Hierarchical assembly of a self-replicating spacecraft

Abstract

Extraterrestrial fabrication of spacecraft by current best-practice manufacturing methods is complicated by the need to integrate thousands of unique parts, each made using a diversity of processes and raw materials. Reducing this complexity could enable exponential space exploration via self-replicating spacecraft (known as Von Neumann probes). We propose a hierarchical model for machine design, based on 13 reversiblyassembled part types, reducing the complexity of machine selfreplication and bridging prior work in the areas of in-situ resource utilization (ISRU) and modular robotics. Analogous to amino acids in biological systems, these parts form a basis set for the electronic and mechanical subsystems of an exploratory spacecraft. In simulation we validate representative subsystem designs and develop a hierarchical architecture for the design of mechanisms, actuation, and electronics. By standardizing and modularizing the parts, we drastically reduce the diversity of the required supply chain as well as the minimum viable payload mass. We estimate that a seed launch could contain approximately 10 5 parts, fit within the envelope of a 3U cubesat, and enable the assembly of over one hundred self-replicating assemblers.

Robotic Self-Replication

“…Figure 6 shows graph network representations for four types of systems: industrial robot assembly lines, track-following robots, reconfigurable modular robots, and RepRaps. Some of the machines presented here are designed explicitly with self-replication in mind (25,29,30,34,79,80,93,118), some are not (28,119), and some are equipped to perform self-replication incidentally as a subset of broader capabilities (96,120).…”

Near-term self-replicating probes - A concept design

“…Chirikjian [13] and Boston et al [20] proposed concepts and architectures for self-replicating systems; however, those are not envisioned to be developed with current technologies. Langford et al [26] propose a hierarchical self-replicating spacecraft concept, focusing on defining standardized, modular spacecraft parts, fitting into a 3U-CubeSat. The use of in-situ resources and the concept of operations are not considered in this bottom-up approach.…”

“…Therefore, the objective of this paper is to propose a concept for a self-replicating probe for space exploration based on current and near-term technologies, with a focus on small spacecraft (here: < 100 kg). Instead of a bottom-up approach, such as in Langford et al [26], we use a top-down approach, starting from mission objectives, defining system modules and technology alternatives, and proposing a concept design for a self-replicating probe. Instead of aiming at complete replication, we estimate the degree of self-replication, which is achievable with current and nearterm technologies.…”