NISAR (acronym for NASA-ISRO Synthetic Aperture Radar or NASA-ISRO SAR), a joint collaborative mission of NASA and ISRO, was successfully launched into space on 30 July 2025. NISAR mission’s aim is to study land and ice deformation, land ecosystems, and oceanic regions. Equipped with the unique dual-band Synthetic Aperture Radar that employs novel SweepSAR technique to provide high resolution and large swath imagery, NISAR will systematically map Earth including the key processes like ecosystem disturbances, ice-sheet collapse, natural hazards, sea level rise, and groundwater issues. It will monitor and make precise measurement at centimetre scale of changes in Earth’s landmass and ice regions twice every 12 days. The data collected by the mission will be freely and openly available in line with open access policy to help public authorities better manage natural resources and natural disasters. Studies using the data will improve our understanding of Earth’s crust and the impact and pace of climate change.
Earth scientists strove to observe Earth’s surface from the above in the sky to monitor clouds, weather, crops, forests, rivers, mountains, volcanoes, ocean, sites of natural calamities like earthquakes, floods, cyclones, tsunami and the locations of strategic importance etc for preparedness and effective planning of public services. Technological advancement saw usage of hot air sky balloons followed by customised airplanes. Both had limitations particularly in terms of duration and area of coverage which were addressed by the arrival Earth observation satellites in 1960s following advancements in space technology. These satellites observe various phenomena on the surface of Earth from space using either optical (visible, near-infrared, infrared) sensors or microwave sensor installed on them. Since microwaves pass through the clouds, satellites equipped with the microwave sensors can make observations of Earth’s surface regardless of day and night or weather conditions.
TIROS-1 was the earliest earth observation satellite. Launched in 1960 by NASA, it transmitted the first images of Earth’s weather systems home. The first earth observation satellite specifically designed to study and monitor Earth’s landmasses was Landsat 1, which was launched by NASA in 1971. Since then, there is steady growth in Earth observation satellites in space. In 2008, there were about 150 such satellites in Earth’s orbit. The number grew to 950 in 2021. Presently, there are over 1100 operational earth observation satellites in space. NISAR is the latest in the series of Earth observation satellites.
NISAR (acronym for NASA-ISRO Synthetic Aperture Radar or NASA-ISRO SAR), a joint collaborative mission of NASA and ISRO, was successfully launched into space on 30 July 2025.
| Objectives of NISAR Mission |
| NISAR mission’s aim is to study land and ice deformation, land ecosystems, and oceanic regions. The collected data would help in monitoring changes in plant biomass, crop pattern, and wetlands. It will also map Greenland’s & Antarctica’s ice sheets, dynamics of sea ice and mountain glaciers and characterize land surface deformation related to seismicity, volcanism, landslides, and subsidence and uplift associated with changes in subsurface aquifers, hydrocarbon reservoirs, etc |
Currently, the mission is in phase 1 and will shortly enter phase 2 when antenna will be deployed. Entire commissioning should be completed in 90 days from the launch when the mission will enter science operation phase.
| Phases of NISAR Mission |
| Phase 1 (Launch): (Post-launch Days 0-9): Launched onboard GSLV-F16 launch vehicle on 30 July 2025 from Sriharikota on the southeast coast of the Indian peninsula. |
| Phase 2: Deployment (Post-launch Days 10-18): The spacecraft carries a large reflector of 12 m diameter to act as a radar antenna. It will be deployed in orbit 9m away from the satellite by a complex multistage deployable boom system. The process of deployment of antenna begins on the 10th day from launch (hence “Mission Day 10” corresponds to “Deploy Day 1”) with pre-deployment checks and completes on deployment day 8 with the satellite performing a ‘yaw manoeuvre’ (rotation) to orient itself correctly, following which the and the circular radar reflector will open. |
| Phase 3: Commissioning Until the 90th day from the launch after deployment of antenna, all systems will be checked and calibrated in preparation for science operations. |
| Phase 4: Science operations Once commissioning phase is complete, science operations phase begins and continues till the mission life of five years. SARs captures data about ground movement, ice sheets, forests and land use across both L-band and S-band frequencies and makes that available to researchers worldwide. |
Parked in the Sun synchronous, polar orbit at an altitude of 747 km and equipped with two powerful microwave synthetic aperture radars (SAR), an L-Band SAR and an S-Band SAR, NISAR is a microwave imaging mission, with capability to collect polarimetric and interferometric data.
| Technical prowess of NISAR Mission |
| NISAR is equipped with the unique dual-band Synthetic Aperture Radar that employs novel SweepSAR technique to provide high resolution and large swath imagery. Synthetic aperture radar (SAR) produces fine-resolution images from a resolution-limited radar system. |
NISAR is designed to systematically map Earth including the key processes like ecosystem disturbances, ice-sheet collapse, natural hazards, sea level rise, and groundwater issues. It will monitor and make precise measurement at centimetre scale of changes in Earth’s landmass and ice regions twice every 12 days.
The data collected by L-band and S-band SARs of the NISAR mission will be freely and openly available to the public, public authorities and researchers in line with open access policy. It will help public authorities better manage natural resources and natural disasters. Studies using the data will improve our understanding of Earth’s crust and the impact and pace of climate change.
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References:
- Earth Data. Now That NISAR Launched, Here’s What You Can Expect From the Data. Posted 4 August 2025. Available at https://www.earthdata.nasa.gov/news/now-that-nisar-launched-heres-what-you-can-expect-from-the-data
- NASA. NISAR (NASA-ISRO Synthetic Aperture Radar). Available at https://science.nasa.gov/mission/nisar/
- ISRO. NISAR – NASA ISRO Synthetic Aperture Radar Mission. Available at https://www.isro.gov.in/Mission_GSLVF16_NISAR_Home.html https://www.isro.gov.in/media_isro/pdf/GSLV_F16NISAR_Launch_Brochure.pdf
- Rosen P.A. et al., 2025. The NASA-ISRO SAR Mission: A summary. IEEE Geoscience and Remote Sensing Magazine. 16 July 2025. DOI: https://doi.org/10.1109/MGRS.2025.3578258
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, a joint collaborative mission of NASA and ISRO, was successfully launched into space on 30 July 2025. NISAR mission’s aim is to study land and ice deformation, land ecosystems, and oceanic regions. Equipped with the unique dual-band Synthetic Aperture Radar that employs novel SweepSAR technique to provide high resolution and large swath imagery, NISAR will systematically map Earth including the key processes like ecosystem disturbances, ice-sheet collapse, natural hazards, sea level rise, and groundwater issues. It will monitor and make precise measurement at centimetre scale of changes in Earth's landmass and ice regions twice every 12 days. The data collected by the mission will be freely and openly available in line with open access policy to help public authorities better manage natural resources and natural disasters. Studies using the data will improve our understanding of Earth’s crust and the impact and pace of climate change.){kind=link}