Towards synthetic biological approaches to resource utilization on space missions

Abstract

This paper demonstrates the significant utility of deploying non-traditional biological techniques to harness available volatiles and waste resources on manned missions to explore the Moon and Mars. Compared with anticipated non-biological approaches, it is determined that for 916 day Martian missions: 205 days of high-quality methane and oxygen Mars bioproduction with Methanobacterium thermoautotrophicum can reduce the mass of a Martian fuel-manufacture plant by 56%; 496 days of biomass generation with Arthrospira platensis and Arthrospira maxima on Mars can decrease the shipped wet-food mixed-menu mass for a Mars stay and a one-way voyage by 38%; 202 days of Mars polyhydroxybutyrate synthesis with Cupriavidus necator can lower the shipped mass to three-dimensional print a 120 m(3) six-person habitat by 85% and a few days of acetaminophen production with engineered Synechocystis sp. PCC 6803 can completely replenish expired or irradiated stocks of the pharmaceutical, thereby providing independence from unmanned resupply spacecraft that take up to 210 days to arrive. Analogous outcomes are included for lunar missions. Because of the benign assumptions involved, the results provide a glimpse of the intriguing potential of 'space synthetic biology', and help focus related efforts for immediate, near-term impact.

Keywords: Spirulina; acetaminophen; cyanobacteria; methanogens; polyhydroxybutyrate; space synthetic biology.

Figure 1.

Projected Moon and Mars missions have the greatest destination residence times, thereby necessitating in situ resource utilization when at the destination on these missions to reduce costs and risk. The Mars mission also has the longest journey times, comparable to that of the asteroid visit mission; thus, effective resource utilization during Mars mission travel is also necessary, with any analysis applicable also to the asteroid mission.

Figure 2.

The biology mapping that is sought in this paper is from a constrained set of inputs (carbon dioxide, nitrogen, hydrogen and oxygen) to a fixed set of output classes (propellant, food, biopolymer, pharmaceutical) where the exact output in each class (e.g. propellant chemical name) is unspecified. The map is unconstrained in the type or number of intermediates that is required to manufacture one or more outputs, but it is desired that the number of these intermediates be minimized and that the use of any intermediate be kept in common as far as possible to ensure that the production of all outputs is efficient.

Figure 3.

This paper limits the sought biological map of figure 2 to single-steps (from one or more of the four input resources on the left side of the figure, e.g. by deploying cyanobacteria) or single-intermediate (e.g. acetate) processes, so that a greedy approach to produce the desired intermediates and outputs is optimally efficient. Although not illustrated, the biological transformation of the intermediates into outputs can also make use of available resources.

Figure 4.

The mass of the Mars atmosphere processing plant and required hydrogen or water input in each of the three Design Reference Architecture 5.0 mission scenarios [84] can be reduced by using a Methanobacteria (either KN-15 or thermoautotrophicum) bioreactor instead of a Sabatier reactor. (a) Atmosphere processing plant and (b) required hydrogen or water input.

Figure 5.

The mass of the Moon oxygen and carbon generation mechanisms and required hydrogen or water input in each of the lunar mission scenarios can be reduced by using a Methanobacteria (either KN-15 or thermoautotrophicum) bioreactor. (a) Oxygen and carbon generation mechanisms and (b) required hydrogen or water input.

Figure 6.

Current Spirulina biomass production techniques can represent a mass savings for food production on a Martian mission but not on a lunar mission.

Figure 7.

It may be significantly cheaper to three-dimensional print a habitat on both Mars and Moon missions by switching from stereolithographic additive manufacturing to biopolymer-based fused deposition modelling.

Figure 8.

It is hypothesized that acetaminophen production in space is possible despite resource availability constraints if an analogous synthetic biology approach to one that was recently successfully experimentally tested is used. (a) Current synthetic biology approach [150] to manufacturing acetaminophen. (b) Proposed synthetic biology approach to manufacturing acetaminophen.

Figure 9.

The solution biology map that uses the organisms in table 5.

Figure 10.

Comparative schematic analysis of the proposed solution to the Mars biology mapping problem.

Figure 10.

Comparative schematic analysis of the proposed solution to the Mars biology mapping problem.