Engineered Exogenesis: Nature’s Model for Interstellar Colonization

Is seeding life into the universe to be a part of the human future? Space probes conceivably could be doing this inadvertently, and the processes of panspermia also may be moving biological possibilities between planets and even stars. Robert Buckalew has his own take on what humans might do in this regard, as discussed below. Robert has written fiction and non-fiction since 2013 under the pen name Ry Yelcho for the blog Yelcho’s Muses. In 2015 he received the Canopus Award for Excellence in Interstellar Fiction from 100 Year Starship for the story “Everett’s Awakening.” His short story “The Interlopers” appears on Literally Stories. What follows draws on his speculative science article “Microbots—The Seeds of Interstellar Civilization,” which was awarded the Canopus Award for Original Non-Fiction. The essay that follows is based on his presentation at the Icarus Interstellar Starship Congress 2019.

by Robert Buckalew

The series of pivotal events that led to the development of intelligent life on Earth are so numerous and seemingly random that the occurrence of intelligent life at other places in the galaxy may be very rare. The chance extinction of the dinosaurs which led to the diversification and opportunistic evolution of mammals is but one of many such events. Assuming the extraordinary rarity of this occurrence elsewhere in the galaxy should be a compelling reason for humans to presume our gifts of intellect exceptional and assume the obligation to prevent this cosmic largess from vanishing through global natural disaster, nuclear war or self-made neglect. Even if intelligent life is found to be common in the universe, it is certain that our form of intelligent life is unique. If we wish, someday, to communicate and interact with these various sentient species and contribute our singular human culture to their diverse communities, we must project our species’ existence into cosmic time frames.

The creation of dispersed, self-sufficient human settlements both interplanetary and extra-solar is the best way to ensure our long term survival as a species. Because of the unimaginable distances to other star systems, most proposals for interstellar colonization involve large multi-generational starships, warp drives or wormholes. Although common plot devices to create science fiction stories, wormholes and warp drives appear unworkable travel methods given the constraints of known physics. Multi-generational starships come with their own technological, political, biological, social and psychological challenges that make their realization daunting to consider.

Nature, however, has developed efficient methods to spread life on Earth that could be employed for interstellar colonization. Engineered Exogenesis, modeled after successful natural processes, proposes a method to spread Earth-life throughout our local stellar neighborhood.

Exogenesis, in astrobiology, is the hypothesis that life originated elsewhere in the universe and was conveyed here to Earth. For example, there is evidence that life in our solar system originated on Mars and was brought to this planet aboard a meteorite. The plausibility of Earth-life having been transplanted is supported by our inability to create spontaneous life from primordial organic chemicals in the laboratory and by the fact that there is no known remnant of pre-genetic life on Earth.

Engineered Exogenesis will use an additional strategy derived from nature. The survival system used by plants, insects and many aquatic lifeforms is based on the overproduction of seeds, larvae or spores in order to overcome their natural failure rate. Mass produced microbots can be designed to intentionally deliver engineered genetics to prospective exoplanets in numbers sufficient to assure that some will likely reach their destination and survive. As with seeds, this may require the dissemination of thousands to millions of them, based on the projected failure rate of the delivery system and the expected germination rate.

We know that water and organic compounds, known as tholins, have been found on planets, moons, comets and asteroids throughout our solar system. These precursors for life are believed to exist on interstellar comets and asteroids as well. Planetary exo-systems are expected to offer a similar fertile environment ready for the introduction of earthly genetic material.

The major components of an Engineered Exogenesis system might include 1) a microbiotic vessel that travels to the extra-solar planet, 2) a space-based magnetic accelerator capable of providing the inertial energy to send the vessel to other solar systems, 3) a space-based laser providing communication and supplemental energy for solar sail navigation and maneuvering, and 4) the engineered genetic material capable of growing a bio-robotic agent on the exoplanet to prepare the planetary environment for humans.

The Microbot

The microbiotic vessel, hereafter referred to as the microbot, would transport hermetically encapsulated, genetic material to the destination exoplanet while providing radiation, magnetic and acceleration protection. This vessel would be designed to open in the presence of liquid water, deploy a biobot zygote and, if necessary, a photosynthesizing food source such as phytoplankton or other aqueous plant food. The engineering of the microbot would incorporate nano technology, bio-robotics, AI and neural networks. It could be very small, possibly the size of a grain of rice, and constructed of low mass materials to minimize the energy required for acceleration. Construction materials might include carbon fiber, graphene or Kevlar designed to withstand the high magnetic fields and high acceleration rates and to provide heat shielding for atmospheric entry. Microbot vessels would possess no on-board propulsion using only their initial inertial energy for space travel. A ferromagnetic mass at the leading end of the vessel would be required for magnetic acceleration and inertial stability. This mass might be separated for deceleration upon arrival at the planetary system or retained for atmospheric entry shielding.

