At the end of last month, specifically on July 30, 2025, a satellite marking a turning point in the observation of our planet was successfully launched from the Satish Dhawan Space Centre in Sriharikota, India. The NISAR (NASA-ISRO Synthetic Aperture Radar) project, the fruit of the most significant collaboration to date between the American space agency NASA and the Indian Space Research Organisation (ISRO), aims to provide a dynamic and unprecedentedly detailed three-dimensional view of the Earth. The successful launch was carried out using India's GSLV (Geosynchronous Satellite Launch Vehicle) rocket at 8:10 AM Eastern Time, or 5:10 PM Indian Standard Time. Mission controllers at ISRO established communication with the satellite approximately twenty minutes after liftoff, confirming that all systems were operating as expected and the spacecraft was on its way to its operational orbit.

Revolutionary Radar Technology for Planetary Monitoring

What makes NISAR unique is its advanced radar system. Positioned at an altitude of 747 kilometers above the Earth, the satellite uses two sophisticated radar instruments operating at different frequencies – the L-band, developed by NASA, and the S-band, developed by ISRO. This dual-frequency capability allows it to penetrate through clouds, smoke, dense vegetation, and darkness, ensuring continuous data collection regardless of weather conditions or time of day. Unlike optical satellites that require daylight and clear skies for imaging, NISAR can "see" the Earth's surface under all conditions. The heart of the system is a huge 12-meter diameter mesh antenna, the largest of its kind ever sent into space, mounted on a 9-meter long boom. Its task is to direct and receive microwave signals. By analyzing the differences in the return signals from both radars, scientists can create incredibly precise images and detect changes on the surface with an accuracy of just one centimeter.

Monitoring the Earth's Crust and Natural Disasters

One of the primary goals of the mission is to monitor subtle movements of the Earth's crust. The ability to detect shifts of just a few millimeters is crucial for a better understanding of the tectonic processes that lead to earthquakes, volcanic eruptions, and landslides. NISAR will systematically monitor seismically active areas and volcanoes, measuring ground deformations that can precede, accompany, and follow such events. This data will allow scientists to refine models for assessing earthquake risk and potentially identify early warning signs that herald eruptions. This opens up new possibilities for protecting communities in vulnerable areas, giving decision-makers key information for planning evacuations and disaster responses.

Ecosystem Monitoring and Climate Change

The mission will also have a huge impact on monitoring global ecosystems and the consequences of climate change. NISAR will track changes in forest and wetland areas, providing precise data on deforestation, biomass growth, and carbon stocks in vegetation. This data is vital for understanding the global carbon cycle and combating climate change. A particularly important task will be the monitoring of the cryosphere – ice sheets, glaciers, and sea ice. The satellite will provide continuous and detailed information on the rate of ice melt in Greenland and Antarctica, which is a key factor for predicting sea-level rise. It will also monitor changes in permafrost, the thawing of which releases large quantities of methane, a potent greenhouse gas.

Application in Agriculture and Resource Management

The data that NISAR will collect will also have direct practical applications in agriculture and water resource management. By monitoring soil moisture and crop health, the satellite will help farmers optimize irrigation and improve yields, which is crucial for global food security. It will also enable better management of groundwater supplies, monitoring land subsidence due to water extraction, and overseeing the condition of vital infrastructure such as dams, levees, and bridges. The ability to detect minimal deformations in infrastructural objects can indicate potential problems before they become critical.

Global Coverage and the Future of the Mission

The satellite will scan nearly the entire land and ice-covered surface of the planet twice every 12 days. This frequency of revisits will allow scientists to create time-series data that reveals how surface characteristics change over time. It will particularly cover areas of the southern polar hemisphere that are rarely the focus of other radar satellites. Following its successful launch, NISAR enters an approximately 90-day commissioning phase. During this period, the spacecraft will deploy its large radar antenna and perform instrument calibration. Once this phase is complete, the three-year primary science mission will begin. In line with its open data policy, all data collected during the mission will be freely available to the scientific community, government agencies, and the public worldwide, fostering global collaboration in addressing some of the greatest challenges facing humanity today.