Madrid Deep Space Communications ComplexThe icy moons in our solar system, provided with potentially habitable oceans under their frozen crust, are a perfect place to conduct research and thus try to answer the enigmatic question about the existence or not of extraterrestrial life.But searching for signs of life in a frigid sea hundreds of millions of miles away poses enormous challenges.The scientific equipment used must be exquisitely complex, capable of withstanding intense radiation and operating in cryogenic temperatures.In addition, the instruments must be able to take several independent and complementary measurements that, together, can produce a scientifically defensible proof of life.To address some of the difficulties that future life-detection missions might encounter, a team at NASA's Jet Propulsion Laboratory in southern California has developed a powerful suite of scientific instruments called OWLS, or Oceans Worlds LifeSurveyor).OWLS is designed to ingest and analyze liquid samples.It has eight instruments, all automated, which, in a laboratory on Earth, would require the work of several dozen people.One possible use for OWLS would be to analyze frozen water from one of the steam plumes that erupts from Saturn's moon Enceladus."How do you take a speck of ice a billion miles from Earth and determine, with only one chance you get, while everyone on Earth waits with bated breath, if there is evidence of life?"said Peter Willis, co-principal investigator and scientific lead on the project."We wanted to create the most powerful instrument system you could design for that situation, to look for both chemical and biological signs of life."OWLS has been funded by JPL Next, a technology development drive program run by the Laboratory's Office of Space Technology.In June, after half a decade of work, the project team tested their equipment, which is currently the size of a few filing cabinets, in the salty waters of Mono Lake in California's Eastern Sierra.OWLS found chemical and cellular evidence of life, using its built-in software to identify that evidence without human intervention.“We have tested the first generation of OWLS equipment,” said Willis."The next step is to format and miniaturize it for specific mission environments."A key challenge facing the OWLS team was how to process liquid samples in space.On Earth, scientists have gravity, a reasonable laboratory temperature, and the air pressure needed to hold samples in place, but those conditions don't exist in a spacecraft traveling through the solar system or crashing down. to the surface of a frozen moon.Therefore, the team designed two instruments that can extract a liquid sample and process it in the prevailing conditions of space.Since it is unclear what form life might take in an ocean body, OWLS needed to also include the widest possible range of instruments, capable of measuring a range of sizes from single molecules to microorganisms.To that end, the project brought together two subsystems: one that employs a variety of chemical analysis techniques using multiple instruments, and another with multiple microscopes to examine visual clues.The OWLS microscope system will be the first in space capable of imaging cells.It has been developed in conjunction with scientists at Portland State University (in Oregon), it combines a digital holographic microscope, which can identify cells and movement throughout the volume of a sample, with two fluorescent imagers, which use dyes to observe the chemical content and cell structures.Together, they provide overlay views with a resolution of less than a micron, or about 0.00004 inches.ELVIS (Dubbed Extant Life Volumetric Imaging System) is the microscope subsystem that has no moving parts, a rarity.And it uses machine learning algorithms to zero in on realistic motion and detect objects illuminated by fluorescent molecules, either produced naturally in living organisms or as added dyes attached to parts of cells."It's like looking for a needle in a haystack without having to pick up and examine every single blade of hay," said co-principal investigator Chris Lindensmith, who leads the microscope team."We're basically grabbing big armfuls of hay and saying, 'Oh, there are needles here, here and here.'"To examine much smaller trace life forms, OWLS uses its Organic Capillary Electrophoresis Analysis System (OCEANS), which essentially pressure-cooks liquid samples and moves them into instruments that look for the building blocks of life: all varieties of amino acids, as well as fatty acids and organic compounds.The system is so sensitive that it can even detect unknown forms of carbon.Willis, who led the development of OCEANS, likens it to a shark that can smell just one molecule of blood in a billion molecules of water, and distinguish blood type.It would be only the second instrument system to perform liquid chemical analysis in space, after the MECA instrument aboard NASA's Phoenix Mars Lander.OCEANS uses a technique called capillary electrophoresis, basically passing an electrical current through a sample to separate it into its components.The sample is then sent to three types of detectors, including a mass spectrometer, the most powerful tool for identifying organic compounds.These subsystems produce massive amounts of data, only 0.0001% of which could be sent to distant Earth due to data transmission rates that are more limited than the dial-up Internet of the 1980s. OWLS has been designed with what is called “autonomy of scientific instruments on board”.Using algorithms, the computers would analyze, summarize, prioritize and select only the most interesting data to send home, while providing a "manifest" of information still on board.“We are starting to ask questions that now require more sophisticated instruments,” said Lukas Mandrake, instrument autonomy system engineer for the project.“Are any of these other planets habitable?Is there defensible scientific evidence for life rather than a hint that it might be there?That requires instruments that need a lot of data, and that is what OWLS and its scientific autonomy are poised to achieve.”Original news (in English)