The GAs Extraction and Analyses system (GAEA) for immediate extraction and measurements of volatiles in the Hayabusa2 sample container

Hayabusa2 returned surface samples from the C-type near-Earth asteroid (162173) Ryugu to Woomera, South Australia, in December 2020. The samples returned from Ryugu are expected to contain not only volatile components reflecting its primitive nature, but also solar wind components due to exposure to space. Such volatiles may partly be released inside the sealed sample container enclosing Ryugu samples due to particle destruction or container heating in a contingency case. In order to collect and analyze volatiles released in the container prior to the container-opening, we set up a gas extraction and analyses system (GAEA: GAs Extraction and Analyses system). The system requires ultra-high vacuum conditions, small vacuum line volume to minimize dead volume and simple configuration as well as having an interface to connect the container. The system includes gas bottles for passive collection of volatiles at room temperature and bottles for active collection at liquid nitrogen temperature. A quadrupole mass spectrometer is installed to analyze gases in the vacuum line, and a non-evaporative getter pump is also used when noble gases are analyzed. The rehearsal operation of the GAEA was made at ISAS/JAXA as well as transportation tests in Japan. In November 2020, it was transported safely to the Quick Look Facility (QLF) in Woomera. It was set up at the QLF and worked as planned for collection and analysis of gas components from the returned sample container. Here we report the concept, design and calibration results for the GAEA and an outline of analytical protocols applied in Woomera. Graphical Abstract