Artist's rendering of the SMAP instrument. Image via NASA
NASA’s latest advanced weather satellite, the Soil Moisture Active Passive (SMAP) instrument, is due for launch on 29 January, giving climate scientists and farmers advanced predictions for drought like never before.
With Earth’s weather fluctuating massively in recent years, there has never been a more important time for climate scientists and those in agriculture to be able to measure moisture levels in the planet’s soil.
Compared with most satellites, the SMAP will certainly stand out from other satellites orbiting the Earth because of its rotating antenna which to the un-trained eye resembles a lasso that rotates at 14 revolutions per minute.
As the largest rotating antenna ever sent into space, the SMAP satellite will be able to measure the planet’s entire land surface area for moisture at most every three days.
Unprecedented accuracy
According to NASA, the SMAP’s radar will detect the levels of water within land by transmitting microwave frequencies back to Earth that will penetrate a few inches through the surface and when the signal returns to the satellite, its on-board systems will be able to detect minute differences in the soil’s moisture.
Its radar is one of the most powerful available today as when its signals return to the SMAP, it will be able to produce ultra-sharp images with a resolution of about 1-3km.
Speaking of the process of getting the ‘lasso’ antenna into space, Wendy Edelstein of NASA’s Jet Propulsion Laboratory said it was by no-means an easy task.
“The antenna caused us a lot of angst, no doubt about it. Making sure we don’t have snags, that the mesh doesn’t hang up on the supports and tear when it’s deploying – all of that requires very careful engineering,” Edelstein said. “We test, and we test, and we test some more. We have a very stable and robust system now.”
