MADRID, 18 (EUROPA PRESS)
The NISAR Earth observation satellite has successfully deployed its 12-meter-wide antenna reflector, the largest NASA has ever deployed in space.
Seventeen days after the launch of NASA and the Indian Space Research Organization (ISRO)'s NISAR (NASA-ISRO Synthetic Aperture Radar) from southeastern India, the essential piece of the mission has been deployed into orbit.
The reflector remained retracted, like an umbrella, until the 9-meter arm that supports it could be unfolded and secured in place.
NISAR will track the movement of ice sheets and glaciers, ground deformation caused by earthquakes, volcanoes, and landslides, and changes in forest and wetland ecosystems with centimeter accuracy. It will also assist decision-makers in fields as diverse as disaster response, infrastructure monitoring, and agriculture.
The mission incorporates the most sophisticated radar systems ever launched as part of a NASA mission. For the first time, the satellite combines two synthetic aperture radar (SAR) systems: an L-band system that can see through clouds and forest canopy, and an S-band system that can also see through clouds but is more sensitive to light vegetation and snow moisture. The reflector plays a critical role in both systems, which is why the successful deployment of the hardware is such a significant milestone, NASA reported in a statement.
THIS IS HOW THE REFLECTOR WORKS
Weighing approximately 64 kilograms, the reflector features a cylindrical frame composed of 123 composite struts and a gold-plated wire mesh. On August 9, the satellite's mast, which had been positioned near its main body, began to unfold, joint by joint, until it was fully extended about four days later. The reflector assembly is mounted at the end of the mast.
On August 15, small explosive bolts holding the reflector assembly together were fired, allowing the antenna to begin a process called "blooming": its unfolding by the release of the stored tension in its flexible frame while folded like an umbrella. The subsequent activation of motors and cables brought the antenna to its final, locked position.
To obtain images of the Earth's surface with pixels about 10 meters wide, the reflector was designed with a diameter similar to that of a school bus. Using SAR processing, the NISAR reflector simulates a traditional radar antenna, which, for the mission's L-band instrument, would have to be 19 kilometers long to achieve the same resolution.
