LAS VEGAS — The launch of a joint U.S.-Indian radar imaging satellite will not take place before February 2025 because of work on the spacecraft’s antenna and orbital constraints, NASA said July 29.
In a blog post, NASA said it was completing work on the large deployable antenna on the NASA-ISRO Synthetic Aperture Radar (NISAR) spacecraft, which had been shipped back from India to the United States earlier this year. NASA said in March it needed to add a “special coating” to the antenna after analyses found that the reflector could encounter higher-than-expected temperatures while in its stowed configuration for launch.
At the time, NASA said it would provide a new launch date for NISAR at the end of April. However, the agency provided no updates on the status of the work on the spacecraft or a new launch date until now.
The update came after a SpaceNews inquiry about the status of the mission prompted by reports in Indian media that the mission, once scheduled to launch this spring, was no longer expected to launch this year. In a July 24 response to a question from the Lok Sabha, one of the houses of the Indian parliament, Jitendra Singh, the government minister responsible for space, listed the upcoming missions and launches planned by the country in space in 2024. The list notably excluded NISAR.
NASA stated in its update that the work on the antenna, which is 12 meters in diameter when fully deployed, was nearing completion. That work included installing reflecting tape as well as “other precautionary measures” to mitigate temperature increases when the antenna is stowed. The antenna will be shipped back to India once testing of those changes is complete, where it will be reinstalled on the NISAR spacecraft.
NASA did not disclose a timetable for that work, stating that after the antenna is reinstalled on the spacecraft “a launch readiness date will be determined by ISRO, in coordination with NASA.”
However, the statement noted that the launch cannot take place between early October and early February 2025 “because that launch window would put the satellite into periods of alternating sunlight and shadows” that would create temperature fluctuations affecting deployment of the antenna’s boom. That suggests that the spacecraft will not launch before February given the work remaining to prepare NISAR for launch.
NISAR is the first Earth science spacecraft collaboration between NASA and ISRO and represents one of the biggest partnerships between the agencies in general, with NASA alone spending more than $1 billion in formulation and development of the mission. NASA is providing an L-band radar and engineering payload, while ISRO is providing the S-band payload, spacecraft bus and GSLV launch vehicle.
The radars on NISAR will be capable of advanced radar imaging to support a wide range of Earth science needs, from measuring the flow rates of glaciers to volcanic activity. The spacecraft will be able to map the entire Earth every 12 days.
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