An environmental sensor attached to the the international space station’s Kibo Japanese Experiment Module to monitor global distributions of trace gases in the Earth’s stratosphere stopped transmitting April 21, the Japan Aerospace Exploration Agency said April 23. The Japanese sensor, the Superconducting Submillimeter-Wave Limb-Emission Sounder, or SMILES, was put into service last November to help scientists understand ozone depletion and global climate change.