The Joint Mission: ISRO-NASA's Plan to Launch the "NISAR" Satellite in 2025

Synthetic Aperture Radar (SAR) technology, which is the foundation of NISAR, allows the satellite to use radio waves to take high-resolution pictures.

The NASA-ISRO Synthetic Aperture Radar (NISAR) satellite is scheduled to launch in March 2025 by NASA and the Indian Space Research Organization (ISRO).

With state-of-the-art equipment and unmatched accuracy, this collaborative project, valued at ₹5,000 crore, seeks to transform Earth observation.

The 2.8-ton satellite will be launched from the Satish Dhawan Space Centre (SDSC) in Sriharikota, India, on board ISRO's GSLV Mk-II rocket. NISAR is scheduled to operate for three years at an altitude of 747 kilometers in a sun-synchronous orbit.

The Goals of NISAR

The NISAR mission, which was conceived in 2009, is the culmination of a ten-year collaboration between NASA and ISRO.

After ISRO's successful missions, such as Chandrayaan-1 and RISAT-2, NASA joined with India after initially seeking Germany's participation. The official launch of the mission in 2014 highlighted the two space agencies' shared dedication to scientific progress.

The main goal of NISAR is to provide unparalleled accuracy in monitoring changes on the Earth's surface. The satellite will gather detailed information about ecosystems, land dynamics, ice formations, and geological events by scanning almost all of Earth's land and ice surfaces twice every 12 days.

NISAR's Advanced Technology Makes It Unique

Synthetic Aperture Radar (SAR) technology, which is the foundation of NISAR, allows the satellite to use radio waves to take high-resolution pictures. SAR can work in bad weather, through thick foliage, and in complete darkness, unlike optical imaging satellites.

NISAR uses dual-frequency radars, ISRO's S-band (3.20 GHz) and NASA's L-band (1.25 GHz), to balance high-resolution imaging and deep penetration. It is one of the most sophisticated Earth observation satellites ever constructed, with a 12-day revisit cycle, 10-meter resolution, and a 240-km sweep width.

NASA provided the satellite's enormous 12-meter drum-shaped reflector, which is used to send and receive microwave signals to and from the surface of the Earth. Before being shipped to Bengaluru, India, in October 2024 to be integrated with the spaceship, this reflector underwent extensive testing in California. To ensure that the reflector could deploy smoothly throughout operations, engineers used reflective tape to control temperature variations.

NISAR's Transformative Applications

The capabilities of NISAR have the potential to revolutionize a number of fields:

Earth Observation: By keeping an eye on plants, ecosystems, and land use, the satellite will provide important information for study on biodiversity and climate change.

Geological Monitoring: It will help predict and respond to disasters by tracking minute surface changes, such as movements brought on by landslides, earthquakes, and volcanic activity.

Infrastructure Assessment: NISAR can assess the integrity of vital infrastructure, such as buildings, bridges, and dams, by spotting changes as tiny as an inch.

Climate Research: Understanding climate change and its effects on the earth will be possible through observations of glaciers, ice sheets, and wetlands.

It is anticipated that the satellite will produce an astounding 26 terabits of data every day. A streamlined management system will be used to process this data, guaranteeing prompt delivery of vital information for practical and scientific applications.

Overcoming Obstacles

Technical difficulties, especially with its radar antenna reflector, caused delays in the NISAR mission. To ensure that the satellite is prepared for its 2025 launch, NASA and ISRO overcame these obstacles.

An important turning point in the mission's development was reached when the reflector and other parts were successfully reintegrated at ISRO's Spacecraft Integration and Test Establishment (ISITE) in Bengaluru.