NASA and ISRO Join Hands to Launch NISAR Satellite (updated)

NISAR is acronym for Nasa Isro Synthetic Aperture Radar. NISAR is a billion-dollar satellite designed primarily to reveal Earth's heartbeat. On 30th July 2025, a day when Donald Trump, President of USA imposed 25% tariff on India to be effective from, 1 August 2025; India’s space agency ISRO joined hands with NASA, the space agency of USA to launch NISAR satellite. NISAR more specifically is designed to reveal a detailed view of the Earth allowing scientists to observe and measure some of the planet's most complex processes, including ecosystem disturbances, ice-sheet collapse, natural hazards, sea level rise, and groundwater issues. It will also help in ship detection, shoreline monitoring, storm characterisation, changes in soil moisture, mapping and monitoring of surface water resources. The satellite houses a huge Synthetic Aperture Radar, the first-of-its-kind installed in space, that will systematically map Earth, measuring all changes of planet's surface down to the last centimeter.

NISAR is an orbiter with 2 key instruments, namely L-SAR (24cm wavelength) and S-SAR (12cm wavelength) will circle the earth at an altitude of 743 km and at an inclination of 98.4°. Data from NISAR can help people worldwide to better manage earth’s natural resources and hazards more specifically climate monitoring and disaster response. NISAR will also provide information to scientists to better understand the effects and pace of climate change. NISAR will also boost our ability to understand our planet's hard outer layer, called its crust. NISAR will be the first radar of its kind installed in space to systematically map Earth, using two different radar frequencies equipped with dual-frequency synthetic aperture radar (L-band and S-band) to measure changes of our planet’s surface. Synthetic Aperture Radar (SAR) refers to a technique for producing fine-resolution images from a resolution-limited radar system.

 

NISAR mission, is a joint venture between ISRO and NASA, costing US$ 1.5 billion that is meant to help not just USA and India, but worldwide. NISAR satellite weighing a massive 2393-kilogram is meant to orbit the planet earth every 97 minutes, and map earth every 12 days. It was launched aboard ISRO's work horse launch vehicle Geosynchronous Satellite Launch Vehicle (GSLV-F16) from the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh at 5:40 pm IST. This is the first time that a GSLV has put a satellite in a sun-synchronous polar orbit. This combination of NASA's L-band radar and ISRO's S-band radar will enable Nisar to capture the faintest shifts on Earth’s surface whether under forests, clouds, or even in darkness detecting movements as small as a few millimetres.

The synthetic aperture radar combines multiple measurements, taken as a radar flies overhead, to sharpen the scene below. It works like conventional radar, which uses microwaves to detect distant surfaces and objects, but steps up the data processing to reveal properties and characteristics at high resolution. NISAR’s freely accessible, nearly real-time data will empower Indian researchers, disaster managers, and policymakers to detect and monitor glacier movements in the Himalayas, fault-line shifts before earthquakes, track agricultural cycles, and manage water resources more effectively. This will help India is set to improve forecasting for floods, droughts, and landslides, enabling the government to develop a rapid response and informed policy decisions. The satellite launch, dubbed a historic mission, not only cements India’s position as a leader in space-based climate monitoring but also demonstrates how international collaboration can drive scientific progress for the collective good.

The development of the satellite that has spanned just over a decade is a result of the NASA-ISRO Synthetic Aperture Radar (NISAR) agreement signed on September 30, 2014. The S-Band SAR and L-Band SAR were independently developed, integrated, and tested by ISRO and Jet Propulsion Laboratory (JPL) of NASA, respectively. The Integrated Radar Instrument Structure (IRIS), comprising of both SAR systems and additional payload elements, was assembled and tested at JPL/NASA before being delivered to ISRO. The mainframe satellite elements and all payloads were then assembled, integrated, and tested at ISRO’s U R Rao Satellite Centre (URSC).

The NISAR mission comprises of four main phases, namely launch, deployment, commissioning, and science operations. After today’s launch; in the deployment phase, a 12-meter diameter reflector will be extended 9 meters from the satellite using a complex deployable boom developed by JPL/Nasa. The 90-day commissioning phase divided into sub-phases involves system checks and calibrations. These in-orbit checkouts of mainframe elements are meant to prepare the observatory for science operations, followed by JPL engineering payload and instrument checkout. In the next science operations phase the satellite’s mission's objective are fullfilled with regular orbit manoeuvres, calibration/validation activities, and coordinated observation plans for L-band and S-band instruments managed jointly by JPL and ISRO. During this phase, the science orbit will be maintained via regular manoeuvres, scheduled to avoid or minimise conflicts with science observations. Extensive calibration and validation activities will take place.

