SMAP

Soil Moisture Active Passive (SMAP) is a mission that was initiated by NASA in February 2008, due to launch in November 2014.  It is an environmental research satellite that was developed in order to measure surface soil moisture and freeze-thaw state in order to provide for scientific advances and benefits regarding the water cycle.  This mission will globally enhance weather forecasts as well as climate changes/predictions, especially flood conditions and drought monitoring.  Although the amount of water on Earth remain the same, the SMAP mission will highlight water availability around the world.  In addition to the amount of useful information the satellite will present, it will also produce these measurements at a rather rapid pace: SMAP will provide global coverage within 3 days.  However, the research satellite will remain in orbit around the earth for a period of three years in order to acquire the most accurate environmental measurements.

I find this mission to be of great importance because it’s measuring one of the worlds most important and useful natural resources: soil.  Soil allows plants to grow and provides vegetation for all animals and human beings.  In addition, soil allows for trees to grow which provide us with oxygen to breathe.  Also, without trees, we wouldn’t have wood, which in turn would mean we would no longer be able to use wood as a resource for building necessary structures such as homes and buildings.  In addition, soil allows for storage of water that falls from the sky in the form of rain, which the plants then use in order to grow.  Also, the evaporation of soil helps cool down the earths surface as well as cool the lower atmosphere and provide water in order to form clouds.  SMAP will be able to measure the amount of water that is present in the soil (or soil moisture) all over the entire world.  Growing crops is necessary to sustain life on Earth, so through the use of SMAP, scientists will be able to measure the amount of soil moisture that is available to us in order to predict sustainability (whether the soil is frozen or thawed) as well as foresee and monitor future droughts and/or floods. The total amount of water on Earth isn’t necessarily changing, but the availability of soil moisture in certain regions may be changing, and SMAP will allow us to monitor that.  By studying soil moisture, SMAP will be able to present us with measurements that will benefit mankind and make Earth a better place to live.

SMAP will apply two microwave instruments that share a single antenna. The first instrument that they will be flying is a microwave radiometer and the second is a microwave radar.  The radar is restricted to functioning at the L-band frequency, which unfortunately can cause a lot of interference because of the large amount of cellphones present on Earth.  However, they can’t use a higher frequency because it can potentially harm the environment through such strong rays.  Nevertheless, the radar is still successful in transmitting a signal down to Earth to be received back in space, signaling a swath of 1,000 kilometers in diameter at a single time. SMAP’s ability to scan such a large circular swath is what allows us to measure the entire Earths surface in just 3 days.