Microbots would also use leading and trailing photo-sensors for navigational aids with the leading photo-sensor directed at the destination star and the trailing sensor pointed at Sol. Fore and aft modulated, bio-luminescent lasers would provide communication between traveling microbot ships reminiscent of fireflies on a summer night.

A series of pivoting, flat panels would be extended following launch. Each panel would use one side for solar energy collection. Solar electric storage might be achieved by capacitance of the microbot body. The obverse side, capable of adjustable reflectivity, would be used as a solar sail. The panel ends would also be capable of latching with other microbot panels for the creation of microbot arrays, connected clusters of individual microbots. A powdered iron substrate layer which would become magnetized during acceleration could aid in microbot arraying and later become a magsail for magnetic braking. A superconducting loop for magnetic braking could be incorporated into the perimeter of the solar panels or otherwise deployed as an independent loop. Finally, the panels could be positioned for autogyro aerobraking during atmospheric entry in the same way maple seeds can dissipate energy by helicoptering to Earth.

The Accelerator

Magnetic acceleration happens by activating each electromagnet ahead of the projectile to pull it forward. As the projectile accelerates, the rate of coil activation increases to stay ahead of the accelerating mass. Projectile acceleration would be limited by the inertial mass of the projectile and the force produced by the electromagnets. Magnetic accelerators can include a circular or linear motor configuration.

Aimed at the destination star, the microbots would be accelerated sequentially for a maximum exit velocity with a minimum energy expenditure. This must be a space based as the atmospheric heating from the very high exit velocity precludes microbots being launched from Earth. By timing the sequencing of the magnets the rate of acceleration can be optimized for the given projectile mass and the vulnerability of the vehicle and payload to the forces of acceleration. The length of a linear accelerator is inversely related to the acceleration needed for a given exit velocity – the longer the coil gun, the less acceleration needed. A circular, toroidal accelerator would not have this length constraint as it could use multiple cycles to obtain projectile terminal velocity. Once the system is deployed it could be used for numerous target stars. If microbots can be accelerated to 10% light speed, a trip to Alpha Centari (4.37 light years away) would take 43 years and a trip to Tau Ceti (10.4 light years away) would take 104 years. Reaching these speeds would be a function of the length and power of the accelerator and the mass of the microbot ship.

The Laser

The laser is not for propulsion, as suggested by Yuri Milner’s Breakthrough Starshot, but would be used for communication and programming updates by modulation of the laser beam. It could also provide energy for course correction and arraying maneuvers. It is also best located in space to reduce atmospheric light scattering.

Arrays

Microbots would be programmed to array although some microbots would necessarily remain as self sufficient individual ships. The primary purpose of arraying is to improve communication with Earth as a larger antenna area can enhance both transmission and reception performance. However, arraying may also be used to collectivize the solar power and energy storage and to organize the use of this power.

Implementing Arrays

Microbot arraying could be achieved through use of swarm intelligence, a naturally occurring function among social insects, migrating birds and fish schools. Known in robotics as distributed AI, microbots could communicate with each other while traveling in space through their fore and aft photo-sensors and modulated bio-luminescence. As the trip may take 100 years or more, there should be adequate time for arraying even considering the limited maneuvering power provided by the angular incident positioning and variable reflectivity of their panels. Although launched individually, the first vessels would be accelerated at a slower velocity than the later vessels causing their clumping in space as they travel and increasing their ability to form arrays.

Microbots Arrival and Descent to the ExoPlanet

Deceleration from near relativistic speeds to that of planetary orbit velocity is always problematic. Explosive ejection of the leading ferromagnetic mass could substantially decelerate the containment vessel while reducing the remaining microbot maneuvering mass. Employing the resistance of the reflective solar sails and the magsail, braking and maneuvering could be achieved by using the retrograde radiant photon pressure, plasma energy streams and charged magnetosphere of the destination star. Solar and magnetic braking could continue after entering an elliptical orbit of the star, until a matching planetary orbital velocity is obtained. With aerobraking the arrays could go from an elliptical orbit of the planet to a circular one. For the solitary microbots aerobraking would slow them for atmospheric entry.

Microbots entering the atmosphere would experience further braking through atmospheric drag. With reduced velocity, low gravitational attraction and high surface-to-mass ratios, atmospheric entry damage to the microbots might be kept to a minimum. Descent might be further dampened and controlled by positioning the panels for autogyro energy dissipation.

Engineered Genetic Materials

Genetics has become a game-changing technology allowing for man-made biological creativity. Genetic engineering has been revolutionized through CRISPR and the creation of artificial life by scientists like Craig Venter. Expanding the genetic alphabet beyond the 4 chemical bases found in DNA could add functions capable of assembling metal or silicon components into planet inhabiting biobots.

Although the microbot starship incorporated some bio-robotic functions such as neural networks and bio-luminescence for communication, it did not need the biobot ability to grow and reproduce. The biobots used for planetary exploration, terraforming and habitat construction would be grown from the genetic material in the microbot after acquiring a suitable watery environment for germination/gestation. These bio-life forms would be genetically designed to be suitable for the anticipated planetary environment but might also incorporate a greater degree of robotics into their biology for laser communication with Earth and reprogrammability.

