In Shakespeare’s famous lines from The Tempest, the spirit Ariel addresses Ferdinand, prince of Naples, now grieving over the death of his father in the shipwreck that has brought them to a remote island in an earlier era of exploration. The lines have an eerie punch given our discussion of the changes humanity may bring upon itself as we adapt to deep space:

Full fathom five thy father lies;
Of his bones are coral made;
Those are pearls that were his eyes;
Nothing of him that doth fade,
But doth suffer a sea-change
Into something rich and strange…

From this has emerged the modern shadings on ‘sea-change,’ yet another Shakespearean coinage that has enriched the language. I thought about The Tempest while reading through the Working Track Report from TVIW 2016, a symposium in which these adaptations took center stage. The new edition of Stellaris: People of the Stars (Baen, 2020), discussed last Friday, contains the short report, prompting this examination of its conclusions along with a look at some of the fiction and non-fiction that takes up the bulk of the volume, all on the topic of human transformation.

Species Bifurcation at the Oort

In what sense will interstellar travelers be humans like us, and in what sense will they become a new species? One point that emerged in the discussions in Chattanooga was that adaptations to our species will be mission-specific. Exploratory expeditions have the need to adapt to issues like isolation and long confinement as well as, depending on spacecraft configuration, low gravity or other controllable environmental factors. Actual colonies have far different needs: Long-term adaptation to an environment possibly much unlike Earth and the need to support and sustain a growing population. The kinds of human engineering we’ve been discussing come into play, though through a natural process of development, destination by destination.

Imposing genetic and/or physical changes will be slow and adaptive, and doubtless the process will only be possible if begun and examined thoroughly in a space-based infrastructure right here in the Solar System. A multi-generational human presence in space also allows the social structures to develop that can support life off-planet, though these will doubtless evolve within specific mission parameters.

The generation that leaves the Solar System for the first time may face sharp distinctions in its mode of travel. Shorter exploratory missions to nearby stars make their own demands, different from those experienced by worldships that move at much slower pace, producing generations that are born and live out their lives on the vessel. In a sense, worldships can be seen as antithetical to interstellar colonization, if as the working track participants did, we make the assumption that spacecraft on this scale develop their own kind of inhabitants:

Worldships are an end in and of themselves. Moving such a large biosphere to another star system would likely take centuries. If a worldship would be viable for the projected duration of the mission, then it would most likely be viable well in excess of that timeline. Thus, a worldship is a colony; once established, attaching engines or even an interstellar drive to a worldship may provide mobility, but to what end? Furthermore, if it is used merely as a vessel to transport colony and crew, then what is the guarantee that they will want to leave the habitat once the destination is reached?

I’ve written before about the prospect of an important bifurcation in our species on this issue. Those who inhabit massive space structures — perhaps hollowed-out asteroids, or arcologies ‘grown’ in space by future forms of nanotech — and those who live on planetary surfaces and choose to travel through faster technologies to planets around other stars. I can imagine ‘slow boat’ travel between the stars as humans move gradually out into the Oort Cloud exploiting cometary resources and eventually moving into a presumably similar cloud around the Centauri stars, for example. Here we’re talking about missions in the thousands of years, and ‘crews’ — inhabitants — who may well choose to move on to another system after studying the first.

By contrast, those shorter exploratory missions, given the problems of propulsion, may themselves be, at minimum, decades long and likely centuries. Here the Working Track saw the need for deep sleep:

…interstellar exploration will most likely require some form of metabolic suspension. While such medical technology is still science fiction, it has its roots in present-day advances in surgical techniques, in the as-yet-unexplored functions resident in what has been called junk DNA, and in lessons learned from vertebrate animals which can successfully survive freezing temperatures without damage to cells caused by the formation of ice crystals.

Alternating crew shifts into and out of hibernation could sharply reduce the subjective passage of time, with ramifications for both social engineering and life support systems.

Image: The vast interior of an O’Neill cylinder presents a more spacious view of what a worldship might become. Credit: Rick Guidice/NASA.

The Biomedical Transition: Shifting the Curves

You would think that technologies like CRISPR already take us a long way toward the modification of the human genome, but the way ahead is challenging indeed as we go from treating single diseases like cystic fibrosis to modifying complex traits of intelligence or longevity. It’s the difference between single-gene engineering and dealing with hundreds of genes and their interactions over time and changing environments. Thus Nikhil Rao (University of Florida), whose contribution to Stellaris explores the outcomes we want to achieve as we go transhuman.

No easy matter, this, for as Rao puts it:

Ultimately, most positive traits in humans are emergent functions of genes, environment, our interactions, and time. While gene manipulation and nanotechnology may modify these processes, potentially eliminating negative traits, they will likely not change the fact that human traits are ultimately distributed along a series of bell curves, even as science shifts the shape of those curves.

Shifting those curves will involve adjustments to the human immune function, mild immunodeficiency being surprisingly common. We might see accelerated evolution in Earth-based pathogens that have been unwittingly carried with us onto a worldship, for example. A seasonal allergy is an example of something that triggers inflammation and destruction of the body’s own tissues as a response to pollen, bacteria or viruses. Genetic engineering may eventually produce altered immune systems to cope with deadly reactions.

If you watch shows like The Expanse, you’ll see one visualization of changes to the human form resulting from lower levels of gravity, as in the example of the ‘Belters’ who live far from a planetary surface. Candidate planets for future settlement beyond Sol will demand body adjustments to cope with blood circulation and connective tissue issues, perhaps ruling out higher-gravity worlds. To the extent we can engineer for it, we may keep the example of Earth cultures in mind, says Rao. The short-stature, thick-torso Inuit are an adaptation to issues of heat dissipation and retention. Contrast them with “the long and lanky Masai of the hot, dry savannah.” Over time, we can expect adaptive evolution, or engineer for it in advance.

