but an insurance policy for civilization and our species. I love archaeology, and the human past; but there is also a human future, and I'm working on that in the somewhat longer-term than the usual political or even human-life time-spans.

Pirates of Ancient Britanny!

From a letter of about 466AD, describing pirates of Brittany;

"Shipwreck, far from terrifying to them, to them is training. With the perils of the sea they are not merely acquainted, they are familiarly acquainted...they gladly endure dangers amid billows and jagged rocks in order to achieve a surprise."

From p.15 of Wooding, J.M. 1996. "Communication and Commerce Among the Western Sea Lanes AD 400-800. British Archaeological Reports, International Series 654.

Yet Another Pressure Test

This pressure test included Alexander Knapton (to my right), Ben Wilson(a little down the line), and Ben Robbins, who shot some great video of the test. Some impressions:

"Having Ben Wilson get in the suit and pressurize, and breathe through the various systems, so that I can see it from the outside, is a revolutionary step ahead. Luckily Ben is a very level-headed guy in the suit. He is a mountaineer, like I was for a decade, and he is happy to engage some danger in the pursuit of something larger.

Huge progress last few weekends. Now a big change to put a laser focus on preparing for the altitude chamber test in August; that means a new To Do list, which I will build this week. This is what a DIY space program looks like :) We lose suit comms every time the suit is pressurized, something to do with mike and earpiece diaphragms being deformed by increased pressure in the suit. In the photo I'm visually confirming with Ben that all is A-OK, using SCUBA sign language. Also a photo of me in the suit, Ben standing by and Nicholas monitoring the webcam and talking with me on radio."

The Gales

Incredibly evocative image of the colonization of Australia, more than 50,000 years ago, as told from an aboriginal perspective!

"The gales brought us here. They picked us up from the reef out at sea, they tossed us and rolled us and pushed us up high on the sandy head and now we lie here in the sun."

-- Oodgeroo Nunuccal, Australian aboriginal poet, Queensland.

'The Lost Raft' by John. F. Haslett

My buddy John F. Haslett, skipper of our sailing vessels off the Pacific Coast of South America, has re-released his book in a Kindle edition! This is a great read that John has packed with information about the original sailing cultures of Western Ecuador, and why Thor Heyerdahl's famous expeditions were simply wrong in their premises, sailing destinations and even building methods. Great reading! I am so proud of my friend, John, for finally putting these tales to paper--not nearly as easy as it sounds!

“Haslett’s two most important characters are the sea and the raft, and they come alive on almost every page." –Publisher’s Weekly

“Haslett’s prose vibrates with energy … [he] makes you feel the lash of the sail and hear the breakers exploding against the rocks … This is a loud, insistently physical read … ” –San Francisco Chronicle

"Haslett’s narrative begins with the launching of a thirty-five thousand-pound balsa raft, the Illa-Tiki, and then follows up by thrusting the reader into life on the Pacific Ocean. Over the next five years the author and his crews alternate between living aboard primitive rafts and being marooned in alien worlds." -- St. Martins Press