The cooling experiment of camera modules for spectrograph is going on at Johns Hopkins University, the US. In order to observe faint stars and galaxies, astronomical detectors in visible and near infrared are used under very low temperature (-100 degree Celsius / -148 degree Fahrenheit or less than it) and high vacuum (less than one billion of atmospheric pressure). By this experiment we verify such a special environment is achieved stably.
After the experiment, the camera units are shipped to Marseille Observatory in France, where the spectrograph are building up.
related post: https://pfs.ipmu.jp/blog/2015/08/p17