The NISAR Earth science mission has moved a step closer to its 2024 launch. Its science payload of two radar systems, one built by NASA and the other by the Indian Space Research Organisation (ISRO), recently completed the journey from NASA’s Jet Propulsion Laboratory in Southern California to ISRO’s U R Rao Satellite Centre in Bengaluru, India.
Short for NASA-ISRO Synthetic Aperture Radar, NISAR will observe nearly all of Earth’s land and ice surfaces twice every 12 days, measuring movements in extremely fine detail. It will also survey forests and agricultural regions to help scientists understand carbon exchange between plants and the atmosphere.
NISAR’s payload will be the most advanced radar system ever launched as part of a NASA science mission, and it will feature the largest-ever radar antenna of its kind: a drum-shaped, wire mesh reflector nearly 40 feet (12 metres) in diametre that will extend from a 30 foot (9 metre) boom.
NASA is also providing the radar reflector antenna, the deployable boom, a high-rate communication subsystem for science data, GPS receivers, a solid-state recorder, and payload data subsystem
The mission’s science instruments consist of L- and S-band radar, so named to indicate the wavelengths of their signals. ISRO built the S-band radar, which it shipped to JPL in March 2021. Engineers spent much of the last two years integrating the instrument with the JPL-built L-band system, then conducting tests to verify they work well together.
In late February 2023, technicians and engineers working in a JPL clean room put the science payload into a specially designed shipping container before hoisting it onto a flatbed truck for the drive to March Air Reserve Base in California’s Riverside County. A US Air Force C-17 cargo plane carried it from there to Bengaluru, touching down on March 6.
The next time the satellite is airborne will be aboard ISRO’s Geosynchronous Satellite Launch Vehicle Mark II rocket, which is set to lift off in 2024 from Satish Dhawan Space Centre on India’s southeastern coast and deliver NISAR into a near-polar Earth orbit.
Once in operation, NISAR will be able to collect measurements day and night, in all weather conditions, and its trove of data will help researchers better understand a broad range of Earth science topics, including landslides, groundwater loss, and the carbon cycle.
NISAR is the first-ever collaboration between NASA and ISRO on an Earth-observing mission. JPL, which is managed for NASA by Caltech in Pasadena, leads the U.S. component of the project and is providing the mission’s L-band SAR. NASA is also providing the radar reflector antenna, the deployable boom, a high-rate communication subsystem for science data, GPS receivers, a solid-state recorder, and payload data subsystem. ISRO is providing the spacecraft bus, the S-band SAR, the launch vehicle, and associated launch services and satellite mission operations.
