|Names||NASA-ISRO Synthetic Aperture Radar|
|Mission type||Radar imaging|
|Operator||NASA / ISRO|
|Mission duration||3 years (planned) |
|Launch mass||2,800 kg (6,200 lb) |
|Start of mission|
|Launch date||January 2024 (planned)|
|Rocket||GSLV Mk. II|
(4 meter fairing) 
|Launch site||Satish Dhawan Space Center|
|Reference system||Geocentric orbit|
|Altitude||747 km (464 mi)|
|Perigee altitude||747 km (464 mi)|
|Apogee altitude||747 km (464 mi)|
|L-band (24-cm wavelength) Polarimetric Synthetic Aperture Radar|
S-band (12-cm wavelength) Polarimetric Synthetic Aperture Radar
NISAR mission logo
The NASA-ISRO Synthetic Aperture Radar (NISAR) mission is a joint project between NASA and ISRO to co-develop and launch a dual-frequency synthetic aperture radar on an Earth observation satellite. The satellite will be the first radar imaging satellite to use dual frequencies. It will be used for remote sensing, to observe and understand natural processes on Earth. For example, its left-facing instruments will study the Antarctic cryosphere. With a total cost estimated at US$1.5 billion, NISAR is likely to be the world's most expensive Earth-imaging satellite.
The NASA-ISRO Synthetic Aperture Radar, or NISAR satellite, will use advanced radar imaging to map the elevation of Earth's land and ice masses 4 to 6 times a month at resolutions of 5 to 10 meters. It is designed to observe and measure some of the planet's most complex natural processes, including ecosystem disturbances, ice-sheet collapse, and natural hazards such as earthquakes, tsunamis, volcanoes and landslides.
Under the terms of the agreement, NASA will provide the mission's L-band synthetic aperture radar (SAR), a high-rate telecommunication subsystem for scientific data GPS receivers, a solid-state recorder, and a payload data subsystem. ISRO will provide the satellite bus, an S-band synthetic aperture radar, the launch vehicle, and associated launch services.
All data from NISAR would be freely available 1 to 2 days after observation and within hours in case of emergencies like natural disasters. Data collected from NISAR will reveal information about the evolution and state of Earth's crust, help scientists better understand our planet's natural processes and changing climate, and aid future resource and hazard management. The mission is a partnership between NASA and ISRO.
The satellite will be three-axis stabilized. It will use a 12 m (39 ft) deployable mesh antenna and will operate on both the L- and S- microwave bands. The aperture mesh reflector (antenna) will be supplied by Astro Aerospace, a Northrop Grumman company.
The satellite will be launched from India aboard a GSLV Mk II in early 2024. The orbit will be a Sun-synchronous, dawn-to-dusk type. The planned mission life is three years. The project has passed the first stage of the design validation phase and has been reviewed and approved by NASA.
ISRO's share of the project cost is about ₹788 crore (US$99 million), and NASA's share is about US$808 million.