Unconnected wiring led to failure of India's navigation satellite, ISRO reveals

Spacefaring is a zero-error business. The smallest of errors or acts of negligence can lead to million-dollar failures and capability loss. A year after the failure of its strategic-use NVS-02 Navigation satellite, the Indian Space Agency, ISRO, has now revealed that something as simple as an unconnected/disconnected part of a circuit could have been the cause. In the GSLV-F15/NVS-02 mission carried out in January 2025, ISRO's GSLV rocket placed the NVS-02 satellite in its initial orbit.

Thereafter, the satellite had to fire its onboard engines to push itself to its final destination, a higher orbit that is almost 36,000 km above the Earth. However, the engine firing and orbit raising did not take place. Stuck in its initial orbit, the expensive satellite was unable to serve its core purpose of providing Position, Navigation, and Timing. ISRO said that it constituted an Apex Committee to review the observations and recommend further course of action regarding the NVS-02 satellite failure. Based on available Telemetry data, detailed simulation studies were further carried out.

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The Apex Committee concluded that the prime reason for the observation was found to be the drive signal not reaching the pyro valve of the oxidizer line of the engine meant for orbit raising. “The committee concluded that the most likely cause for the observation is the disengagement of at least one contact (in each of the main and redundant paths) of the connector.” In simple terms, there were two circuits-a primary and a backup- but there was a "disengagement" in a contact(a connecting component) in both of them. Therefore, the signals for engine firing were not delivered; it can be inferred. However, this incident also raises questions about the agency's quality control and inspection standards, as both the primary and secondary systems seem to have failed in the same manner.

Further, ISRO mentioned that the committee had provided a set of recommendations aimed at enhancing the redundancy and reliability of the engine firing system for future missions. In line with these recommendations, all the corrective actions were successfully implemented in the CMS-03/GSAT-7R satellite launched for the Indian Navy in November 2025, ISRO said. It was added that the engine firing systems performed satisfactorily and placed the CMS-03/GSAT-7R satellite in the intended orbit. Further, this set of recommendations will be followed for all future missions, as applicable, ISRO said.

The NVS-02 failure was a costly one for India, as the failure rendered India's desi-GPS 'NAVIC' near-defunct. Back in 2025, the author had reported on the perilous condition of NAVIC after the NVS-02 failure. Even a year after the failure, ISRO has not launched the replacement for the NVS-02.