The ambitious NISAR (NASA ISRO Synthetic Aperture Radar) mission, a big collaboration between Nasa and the Indian Space Research Organisation (Isro), has encountered a slight delay, with the launch readiness date now set to be determined by the end of April.
This Earth-observing satellite, poised for launch from the Satish Dhawan Space Centre on India’s southeastern coast, is in the final stages of preparation.
A critical component of the mission's final preparation involves putting a special coating to the satellite’s 39-foot-diameter (12-meter) radar antenna reflector. This hardware piece, a significant contribution from NASA, requires the coating as a precautionary measure against likely temperature increases that could impact its deployment in space.
Recent tests conducted by Isro have revealed that the reflector might face higher-than-expected temperatures when stowed during flight, prompting this additional step.
The Nisar mission aims to revolutionise our understanding of Earth’s surface changes by using microwave signals to scan nearly all land and ice surfaces globally every 12 days. This frequent, high-resolution monitoring is expected to provide invaluable data on ice sheet movements, forest growth, and natural hazards such as earthquakes and volcanic eruptions.
The special coating, designed to reflect solar radiation and thus limit temperature increases, is currently being applied at a specialised facility in California. This process involves shipping the reflector from Isro's assembly site in India, highlighting the international cooperation at the heart of this mission.
Once the coating's thermal performance is verified, the reflector will return to India for integration onto the satellite, marking one of the final steps before launch.
Nisar is the first hardware collaboration between Nasa and Isro on an Earth-observing mission. By combining L-band and S-band synthetic aperture radars, Nisar will offer unprecedented measurements of Earth’s dynamic surfaces.
This includes tracking changes in glaciers, monitoring wetlands and forests, and observing land around key geological features.
