Mochii successfully completed end-to-end testing during NASA's 23rd Extreme Environments Mission Operations (NEEMO 23) off the coast of Florida. Potential ISS-National Laboratory clients were able to operate Mochii on-vehicle from across the continent while in-mission, similar to planned utilization on ISS.
Technology considerations for spectroscopic electron microscopy in this novel extreme environment, for which conditions exceeded 2.5 atm and 90% relative humidity, included modifications of Mochii’s integrated metal coater observation window, and adjustment of automated vacuum processes to protect the spectrometer’s X-ray detector window from elevated pressure gradients.
Four crew members, (Drs. Ari, Pomponi, Watkins, and Cmdr. Cristoforetti) each conducted in-situ analyses on samples acquired from the marine environment on-board and during EVA, using model crew procedures under test for use on ISS. These analyses – of cnidaria skeleton, brine shrimp eggs, sediment, and marine sponge as well as pre-prepared samples – additionally model activities at the forefront of exploration on other worlds, for example for future crewed missions to the Moon and Mars. Over multiple visits by crew, plus simultaneous remote analyses by researchers at mission control and across the country, a picture of the diversity and chemistry of the local environment was ascertained. In the cnidarian skeleton, C, O, Na, Ca, and P compounds were identified, common to the reef environment where Ca-shelled organisms are abundant, while sediment consisted primarily of coral and reef crustacean shells and skeletons, plus silica. Marine sponges sampled during EVA had Ca shells and silicate spines. Sulfur and metals important to the ecosystem such as Ni, Fe, Mg, and Al were detected in trace amounts in organic structures. The marine samples imaged surprisingly well without need for the metal coating capability of Mochii, expediting results.
The Mochii team was fortunate to achieve all target mission objectives, ranging from end-to-end crew operations testing for ISS (including experience handling remote telemetry outages and planned loss of signal), to crew-driven in-situ exploration of the environment at the microscopic scale. NEEMO XXIII marks the first time electron microscopy and spectroscopy have been operated successfully in an underwater environment, opening up the benefits of SEM technology to exciting new areas such as ocean exploration, natural resources prospecting, and on-vehicle safety such as nuclear containment monitoring.