India successfully launched NISAR, the world’s costliest Earth-observation satellite, on Wednesday. The launch happened at the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh. This advanced satellite, valued at $1.3 billion, is seen as a major milestone in space technology.

What makes this mission even more special is that NISAR is a collaborative effort between ISRO and NASA. It is the first big space partnership between the Indian and American space agencies.

At exactly 5:40 PM, ISRO’s GSLV-F16 rocket blasted off, carrying NISAR into orbit. Just moments after the launch, ISRO confirmed the success with a post on X (formerly Twitter), stating, “Liftoff. And we have liftoff! GSLV-F16 has successfully launched with NISAR onboard.”

GSLV-F16/NISAR

Liftoff
And we have liftoff! GSLV-F16 has successfully launched with NISAR onboard.

Livestreaming Link: https://t.co/flWew2LhgQ

For more information:https://t.co/XkS3v3M32u #NISAR #GSLVF16 #ISRO #NASA

— ISRO (@isro) July 30, 2025

The satellite is now on its journey to a sun-synchronous polar orbit located 747 kilometers above the Earth. It was placed into space using ISRO’s GSLV Mk-II rocket, which is known for launching heavy satellites into high orbits.

NISAR stands as a symbol of growing cooperation between India and the United States in the field of space science, and its success marks a new chapter in Earth observation technology.

What is NISAR?

NISAR stands for NASA-ISRO Synthetic Aperture Radar. It weighs around 2,392 kg and is unique because it uses two radar frequencies—L-band (by NASA) and S-band (by ISRO). This combination allows it to detect Earth changes with great precision.

NASA said, “Each system’s signal is sensitive to different sizes of features on Earth’s surface, and each specialises in measuring different attributes, such as moisture content, surface roughness, and motion.”

The satellite, which cost more than $1.5 billion to build, took about ten years to complete. It includes a 12-meter-wide gold mesh antenna, the largest ever in low-Earth orbit. This antenna is attached to ISRO’s I-3K spacecraft bus, which provides power (4 kW), propulsion, and communication systems.

How NISAR Will Work

After entering its orbit at a tilt of 98.4 degrees, NISAR will not start working immediately. The first 90 days will be used for In-Orbit Checkout (IOC), where scientists will ensure everything functions correctly before starting its actual operations.

Using Synthetic Aperture Radar (SAR), the satellite will send radar signals to the Earth’s surface and measure how long it takes for the waves to return and how their phase shifts. These signals help create high-resolution images.

NISAR’s L-band radar (1.257 GHz) will penetrate through thick forests and the ground to detect soil movement and deformation. Meanwhile, the S-band radar (3.2 GHz) will observe surface features like water bodies and crops.

According to ISRO, the satellite will scan a 242 km wide area using SweepSAR technology, which allows it to capture clear, high-resolution images in all weather, during both day and night.

Every 12 days, NISAR will complete a full scan of the Earth, offering regular updates on surface changes.

Why NISAR Matters

NISAR marks a significant milestone in India-US space collaboration. Union Minister Dr. Jitendra Singh said, “This mission is not just about a satellite launch — it is a moment that symbolises what two democracies committed to science and global welfare can achieve together.”

The satellite will help track and study:

• Earth’s ecosystems and forest cover

• Changes in ice sheets and sea levels

• Underground water levels

• Natural disasters such as earthquakes, tsunamis, landslides, and volcanic eruptions

Importantly, the satellite’s data will be available to everyone around the world within a few hours. Dr. Paul Rosen from NASA told NDTV, “The data will be placed in the public archive almost instantly after processing. NASA and ISRO have agreed - this is a science mission, and all radar data will be open.”

Dr. Rosen also pointed out that NISAR can detect signs of landslides and monitor melting glaciers that might burst and flood downstream areas. “We can see precursory motion before landslides. And we will monitor glacier dynamics to assess GLOF (Glacial Lake Outburst Flood) risks,” he said.

NISAR will also be crucial for seismic zones like the Himalayas. It can detect ground movement with millimetre accuracy. This can help scientists better understand how earthquakes happen and improve early warning systems.

Overall, NISAR is expected to play a vital role in understanding and responding to climate change, natural disasters, and environmental shifts around the globe.