Strategies for Mitigating Contamination Risk for Ultra-Sensitive Life-Detection Missions to Ocean Worlds

Contamination control (CC) strategies for Ocean World missions that aim to search for signatures of life are an essential part of mission design as they are critical for mitigating risks of false positive detections from terrestrially sourced contaminants. Such missions require highly sensitive instrumentation with low limits of detection and signal-to-noise ratios. Contamination control strategies aim to meet CC requirements derived from instrument performances by reducing, protecting from, and preventing science-relevant contamination of the science payload during science operations. Doing so helps establish high confidence in life-detection determinations. Here we report on technology advances that focus on understanding contamination transfer from pre-launch processing to science operations using computational fluid dynamics and high-fidelity physics for monolayer molecular behavior. Moreover, we developed a new full-spacecraft bio-molecular barrier design that protects the spacecraft and instruments from possible contaminants introduced by launch vehicle hardware. The bio-molecular barrier concept isolates the spacecraft from the external molecular and particulate contamination, including all possible biological components. The new model enabled us to evaluate contamination transport for a plume-flyby reference mission that utilized the barrier and an in-flight decontamination activity. Model results verify the efficacy of both. Furthermore, the model provides detailed tracking of contamination for each mission stage to assess the expected overall impact on science operations. For the reference mission, the model demonstrated an exceptionally low probability for femtomolar-levels of specific molecular contaminants impacting science measurements. The new barrier design and high-fidelity physics contamination transport model are key innovations enabling life-detection missions by providing a means to protect spacecraft and a tool to understand what, when, and how critical contaminants move about an ultraclean spacecraft before and after launch.