NASA, ISRO reviewing dates for launch of INDO-US joint NISAR mission

The NASA-ISRO Synthetic Aperture Radar (NISAR) mission, a joint Earth-observing satellite project, is facing launch delays due to technical issues with its reflector antenna.

• Mission Overview:
  • NISAR is designed to provide global measurements of Earth’s surface changes, including land deformation, glacier movement, and forest degradation, using L-band and S-band Synthetic Aperture Radar (SAR).
  • It will scan nearly all of Earth’s land and ice surfaces every 12 days.
  • The mission’s primary goals include monitoring ecosystems, ice mass, vegetation biomass, sea-level rise, groundwater, and natural hazards like earthquakes, tsunamis, volcanoes, and landslides.
  • The planned mission life is three years.
• Technical Challenges and Delays:
  • The 12-meter diameter reflector antenna experienced a potential overheating problem during testing.
  • The antenna was returned to the US for a special thermal coating application.
  • This issue caused the satellite to be returned from the Satish Dhawan Space Centre (SDSC) SHAR, Sriharikota, India to Bengaluru, for further testing.
  • The original target launch readiness date of March 2025 has been pushed back.
  • The launch is now being reviewed for a potential window in May or June, but this is dependent on further testing and launch window availability.
• Launch and Operations:
  • ISRO will provide launch services using the Geosynchronous Launch Vehicle Mark-II (GSLV Mk-II) to place NISAR into a Low Earth Orbit.
  • The launch sequence and initial 90-day commissioning phase, including in-orbit checkout (IOC), are critical for ensuring successful science operations.
  • Extensive calibration and validation (CalVal) activities will occur during the first five months of operation.
  • JPL and ISRO will collaborate on mission planning and science observation scheduling.
  • NASA is providing the L-Band SAR payload system, and engineering payloads including a Payload Data Subsystem, High-rate Science Downlink System, GPS receivers and a Solid State Recorder.
  • ISRO is providing the S-Band SAR payload and the launch vehicle.