In a 2020 paper in the journal Biomimetics, Alex Ellery who heads the Space Exploration Engineering Group in the Department of Mechanical & Aerospace Engineering at Carleton University, Ottawa, lays out a case for engineering mechanical systems that emulate biological life in the same vain as a Von Neumann universal constructor. This concept, conceived by the Hungarian-American mathematician John von Neumann in 1940s prior to the invention of the computer, is a machine that can make copies of itself given a set of instructions, sufficient materials and a source of energy.
Ellery begins by examining theories on the origin of life on Earth to distill down the essence of how inanimate material was transformed into living systems. He then goes on to define the basic characteristics of how organisms use energy to process materials to evolve and reproduce. Applying these principles to mechanical systems he envisions bioinspired machines be used to propagate self-replicating factories on the Moon in a lunar industrial ecology. Materials mined in situ by robots would be processed using solar energy via automated additive manufacturing processes analogous to living organisms reproducing to expand the facility.
“Adopting the notion of a biological ecosystem, we can envisage a modest self-sustained metabolism.”
In an examination of what life is, Ellery makes the analogy between ribosomes, the basic macromolecular machine that performs protein synthesis in living cells, and a 3D printer called the Replicating Rapid Prototyper (or RepRap), a key element of his research. Through additive manufacturing this device can print some of its own plastic components.
Eventually, Ellery’s goal is for the device to be able to fabricate most of its own parts including the metal components. However, a fully autonomous self-replicating machine will required considerable advancements in artificial intelligence and automation. Initially, prefabricated complex components such as electronic circuitry, actuators, and sensors may be supplied independently as “vitamins” from Earth and assembled automatically during fabrication to enable automatic manufacture of the robots. Ellery introduces his team and describes his research at Carlton University in this short video.
Self-replicating factories designed for the production of space settlement infrastructure have been covered previously by SSP. Hybrid approaches that include humans in the loop to guide the process may be a near term solution until AI and robotic technologies become fully autonomous.
Some have postulated that if Von Neumann probes have been used by alien civilizations to colonize the galaxy there may be ways to detect them.