Tracking a Changing Planet: The NASA-ISRO NISAR Mission

On July 30, 2025, the NASA-ISRO Synthetic Aperture Radar (NISAR) mission successfully launched from India’s Satish Dhawan Space Centre. While the SETI Institute is not involved in the NISAR mission, the data it will provide could be relevant to our researchers. To understand the possibility of life beyond Earth, our scientists also study the systems that make life on Earth possible. Missions like NISAR help us understand the co-evolution of environment and life. The search for habitability and life beyond Earth begins with understanding life on Earth.

This Earth-observing mission is a collaboration between NASA and the Indian Space Research Organisation (ISRO). This endeavor could transform how we understand and monitor how our planet changes over time, capturing shifts as small as a few centimeters across Earth’s landmass. NISAR will deliver comprehensive, high-resolution radar imagery of Earth ever collected, tracking shifting glaciers, rising sea levels, sinking land in urban areas and loss of forests.

NISAR is a radar imaging mission. It’s the first Earth-observing satellite to carry two advanced synthetic aperture radar (SAR) systems: NASA’s L-band radar and ISRO’s S-band radar. Together, these instruments allow scientists to track a wide range of changes on Earth’s surface, including shifting tectonic plates and rising sea levels, glacial melt, deforestation, and infrastructure movement, such as groundwater depletion.

Unlike optical satellites, radar systems can penetrate clouds, smoke, and vegetation, making NISAR ideal for continuous, all-weather, day and night monitoring. NISAR’s synthetic aperture radar (SAR) system works by sending microwave pulses toward Earth and measuring how those signals scatter back. The result is a finely detailed image, where each pixel contains both the amplitude (strength) and phase (timing) of the radar echo. NISAR will provide early warning insights. By comparing this data over time, scientists can detect small changes in the land’s elevation and structure, often before a crisis occurs.

NISAR’s data will support climate science by measuring ice sheet dynamics, forest biomass, and soil moisture. It can also track crop cycles, flood impacts, and land subsidence from groundwater loss or heavy infrastructure. Orbiting 747 kilometers above Earth in a sun-synchronous path, NISAR will scan nearly every land and ice-covered region every 12 days, sampling most areas every 6 days when accounting for passes in both directions. Its radar swath covers ~240 kilometers, with spatial resolution between 3 and 10 meters, depending on the mode.

At the heart of the spacecraft is a 12-meter deployable reflector antenna, which will unfurl in orbit to collect massive volumes of radar data. All of NISAR’s imagery will be freely and openly available to researchers, governments, and the public worldwide.

Now in a 90-day commissioning phase, NISAR’s operations are expected to begin later this year and continue for at least three years.

Whether we’re monitoring methane on Mars or technosignatures around distant stars, our research is grounded in the science of planets – including our own.

To learn more about NISAR, visit: https://science.nasa.gov/mission/nisar/