Soil Moisture Active Passive (SMAP): From a Roadside View to a Global View

January 30th, 2015 by Kate Ramsayer
Credit: NASA/Kathryn Hansen

Credit: NASA/Kathryn Hansen

California road trips cry out for a game I like to call “Guess What’s Growing by the Side of the Road.” The rules are simple – glance at the green leaves sprouting from the ground and guess whether they’re carrots or kale – and you can discover fascinating facts (artichokes are thistles!). This week, I’ve introduced a colleague to the game as we drove back and forth between our hotel and Vandenberg Air Force Base in California, past vineyards and rows of green plants in dark soil.

We’re here for the launch of the Soil Moisture Active Passive satellite, NASA’s latest mission to look back at our home planet. SMAP is designed to measure water content with unprecedented accuracy – and after talking with scientists and listening to briefings all week, I can’t think about the mystery roadside crops without wondering about water.

Soil’s water content is a key element in Earth’s ecosystem, scientists involved with the mission said this week. While agricultural fields now produce substantially more crops per acre than they did 50 years ago, agriculture is still very vulnerable to ’shocks’ like droughts, said Wade Crow, a research physical scientist with the USDA and SMAP science team member. An agricultural drought was one of the triggers for the 2008 food crisis when global food prices shot up, causing humanitarian crises, he said.

And measurements of soil moisture – the kind of information SMAP will gather – are the most direct and earliest indicator of agricultural drought.

“If you detect that directly, you are in a position to mitigate the effects. With better monitoring you can better respond so you can have less humanitarian and economic impact,” Crow said.

Soil moisture measurements will also be plugged into the weather models that help meteorologists forecast the rain that falls on those crops and other surfaces. Soil has an ’inherent memory’ when it comes to moisture, said Randy Koster, SMAP science team member and hydrologist at NASA’s Goddard Space Flight Center.

If it’s rainy in mid-June and the soil is wetter than usual, for example, it will probably also be wetter than usual in July, he said. That could impact how much water evaporates into the atmosphere to fall back as rainfall, as well as air temperature. Rainfall on wet soil is also more likely to run off, compared to rainfall that’s soaked up by parched soil, leading to better stream flow predictions.

“SMAP’s going to be providing unprecedented amounts of data on soil moisture, and utilized in these kinds of ways, we have the potential for better forecasts,” Koster said.

Soil Moisture Active Passive (SMAP): Aw, SMAP!

January 30th, 2015 by Kathryn Hansen

For the time being, NASA’s Soil Moisture Active Passive (SMAP) satellite is waiting to rocket into orbit.

Credit: NASA/Kate Ramsayer

Credit: NASA/Kate Ramsayer

Media packed up their cameras after the first scheduled launch from Vandenberg Air Force Base in California was scrubbed on January 29, 2015 (above) due to upper level winds. The second targeted launch window on January 30 was delayed to January 31, “pending completion of minor repairs to the United Launch Alliance Delta II launch vehicle,” according to a NASA press statement.

Credit: NASA/Bill Ingalls

Credit: NASA/Bill Ingalls

Soil Moisture Active Passive (SMAP): The Reveal

January 29th, 2015 by Kathryn Hansen



The Soil Moisture Active Passive (SMAP) mission is one step closer to launch. On January 28, the mobile service tower (top) rolled back to reveal the Delta II rocket (second image). Liftoff of the Delta II rocket and its satellite cargo is targeted for launch from Vandenberg’s Space Launch Complex 2 at 6:20 a.m. PST on Thursday, January 29.


NASA administrator Charles Bolden attended the rollback event, where he spoke to a group gathered to watch the reveal. “What will SMAP measure?” asked a second-grade student (above).


Bolden was not the only one answering that question on the day before launch. SMAP scientists Dara Entekhabi, Randy Koster, Wade Crow, and Susan Moran (above, from left to right) started the day explaining the mission’s science to a gathering of social media mavens. So, what will SMAP measure? Visit the mission page to find out.

