Extraction chamber for the Ocean Worlds Life Surveyor (OWLS) instruments suite

The JPL OWLS is an instrument suite that combines chemical analysis with microscopy in order to search for life on multiple fronts. In order to accomplish this, it needs a front-end sample processing unit that can deliver specifically prepared sample aliquots to the specific instruments’ inlet ports. The microscope requires a liquid sample that is unperturbed from the in situ environment. The chemical analyzer requires a digestion step to access the organic molecules locked within macromolecules and cell walls. The extraction is particularly important to finding molecular biosignatures in samples containing extant life. Since the majority of monomers are embedded in larger biomolecules, a technique is required to lyse cells and hydrolyze biomolecules, such as larger protein molecules, into their constituent amino acids. SubCritical Water Extraction (SCWE) is a digestion process that can be applied to liquid samples using only temperature and pressure to break down proteins into constituent amino acids. While it is possible to add additional solvents, the technique requires only water to break down these large macromolecules. Here, we present the design of the OWLS extraction chamber. In addition to performing SCWE up to 200 °C, the new design has the added functionality of mixing, filter concentration of cells, and customized aliquot delivery.