NISAR is the first of its kind mission, jointly developed by ISRO and NASA. It is an L and S-band, global, microwave imaging mission, with capability to acquire fully polarimetric and interferometric data.

NISAR mission’s primary objectives are to study land & ice deformation, land ecosystems, and oceanic regions in areas of common interest to the US and Indian science communities.

NISAR mission will help to

measure the woody biomass and its changes
track changes in the extent of active crops
understand the changes in wetlands’ extent
map Greenland’s & Antarctica’s ice sheets, dynamics of sea ice and mountain glaciers
characterise land surface deformation related to seismicity, volcanism, landslides, and subsidence & uplift associated with changes in subsurface aquifers, hydrocarbon reservoirs, etc.

Spacecraft Configuration

The Spacecraft is built around ISRO’s I-3K Structure. It carries two major Payloads viz., L & S- Band Synthetic Aperture Radar (SAR). The S-band Radar system, data handling & high- speed downlink system, the spacecraft and the launch system are developed by ISRO.

The L-band Radar system, high speed downlink system, the Solid-State Recorder, GPS receiver, the 9m Boom hoisting the 12m reflector are delivered by NASA. Further, ISRO takes care of the satellite commanding and operations, NASA will provide the orbit manoeuvre plan and RADAR operations plan. NISAR mission will be aided with ground station support of both ISRO and NASA for downloading of the acquired images, which after the necessary processing will be disseminated to the user community

The data acquired through S-band and L-band SAR from a single platform will help the scientists to understand the changes happening to Planet Earth.

Mission CharacteristicsParameter
Mainframe BusI3K Structure with ~2400Kg Lift Off Mass. 70V Bus.
3-axis stabilised spacecraft
Imaging Payload Dual Frequency (L & S-Band) Synthetic Aperture Radar (SAR).
L-band SAR (NASA); S-band SAR (SAC-ISRO).
Large size 12m diameter common unfurlable reflector antenna mounted on deployable 9m Boom.
~240 km observable swath with 5-100 m resolution.Free and open data policy
OrbitSun synchronous. Polar (6PM)
Orbit altitude747 km – Circular
Inclination98.405 deg
LauncherGSLV MK-II with 4m PLF
Mission Life5 Years

Realisation of NISAR

The complex payloads and mainframe systems have been designed, developed, qualified and realised over a period of 8 to 10 years.

The S- Band SAR and L- Band SAR were independently developed, integrated and tested at ISRO and JPL/NASA respectively.

The Integrated Radar Instrument Structure (IRIS), consisting of S – Band and L – Band SAR and other payload elements were integrated and tested at JPL/NASA and delivered to ISRO.

Mainframe satellite elements and payloads were assembled, integrated and tested at URSC/ISRO.

NISAR Mission Phases

NISAR mission phases can be broadly classified into: Launch phase, Deployment Phase, Commissioning Phase and Science Phase.

Launch Phase

NISAR will be launched onboard GSLV-F16 launch vehicle on July 30, 2025 from ISRO’s Satish Dhawan Space Centre (SDSC), also referred to as Sriharikota High Altitude Range (SHAR), located in Sriharikota on the southeast coast of the Indian peninsula

Deployment Phase

NISAR hosts a 12m dia large reflector which shall be deployed in-orbit 9m away from the satellite by a complex multistage deployable boom designed and developed by JPL/NASA.

Commissioning Phase

The first 90 days after launch will be dedicated to commissioning, or In-Orbit Checkout (IOC), the objective of which is to prepare the observatory for science operations. Commissioning is divided into sub-phases of initial checks and calibrations of mainframe elements followed by JPL engineering payload and instrument checkout.

Science Operations Phase

The science operations phase begins at the end of commissioning and extends till end of mission life. During this phase, the science orbit will be maintained via regular manoeuvres, scheduled to avoid or minimize conflicts with science observations. Extensive calibration and validation (CalVal) activities will take place. The observation plan for both L and S-band instruments, along with engineering activities (e.g., manoeuvres, parameter updates, etc.), will be generated pre-launch via frequent coordination between JPL and ISRO.

ISRO