NISAR Satellite Deploys Antenna and Begins Science Operations

The NASA–ISRO Synthetic Aperture Radar (NISAR) mission has achieved a major milestone with the successful deployment of its 12-metre antenna reflector, marking the formal commencement of its science phase. Launched aboard GSLV-F16 in July 2025, the satellite is now delivering high-resolution radar data crucial for Earth observation.

Successful Antenna Deployment in Orbit

The antenna, developed by NASA and launched in a stowed configuration on a nine-metre boom, underwent a multi-stage unfolding sequence. Joint deployments began on 9 August 2025 and continued over five days covering wrist, shoulder, elbow and root mechanisms. The reflector assembly was fully deployed by 15 August, with all systems performing satisfactorily.

First S-Band SAR Images Released

NISAR’s S-Band SAR captured its first image on 19 August 2025, showcasing the fertile Godavari River Delta. Distinct vegetation types, including mangroves, agricultural fields and aquaculture zones, were mapped with clarity. The image demonstrated the satellite’s capacity to analyse deltas, croplands and landscape patterns with high precision.

Calibration for High-Quality Data

Calibration activities included reference targets placed near Ahmedabad and other locations. Additional datasets from the Amazon rainforests were used to refine spacecraft pointing and fine-tune acquisition parameters. These steps enhanced the quality of both S-Band and L-Band datasets, enabling reliable scientific analysis across India and global validation sites.

Exam Oriented Facts

• NISAR carries dual-frequency SAR payloads: ISRO’s S-Band and NASA’s L-Band.
• The antenna reflector measures 12 metres in diameter.
• The mission was launched on GSLV-F16 in July 2025.
• First S-Band SAR image captured the Godavari Delta on 19 August 2025.

Applications Across Earth Science Domains

Initial analysis highlights the potential of NISAR data for agriculture, forestry, hydrology, geosciences, polar studies and oceanographic research. Regular imaging of the Indian landmass and global calibration sites positions the mission to support climate monitoring, disaster management and resource assessment through consistent, high-resolution radar observations.