The upcoming US-India NISAR (NASA-ISRO Synthetic Aperture Radar) mission promises to observe Earth in unprecedented detail, offering valuable insights into the planet’s dynamic surface.
NISAR is a groundbreaking dual-band radar satellite that will measure land deformation caused by earthquakes, landslides, and volcanic activity, providing critical data for both scientific research and disaster management. It will also monitor the movement of glaciers and ice sheets, as well as track the expansion or loss of forests and wetlands, contributing to our understanding of the global carbon cycle.
The mission’s impact will be wide-ranging, but the journey to its launch — just a few months away — has been just as remarkable. Paul Rosen, NISAR’s project scientist at NASA’s Jet Propulsion Laboratory, has been involved at every stage of the mission. He recently shared insights about what makes NISAR so unique.
What makes NISAR unique?
NISAR will be the first Earth-observing satellite to feature two radar systems: an L-band with a 10-inch (25-centimeter) wavelength and an S-band with a 4-inch (10-centimeter) wavelength.
The way microwaves interact with objects depends on their wavelength. Shorter wavelengths are more sensitive to smaller features like leaves or rough surfaces, while longer wavelengths are better at detecting larger objects like boulders or tree trunks.
By using two distinct radar wavelengths, NISAR will allow scientists to examine a broader range of Earth’s surface features than with either radar alone, providing a more comprehensive view of the environment.
What will happen to the data?
NISAR’s data will serve various scientific areas, including ecosystems, the cryosphere, and solid Earth, with applications beyond basic research, such as monitoring soil moisture and water resources.
To ensure easy access, NASA will make all mission data available for free through the cloud. Given the large volume of data, it will be processed and stored online, providing an accessible platform for users worldwide.
Partnership with ISRO
The collaboration between NASA and ISRO started with the proposal for the DESDynI (Deformation, Ecosystem Structure, and Dynamics of Ice) mission, an L-band satellite, following the 2007 Decadal Survey by the National Academy of Sciences, Rosen said. At the time, ISRO was considering launching an S-band satellite. In 2014, both science teams proposed a dual-band mission, and NASA and ISRO decided to partner on NISAR, he added.
Since then, the two agencies have worked together. The hardware was developed on different continents before being brought together in India to complete the satellite.
More about NISAR
NISAR is a joint project between NASA and ISRO, marking the first time the two agencies have collaborated on hardware development for an Earth-observing mission. Managed by Caltech, JPL leads the US component of the project and is responsible for the L-band Synthetic Aperture Radar (SAR). NASA also contributes the radar reflector antenna, deployable boom, high-rate communication subsystem for science data, GPS receivers, solid-state recorder, and the payload data subsystem.
ISRO's Space Applications Centre in Ahmedabad is providing the S-band SAR and handling its calibration, data processing, and the development of science algorithms. The U R Rao Satellite Centre in Bengaluru, which leads ISRO’s efforts on the mission, is providing the spacecraft bus. The launch vehicle comes from ISRO’s Vikram Sarabhai Space Centre, with launch services through ISRO’s Satish Dhawan Space Centre. ISRO Telemetry Tracking and Command Network will manage the satellite's mission operations, while the National Remote Sensing Centre in Hyderabad will oversee S-band data reception, operational product generation, and dissemination.
NISAR launch date
The NASA-ISRO Synthetic Aperture Radar (NISAR) satellite is expected to launch in March 2025 from the Satish Dhawan Space Centre in Sriharikota, India. NASA and ISRO will coordinate to determine an official launch readiness date, taking into account technical and environmental factors.