Microalgae-based Photobioreactors for a Life Support System of a Lunar Base

Date

2019-07-07

Journal Title

Journal ISSN

Volume Title

Publisher

49th International Conference on Environmental Systems

Abstract

Environmental Control and Life Support Systems (ECLSS) for a crewed lunar base differ from those for Space Stations in Low Earth Orbit (LEO), mainly due to the increased distance, and therefore more expensive resupply possibilities. Microalgae-based photobioreactors (PBR) can help reducing the required resupply mass by closing material flows with the help of regenerative elements. By means of photosynthesis, the microalgae use CO2, water, light energy and nutrients from waste to provide oxygen and biomass for the astronauts. Moon based PBRs have different requirement priorities than PBRs for Earth bound applications. Criteria such as: long term process stability and controllability, energy-efficiency, scalability and space-efficiency have high priority. One way to influence microalgae growth phases and biomass composition with non-intruding methods is to adjust the spectrum of the lightning system. This paper presents the theoretical possibilities of matching the total emitted spectrum of a limited amount of different LEDs with a desired spectrum. In an artificially LED-illuminated PBR, the LEDs are the main source of heat. The possibility of reducing space between stacked PBR cells without disturbing the thermal control of the reactors by using mirror systems to guide and distribute the light will be investigated. Another important issue that has a great impact on cultivation efficiency is the reactor chamber geometry. It is critical that nutrients dilute evenly throughout the algae medium. To realize that, many earthbound reactors rely on gravity and the resulting air lift. The paper will also elaborate on lunar specific air lift chamber-designs due to the lower gravity compared to Earth and evaluate other reactor concepts for a lunar application.

Description

Johannes Martin, University of Stuttgart, Germany
Gisela Detrell, University of Stuttgart, Germany
Jochen Keppler, University of Stuttgart, Germany
Harald Helisch, University of Stuttgart, Germany
Stefanos Fasoulas, University of Stuttgart, Germany
Reinhold Ewald, University of Stuttgart, Germany
ICES500: Life Science/Life Support Research Technologies
The 49th International Conference on Environmental Systems as held in Boston, Massachusetts, USA on 07 July 2019 through 11 July 2019.

Keywords

Microalgae, Lunarbase, Life Support System

Citation