NISAR satellite launched, to monitor Earth’s surface like never before: All you need to know

NASA-ISRO NISAR satellite onboard GSLV-F16 launched from Satish Dhawan Space Centre (SDSC) in Sriharikota. (Image: ANI)

The India Space and Research Organisation (ISRO), in collaboration with NASA, successfully launched an Earth observation satellite on Wednesday called NISAR.

NISAR, an acronym for NASA-ISRO Synthetic Aperture Radar satellite, weighing 2,393 kg, took off on a 51.7 metre tall, three-stage, GSLV-F16 rocket at 5.40 pm from the second launch pad at this spaceport situated about 135 km from Chennai on Wednesday.

The satellite, developed at a cost of $1.5 billion, is termed the most expensive and advanced Earth-observation satellite ever built to monitor the earth's atmosphere from space.

NISAR, or the NASA-ISRO Synthetic Aperture Radar, is a collaborative Earth observation satellite mission between NASA (United States) and ISRO. The satellite is designed to monitor changes in Earth's surface and atmosphere using powerful radar technology that can penetrate through clouds, fog, smoke, dense vegetation, and even ice.

NISAR is engineered to detect subtle changes in ecosystems, climate, and natural hazards. It will help scientists track phenomena such as earthquakes, volcanic activity, landslides, and the movement of land ice sheets. The satellite will also monitor soil moisture, wetlands, and vegetation, vital data for disaster management and agricultural planning.

The first 90 days after launch would be dedicated to commissioning or performing In-Orbit Checkout, the objective of which is to prepare the observatory for science operations, ISRO said.

Weighing around three tonnes and built at a cost of $1.5 billion, NISAR is considered the world’s most advanced and expensive civilian Earth observation satellite. It can capture high-resolution images of Earth’s surface in all weather conditions, day or night, and will map the entire globe and its ice cover every 12 days.

NISAR is expected to produce nearly 80 terabytes of data per day. According to NASA, the imagery will be both detailed enough to capture local changes and broad enough to assess regional trends. This will allow scientists worldwide to access crucial data for environmental monitoring and policy planning.

One of NISAR’s unique features is its dual radar system. It uses:

L-band radar (from NASA) to observe dense forests, soil, and subsurface features.

S-band radar (from ISRO) to detect surface-level changes such as plant growth and variations in water levels.

This dual-band approach allows for a comprehensive view of changes both above and below the surface.

This marks the first time NASA and ISRO have jointly developed an Earth observation satellite. The mission symbolises growing cooperation between the two space agencies in addressing global environmental and climate challenges. The life of the NISAR Mission is 5 years, ISRO said.