NASA is now pitching in with the water crisis in California.
Researchers made their first flight over the high Sierra this weekend in a specially equipped plane.
It has equipment that measures how fast the snow is melting, and where it is melting the fastest.
NASA's Airborne Snow Observatory operates at 20,000 feet.
The instruments help measure the depth of the Sierra snowpack to amazing accuracy-- within four inches.
Equipment also measures the amount of sunlight hitting the snowpack and how quickly it will melt into runoff.
The snowpack makes up as much as 80-percent of the water that fuels our lives.
In the past, surveyors have hiked to the sierra and plunged a tube to take measurements of the snowpack.
But they only reached low and medium elevations.
Most of the snowpack is higher and out of reach.
NASA is literally taking this practice, to new heights.
The agency plans to share the data with the Department of Water Resources and local water districts.
Scientists plan to carry out the flights until the end of the snowmelt season.