NISAR, first joint satellite of NASA and ISRO, scheduled to be launched on July 30, Pg12

Key Highlights:

• Launch Date & Time: July 30, 2025, at 5:40 PM IST.
• Launch Site: Satish Dhawan Space Centre, Sriharikota.
• Launch Vehicle: GSLV-F16.
• Orbit: 743 km sun-synchronous orbit with 98.4° inclination.
• Technology: First satellite to use dual-frequency Synthetic Aperture Radar (SAR) — L-band (NASA) and S-band (ISRO).
• Antenna: NASA’s 12m unfurlable mesh reflector.
• Data Frequency: Revisits every 12 days, providing all-weather, day and night coverage.

Detailed Insights:

• NISAR stands for NASA-ISRO Synthetic Aperture Radar, symbolizing collaboration in Earth science and space-based observations.
• The dual-frequency SAR allows high-resolution imaging for monitoring land and ice movements, infrastructure changes, and vegetation dynamics.
• It will be used for ground deformation monitoring, ice sheet tracking, soil moisture changes, storm characterization, and surface water mapping.
• NISAR will aid in disaster response by providing near real-time data during floods, landslides, and cyclones.
• The satellite features SweepSAR, a cutting-edge radar technology enabling large-area, high-resolution coverage.
• NISAR builds on over a decade of cooperation between ISRO and NASA’s Jet Propulsion Laboratory (JPL).
• The mission represents a strategic technological and diplomatic milestone in India–US relations in space exploration.
• The satellite bus is based on ISRO’s modified I3K platform, ensuring indigenous integration and support.

Scientific/Technical Concepts Involved:

• Synthetic Aperture Radar (SAR): A radar technique to produce high-resolution images by simulating a large antenna using motion.
• L-band and S-band: Frequency bands used for remote sensing; L-band penetrates deeper into vegetation/soil, while S-band is better for surface-level observation.
• SweepSAR: Advanced SAR technique that enables wide-swath coverage with consistent resolution.
• Sun-synchronous Orbit: Polar orbit that enables satellite to pass over the same part of Earth at the same local solar time, useful for consistent lighting in imaging.