Space CATS Surveys


By Rachel Simons

Photo courtesy of NASA.

As concern about climate change has increased over these past few decades, scientists have continuously used many methods to study the dynamics of the Earth’s weather patterns. Researchers examine an array of environments and other variables–from sea levels to greenhouse gases to ecosystems–to try and comprehend the ways in which human-induced and natural pollution affect the state of the climate.

Until recently, technological limitations made it difficult to gather accurate atmospheric data on these pollutants. However, scientists just began studying such conditions through a new technique: measuring them from outer space.

The Cloud-Aerosol Transport System (CATS) instrument is a device that measures aerosols, the tiny particles in the atmosphere made up of dust, smoke, and pollution. The technology also surveys volcanic ash and the changes of clouds. CATS measures the data using a low energy, high repetition laser that pulses 5,000 times per second.

A small team at Goddard Space Flight Center in Greenbelt, Maryland, built and designed CATS using funds from NASA. The device was launched into on a SpaceX Dragon spacecraft in January. From space, CATS connects to the outer area of the International Space Station and is meant to collect climate information for the next six months to three years.

“CATS works like a radar, sending out a signal and timing how long it takes to bounce off particles, but uses low-energy pulses of visible and near-visible laser light,” John E. Yorks, CATS science lead at the Goddard Space Flight Center, tells BTR.

Yorks continues that the laser generates three wavelengths of light by using special optical crystals.

“The final output beam is made up of all three wavelengths and these photons are transmitted in groups, towards the atmosphere, at the speed of light,” Yorks says. “As photons encounter clouds or particles, scattering of the laser beam occurs. By timing the difference between emission and detection, the precise altitude of the particles can be determined.”

Photo courtesy of Space Exploration Technologies.

With the CATS device, scientists will be able to make significant breakthroughs in both climate studies and technological testing for Earth Science instruments–tools that could potentially be utilized in future planet observing missions.

According to Yorks, one of the biggest hurdles in predicting climate change is collecting precise representation data on clouds because they are the key regulator of Earth’s average temperature. If humans can track the changes in the clouds, the information will lead to increased accuracy of climate models for scientists to work with, plus a better understanding of how weather will change in years to come.

Besides improved observance of the clouds, CATS will break down the makeup of which components pollute our air. Because the world’s industry relies heavily on the rapid burning of fossil fuels and other toxic chemicals, human created air pollutants such as smog are a significant concern. In addition, natural pollutants contaminate the air, including dust from desert storms, smoke from forest fires, and ash from volcanic eruptions. In February, Yorks and other scientists used the data from CATS to monitor dust storms from the Sahara Desert in Africa.

If scientists can differentiate these aerosol layers from one another and figure out how responsible humans are for causing them, they can then educate the public more accurately on how much humans’ carbon footprints actually affect the planet. This in turn will help governments and other organizations differentiate which environmental policies are impactful from the ones that are ineffective.

Along with developing scientists’ knowledge of long-term climate change, the CATS instrument can also provide information to the public regarding natural disasters like hurricanes, tornados, or even volcanic eruptions.

“CATS can determine the top and bottom altitude of volcanic plumes, which airlines can then use to make better decisions on flight routings or cancellations,” says Yorks. “The volcanic eruption in Iceland in 2010 grounded 95,000 flights and cost the airline industry $1.7 billion because they could not risk sending aircraft into the plume for fear of damaging the engines.”

While natural occurrences are largely unavoidable, taking advantage of CATS’ monitoring capabilities could minimize the damage of a crisis.

The CATS instrument will stay on the International Space Station and be observed by the team of scientists at Goddard in Maryland until it needs to be brought back for repairs. NASA says that they are currently developing other Earth Science technologies and hope to add these devices onto CATS in the future.