ISRO and NASA's billion-dollar baby is ready to launch. NISAR will watch every inch of Earth

The Print

26-07-2025

The project is significant not only because it marks the first collaboration between ISRO and NASA on this scale, but also because of the satellite's ability to scan all of Earth's land and ice-covered surfaces twice every 12 days. This will help record both large and small climatic and geographical changes over time.
After a delay of over a year, the NASA-ISRO Synthetic Aperture Radar ( NISAR ) mission is now scheduled to launch on 30 July from the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh, aboard India's heavy-lift rocket, the Geosynchronous Satellite Launch Vehicle-F16 (GSLV-F16).
New Delhi: The Indian Space Research Organisation and the United States' National Aeronautics and Space Administration are set to launch a first-of-its-kind Earth observation satellite, designed to survey the planet like never before.
As an equal partner in NISAR's development, ISRO is consolidating India's position in the global space sector as a trusted and dependable business associate.
It is for this reason that the ISRO-NASA partnered NISAR satellite is ThePrint's Newsmaker of the Week.
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What does NISAR promise?
NISAR promises to usher in a new era of global Earth observation capabilities.
The high-resolution images it provides will enable scientists to better understand the processes behind natural hazards and catastrophic events such as earthquakes, landslides, and volcanic eruptions. Its ability to penetrate cloud cover will be key in improving emergency responses during weather-related disasters like floods, storms, and hurricanes.
According to NASA, the NISAR satellite will also provide crucial data on changes in ice sheets, glaciers, and sea ice, and enhance scientific understanding of how deforestation, permafrost loss, and fires affect the carbon cycle.
'The data will be accessible to all users across a range of disciplines, with potential applicability in disaster response, infrastructure monitoring and agricultural decision support,' NASA said in a mission document.
Data from NISAR could change our approach to disaster preparedness and management. All data from the satellite will be available within one to two days of observation. In emergencies such as natural disasters, the turnaround time will shrink to just a few hours.
NASA's Sanghamitra Dutta, the programme executive for NISAR, highlighted the massive scale of data generation.
'NISAR will capture over 4,300 GB of Earth imagery each day. You will need nearly eight 512 GB laptops to hold such a volume of data,' she said.
Over its expected lifespan of more than three years, NISAR satellite will accumulate over 5,00,000 GB of data—enough to fill approximately 3,000 laptops.
At a recent press conference, NASA announced that 80 organisations, both public and private, have already signed up to use NISAR data.
'Remote-sensing missions like NISAR are storytellers about how the Earth and humans interact, and how we connect with the planet,' said Paul Rosen, project scientist for NISAR. 'NISAR is a truly unique storyteller,' he added.
The partnership—first conceptualised in 2007 and finally inked in 2014—is the most expensive Earth observation satellite mission ever, with a price tag of $1.5 billion. Of the total project cost, ISRO has contributed Rs 469.4 crore and will also cover the launch costs.
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NISAR satellite—the technology
NISAR is being touted as the most powerful Synthetic Aperture Radar (SAR) satellite ever developed.
At the press conference, NASA revealed that the satellite will be roughly the size of a pickup truck. Its main body houses engineering systems and a first-of-its-kind dual radar payload—an L-band radar with a 10-inch wavelength, and an S-band radar, also with a 10-inch wavelength.
India's contribution is significant: the S-band radar was built by the ISRO Space Applications Centre in Ahmedabad. It was shipped to NASA's Jet Propulsion Laboratory (JPL) in 2021, where the L-band radar was being developed.
NASA and ISRO scientists integrated the two systems between 2021 and 2022. The satellite was then sent to India in March 2023 for final preparations and launch.
NISAR launch delay
This 9,000-mile-long partnership between India and the US faced its share of hurdles.
NISAR satellite, which took over a decade to come together, was first scheduled for launch in 2024. But technical faults led to a delay.
Just weeks before the initial launch window in March-April 2024, engineers discovered a problem with the large deployable antenna. The component had to be returned to the US to protect the spacecraft's reflector—a 12-metre-wide antenna—while in its stowed configuration.
'Testing and analysis identified a potential for the reflector to experience higher-than-previously-anticipated temperatures in its stowed configuration in flight,' NASA said in a statement.
To mitigate this, engineers applied a special coating to increase the antenna's reflectivity and reduce heat absorption.
Although NASA resolved the issue within a few months, the wait for NISAR's launch did not end.
Between October 2024 and February 2025, the launch was deemed unfeasible. During this period, the Sun's position would expose the satellite to alternating cycles of heat and shadow, potentially causing temperature fluctuations that could jeopardise the satellite's boom and radar antenna.
But now, NISAR's time has finally come. The world is about to receive a treasure trove of Earth data like never before.
And along with ISRO and NASA, the entire scientific community is watching with excitement.
(Edited by Prashant)