NASA and ISRO partner to develop NISAR, a Space Observatory to Map the Planet Every 12 days.

NASA and ISRO are working together to develop a Low Earth Orbit (LEO) observatory called NASA-ISRO SAR (NISAR). (SAR stands for Synthetic Aperture Radar). NISAR’s goal is to map the entire planet every 12 days, providing consistent spatial and temporal data to better understand changes in the Earth’s ecosystems, ice mass, vegetation biomass, sea level rise, groundwater, earthquakes, tsunamis, volcanoes, and landslides.

NISAR

NISAR carries a dual-band Synthetic Aperture Radar (SAR) operating with the Sweep SAR technique, which can achieve a large swath of high-resolution data. The SAR payloads, mounted on the Integrated Radar Instrument Structure (IRIS), and the spacecraft bus together form an observatory. The observatory is being built by the Jet Propulsion Laboratories and ISRO to meet national needs and provide data to encourage surface deformation studies through the repeat-pass InSAR technique.

NISAR

NISAR

This partnership between NASA and ISRO will make major contributions from both agencies. NASA is responsible for providing the L-Band SAR payload system, while ISRO is supplying the S-Band SAR payload. The two SAR systems will use a large, 12-meter diameter common unfurlable reflector antenna. Additionally, NASA will provide engineering payloads for the mission, including a Payload Data Subsystem, High-rate Science Downlink System, GPS receivers, and a Solid State Recorder.

NISAR NISAR

The NASA-ISRO SAR (NISAR) mission will be the first to use dual frequency radar imaging in L-Band and S-Band, utilizing advanced Sweep SAR techniques to provide high-resolution, repeat cycle, and larger swath space-borne SAR data in full-polar metric and interferometric modes of operation. This mission will clarify spatially and temporally complex phenomena, ranging from ecosystem disturbances to ice sheet collapse and natural hazards such as earthquakes, tsunamis, volcanoes, and landslides. It is expected to advance microwave remote sensing applications in geosciences.

NISAR’s precision interferometric orbits will enable the mapping of few millimetres of deformations in the land surface. The selection of lower frequency bands will aid in characterizing vegetation, which is vital for global carbon stock estimation and monitoring of carbon fluxes from vegetation. The selection of L- and S-band frequencies will enable the characterization of targets beneath tree canopy and sub-surface features due to the differential penetration of the signals in two frequencies.

NISAR’s Synthetic Aperture Radar mission aims to determine Earth changes in three disciplines: ecosystems (vegetation and the carbon cycle), deformation (solid Earth studies), and cryosphere sciences (primarily as related to climatic drivers and effects on sea level). NISAR will acquire data over the Indian coasts and monitor annual changes in the bathymetry along the deltaic regions, as well as shoreline erosion and accretion. The mission will also observe sea ice characteristics over the seas surrounding India’s Antarctic polar stations and detect marine oil spills, providing location information for preventive measures during accidental oil seepage.

The NISAR observatory is a joint project between NASA and ISRO, and it carries a 12m wide deployable mesh reflector mounted onto a deployable 9m boom developed by JPL. This reflector will be used by both the L-Band SAR payload system developed by JPL and the S-Band SAR payload developed by ISRO. The Integrated Radar Instrument Structure (IRIS) hosts the S-SAR and L-SAR tiles along with their electronics and data handling systems. The spacecraft contains all the attitude and orbit control elements, power systems, and thermal management system. JPL is responsible for providing the LSAR Data Handling system, High-rate Science data Downlink System, GPS receivers, and a Solid State Recorder. ISRO, on the other hand, is responsible for providing the SSAR data handling system, High rate downlink system, spacecraft bus systems, the GSLV launch system, and Mission Operations Related Services. NISAR will provide global coverage and map the entire globe in 12 days, with the ability to provide spatially and temporally consistent data for understanding changes in Earth’s ecosystems, ice mass, vegetation biomass, sea level rise, ground water, and natural hazards including earthquakes, tsunamis, volcanoes, and landslides. The observatory will acquire data over the Indian Coasts and monitor annual changes in the bathymetry along the deltaic regions. It will also observe sea ice characteristics over the seas surrounding India’s Antarctic polar stations and can be used to detect marine oil spills. NISAR is being developed in three phases: the SIT-2 phase, during which the SAR payloads and the Engineering Systems will be independently developed; the SIT-3 phase, when the SAR payload along with other related systems will get integrated to the Radar Instrument Structure and tested at JPL; and the SIT-4 phase, during which the IRIS will be integrated with the spacecraft and evaluated as an observatory at ISRO. The SIT-4 testing phase is ongoing, and the NISAR observatory is expected to be launched from Indian Soil in the first quarter of 2024.

NISAR

MISSION PHASE

LAUNCH PHASE

The NISAR Observatory is scheduled to be launched in January 2024 from the Satish Dhawan Space Centre (SDSC) SHAR, located on the southeast coast of the Indian peninsula. The launch vehicle, the GSLV expendable launch vehicle, will be provided by ISRO. The launch sequence is a crucial event that includes the observatory’s journey from the ground, encapsulated in the launch vehicle fairing, to its separation, solar array deployment, and finally, being in an Earth-pointed attitude with two-way communication with the ground.

COMMISSIONING PHASE

During the first 90 days following the launch, the NISAR observatory will undergo a commissioning process known as in-orbit checkout (IOC). The primary goal of this process is to prepare the observatory for scientific operations. The commissioning process is divided into sub-phases that involve initial checkout of ISRO engineering systems and JPL engineering payload, spacecraft checkout, and instrument checkout. These sub-phases are designed as a step-by-step buildup in capability towards full observatory operations. The process begins with the deployment of all deployable parts, excluding solar arrays, and then proceeds with checking out the engineering systems. The next step involves turning on the radars and testing them independently, followed by conducting joint tests with both radars operating.

