The joint collaborative effort between Indian Space Research Organisation (ISRO) and US National Aeronautics and Space Administration (NASA) is about to hit a major milestone and near its completion as NASAs C-130 Hercules aircraft is en route to deliver a crucial radar antenna reflector for the NISAR satellite to Bengaluru, India. This delivery is a significant step in the collaborative NASA-ISRO Synthetic Aperture Radar (NISAR) mission, aimed at providing unprecedented insights into Earths dynamic systems.

The C-130 Hercules will make several stops en route to India, including a key stop at March Air Reserve Base in California. Here, the radar antenna reflector will be picked up from NASAs Jet Propulsion Laboratory (JPL). This component had been sent back to the U.S. in March for a special thermal coating to ensure it can withstand higher-than-expected temperatures during its deployment in space. The reflector is expected to arrive in India by early November for integration into the NISAR satellite.

The NISAR Mission

NISAR, a joint mission between NASA and ISRO, is set to launch in February 2025 from the Satish Dhawan Space Centre in Sriharikota, Andhra Pradesh, India. The satellite will be carried into space aboard ISROs Geosynchronous Satellite Launch Vehicle Mark-II (GSLV Mk-II). Once operational, NISAR will provide essential data for scientists studying environmental changes and natural hazards around the globe.

The NISAR satellite will orbit Earth in a sun-synchronous orbit at an altitude of 747 kilometers (464 miles). This type of orbit allows the satellite to consistently pass over the same regions at the same local solar time, which is ideal for observing changes over time.

NISAR will bounce radar signals off nearly all the planet’s solid surfaces twice every 12 days on both ascending and descending orbits, tracking the motion of those surfaces down to fractions of an inch. This will allow it to sample Earths surface approximately every 6 days over a planned 3-year mission.

Objectives and Capabilities

The NISAR satellite will measure key Earth vital signs, including the health of wetlands, ground deformation by volcanoes, and the dynamics of land and sea ice. It will observe Earths land and ice-covered surfaces globally with 12-day regularity, sampling Earth on average every 6 days for a baseline 3-year mission.

NISARs unique insights into Earths cryosphere will come from the combined use of two radars: an L-band system with a 10-inch (25-centimeter) wavelength and an S-band system with a 4-inch (10-centimeter) wavelength. The L-band radar can see through snow, helping scientists track the motion of ice underneath, while the S-band radar is more sensitive to snow moisture, indicating melting. Both signals can penetrate clouds and darkness, enabling observations during the polar winter nights.

This historic mission marks the first time NASA and ISRO have cooperated on hardware development for an Earth-observing mission. NASAs Jet Propulsion Laboratory leads the U.S. component of the project, providing the L-band SAR, radar reflector antenna, deployable boom, high-rate communication subsystem for science data, GPS receivers, solid-state recorder, and payload data subsystem. ISROs U R Rao Satellite Centre in Bengaluru is providing the spacecraft bus, launch vehicle, and associated launch services and satellite mission operations. ISROs Space Applications Centre in Ahmedabad is providing the S-band SAR electronics.