The Cloud-Aerosol Transport System (CATS), is a lidar remote sensing instrument that will provide range-resolved profile measurements of atmospheric aerosols and clouds from the International Space Station (ISS).

CATS will provide vertical profiles at three wavelengths, orbiting between ~230 and ~270 miles above the Earth's surface at a 51-degree inclination with nearly a three-day repeat cycle.  For the first time, it will allow scientist to study diurnal (day-to-night) changes in cloud and aerosol effects from space by observing the same spot on Earth at different times each day.

CATS, a spaceborne lidar instrument that fired more laser pulses than any previous orbiting instrument has ended its operations on the International Space Station (ISS), after a successful 33-month mission to measure clouds and tiny atmospheric particles that play key roles in Earth's climate and weather. Launched on Jan. 10, 2015, CATS was designed to operate at least six months, but lasted five times its life expectancy. On Oct. 30, 2017, the onboard power and data system stopped working and could not be resuscitated. Read about CATS Operation Status and the "NASA's CATS Concludes Successful Mission on Space Station" article.