2025 for January 1970

The Indian Space Research Organisation (ISRO) is planning to launch the NISAR satellite from Sriharikota onboard a GSLV Mk-II rocket.

India and the United States are set to launch their most ambitious joint space mission to date, the NASA-ISRO Synthetic Aperture Radar (NISAR) satellite.
Scheduled for lift-off on July 30 from Sriharikota onboard a GSLV Mk-II, the Rs. 12,000-crore mission has been over a decade in the making and is being considered as one of the world’s most advanced Earth observation missions.
NISAR will provide real-time, high-resolution radar data on land deformation, biomass, disaster impact, crop patterns, and climate-related changes, not just for India but globally.
It combines NASA’s strength in long-range radar systems with ISRO’s spaceflight engineering and S-band radar technology.

First Dual-Band Radar Satellite for Earth Observation
- NISAR is the world’s first Earth-observing satellite with dual-frequency synthetic aperture radar (SAR).
- L-band radar (1.257 GHz) from NASA can penetrate dense forests and soil layers to detect ground deformation and subsurface movement.
- S-band radar (3.2 GHz) from ISRO is optimised for surface-level changes like crop growth, biomass estimates, and water levels.
- This dual-frequency advantage allows for all-weather, day-and-night imaging, even through clouds, smoke, or vegetation cover.

Wide Swath and High Resolution
- NISAR’s radar swath width is 240 km, allowing it to scan large areas in one go.
- It offers a spatial resolution of 3-10 metres and vertical displacement mapping accuracy down to centimetres, enabling early detection of phenomena like land subsidence in cities.
- Every spot on Earth will be revisited once every 12 days, providing consistent monitoring.

NISAR is designed to support research and operations across six broad themes:
- Solid Earth Processes - Tracking earthquakes, landslides, and land deformation.
- Ecosystems - Monitoring forests, woody biomass, and biodiversity.
- Ice and Snow Dynamics - Measuring glacial movements and polar ice thickness.
- Coastal and Ocean Monitoring - Tracking shoreline erosion, oil spills, and storm surges.
- Disaster Response - Providing near-real-time damage maps after floods, quakes, or cyclones.
- Agriculture and Infrastructure - Supporting food security and monitoring subsidence near dams, roads, and reservoirs.
During natural disasters, NISAR can provide damage proxy maps within five hours, crucial for emergency relief planning and response.

While NISAR will operate globally at the L-band, ISRO will routinely operate the S-band radar over Indian territory, enabling:
- Enhanced biomass and soil moisture mapping
- Improved agricultural forecasting
- Ionospheric noise correction for high-precision imagery
All of this aligns with India’s national needs in agriculture, disaster management, forestry, and rural development.

Once launched, NISAR will be placed in a sun-synchronous polar orbit at an altitude of 747 km.
It features a massive 12-metre mesh radar antenna and a 9-metre boom to support deployment and scanning.
To overcome size constraints in space, the SAR system mimics a large antenna by collecting radar pulses over time and combining them through complex processing, hence the term “synthetic aperture.”
Its advanced SweepSAR mode allows electronic steering of radar beams, providing consistent swath coverage without compromising resolution.

NISAR’s open-data policy ensures that data is freely available to all users, typically within a few hours of acquisition.
NASA’s Near Earth Network (in Alaska, Norway, and Chile) will handle most global data downlinks (up to 3 TB/day).
ISRO’s Ground Stations in Shadnagar and Antarctica will manage India’s data needs.
India’s National Remote Sensing Centre (NRSC) will process and distribute NISAR products for domestic use.

The mission exemplifies balanced international collaboration:
- ISRO contributed the spacecraft bus, the entire S-band radar system, Ka-band telemetry systems, and launch support via GSLV Mk-II.
- NASA provided the L-band radar, radar structure, antenna, onboard avionics, and high-capacity data systems.
The satellite was integrated and tested in Bengaluru, symbolising “Made-in-India” ownership of a global science instrument.

Source : TH

NISAR Satellite FAQs

Q1: What is the NISAR satellite?

Ans: NISAR is a joint NASA-ISRO satellite equipped with dual-band synthetic aperture radar for advanced Earth observation.

Q2: What makes NISAR unique?

Ans: It is the first satellite to combine L-band and S-band radar systems, enabling high-resolution imaging through clouds and vegetation.

Q3: What are the main applications of NISAR data?

Ans: NISAR will support disaster response, agricultural forecasting, biomass mapping, and climate research globally.

Q4: How will NISAR benefit India specifically?

Ans: India will gain access to S-band radar data focused on its territory for improved crop, forest, and disaster monitoring.

Q5: When and where will NISAR be launched?

Ans: NISAR is scheduled for launch on July 30, 2025, from Sriharikota using ISRO’s GSLV Mk-II rocket.