Shoe-box Sized Tiny Satellites May Soon Help Track Global Storms

A satellite, no bigger than a shoebox, may soon help predict and forecast the most accurate weather details. Small enough to fit inside a backpack, the aptly named RainCube (Radar in a CubeSat) uses experimental technology to see storms by detecting rain and snow with very small instruments. The people behind the miniature mission celebrated after it sent back its first images of a storm over Mexico in a technology demonstration in August. Its second wave of images in September caught the first rainfall of Hurricane Florence.

The small satellite is a prototype for a possible fleet of RainCubes that could one day help monitor severe storms, lead to improving the accuracy of weather forecasts and track climate change over time. According to Graeme Stephens, Director of the Center of Climate Sciences at NASA's Jet Propulsion Laboratory in Pasadena, California, the world currently doesn't have any way of measuring how water and air move in thunderstorms globally.

RainCube is a type of "tech demo," an experiment to see if shrinking the weather radar into a low-cost, miniature satellite could still provide a real-time look inside storms. It sees objects by using a radar, much like a bat uses sonar. The satellite’s umbrella-like antenna sends out chirps, or specialized radar signals, that bounce off raindrops, bringing back a picture of what the inside of the storm looks like. Engineers like Principal Investigator Eva Peral had to figure out a way to help a small spacecraft send a signal strong enough to peer into a storm. The radar signal penetrates the storm, and then the radar receives back an echo, according to Peral. As the radar signal goes deeper into the layers of the storm and measures the rain at those layers, they get a snapshot of the activity inside the storm.

Because RainCube is miniaturized, making it less expensive to launch, many more of the satellites could be sent into orbit. Flying together like geese, they could track storms, relaying updated information on them every few minutes. Eventually, they could yield data to help evaluate and improve weather models that predict the movement of rain, snow, sleet and hail.

What RainCube offers on the one hand is a demonstration of measurements that are currently in space today. But what it really demonstrates is the potential for an entirely new and different way of observing Earth with many small radars. That will open up a whole new vista in viewing the hydrological cycle of Earth. RainCube is a technology-demonstration mission to enable Ka-band precipitation radar technologies on a low-cost, quick-turnaround platform. It is sponsored by NASA's Earth Science Technology Office through the InVEST-15 program. NASA’s JPL is working with Tyvak Nanosatellite Systems, Inc. in Irvine, California, to fly the RainCube mission.