Planetary Protection for the JUpiter ICy moons Explorer (JUICE) Mission Candidate
Abstract
The JUICE mission is being studied by ESA in the framework of its Cosmic Vision programme, addressing the topical questions ``What are the conditions for planet formation and emergence of life?'' and ``How does the Solar System work?''. Jupiter can be seen as a paradigm of planetary systems forming a mini-solar system on its own. By investigating its diverse satellites, the understanding of the formation and evolution such of systems would be advanced. The question of whether possible habitats of life are provided underneath the surfaces of the icy satellites Callisto, Ganymede and Europa would be addressed by remote sensing and in situ observations of their surfaces, their compositions and their interiors, including the characterizations of subsurface liquid water oceans, including targeting of recently active regions on Europa for inferring the minimal thickness of the icy crust. JUICE would furthermore provide observations of Jupiter's atmosphere addressing open questions on the circulation at mid-latitudes, and also including coverage of the polar region from a distance of about 29~R_J (see also L. Fletcher et al. in meeting C3.1 "Planetary Atmospheres"). JUICE would study the properties of the magnetosphere and would provide extensive monitoring of Jupiter's plasma environment at distances ranging from more than 100 to 8.5~R_J, which is the distance of Europa. The unique magnetic and plasma interactions between the Jupiter environment and Ganymede would be target to focused investigations, from orbit around Ganymede (see also A. Coates et al in session C3.2 ``Planetary Upper Atmospheres, Ionospheres and Magnetospheres''). The magnetic field and its potential habitability of Ganymede makes it a unique target for specific investigation. The presentation will briefly describe the science objectives of the JUICE mission (see also C.~Erd et al. in session B0.3 ``Active Natural Satellites in the Solar System''), and will then discuss the baseline mission profile, which includes two Europa flybys, causing the mission to be in Planetary Protection Category III, requiring the probability of deposition of a viable organism to be <10^{-4}. The intended approach for complying with the planetary protection requirements is to avoid active sterilization measures by ensuring that the spacecraft's probability for critical failure is sufficiently low. The duration of critical contamination of Europa is limited by the fact that that the spacecraft's trajectory needs to be actively modified towards Europa for the flybys, and afterwards the spacecraft will be on a trajectory with higher pericenter, significantly reducing any accidental collision. The presentation will specifically discuss plans on mitigating the risk of contamination of Europa. It is intended as early information for planetary protection group and to seek comments and feed-back on the approach. At the time of writing the JUCE mission is still in competition with two other missions (ATHENA, NGO) for the L1 launch slot in ESA's Cosmic Vision Programme. The decision on which mission to be carried forward to Definition Phase is expected to be taken in April 2012, and will be reported at the meeting. The current status of the development and next steps will be summarized too.
- Publication:
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39th COSPAR Scientific Assembly
- Pub Date:
- July 2012
- Bibcode:
- 2012cosp...39..513E