The final configuration of the algae-based ISS experiment PBR@LSR

摘要

The spaceflight experiment PBR@LSR (Photobioreactor at the Life Support Rack) shall demonstrate the technology and performance of a hybrid life support system under real space conditions during an operation of half a year. To be launched to the International Space Station (ISS) in 2018, PBR@LSR combines a microalgae photobioreactor (PBR) and the carbon dioxide (CO2) concentrator of ESA’s Life Support Rack (LSR), also known as the European ACLS. Accommodated in the Destiny module, LSR will absorb and concentrate CO2 out of the cabin atmosphere. A dedicated interface allows the utilization of highly concentrated surplus CO2 for cultivation of microalgae in the PBR. The microalgae species Chlorella vulgaris uses CO2 to conduct photosynthesis. Biomass is produced and oxygen (O2) is released. Besides this technical approach of a hybrid life support system, PBR@LSR also pursues scientific goals: stability and performance of a non-axenic long-term cultivation in the μg-adapted PBR as well as on-ground analyses of returned microalgae samples. This paper highlights different subsystems of the spaceflight experiment PBR@LSR in the final configuration, especially the algae suspension loop, lighting, gas handling, humidity control, liquid exchange. Within the different subsystems, the selection of critical components is explained. The overall system design is verified with experimental data.