Valve malfunction blamed for failure of Indian satellite to raise its orbit

HOUSTON — India’s space agency says a valve failure prevented a navigation spacecraft launched more than a year ago from raising its orbit.

In a Feb. 25 statement, the Indian Space Research Organisation (ISRO) announced the outcome of an investigation by an “Apex Committee” into the January 2025 launch of the NVS-02 navigation satellite on a GSLV Mark 2 rocket.

The rocket successfully placed NVS-02 into a geostationary transfer orbit. However, the spacecraft was unable to fire its own engine to raise its orbit, stranding it in that transfer orbit that largely prevents the spacecraft from carrying out its mission. The spacecraft remains in a transfer orbit ranging from 287 and 37,252 kilometers at an inclination of 20.85 degrees, according to data from the U.S. Space Force’s Space-Track service.

In the statement, ISRO said the committee concluded that a pyrotechnic valve failed to open, preventing oxidizer from reaching the spacecraft’s orbit-raising engine. The signal commanding the valve to open failed to reach it.

“The committee concluded that the most likely cause for the observation is the disengagement of at least one contacts (in each of the main and redundant paths) of the connector,” the agency stated.

ISRO did not go into further details about the problem, but said it made changes “aimed at enhancing the redundancy and reliability of pyro system operations.” Those changes were successfully tested on another satellite, CMS-03, launched in November.

The problem with NVS-02 was one of three failures that ISRO suffered within 12 months. In May 2025, a Polar Satellite Launch Vehicle (PSLV) carrying a radar imaging satellite failed to reach orbit when its third stage malfunctioned. The PSLV returned to flight Jan. 11, only to suffer another failure in its third stage, causing the loss of the EOS-N1 imaging satellite and 15 secondary payloads.

ISRO did not disclose the root cause of the May 2025 PSLV failure before returning to flight, and has provided few details about the investigation into the more recent PSLV failure.

“A National level expert committee constituted is reviewing the reason for anomaly in PSLV Vehicle,” ISRO said in a separate statement Feb. 25. It did not disclose any other information about the committee or investigation.

According to a Feb. 23 report by the Indian newspaper The Hindu, the committee includes a former chairman of ISRO, S. Somanath, and a former principal science adviser in the Indian government. The committee will be charged with reviewing potential “organizational” causes for the two PSLV failures and provide a report to the space agency by April.