CATS: Cloud-Aerosol Transport System Earth remote sensing instrument

Roughly the size of a refrigerator, CATS will use the same two laser wavelengths on NASA’s CALIPSO mission, 1064 and 532 nanometers, and it will incorporate a third laser wavelength--355 nanometers. 

This will provide more detailed information about the particles in Earth's atmosphere. 

Credit: NASA

While felines in space may be what you're thinking, the Cloud-Aerosol Transport System (CATS) is a much more helpful accompaniment planned for the International Space Station.

CATS will study the distribution of aerosols, the tiny particles that make up haze, dust, air pollutants, and smoke.

When Iceland's Eyjafjallajökull volcano erupted nearly four years ago, for example, officials grounded flights in Europe because particles contained within its massive plume could damage aircraft engines, resulting in potentially deadly consequences for passengers.

NASA couldn't dispatch aircraft-borne instruments for the very same reasons European officials had grounded commercial aircraft.

When the next volcano erupts, NASA will have a new tool in orbit that can monitor the spread of particles in Earth's atmosphere from its space-based perch.

This Earth remote sensing instrument is scheduled to launch to the space station in September 2014 as a demonstration project.

Its sensors will help researchers determine for the first time what state-of-the-art, three-wavelength laser technology can do from space to measure tiny airborne particles—also known as aerosols—in Earth's atmosphere.

Matt McGill

Developed by NASA's Goddard Space Flight Center scientist Matt McGill, and his team, CATS will be able to see the character as well as vertical and horizontal distribution of aerosols in a whole new light.

When CATS begins operations from its docking port on the Japanese Experiment Module-Exposed Facility (JEM-EF), the refrigerator-sized sensor will continue measuring atmospheric aerosols using the same two-laser wavelengths as NASA's Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) mission—the 1064 and 532 nanometer wavelengths.

The demonstration flight also is technologically important, using the space station as a test bed. The third laser is in the ultraviolet wavelength, just outside the visible range.

Though it adds an advanced capability, particularly when coupled with the new detectors, scientists believe it is susceptible to contamination.

"If you get contamination on any of your outgoing optics, they can self-destruct, and then your system's dead," McGill said. "You end up with very limited instrument lifetime."

Combating this risk to instruments is part of the CATS mission, showing how the equipment will fare in the space environment over time.

"[The space station] is a good, relatively low-cost, quick way to do that," said McGill. "In our current budget-constrained environment, we need to use what we already have, such as the [station], to do more with less."

If the CATS instrument succeeds and operates well in space, it can be scaled up to be a stand-alone satellite payload or 'free-flier' mission.

"One of the most exciting things for me has been the opportunity to develop a small, low-cost, quick-turnaround payload for the [space station], a pathfinder project representing what's possible for future technology investigations," said McGill.

"We did this using a small team, a streamlined process, and a build-to-cost mentality – and we proved it can be done."