Planetary Protection for accessing the oceans of icy satellites
Abstract
Direct exploration of extraterrestrial oceans, would present the most difficult Planetary Protection challenge ever undertaken in the exploration of other Solar System bodies. Planetary Protection (PP) is the practice of ensuring science integrity by preventing Earth organisms from proliferating on foreign planetary bodies (forward contamination) and preventing contamination of Earth by extraterrestrial biology (back contamination). Contacting, and sampling, water on an Ocean World requires that robotic probes have an extremely low probability of contamination; NASA PP protocols require a PC of <10-4.
In practice, this means that all water-contacting surfaces of a probe and any surfaces with a direct view to that probe (e.g. carrier stages) would be sterilized. While challenging, sterilizing the external surfaces of a sub-ice probe could be facilitated by the power generation, thermal management and hydrostatic pressure integrity required for such a mission. These capabilities, while driven by environmental requirements, provide direct compatibility with a variety of sterilization options. For example, an autonomous, ice-penetrating probe would be wholly compatible with microbial sterilization chemistries, from the perspective that interior compartments would be sealed to prevent liquid ingress and structures would be chosen to tolerate unknown environments such as high brine concentrations. The same is true for heat sterilization-pressure hull integrity would support heating, even in an enclosed water bath, similar to a biomedical autoclave process. Beyond the probe's ocean access phase, Planetary Protection would also be addressed for end of mission sterility assurance as well as the landed and orbiting spacecraft components. Strategies for the orbiting elements could be modeled on the Europa Clipper mission, while end of mission sterilization and landed elements would draw from the Europa Lander mission concept developed by NASA and JPL. The combination of these elements can be used to describe a potential end-to-end Planetary Protection strategy for ocean access missions. Our work on such a strategy, for a Europa-capable probe concept will be described and discussed, including areas of future research. Abstract contains pre-decisional information, for planning and discussion only.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.P53E3505K
- Keywords:
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- 0728 Ice shelves;
- CRYOSPHERE;
- 6221 Europa;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS;
- 6282 Enceladus;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS;
- 6297 Instruments and techniques;
- PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS