The Cloud Aerosol Transport System (CATS) is a Light detection and ranging remote sensing instrument designed to measure the location, composition and distribution of pollution, dust, smoke, aerosols and other particulates in the atmosphere. CATS is to be installed on the Kibo module of the International Space Station and is expected to run for at least six months, and up to three years.
It was launched in January 2015 aboard the SpaceX CRS-5 resupply mission. CATS will use a laser operating at three wavelengths (1064, 532, and 355 nm) to determine cloud layer height, thickness, and depth. Some of the applications of the data gathered will be to develop and refine climate models as well as providing insight for future examinations of the atmospheres of Mars, Jupiter, and other extraterrestrial atmospheres.