Meanwhile, life extension continues to be explored, with cellular repair mechanisms running headlong into the threats of toxins or radiation on a space voyage. Direct intervention to prevent gene mutation through gene editing may strengthen our protective systems, as could tinkering with the monoclonal antibodies that can be used to rid the body of mutation. Perhaps nanomedicine will emerge to intervene against everything from cancer to dementia.

Rao also talks about forms of cryonic storage, which has been in the interstellar voyage conversation for decades. Here we have the kind of suspended animation science fiction has long advocated as a solution to long voyages (and the plot problems they introduce into a story). He sees few advances in true cryonics but leans toward hibernation as a solution. After all, we know that animals can manage it, so it is biologically feasible and perhaps enhanceable through gene editing. Hibernation also has “clear endogenous (hormone and blood protein) triggers for induction and exit,” and offers the advantage of dramatically slowing metabolic processes to delay waste accumulation and cell damage (lower rates of cellular turnover).

Image: A Bussard ramjet in flight, as imagined for ESA’s Innovative Technologies from Science Fiction project. Credit: ESA/Manchu.

Here Rao echoes the working group in the idea of crew shifts:

Hibernation could reduce caloric needs by up to ninety percent based on animal models and produce up to a ninety-percent lengthening of lifespan at the theoretical high end. Simply stated, a month of lifespan is earned for every year of hibernation. Ten individuals in hibernation would strain life-support systems about as much as one individual active and awake. If every individual spent one year as crew and nine in hibernation during the journey to Alpha Centauri, that 150-year journey suddenly becomes a fifteen-year journey, which is far more doable within a single crew’s lifespan.

Rao is a psychiatrist specializing in critically and chronically ill children, a perspective that reminds us that shipboard and colony life in a strange new environment will stress the human personality over perhaps multigenerational timescales. He offers no easy solutions, but rather falls back on the persistence of older traits amidst whatever bioengineering we are able to pull off. He sees humans as capable of long-lasting cooperative networks and the kind of reciprocal altruism that took our species out of Africa, creating dreams of destinations as distant as the stars. Along the way, we’ll use our technological tools to adjust the human genome as needed.

Imagining the Mission

Although generally unmodified, I now wear glasses, so it could be argued, as editor and contributor Les Johnson does in Stellaris, that I am partly cybernetic.

I doubt many Centauri Dreams readers have trouble envisioning or accepting some physical changes to the human form — some noticeable, some not — or even machine/human interfaces that internalize digital technologies and offer access to information. But I think many in the general public would need to think twice about the fact that an insulin pump for diabetics, or an artificial heart, takes us into cyborg territory even today. We’re well on our way, in other words, to the kind of implants that may one day be common among deep space crews.

Transhumanism has been explored by many a science fiction writer, and I think immediately of David Brin’s ‘uplifted’ dolphins and chimpanzees as an example of what future technologies might allow. Johnson mentions bioengineered super-abilities in Timothy Zahn’s novels, or Nancy Kress’ explorations of humans that tech allows to ‘turn off’ sleep. I also think back to the four stories that went into James Blish’s The Seedling Stars (1957), where humans alter themselves to fit alien environments, already a well established trope in science fiction.

Blish referred to adapting the human form to an alien environment as ‘pantropy.’ Such adaptations can become extreme indeed: In the wonderful “Surface Tension,” an original human crew seeds a water world with new humans that are virtually microscopic and released into fresh water ponds. I also think back to Frederick Pohl’s Man Plus, which copped the Nebula for best novel in 1976. Here a cyborg is vividly adapted to handle the rigors of the Martian surface as a way of setting up a future colony on the planet. The transformation is grim as the protagonist loses his links with humanity on Earth but explores his new identity on Mars.

Johnson’s entry in Stellaris posits an extension of the issue. If our propulsion technologies still demand centuries to get to the stars, can we overcome the problem by sending human embryos that can be activated upon arrival to form a colony? The issues are vexing: Who raises the infants? In “Nanny,” Johnson writes of a starship that contains a crew that alternates in and out of cryostorage to maintain the ship and is intended to raise the first human generation born on the new world, but a catastrophe aboard the ship alters the plan.

Image: Les Johnson, shown here with a sample of solar sail material that may one day be used to send a spacecraft deep into the outer system using only the pressure of sunlight for propulsion.

Are there other kinds of nannies that can raise children? The child whose voice introduces the tale seems to have few problems with hers:

Yesterday was Birthday One and we had a big party. Nanny said the day the first group of us were born was the happiest in memory. Thirteen Earth-years ago, the first fifty of us were removed from the artificial wombs and put in Nanny’s care. Fifty. I cannot even begin to imagine what it was like shepherding fifty babies, and then toddlers, around the house. But then I remembered that eight of the first group died, leaving just forty-two. Nanny doesn’t like to talk about that and has never told us exactly what happened to them.

I won’t either — no spoilers here — but how humans fit into the loop of automated systems is very much on Johnson’s mind in this cunning tale. An expert in deep space propulsion with extensive experience in solar sails (he is principal investigator for a mission we’ve discussed here, Near-Earth Asteroid Scout, as well as the much more ambitious Solar Cruiser), Johnson is an author and editor who sees abundant scope for humans as we populate first the Solar System and then nearby stars, beings who, “no matter their form, will be much like us.”