ISRO and NASA Begin Countdown for Joint Earth-Observing NISAR Satellite Launch

30 July, 2025

The countdown has commenced for the launch of the NISAR (NASA-ISRO Synthetic Aperture Radar) satellite, a landmark joint mission. Scheduled to lift off from Sriharikota aboard an ISRO GSLV rocket, the satellite is the world's most expensive Earth-imaging satellite. It will map the entire globe every 12 days, providing unprecedentedly detailed data on climate change, ice-sheet collapse, and natural hazards. The collaboration is being hailed as a new high in India-US space partnership.

Unpacked:

Why is NISAR considered the world's most expensive Earth-imaging satellite?

NISAR’s high cost is due to its advanced dual-band (L- and S-band) synthetic aperture radar technology, large 12-meter deployable antenna, and international collaboration. The mission aims to deliver frequent, high-resolution global data, which requires sophisticated hardware and significant investment from both NASA and ISRO.

What specific scientific goals will NISAR address regarding climate change and natural hazards?

NISAR will monitor land and ice deformation, track ice-sheet collapse, measure biomass, and detect changes in ecosystems. It will provide data on earthquakes, volcanoes, landslides, and flooding, helping scientists understand and predict climate change impacts and natural hazards globally.

How does the NISAR satellite’s technology differ from previous Earth observation missions?

NISAR is the first satellite to use dual-frequency synthetic aperture radar (L- and S-band), enabling it to penetrate vegetation and ice, and to provide detailed, frequent, cloud-independent imaging. Its large swath width and high resolution allow for comprehensive, regular coverage not possible with earlier satellites.

What is the significance of the India-US partnership in the NISAR mission?

The NISAR mission represents an unprecedented level of collaboration in Earth sciences between NASA and ISRO. It combines technical expertise, shares costs and responsibilities, and is seen as a milestone in strengthening strategic and scientific ties between the two countries.