Astrobiology Group

Astrobiology is a natural sciences research area concerned with the origin, evolution, distribution, and future of life in the universe. Astrobiology is interdisciplinary and encompasses amongst other disciplines biology, chemistry, physics, geosciences, planetary sciences and astronomy. The aim of this research is to learn more about the origin and evolution of life on Earth, about the formation of planetary systems, about organic compounds in space and to find out, if life exists or might exist elsewhere. Our neighbor planet Mars, but also the icy moons in the outer solar system, here in particular Europa and Enceladus, are of astrobiological interest. These solar system bodies are the target of ongoing and future international space missions with substantial contributions from DLR.

The main astrobiological question is whether the origin of life is an inevitable process, i.e. if the laws of biology are universal such as the laws of chemistry and physics, or if the origin of life on Earth was a unique event. The most important questions in astrobiology are; (i) How can we define habitability? (ii) Is there life on other planets and moons in our solar system and beyond? (iii) Where and how should we search for sign of past or present life?

The Research Group ‚Astrobiology‘ in the Institute of Aerospace Medicine in Cologne (led by Petra Rettberg) is working on this subject since the Apollo era with a main focus on the biological aspects of astrobiology. The cellular and molecular reponses to extreme environmental parameters as they occur on other planets and moons in our solar system are studied in microorganisms. Examples for parameters relevant for habitability are ionising and non-ionising radiation, high and low temperatures, low pressure, vacuum, low water activity, oxidising compounds, high salt concentrations, different gravity levels. In addition, the microbiome of manned habitats like the International Space Station (ISS) and the microbiome of plants grown in a confined habitat in Antarctica (EDEN ISS - Ground Demonstration of Plant Cultivation Technologies for Safe Food Production in Space) are under investigation. One important component are activities in the area of planetary protection, here the determination of the bioburden and biodiversity of spacecraft and spacecraft assembly cleanrooms as well as contributions to international planetary protection rules and standards (PANEL ON PLANETARY PROTECTION (PPP)).

The experimental work of the research group is performed in microbiological labs, in planerary and space simulation facilities, by participation in field campaigns, in form of space experiments, e.g. on the ISS, and by contributions to international space missions, e.g. ExoMars2020. These activities are complemented by collaboration in the development of relevant technologies, e.g. plasma-decontamination of space hardware or optimisation of antimicrobial surfaces.

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Links:

Planetary and Space Simulation facilities of DLR in Cologne - https://www.dlr.de/Spacesim

Current and Future Space Experiments of the Department of Radiation Biology

Mikroorganismen unter dem Eis? (Dr. Petra Rettberg in an interview with the television station HYPERRAUM.TV)

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Examples of actual projects:

Alien worlds – alien life? How to protect astrobiologically interesting planets and moons as well as the Earth? – Planetary protection

The internationally accepted COSPAR (Committee on Space Research) Planetary Protection guidelines were set into place to avert the contamination of other habitable planets and moon in our solar system and to protect Earth from potentially harmful extraterrestrial agents. To comply with these requirements the bioburden and biodiversity of spacecraft is routinely monitored and controlled at various stages of its assembly process. The Astrobiology Group is performing Planetary Protection Verification Assays on behalf of ESA since 2003, actually for the upcoming ExoMars 2018 mission in addition to bioburden measurements for other international missions and contributions to international planetary protection rules and standards. (see: PANEL ON PLANETARY PROTECTION (PPP) and The COSPAR Panel on Planetary Protection Role, Structure and Activities).

Cold and salty, is there a chance for life in the oceans of the icy moons? – The space experiment IceCold

The space experiment IceCold (Investigating Cold adapted organisms as model organisms for a Europa ocean environment in CubeSat based hardware, team coordinator Elke Rabbow) was selected by ESA for flight in 2020. IceCold utilizes the ESA EXPO external exposure platform on Bartolomeo, ISS, to test the hypothesis that extremophilic salt and cold adapted organisms from the three domains of life on Earth can survive and possibly grow in the harsh environmental conditions in space and on the icy moons, in particular ionising radiation, short wavelength solar UV radiation, low temperature / temperature oscillations, high salt concentrations. The test organism suite comprises of Halorubrum lacusprofundi, Rhodotorula JG-1b and Rhodococcus JG-3 provided by L. White, Canada, Halobacterium salinarum, Deinococcus radiodurans and geothermalis and the microbial space veteran Bacillus subtilis. Currently, space exposure hardware models are developed and tested and ground based basis data collected.

Is the DNA repair capacity influenced by microgravity? – The space experiment LUX-in-Space

Lux-in-Space (Kinetics of enzymatic repair reactions after irradiation under microgravity by use of a rapid bioluminescence-based bacterial genotoxicity assay, team coordinator Petra Rettberg) investigates radiation induced DNA damage repair in microgravity in the ISS with a bacterial reporter assay develop in the DLR Cologne as a fast genotoxicity test. Both, the radiation damage and the enzymatic repair are induced in space in weightlessness and the repair kinetics is quantified in comparison to in-space 1g controls and to ground 1 g controls. The space experiment is foreseen for the ESA Biolab facility in the Columbus module in the ISS. The respective hardware is under development, ground based test to collect basis data are performed.

Anaerobic microbes from Earth, can they cope with Mars? – The space experiment MEXEM

The space experiment MEXEM (Mars Exposed Extremophiles Mixture, team coordinator Petra Rettberg) is the continuation and complementation of the MASE project (Mars Analogues for Space Exploration, see also http://www.mase-eu.org/). The launch of the passive exposure experiment MEXEM in ESA’s new EXPO facility on the outside of the ISS is planned for the year 2023. MEXEM will test the hypothesis that organisms in oxygen depleted natural samples, artificial anaerobic communities, and isolated strains including ciliates and viruses from Mars analogue sites and from the ISS are not only resistant to the specific environmental conditions from where they originate but also to the combined Mars relevant environmental stress factors due to their highly effective cellular and molecular adaptation and repair mechanisms. Additionally, artificially fossilized strains will be examined. Currently, the selection of the investigated strains and the accompanying first preparation tests are in process.

Head

Dr. rer. nat. Petra Rettberg
German Aerospace Center
Institute of Aerospace Medicine, Radiation Biology
Tel.: +49 2203 601-4637
Fax: +49 2203 601 3726

Veröffentlichung in eLife: Wie das menschliche Gehirn das Herz-Kreislauf-System steuert

5th Human Physiology Workshop, Saturday, 5th of December 2020

Wanted: Male Subjects for Muscle Study

Paper release: Which technologies are required for the exploration of the icy moons Europa and Enceladus?

Drei Veröffentlichungen des Instituts in renommierten Zeitschriften