Progress toward the development of lifeform detection algorithms for the deep phreatic thermal explorer (DEPTHX)

摘要

Based on observations of seemingly hostile aqueous environments on earth, it is possible for lifeforms not only to evolve but to thrive in conditions that, by human standards, are extreme. Such lifeforms, typically termed "extremophiles" can, for example, live in the vicinity of deep water volcanic vents that are spewing superheated water laden with sulfur compounds at intense pressures. Since similar conditions may exist on Jupiter's moon Europa, there is widespread interest in developing an autonomous search-for-life capability that could be deployed in aqueous, extraterrestrial environments. As one step toward this goal, the DEep Phreatic THermal eXplorer (DEPTHX) is a NASA Astrobiology Science and Technology for Exploring Planets (ASTEP) project to design, develop and field-test a robotic vehicle to explore such environments. The principal astrobiological science objective of DEPTHX is to develop an advanced methodology and protocol for the discrimination of microbial life in a sub-aqueous environment. Implementation requires the design, development, and demonstration of a fully autonomous architecture for intelligent biological sample detection and collection, whereby the robotic device will be capable of performing the following functions: 1. Deep hydrothermal springs will be mapped with great accuracy in three dimensions. 2. Data will be acquired from a hierarchical suite of on-board microbial life detection and sensors and processors and will be analyzed to determine whether life is present. 3. Specimens will be aseptically collected and returned for subsequent ex-situ laboratory analysis preserved under ambient conditions. The paper describes current progress toward these objectives, with an emphasis on the analysis of data acquired from the life sensors for the purpose of detecting lifeforms.