NISAR Satellite Delayed To 2025 Due To Special Coating Work and Orbital Constraints

The highly anticipated launch of the NASA-ISRO Synthetic Aperture Radar (NISAR) satellite has been postponed to February 2025; due to the need to complete work on the spacecraft’s antenna and specific orbital constraints.

NASA has confirmed ongoing efforts to finalize the large deployable antenna for the NISAR spacecraft, which had returned from India to the United States earlier this year. The need for additional work arose in March when analyses indicated that the antenna's reflector might face higher-than-expected temperatures in its stowed configuration for launch. Consequently, NASA decided to apply a special coating to mitigate these temperature risks.

NASA had planned to provide a new launch date for NISAR by the end of April. However, updates on the status of the spacecraft's modifications and a revised launch date were not disclosed until the latest announcement.

The update followed reports in Indian media suggesting that the mission, originally scheduled for launch in the spring, would not occur this year. In a response to a question from the Lok Sabha, India’s lower house of parliament, on July 24, Jitendra Singh, the government minister responsible for space, listed upcoming missions for 2024, notably excluding NISAR.

NASA confirmed that work on the antenna, which spans 12 meters in diameter when fully deployed, is nearing completion. The modifications include installing reflecting tape and other precautionary measures to control temperature increases when the antenna is stowed. After completing the testing of these changes, the antenna will be shipped back to India for reinstallation on the NISAR spacecraft.

While NASA did not specify an exact timetable for these final steps, they stated that a launch readiness date would be determined by ISRO, in coordination with NASA, after the antenna is reinstalled on the spacecraft. The statement highlighted that the launch could not occur between early October 2024 and early February 2025 due to the potential for temperature fluctuations affecting the antenna’s boom deployment caused by alternating sunlight and shadows. This timeframe indicates that the launch will be postponed until at least February 2025, considering the remaining preparations needed for NISAR.

NISAR represents the first Earth science collaboration between NASA and the Indian Space Research Organisation (ISRO) and is among the most significant partnerships between the two agencies.

NASA has invested over $1 billion in the formulation and development of the mission. NASA is contributing the L-band radar and engineering payload, while ISRO is providing the S-band payload, spacecraft bus, and GSLV launch vehicle.

The NISAR radars will offer advanced radar imaging capabilities to support a wide range of Earth science applications, from measuring glacier flow rates to monitoring volcanic activity. The spacecraft will be capable of mapping the entire Earth every 12 days, providing critical data for various scientific and environmental studies.

The delay, though disappointing, is crucial to ensure the mission's success and the integrity of the satellite's operations once deployed.