Chlorella vulgaris, a microscopic green algae with a diameter of two to ten micrometers, plays a central role in this. This algae reproduces quickly, and in just 8 hours, the cell population can double its number. In addition, this algae requires little space and water, produces oxygen and is rich in proteins, which makes it ideal for supporting human spaceflight as part of the LSS, supplying breathable air and edible biomass.
In collaboration with the TUM AlgaeTec Center, which has a successful track record in the use of algae for biokerosene and carbon fiber production, Detrell's team uses the latest facilities. These include specialised glass buildings that allow UV radiation, LED lighting and advanced climate system that are able to replicate the light and climate conditions of many Earth locations. Maybe the next step could be the simulation of a lunar or Martian base.
The work focuses on the construction of an efficient photobioreactor in which the algae are cultivated. The researchers are investigating optimal conditions for the growth of microalgae, such as temperature, light intensity and gas concentration, in order to ensure the long-term stability of these systems under the harsh conditions of space.
Current LSS on the International Space Station (ISS) are based on physical-chemical processes that require regular resupply missions. Microalgae-based LSS offer a promising alternative that could provide most of the oxygen and food for the crew. Although their high protein content limits their contribution to nutrition to maximum levels of 10 to 30 per cent, microalgae could significantly improve the sustainability of space missions.
The research at TUM represents the first steps towards realizing this advanced LSS. Through interdisciplinary collaboration with biotechnology experts and utilizing the latest facilities, the team aims to conduct the first microalgae experiment on the lunar surface. This pioneering work could revolutionize the way humanity approaches life support for long-term space missions and ensure that future astronauts have the necessary resources to grow microalgae beyond Earth.
Microalgae require a very complex technology in order to be cultivated in a controlled and stable way as part of a LSS: a photobioreactor. This consists of a reactor chamber, a lighting system which can be composed of blue and red LEDs. Beyond that gas exchange will be required, the algae will require carbon dioxide, while the produced oxygen needs to be extracted and provided to the crew. Finally, a “liquid exchange” will be required: fresh nutrients need to be introduced as they are consumed, and the produced biomass (“potential food”) needs to be extracted and further processed. The team of Prof. Detrell will be focusing on the optimal design of this technology and cultivation techniques for future space missions.
The TUM AlgaeTec Centre, established in cooperation with Airbus Group, in the Ludwig Bölkow Campus in Ottobrunn, is a leader in the mass cultivation of algae under various climatic conditions. This facility presents a unique opportunity to do research with microalgae for future space applications. Detrell is convinced: "We will prove that the long-term cultivation of microalgae in space is possible."
Links:
Prof. Gisela Detrell
Professorship of Human Spaceflight Technology
TUM Research Ecosystem Algae
Werner Siemens-Chair of Synthetic Biotechnology
TUMCREATE Proteins4Singapore