End-to-end mission design for microbial ISRU activities as preparation for a moon village

Highlights

• Synthetic biology can help to bind elemental silicon from lunar regolith simulants.

• E. coli can be combined with magnetism to extract iron from lunar regolith simulants.

• The mission architecture can be accomplished with currently available launchers.

• A lander together with a rover is sufficient for multiple biological experiments.

Abstract

In situ resource utilization (ISRU) increasingly features as an element of human long-term exploration and settlement missions to the lunar surface. In this study, all requirements to test a novel, biological approach for ISRU are validated, and an end-to-end mission architecture is proposed. The general mission consists of a lander with a fully autonomous bioreactor able to process lunar regolith and extract elemental iron. The elemental iron could either be stored or directly utilized to generate iron wires or construction material. To maximize the success rate of this mission, potential landing sites for future missions are studied, and technical details (thermal radiation, shielding, power-supply) are analyzed. The final section will assess the potential mission architecture (orbit, rocket, lander, timeframe). This design might not only be one step further towards an international “Moon Village”, but may also enable similar missions to ultimately colonize Mars and further explore our solar system.

Introduction

Multiple efforts are now under way to enable sustainable exploration beyond the ISS and LEO. Space agencies are embracing exploration with commercial and international partners in order to return to the Lunar surface, and in doing so, bring back new knowledge and potentially resources, and open up new opportunities for innovation. In this context, new technological concept demonstrations are increasingly sought for surface missions and payloads. In particular, activities that can potentially enable sustainable exploration for missions on the surface for lengths up to and surpassing 40 days, are being considered. In this work, we present a novel candidate mission concept which leverages modern advances and understanding in synthetic biology to realize an ISRU focused concept that could become an exploration enabling architecture, as well as enabling valuable scientific investigations pertaining to the lunar environment.

Developing the capability to use local planetary resources is critical for future sustainable long-duration missions on the Lunar and Martian surface. The mission here described proposes a novel ISRU biology-based method, which would permit the extraction of metal and gases from lunar regolith, helping to reduce the cost of human missions [1]. While a primary role of ISRU for a Lunar Outpost would be the production of oxygen [2], accessing lunar metals is needed for the development of a lunar infrastructure, and supply from Earth would be mass and thus cost prohibitive [3]. The production of metals and gases from this mission will not enable full independence of Earth supplies, but it would prove the potential of biological ISRU and reduce the resources that are brought from Earth [4].

The objectives of this mission concept are:

• Test a life-support system designed for the bacteria working in the lunar environment.

• Demonstrate the ability to process lunar regolith and extract elemental iron, silicon and more by landing a fully autonomous bioreactor on the lunar surface. The extracted material could be used as raw material, e.g. for manufacturing using 3D printing technology.

• Prove the capability of storing gases (H₂, O₂, CO₂, CH₄) generated by the bacteria during the metabolic process. Over time, this arrangement could store significant amounts of gas-by-products, useful for a permanent human outpost.

• Test the toxicity of lunar dust and the radiation environment on simple organisms.

• Extend the International Space Station (ISS) cooperation model, allowing international partners to develop systems/subsystems of the rover and bioreactor.

• Increasing the number of complex biomolecules on the moon to enable future food supply (The availability for certain biomolecules (carbon, nitrogen-containing) is key to enable sustainable food supply in situ) [5].

Several major assumptions were made in the conceptual design of the mission architecture and are listed below:

• The mission is assumed to advance the objectives of, and take place within, the overall framework of the Global Exploration Roadmap [6]. Taken as part of a broader effort, the mission would have a higher chance of success, would build key resource utilization knowledge prior to human exploration, and leverage the presence of other capabilities being developed as part of the GER

• The mission will be a collaboration between several ISECG members with different contributions.

• The mission will be a technology development and demonstration mission to advance capabilities required for further incremental, sustainable robotic and human-robotic exploration.

• The bioreactor system will have the capacity of being fully autonomous.

• Public or private launch vehicles capable of carrying the proposed payload space agencies or private companies will be available by the timeframe of the mission.

NASA, ESA, and other space agencies have for long exposed the importance of ISRU to reduce the cost of the missions. Upcoming missions include robotic capabilities to acquire and process local resources:

• ESA drills and science instruments on Roscosmos's Luna 27 (PROSPECT) will demonstrate the thermochemical extraction of water from lunar regolith [6].

• Selected to fly on NASA's Mars 2020 mission, MOXIE (Mars Oxygen ISRU Experiment) is a payload that will produce oxygen from the Martian atmosphere using solid oxide electrolysis (SOXE) [7].

• Instruments aboard the lander and rover from the ISRO's Chandrayaan-2 mission will collect data on the moon's thin envelope of plasma [8].

• As part of the recently canceled Prospector Mission, a rover would have excavated volatiles such as hydrogen, oxygen, and water from the moon [9].

• Other upcoming missions include biological experiments to perform on the lunar surface: the Chang'e 4 Chinese mission planned for 2018 will deliver a lander to the far side of the Moon carrying, among other instruments and experiments, a container with potatoes, Arabidopsis thaliana seeds and silkworm eggs. Together, the plants and silkworms are expected to create a simple ecosystem [10,11].

Also, other methods have been studied to evaluate their potential to produce oxygen and metal from lunar resources to support human exploration of space:

• The electrolysis of molten lunar regolith, also termed Magma process, requires an electrolytic cell where the regolith is molten, and in which a potential is applied such that oxygen evolves at the anode and metal deposits at the cathode [12].

• The electrolysis of solid lunar regolith approach, which derived from the FFC-Cambridge process for the electro-deoxidation of metals and metal oxides [13].

• Additionally, there are numerous mission architectures proposed in scientific literature approaching the structure of telerobotic operations [14,15].