SMAP: NASA’s first satellite to collect global soil moisture

SMAP: Soil Moisture Active Passive

Soil Moisture Active Passive (SMAP) was in news in fourth week of January 2015. It is NASA’s first Earth satellite designed to collect global observations of the vital soil moisture.
The satellite was launched aboard United Launch Alliance Delta II rocket from Vandenberg Air Force Base, California.

The satellite is built to measure moisture in the top 2 inches (5 centimeters) of soil. It can measure the moisture content of the soil from its spot in orbit about 426 miles (685 kilometers) above Earth's surface.

SMAP is equipped with a 20 feet (6 meters) mesh antenna which is the largest of its kind that NASA has ever flown in space can complete an orbit of the earth once in every 98.5 minutes. Its antenna is designed to spin at about 14.6 revolutions per minute while mounted to the end of a long arm on the satellite's body.