 Artist's concept of the NASA-ISRO Synthetic Aperture Radar (NISAR) satellite. | |
| Names | NASA-ISRO Synthetic Aperture Radar NISAR |
|---|---|
| Mission type | Radar imaging |
| Operator | NASA /ISRO |
| COSPAR ID | 2025-163A |
| SATCATno. | 65053 |
| Website | nisar www |
| Mission duration | Planned: 5 years[1][2] Duration: 3 months, 22 days |
| Spacecraft properties | |
| Spacecraft | NISAR |
| Bus | I-3K[3] |
| Manufacturer | NASA & ISRO |
| Launch mass | 2,393 kg (5,276 lb)[4] |
| Power | 6,500watts |
| Start of mission | |
| Launch date | July 30, 2025, 12:10UTC 05:40pmIST[5] |
| Rocket | GSLV F16 (4 meter fairing)[3] |
| Launch site | Satish Dhawan Space Centre |
| Contractor | ISRO |
| Orbital parameters | |
| Reference system | Geocentric orbit[1] |
| Regime | Sun-synchronous orbit[6] |
| Altitude | 747 km (464 mi) |
| Perigee altitude | 747 km (464 mi) |
| Apogee altitude | 747 km (464 mi) |
| Inclination | 98.5° |
| Transponders | |
| Band | S-band L-band |
| Instruments | |
| L-band (24-cm wavelength) Polarimetric Synthetic Aperture Radar S-band (12-cm wavelength) Polarimetric Synthetic Aperture Radar | |
 NISAR mission logo | |
TheNASA-ISRO Synthetic Aperture Radar (NISAR) mission is a joint project betweenNASA andISRO to co-develop and launch anEarth observation satellite (EOS) equipped with dual-frequencysynthetic aperture radar (SAR) in 2025. It will be the firstradar imaging satellite to use dual frequencies. It will be used forremote sensing, to observe and understand natural processes onEarth. For example, its left-facing instruments will study theAntarcticcryosphere.[7] With a total cost estimated at US$1.5 billion, NISAR is likely to be the world's most expensive Earth-imaging satellite.[8]
The NASA-ISROSynthetic Aperture Radar, or NISAR satellite, will use advanced radar imaging to map the elevation of Earth's land and ice masses four to six times a month at resolutions of 5 to 10 meters.[9] It is designed to observe and measure some of the planet's most complex natural processes, includingecosystem disturbances,ice-sheet collapse, and natural hazards such asearthquakes,tsunamis,volcanoes andlandslides.[10][11]
The mission is a partnership betweenNASA andISRO.[10] Under the terms of the agreement, NASA will provide the mission'sL-bandsynthetic aperture radar (SAR), a high-rate telecommunication subsystem for scientific dataGPS receivers, a solid-state recorder, and a payload data subsystem. ISRO will provide thesatellite bus, anS-bandsynthetic aperture radar (SAR), the launch vehicle, and associated launch services.[12]
All data from NISAR will be freely available one to two days after observation and within hours in case of emergencies like natural disasters.[9] Data collected from NISAR will reveal information about the evolution and state ofEarth's crust, help scientists better understand our planet's natural processes andchanging climate, and aid future resource and hazard management.[10]
The satellite will bethree-axis stabilized. It will use a 12 m (39 ft) deployable mesh antenna and will operate on both theL- andS- microwave bands.[10] The aperture mesh reflector (antenna) will be supplied by Astro Aerospace.[13] Weighing about 142 pounds (64 kilograms), the reflector features a cylindrical frame made of 123 composite struts and a gold-plated wire mesh and is the largest of its kind deployed in space.[14]
The National Centre of Geodesy facilities atIIT-Kanpur andIIT-Patna will host acorner reflector for NISAR. It will play a key role in calibration and course correction of the Nisar satellite's radar during the in-orbit checkout phase.[15]
ISRO's share of the project cost is about₹788 crore (US$93 million), and NASA's share is about US$1,118 million ($1.118 billion).[16][17][15]
The satellite was fully integrated in January 2024 and was performing its final testing and analysis in preparation for launch.[18] However, in an interview with theTimes of India, Chairman of ISROSreedhara Panicker Somanath said that though the GSLV for NISAR will be built by March–April 2024, the satellite is still undergoing tests and they were expecting some delay.[19] Tests found that the large primary radar reflector might face higher-than-expected temperatures when stowed during flight and so it was returned toJPL, its manufacturer inCalifornia, to apply a reflective coating to mitigate the risk of overheating.[20][21] It was the first GSLV Mk II launch to Low Earth orbitand to SSPO
On 15 October 2024, after the completion of all checks and tests, NASA'sC-130 took off fromWallops Flight Facility inVirginia to embark on the multi-leg, multi-day journey to India. The flight first stopped atMarch Air Reserve Base to retrieve the spacecraft followed by strategic stops atHickam Air Force Base, Hawaii;Andersen Air Force Base,Guam;Clark Air Base,Philippines and reachedHAL Airport inBengaluru, India.[22][23] By late January 2025, the satellite had finished all preliminary checkout in Bengaluru and was ready to be shipped to SDSC.[24] By May 14 technicians had placed the satellite in a specialized container and transported it about 360 kilometers by truck toSatish Dhawan Space centre, where it arrived following day.[25]
NISAR lifted off aboard an ISROGeosynchronous Satellite Launch Vehicle rocket at 5:40 p.m. IST on the 30th of July 2025. ISRO ground controllers inBengaluru began communicating with NISAR about 18 minutes after launch, at just after 8:29 a.m. EDT, and confirmed it is operating as expected. It was the GSLV rocket’s first mission toSun-synchronous polar orbit.[26][27][28] The satellite will enter a 90-day Checkout phase and deploy its primary Radar reflector before beginning of its operational life.[29] The orbit will be aSun-Synchronous Orbit (SSO), dawn-to-dusk type. The planned mission life is 5 years.[1]
The deployment process for the spacecraft started on August 9, 2025 with the deployment of the 9 meter long booms first joint. The boom was fully deployed by August 13. 17 days after launch, on August 15, ISRO and NASA mission controllers fired smallexplosive bolts to unfurl the 12 meters wide drum-shaped primaryradar reflector for NISAR.The whole bloom process took 37 minutes and was completed with the locking of cables and activation of motors to fix the reflectors final shape. It then proceeded to raise and circularise its 747 km orbit on August 26.Pre-operational checks were then conducted by both NASA & ISRO teams to validate the health and readiness of all major systems, including the radar payload. Mission controllers anticipate they will start receiving science-qualityradar images in September 2025. The spacecraft is expected to begin science operations by Fall 2025, or about 90 days after launch.[14][30][31][32]
NISAR captured its first SAR images using its L-SAR on August 23rd overMount Desert Island inMaine and parts of theForest River inNorth Dakota.[33][34][35]
This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain. This article incorporates text from this source, which is in thepublic domain.| Organisations |
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