Biological Contamination Prevention for Outer Solar System Moons of Astrobiological Interest: What Do We Need to Know?

To ensure that scientific investments in space exploration are not compromised by terrestrial contamination of celestial bodies, special care needs to be taken to preserve planetary conditions for future astrobiological exploration. Significant effort has been made and is being taken to address planetary protection in the context of inner Solar System exploration. In particular for missions to Mars, detailed internationally accepted guidelines have been established. For missions to the icy moons in the outer Solar System, Europa and Enceladus, the planetary protection requirements are so far based on a probabilistic approach and a conservative estimate of poorly known parameters. One objective of the European Commission-funded project, Planetary Protection of Outer Solar System, was to assess the existing planetary protection approach, to identify inherent knowledge gaps, and to recommend scientific investigations necessary to update the requirements for missions to the icy moons

CONSIDERING PLANETARY PROTECTION OF OUTER SPACE BODIES - THE EUROPEAN PPOSS PROJECT

The PPOSS (Planetary Protection of Outer Solar System bodies) project, coordinated by the European Science Foundation is supported by the European Commission Horizon 2020 programme. This project kicked-off in January 2016 and will last for three years. The PPOSS project intends to consider how planetary protection policy has been developed and is being implemented, it will look at case studies, lessons learnt and good practices in order to produce a Planetary Protection handbook that will be widely disseminated. The project will also look forward and address the complex issues of organic and biological contamination of outer solar system bodies, in particular small bodies and moons of gas giant planets. PPOSS will identify knowledge gaps, propose scientific goals and suggest activities to overcome the main hurdles to reach these goals. Besides scientific issues, PPOSS will consider the European engineering landscape and the capacity of the European industry to meet the challenges raised by planetary protection of outer solar system bodies, an engineering roadmap will result from this effort. As a one of the main outcomes, the PPOSS project will eventually review the international planetary protection regulation structure, process and categorization related to outer solar system bodies, it will suggest policy improvements to COSPAR Panel on Planetary Protection. PPOSS is implemented by a consortium of seven European and international organisations (European Science Foundation, DLR, COSPAR, Eurospace, INAF, Space Technology Ireland, Imperial College) as well as by international partners, including the Chinese Academy of Sciences and China Academy of Space Technology. The project intends to broaden its international footprint and allow a dedicated forum to address the scientific, technical and policy challenges raised by planetary protection of outer solar system bodies

SEARCH FOR LIFE ON ICY MOONS - WHAT DO WE NEED TO KNOW FOR PLANETARY PROTECTION?

Planetary protection aims at the preservation of our ability to study planets and moons of astrobiological interest as they exist in their natural state. The contamination with Earth organisms and organics (potential biosignatures) would give false positive results with severe impacts on future exploratory missions. In addition, the Earth's biosphere has to be protected in case of returning extraterrestrial samples. In the past COSPAR's planetary protection policy has mainly focused on the prevention of biological contamination. While the requirements for Mars and the guidelines for their implementation are based on decades of experience the necessary measures for outer solar system bodies, here especially Europa and Enceladus, are less developed. They are based on conservative estimates of poorly known parameters. In the PPOSS project (EC H2020 Grant Agreement 687373) the actual knowledge of the environmental conditions on icy moons and other outer solar system bodies, the geological processes restructuring the icy moons' surfaces and the effects of these environmental parameters on Earth organisms with respect to their capability to survive and to replicate are critically looked at to identify knowledge gaps, recommend further scientifc investigations to specify the requirements in more detail, to identify necessary technological developments and to suggest updates of COSPAR's planetary protection policy. These activities will be summarized in a Research White Book that will be available end 2017