Essential BioBot Characteristics

The first terrestrial biobots might best be designed to be amphibious for food access and terrain mobility and cold blooded for temperature tolerance. They might be capable of solar power or photosynthesis for their energy, but separate genetic material may be included to produce a photosynthesizing food source for the biobots.

Their instinctive behavior would include a work activity for communication and infrastructure building similar to instinctive nest, hive or web building found with Earth life. Their behaviors would be re-programmable from Earth allowing task changing capability. For this they would require a means to transmit and receive laser modulated signals with Earth as well as their interspecies communication using sound or light modulation.

Reproduction could be biological though it would likely be asexual. Reproduction would also be programmable through Earth communication in order to create a series of diverse offspring, specifically-tasked and specialized biobots. Eventually there would be terraforming for human habitation. After successful habitat construction and terraforming, the final genetic download would be human genomes for incubation. This would require specialized biobots for human gestation and nurturing. These humans could be genetically designed for the gravity, atmosphere and temperatures of the exoplanet by adjusting metabolism rate, body mass, lung capacity, skin color, fat, fur covering, etc. These modifications would prognosticate natural changes which would have evolved over time in humans in adapting to their new environment.

The simpler alternative to the more complex remote reproductive reprogramming would be to send sequential waves of microbots each containing subsequent genetics. However, the advantages of remote genetic reprogramming would not only result in faster colonization, but the genetic developments during the 100+ year microbot travel time could be incorporated in the transmitted genetic code.

Advantages of Engineered Exogenesis

There are some obvious advantages that come with with an Engineered Exogenesis approach to interstellar colonization. It would be scalable, specifically, the numbers of microbots manufactured and launch frequencies can be adjusted to suit political or financial circumstances. It would not be limited to one target planet, and any number of planets or newly discovered planets or moons could be added as targets over time. It would be tested in our solar system and modified with improvements before deployment. The seeding and growth of biobots could take place on Earth or in domed environments on the moon or Mars. Finally, it reduces the time scale for starship colonization, and eliminates human exposure to space travel. It, however, it lacks the drama and romance found in human adventure stories in space.

For Engineered Exogenesis to become a reality there are many technical problems to be resolved as well as numerous ethical issues to be considered such as the chauvinistic imposition of our genetics onto other evolving planetary systems, the creation and dissemination of synthetic, reproducing life forms and the alternation of our own human genome. Society, so far, has been accepting of test tube babies, GMO food crops and gene therapy, especially when it seems to improve our lives. Such controversial technological impositions may also be accepted as necessary in order to achieve a human interstellar presence.

Has This Happened Before?

If Engineered Exogenesis is a viable idea, would it not have been done by advanced alien civilizations? If so, why are there no alien biobots roving around on Earth? This is like the Fermi Paradox about space aliens. If they were sent here, maybe ocean Earth life feeds on these undeveloped alien genomes before they grow and reproduce. Possibly life on Earth is the result of an alien exogenesis. Then where are the microbot ships that carried them? They would be tiny, widely scattered and hard to find. Possibly the nascent search for micrometeorites on Earth may yet find one of these artificial nanobots.

References

1. Michael Noah Mautner, “Seeding the Universe with Life: Securing Our Cosmological Future,” The Interstellar Panspermia Society. http://www.panspermia-society.com/

2. N. Mathews, A. L. Christensen, R. O’Grady, F. Mondada, and M. Dorigo, “Mergeable nervous systems for robots,” Nature Communications 8(439), 2017 (full text).

3. Jennifer Doudna, “How CRISPR lets us edit our DNA,’ TED Talk September 2015. https://www.ted.com/talks/jennifer_doudna_we_can_now_edit_our_dna_but_let_s_do_it_wisely?language=en

4. J. Craig Venter, “Watch me unveil ‘synthetic life,’” TED talk. May 2010. https://www.ted.com/talks/craig_venter_unveils_synthetic_life?language=en

5. Daniela Rus, “Autonomous boats can target and latch onto each other,” MIT News June 5, 2019. http://news.mit.edu/2019/autonomous-robot-boats-latch-0605

6. Sarah Hörst, “What in the world(s) are tholins?” Planetary Society July 22, 2015. http://www.planetary.org/blogs/guest-blogs/2015/0722-what-in-the-worlds-are-tholins.html

7. Francesco Corea, “Distributed Artificial Intelligence: A Primer on Multi-Agent Systems Agent Based Modeling and Swarm Intelligence,” https://www.kdnuggets.com/2019/04/distributed-artificial-intelligence-multi-agent-systems-agent-based-modeling-swarm-intelligence.html

8. Paul Gilster, “Starship Surfing: Ride the Bow Shock,” Centauri Dreams March 21, 2012 https://www.centauri-dreams.org/2012/03/21/starship-surfing-ride-the-bow-shock/