SCIENCE OPERATIONS PHASE

The science operations phase for NISAR will last for three years after the commissioning phase is complete. The primary objective of this phase is to collect all the data necessary to achieve the L1 science objectives. Regular maneuvers will be conducted during this phase to maintain the science orbit, while efforts will be made to minimize conflicts with science observations. Calibration and validation activities will take place extensively during the first five months, with yearly updates for one-month duration.

Before the launch of NISAR, frequent coordination between JPL and ISRO will result in the generation of an observation plan for both L- and S-band instruments, as well as engineering activities such as parameter updates and maneuvers. This plan is referred to as the reference mission, and the science observations within that reference mission are known as the reference observation plan (ROP).

The schedule for science observations will be determined by JPL’s mission planning team based on a variety of inputs, such as L- and S-band target maps, radar mode tables, and constraints and capabilities of the spacecraft and ground-station. The goal is to fly the reference mission exactly as planned pre-launch, with accommodations for small timing changes based on the actual orbit.

NISAR

Send-Off Ceremony of Science Instrument Payload of NISAR Held at NASA’s JPL

On February 3, 2023, a send-off ceremony was held at NASA’s Jet Propulsion Laboratory (JPL) for the science instrument payload of NISAR. The ceremony was attended by Shri S Somanath, Secretary of DOS/Chairman of ISRO, Sripriya Ranganathan, Indian Ambassador and Deputy Chief of Mission, as well as officials from ISRO and NASA.

NISAR is a Low Earth Orbit (LEO) observatory jointly developed by NASA and ISRO. It carries L and S dual band Synthetic Aperture Radar (SAR) that uses the Sweep SAR technique to achieve large swath with high-resolution data. The SAR payloads, mounted on the Integrated Radar Instrument Structure (IRIS) and the spacecraft bus, together form the observatory.

The NISAR observatory is equipped with a 12m wide deployable mesh reflector mounted onto a deployable 9m boom developed by JPL. This will be used by both the JPL-NASA developed L-Band SAR payload system and the ISRO developed S-Band SAR payload.

During the ceremony, S Somanath stated, “Today we come one step closer to fulfilling the immense scientific potential NASA and ISRO envisioned for NISAR when we joined forces more than eight years ago. This mission will be a powerful demonstration of the capability of radar as a science tool and help us study Earth’s dynamic land and ice surfaces in greater detail than ever before.”

NISSAR IMAGE

NISAR

NISAR

NISAR

NISAR UPSC

What is the objective of the NASA-ISRO SAR (NISAR) mission?

a. To map the entire planet every 12 days

b. To study the effect of climate change on vegetation

c. To detect marine oil spills

d. To monitor annual changes in bathymetry

What technology does NISAR use to achieve a large swath of high-resolution data?

a. Sweep SAR technique

b. Dual frequency radar imaging

c. Synthetic Aperture Radar

d. All of the above

What is the purpose of the Integrated Radar Instrument Structure (IRIS) in NISAR?

a. To host the SAR tiles along with their electronics and data handling systems

b. To control the spacecraft’s attitude and orbit

c. To provide power to the SAR payloads

d. To monitor annual changes in bathymetry

Which frequency bands are used by NISAR to enable the characterization of targets beneath tree canopy and sub-surface features?

a. L-Band

b. S-Band

c. Both L-Band and S-Band

d. None of the above

Which space agency is responsible for providing the S-Band SAR payload system for NISAR?

a. NASA

b. ISRO

c. JPL

d. All of the above

What kind of data will NISAR acquire related to cryosphere sciences?

a. Deformation studies

b. Solid Earth studies

c. Sea ice characteristics

d. Ecosystem disturbances

Which space agency is responsible for providing the spacecraft bus systems for NISAR?

a. NASA

b. ISRO

c. JPL

d. All of the above

How often will NISAR map the entire planet?

a. Every 24 days

b. Every 12 days

c. Every 6 months

d. Every year

What is the expected launch date for NISAR?

a. January 2024

b. July 2024

c. January 2025

d. July 2025

Which launch vehicle will be used to launch NISAR?

a. PSLV

b. GSLV

c. GSLV Mk III

d. ISRO launch vehicle

Also, read about Shukrayaan : India’s Mission to the Venus.

 

FAQ

Q. What is the full form of NISAR?

A. The full form of NISAR is NASA ISRO Synthetic Aperture Radar.

Q. What is the launch date of NISAR?

A. The launch date of NISAR will be in January, 2024.

Q. Where will NISAR launch?

A. Satish Dhawan Space Center, Sriharikota, Tirupati District, Andhra Pradesh, India.

Q. What is Mission NISAR?

A. NISAR’s goal is to map the entire planet every 12 days, providing consistent spatial and temporal data to better understand changes in the Earth’s ecosystems, ice mass, vegetation biomass, sea level rise, groundwater, earthquakes, tsunamis, volcanoes, and landslides.

Q. Is NISAR a joint product of ISRO?

A. Yes. It is in collaboration with NASA.

Q. Why is NISAR important?

A. NISAR is a crucial tool for observing and comprehending the effects of climate change on the Earth’s terrestrial surface. It will aid in the monitoring of melting glaciers, sea-level rise, and alterations in carbon storage.

Leave a Comment