Soil Moisture Active Passive
| SMAP | |
|---|---|
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|
|
| Type: | Earth observation satellite |
| Country: |
 United States
|
| Operator: | NASA |
| COSPAR-ID : | 2015-003A |
| Mission dates | |
| Dimensions: | 944 kg |
| Size: | 9.7 × 7.1 × 6.8 m |
| Begin: | January 31, 2015 at 2:22 PM UTC |
| Starting place: | Vandenberg SLC-2W |
| Launcher: | Delta II 7320-10C |
| Flight duration: | 3 years |
| Status: | active |
| Orbit data | |
| Orbit inclination : | 98 ° |
| Apogee height : | 685 km |
| Perigee height : | 660 km |
SMAP (Soil Moisture Active Passive) is an Earth observation satellite of NASA .
It was placed in sun-synchronous orbit on January 31, 2015 at 14:22 UTC with a Delta II 7320-10C launcher from the Vandenberg rocket launch site. As part of the scientific cooperation program ELaNa (Educational Launch of Nanosatellite), four nanosatellites were also launched into space as a secondary payload ( ExoCube from California Polytechnic State University, GRIFEX from the University of Michigan in cooperation with the Jet Propulsion Laboratory and FIREBIRD-II (A and B) from Montana State University and the University of New Hampshire).
The three-axis stabilized satellite is equipped with a radar with synthetic aperture and a radiometer that collects data on the moisture distribution in the top 5 cm layer of the ground. Based on this information, more precise weather models should be developed and the consequences of climate change for the supply of water on earth should be better assessed. The data should also be used for disaster control. The radar works on a frequency of 1.26 GHz and achieves a resolution of 1–3 km, the radiometer works on a frequency of 1.41 GHz and achieves a resolution of 30 km, with both instruments using the same 6 m antenna. The antenna rotates at around 15 revolutions per minute, which means that the recording area, which is 30 to 50 km in size, covers an area of 1000 km. As a result, the earth's surface is completely mapped every two days near the pole and every three days near the equator. The energy supply of the satellite is provided by solar cells that deliver around 1500 watts. The planned lifespan is three years.
On September 2, 2015, NASA announced that the radar unit had failed on July 7, 2015. This means that only the radiometer can be used.
Web links
- NASA: operator website
Individual evidence
- ↑ a b raumfahrer.net: SMAP successfully launched on Delta II , accessed on February 8, 2015
- ↑ n2yo.com: SMAP Satellite details 2015-003A NORAD 40376 , accessed February 8, 2015
- ↑ DW: How much water is there on earth? , accessed February 8, 2015
- ↑ NASA: SMAP: Specifications , accessed February 8, 2015
- ↑ SMAP: No more restart for the radar