NISAR has helped India to set a new benchmark in technological leadership and global environmental stewardship, offering its citizens and the world the means to better understand and protect the planet. NASA-ISRO Synthetic Aperture Radar or NISAR satellite launched from the second launch pad of Satish Dhawan Space Centre (SDPC) at Sriharikota in Andhra Pradesh put the satellite 18 minutes later, into a sun-synchronous orbit. NISAR satellite that has a mission life of atleast five years, is the first satellite that has been jointly developed by ISRO and the NASA. Casey Swails, Deputy Associate Administrator at NASA, said NISAR will give decision-makers the tools to monitor critical infrastructure, respond faster and smarter to natural disasters such as earthquakes, floods, and landslides, as well as map farmland to improve crop output and more. NASA said that mission controllers for the NASA-ISRO NISAR mission had received full acquisition of signal from the spacecraft.

The satellite’s dual-frequency Synthetic Aperture Radar, both NASA’s L-band and ISRO’s S-band use NASA’s 12-metre unfurlable mesh reflector antenna, integrated with ISRO’s modified I3K satellite bus. It will observe earth with a swathe of 242 km and high spatial resolution, using SweepSAR technology for the first time. As per ISRO chief, NISAR satellite will be able to monitor tectonic movements accurately. NASA’s Jet Propulsion Laboratory (JPL) built the radar antenna reflection, radar antenna boom, L-Band SAR and engineering payload, while ISRO built the spacecraft bus, solar array S-band SAR and the launch vehicle. NISAR mission will demonstrate Indian space engineering capabilities for Earth observation on a global scale, a top scientist said.

The NISAR mission data will be accessible for download worldwide by users, said Radha Krishna Kavuluru, former Ground Segment Engineer and Ex-Project Manager of NISAR. He also said, the satellite will transmit extensive data covering the Earth, including Antarctica, the North Pole, and oceans. Another scientist said that NISAR will produce an enormous volume of high-resolution data daily, providing critical insights for scientists, disaster management authorities, policymakers, and environmental researchers. He further said, “It will generate a tremendous amount of data per day, which will be greatly useful to many decision makers, disaster managers, and others who want to make a detailed study of the Earth. As of today, it is going to be the most advanced Earth observation satellite.”

17 days after the NASA-ISRO Synthetic Aperture Radar (NISAR) was placed in orbit, the advanced earth imaging satellite fully deployed its massive 39-foot wide radar antenna, a key step in its schedule for commissioning. NASA said the Giant Radar Antenna Reflector on NISAR was an essential piece of science hardware unfurled in orbit. The largest and the most sophisticated radar systems ever sent to space, the drum-shaped antenna had been stowed like an umbrella until the 30-foot (9-meter) boom that supports it could be deployed and locked in place. NISAR will track the motion of ice sheets and glaciers, the deformation of land due to earthquakes, volcanoes, and landslides, and changes in forest and wetland ecosystems down to fractions of an inch. It also will aid decision-makers in fields as diverse as disaster response, infrastructure monitoring, and agriculture.

Weighing about 64 kg, the reflector features a cylindrical frame made of 123 composite struts and a gold-plated wire mesh. On August 9, the satellite’s boom, which had been tucked close to its main body, started unfolding one joint at a time until it was fully extended about four days later. Then, on August 15, small explosive bolts that held the reflector assembly in place were fired, enabling the antenna to begin a process called the “bloom” — its unfurling by the release of tension stored in its flexible frame while stowed like an umbrella, according to information shared by NASA. Subsequent activation of motors and cables then pulled the antenna into its final, locked position.

ISRO will handle the satellite commanding and operations whereas NASA will provide the orbit manoeuvre plan and radar operations plan. The NISAR mission will be aided with ground station support of both ISRO and NASA for downloading of the acquired images, which after the necessary processing will be disseminated to the users. NISAR carries two major payloads — the L-band and the S-band SAR. The S-band radar system, data handling and high-speed downlink system has been developed by ISRO, while the L-band radar system, high-speed downlink system, the solid-state recorder, GPS receiver and reflector have been provided by NASA.