Soil Moisture Active Passive (SMAP): SMAP Set to Investigate Earth

January 28th, 2015 by Kate Ramsayer


SMAP is ready to go!

The Soil Moisture Active Passive (SMAP) mission, which will map the water content of soils worldwide, passed its “launch readiness review” on January 27. There is also a favorable weather forecast for a launch on January 29. So the SMAP team is ready.

“It has reached the point where it’s an amazing energy rush right now,” said Christine Bonniksen, SMAP program executive. “It’s kind of like when you’re listening to Beethoven’s 6th symphony, when you’re getting to the big crescendo, and everybody can feel it coming. It’s amazing to watch all these folks buckle down.”

Bonniksen spoke at a press briefing marking two days before the scheduled launch. She highlighted the role of SMAP among other missions studying our planet: Once it’s in orbit and operational, SMAP will join 19 other NASA satellites and sensors with an eye on Earth. The start of the SMAP mission also will complete a series of five Earth science launches in the past year.

“We’re really looking forward to the synergism from all these instruments,” she said.

Soil moisture factors into three major cycles of Earth’s environment — water, energy, and carbon — said Dara Entekhabi, SMAP science team lead. The three cycles work together like gears in a clock, linked together by soil moisture and the freezing and thawing of the ground. With SMAP, scientists will improve models of climate and weather forecasting, and better understand the workings of the planet.

“SMAP will peer into the metabolism of Earth’s environment,” Entekhabi said.

Operation IceBridge: Antarctic 2014: From Gamma Rays to Glaciers

December 2nd, 2014 by Craig Swenson

Hi, my name is Craig Swenson. I’m one of the newest members of the NASA Operation IceBridge operation, having joined the Airborne Topographical Mapper (ATM) team days before being deployed to Punta Arenas, Chile to join the rest of the IceBridge team.

sonntag and swenson

Airborne Topographic Mapper team members John Sonntag (left) and Craig Swenson aboard NASA’s DC-8 airborne laboratory. Credit: NASA / Jim Yungel

I have been actively involved with other NASA projects for several years, but am new to the world of cryospheric science and lidar instruments. For the past six years I was a member of the NASA Swift Science Operations Team and Ultraviolet/Optical Telescope Team while earning my Ph.D. in Astronomy and Astrophysics at the Pennsylvania State University. Working with a NASA satellite program was an exciting adventure, with each day bringing new discoveries to investigate and new problems to solve. My area of expertise involved searching for and studying flares (sudden increases in the observed brightness) found in the X-ray, ultraviolet and optical signals of a class of astrophysical objects known as gamma ray bursts. As a part of the IceBridge team I will be using the skills I developed while looking to the heavens to help determine the thickness of the ice below me.

aboard the dc-8

A view inside the NASA DC-8. Credit: NASA / Jim Yungel

Working on an airborne observatory can be very different from working on a satellite mission. For instance, I did not need to bring my passport with me to work every day (just in case we land in a different country), and if an instrument malfunctions while in flight, we have the chance to get replacement parts and fix it. But in many ways it is very much the same, with new and challenging problems that need to be addressed every day, constantly looking for ways to improve our methods and obtain the most accurate measurements possible. It is an exciting way to live and work.

Looking out the window of the NASA DC-8 aircraft, I have witnessed sights that were previously only available to me through nature specials on television. The vastness of the Antarctic Peninsula is something that I had not fully appreciated until now. There is a certain beauty to be found in the stark emptiness I see out of my window each day, and it is amazing to hear from my co-workers how much the ice has changed and receded in the few years they have been collecting data here.

Shackleton Range

Mountains of Antarctica’s Shackleton Range. Credit: NASA

I feel privileged to have the opportunity to work on such an important project. Operation IceBridge is instrumental in collecting data and providing answers that are pertinent to our everyday lives and to our future. Understanding the continually changing nature of our planet, and what influence we as humans are playing in the change, is something that affects every man, woman and child on earth and it brings me a sense of accomplishment and wonder to be part of a NASA mission that is addressing such pressing issues.

Notes from the Field