NASA SMAP

SMAP

Soil Moisture Active Passive( SMAP)

         Last Friday we had the opportunity to visit NASA and talk to people who were involved in the SMAP program. SMAP stands for soil moisture active passive. The purpose of SMAP is to measure the moisture of the first ten centimeter of the soil with their satellite. With this data, this is more accurate and precise as before, this measurement would be useful to much science discipline covering from hydrology to the carbon cycle. The National Research Council’s Committee on Earth Science and Applications from Space recommended SMAP as a highly necessary mission in order to gather data of the soil from outer space. Before SMAP, scientists and geologists had to physically go out to measure the soil moisture content.

The most interesting part about this mission to me was that it was possible to gather information and data in order to record CO2 increase in the Earth atmosphere. The freeze thaw state is when the forest and soil freeze and there is no exchange of carbon dioxide and oxygen. When the plants thaw, it releases a huge increase of carbon and no oxygen is made. It would be interesting to see how global warming exactly is affecting our earth.  Erika Podest allowed the Chapman University students to go outside and measure the soil with a simple soil probe. Within 50 ft, there were five different moisture level which shows how difficult it is to even gather accurate data.

       One of the way they gather accurate data is the satellite is installed with a radiometer with radio frequency.  It is an unique shape which is a circle shape. The instrument is designed to make  precise measure  if surface emission and backscatter, with the ability to detect the soil moisture. I think the greatest impact will be how we will able to see the pattern of frozen/thaw. It recorded the carbon measure within the atmosphere. By measuring the moisture of the air, we can also detect which area are more likely infested with diseases.

       The most interesting thing about the SMAP satellite is the Spin Platform Assembly. It is a large circle where it rotates to measure accurate information of soil as accurate at 5cm at depth.  When the satellite is set into the orbit, the SPA is responsible to be deployed and almost automatically start working.  There are two steps where the SPA would be released and deployed. First it would attempt to get the 6 meter mesh antenna which is connected to the spin disc. The reason for the deployment is to provide the most likeable environment for the hardware which conserving the energy of the satellite. Also this method allowed the machine to avoid the approach where the spinning movement doesn’t happen while it deployed. But the problem was when the satellite is in idle state, the satellite can easily drift. This drift can affect the machine where it potentially moved away from the sun, limiting communication and energy. It’s interesting how the SPA cause a new situation where the satellite is forced to adapt to it. 

The Deployment of the Spun Platform Assembly

                                          Spun Platform Assembly