The NISAR (NASA-ISRO Synthetic Aperture Radar) satellite was successfully launched from the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh, this week. What does this mean?
The NISAR satellite lifted off aboard an Indian Geosynchronous Satellite Launch Vehicle (GSLV) at 5:40 p.m. IST (8:10 a.m. EDT) on Wednesday, marking the beginning of a mission that promises to deliver new insights into Earth’s dynamic systems.
Jointly developed by NASA and the Indian Space Research Organisation (ISRO), the NISAR satellite is the most advanced Earth-observing radar satellite ever built. It shows a significant milestone in civil space cooperation between the United States and India, building on more than a decade of planning and development.
Monitoring the planet in new detail
Orbiting 747 kilometres (464 miles) above Earth in a sun-synchronous polar orbit, the NISAR satellite is equipped with two sophisticated radar instruments: an L-band radar provided by NASA and an S-band radar developed by ISRO. These instruments will work together to provide high-resolution, three-dimensional imaging of Earth’s surface, capable of detecting changes as small as a few centimetres.
The NISAR satellite will observe nearly all of the planet’s land and ice surfaces every 12 days, making it one of the most comprehensive Earth observation tools ever deployed. From tracking glacial movements and land subsidence to monitoring forests, wetlands, and agriculture, NISAR’s data will be necessary for a wide range of scientific and humanitarian applications.
Disaster response
NISAR’s capabilities go far beyond scientific research. By detecting surface deformation and land movement, the NISAR satellite will play a huge role in disaster preparedness and response. The ability to monitor changes in the Earth’s crust before, during, and after events like earthquakes, landslides, and volcanic eruptions can help protect communities and critical infrastructure.
Its radar systems can also operate through cloud cover and in darkness, providing uninterrupted monitoring regardless of weather or time of day. This makes NISAR especially valuable for emergency response scenarios where timely data is critical.
Mission design
The NISAR satellite’s advanced radar system is mounted on a 39-foot (12-meter) antenna reflector, which will be deployed during a 90-day commissioning phase following launch. This massive antenna will direct and receive microwave signals, allowing scientists to interpret changes in Earth’s surface over time by comparing repeated measurements.
This mission is also historic as the first free-flying satellite to carry both L-band and S-band synthetic aperture radar instruments. Each radar type is sensitive to different surface characteristics, enabling NISAR to gather a range of complementary data sets. The L-band radar is ideal for observing soil moisture, forest biomass, and glacial movement, while the S-band radar excels in monitoring vegetation and infrastructure.
The NISAR satellite’s impact is expected to be both global and local. While it will provide data for scientists and policymakers around the world, the information it gathers will directly support local decision-making in agriculture, water management, and urban planning. Its findings will help communities adapt to climate change, respond to natural disasters, and better understand how human and natural forces are shaping the Earth.
