NASA-ISRO NISAR Satellite to Launch on July 30

The NASA-ISRO Synthetic Aperture Radar (NISAR) satellite, the first joint Earth observation mission by the Indian Space Research Organisation (ISRO) and the National Aeronautics and Space Administration (NASA), is scheduled for launch on July 30, 2025, at 5:40 p.m. IST from the Satish Dhawan Space Centre (SDSC SHAR) in Sriharikota, Andhra Pradesh.

The satellite will be carried aboard the Geosynchronous Satellite Launch Vehicle (GSLV-F16), which will place it into a Sun-synchronous orbit (SSO) at an altitude of 743 km with an inclination of 98.40°.

“A Sun-synchronous orbit is a type of polar orbit that allows a satellite to pass over the same part of the Earth at roughly the same local solar time, enabling consistent lighting conditions for observations”.

NISAR, weighing 2,392 kg, is a unique and powerful Earth observation satellite that will become the first satellite ever to observe the Earth using dual-frequency Synthetic Aperture Radar (SAR) systems—NASA’s L-band and ISRO’s S-band.

• Synthetic Aperture Radar is a form of radar that is used to create high-resolution images of the Earth’s surface.

• The L-band radar (lower frequency, longer wavelength) can penetrate through thick vegetation and is ideal for monitoring changes beneath forest canopies.

• While the S-band (higher frequency, shorter wavelength) excels at capturing fine surface details.

A key technological highlight of NISAR is its use of NASA’s 12-metre unfurlable mesh reflector antenna, which will be integrated into ISRO’s modified I3K satellite bus. This large antenna enables wide-swath imaging, and in NISAR’s case, it will operate using an advanced technique known as SweepSAR (Sweep Synthetic Aperture Radar). This method allows the satellite to cover a broad swath of 242 km, offering both high spatial resolution and frequent global coverage.

The satellite is designed to scan the entire Earth every 12 days, capturing high-resolution data in all-weather conditions, both day and night. It can detect changes on Earth’s surface as small as one centimetre, which will enable scientists to monitor a wide array of dynamic environmental and geological processes.

Some of the key applications include the retreat of glaciers, movement of sea ice, storm tracking, changes in vegetation and forest cover, earthquake and volcanic activity monitoring, and soil moisture assessment.

Additionally, NISAR will significantly contribute to climate change studies, help track surface water resources, aid in disaster response, and support coastal monitoring through shoreline mapping and ship detection. The satellite’s ability to classify sea ice, characterize storms, and monitor ground deformation makes it one of the most advanced observational tools developed to date.

The mission reflects more than a decade of close technical collaboration between NASA’s Jet Propulsion Laboratory (JPL) and various ISRO centres.

Notably, ISRO's U.R. Rao Satellite Centre (URSC) developed the spacecraft bus, and the Space Applications Centre (SAC) in Ahmedabad contributed the S-band SAR system. The combined radar payload required innovative engineering to ensure both radars—operating at different frequencies—function in a complementary manner without interference.

At a cost of approximately USD 1.5 billion, NISAR is the most expensive Earth observation satellite in the world. ISRO’s contribution amounts to around ₹469.4 crore, excluding the cost of launch and associated logistics. The launch, originally scheduled for an earlier date, was delayed due to technical issues, including the need to repair the unfurlable antenna, which necessitated the satellite being shipped back to the U.S. for modifications.

The upcoming launch of NISAR marky between India and the United States in advancing planetary science and Earth monitoring capabilities. With its cutting-edge design and dual-radar system, NISAR is expected to become the sharpest eye in the sky, transforming our understanding of Earth’s natural systems and bolstering our preparedness for climate and disaster-related challenges.s a historic milestone in space collaboration, symbolizing the synergy between India and the United States in advancing planetary science and Earth monitoring capabilities. With its cutting-edge design and dual-radar system, NISAR is expected to become the sharpest eye in the sky, transforming our understanding of Earth’s natural systems and bolstering our preparedness for climate and disaster-related challenges.

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