The historic NISAR mission, a landmark collaboration between NASA and ISRO, has now entered its crucial 90-day commissioning phase. During this period, scientists will conduct rigorous checks, calibrations, and orbital adjustments to prepare the satellite for full-scale Earth observation. This critical phase follows the successful launch of the radar imaging satellite on July 30th aboard a GSLV-F16 rocket from Sriharikota in Andhra Pradesh.
Speaking to PTI, Gerald W. Bawden, Program Manager for Natural Hazards Research at NASA's Earth Sciences Division, outlined the key activities currently underway. "NISAR is inserted at an altitude of 737 km, and we need to actually rise up to 747 km. It will take about 45-50 days for those operations to take place," he explained. After commissioning is complete, he stated that the radars will be activated, beginning to collect data over "all ice, all land, all the time" from Earth.
"The resolution will be 5 meters by 5 meters, and we will be imaging that every 12 days. So it is a lot of data. It is more data than NASA has collected in any other mission," Bawden added, highlighting the sheer volume of information NISAR will provide.
Gained insights from ISRO
When asked about key lessons learned from the collaboration with the Bengaluru-based space agency for the NISAR mission, the scientist noted that NASA gained insights from ISRO's focus on how science can directly benefit society, while ISRO learned from NASA's deep emphasis on scientific research.
Bawden also commented on the unique aspects of the project, which brought together scientists from two countries on opposite sides of the world, navigating a 12.5-hour time difference and cultural differences. "...we had culture differences and the other thing is that we are on the opposite side of the world. We have to work together and we have the common love for technology," he remarked.
"The two scientists (of ISRO and NASA) are building partnerships by working together, friendships," Bawden observed. "This NISAR partnership is more than building an amazing satellite; it is teams that are together to solve bigger problems".
Responding to a query on the opportunities that the collaboration with ISRO offers for NASA, Sanghamitra B. Dutta, Program Executive at NASA's Earth Sciences Division, stated, "This is the first large Earth-observing mission that India and the United States have put together. India is also working on human spaceflight, so there have been collaborations between the U.S. and India on this over the last 4-5 years".
She proudly mentioned, "An Indian astronaut (Subhanshu Shukla) recently went to the International Space Station, which has also been built as part of a collaboration between the U.S. and India. We are enormously proud to work with each other, and it will continue in the future in the commercial area, space collaboration, and technology development, as well as the science area".
Dual-band radar
Regarding the mission's dual-band radar, Dutta explained that while radar missions have occurred in the past, "simultaneous observation (of the Earth) in two different frequencies by two different radars flying together did not happen before. Scientists need not confine to the boundary of a country, and they always discuss possibilities of new missions and bigger and better science".
She further elaborated that during discussions, scientists from ISRO and NASA conceived the idea to fly two radars at once, using two different frequencies to collect more diverse technical data. "The idea was first discussed between Space Applications Centre, ISRO Ahmedabad, and scientists from Jet Propulsion Laboratory, NASA. They discussed, brainstormed, and came up with the idea of two radars working simultaneously," she added.
Benefits of two frequencies
Supporting Dutta's statement, Bawden highlighted the major benefits of having two frequencies. "We have a technology challenge, and at the end of the day, we are building the technology to address scientific questions. NASA has the long L Band, while ISRO has the S band. It is fantastic to study agriculture, like how corn grows, [and] soybeans grow," he concluded, illustrating the practical applications of NISAR's advanced capabilities.
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