NASA’s drought monitoring mission probably won't help solve California’s drought

During a press conference on Thursdays, members of NASA’s Soil Moisture Active-Passive (SMAP) mission talked about what the satellite will tell us after it’s launched into space on January 29. Though less flashy than other recent space-bound missions — SMAP won’t land on a comet or bring us any closer to Mars — the satellite will have significance here on Earth, by providing a more accurate than ever measurement of moisture in global soil.

The satellite is set to be in orbit for three years, and will be able to observe the globe’s land surface every two to three days, according to NASA. And, to make sure the read is as good as possible, scientists built a lasso into SMAP:

SMAP engineers at NASA’s Jet Propulsion Laboratory in Pasadena, California, designed and built the largest rotating antenna that could be stowed into a space of only one foot by four feet for launch… “We call it the spinning lasso,” said Wendy Edelstein of NASA’s Jet Propulsion Laboratory, Pasadena, California, the SMAP instrument manager. Like the cowboy’s lariat, the antenna is attached on one side to an arm with a crook in its elbow. It spins around the arm at about 14 revolutions per minute (one complete rotation every four seconds).

SMAP is also equipped with an “active” instrument, a radar which sends out microwaves to Earth, and a “passive” one which collects naturally emitted microwave signals from Earth. From space, the technology will help paint a more comprehensive picture of the moisture in our land.

During the press conference, Twitter users asked NASA about SMAP using the hashtag #askNASA. Some of the questions weren’t totally relevant.

https://twitter.com/GeorgeDickles/status/553266381500977154

https://twitter.com/technicolorstar/status/553267550386409473

https://twitter.com/Bakiklma/status/553275900423602177

Perhaps in anticipation of the underwhelming response, NASA’s SMAP website offers a list of why the mission matters here on Earth: among other things, SMAP will help monitor drought and provide “critical information for drought early warning.” In response to a question on how SMAP data will affect California, which is still suffering from one of the most severe droughts in its history, SMAP science team lead Dara Entekhabi said that the data will help produce a high resolution map of the drought, and examine the larger processes that contribute to it.

So will SMAP help California figure out how to get out of the drought? Not really, said SMAP team member Narendra Das in a phone interview with Fusion.

Das explains that California, which NASA recently found needs 11 trillion gallons of water to replenish its supply, doesn’t rely on local H2O, rendering local soil moisture reads largely irrelevant. “California is a managed watershed…. most of the water is imported from outside.” Rather, the areas that will be affected by soil moisture, and will benefit from SMAP’s data, are in the grasslands of the midwest.

Because of this, SMAP data will be especially important for dairy and other farmers, who can use the information to figure out when to expect drought, went to plant and the types of crops that will respond best to predicted conditions. “SMAP data will let the farmer know when is the best day to plant, when to apply fertilizers… those things can be done in a very efficient and effective way.” He adds, “If you know the soil moisture very well, you can model the crop yield.” The data will offer projections up to three months in advance. The (crop) insurance industry will also benefit from more accurate predictions.

There is some benefit for non-farmers, as well. “It’s going to influence the local weather or the regional weather,” says Das, adding that some are already using satellite information to improve forecasts. “We have early adopters who are going to use SMAP data [like NOAA]… If they use soil moisture information, they can improve the accuracy of the forecast.” So Californian’s may be out of luck, drought-wise, but at least the rest of us will know when to pack an umbrella.