The Indian Space Research Organisation (ISRO) has successfully completed a ground static test of the Polar Satellite Launch Vehicle's (PSLV) third stage, known as PS3, at the Static Test Facility in Satish Dhawan Space Centre, Sriharikota, on 12 November 2026.

The test marks a significant step in validating a strengthened version of the solid-propellant stage after anomalies were observed during the PSLV-C61/EOS-09 and PSLV-C62/EOS-N1 missions.

In response, ISRO undertook a comprehensive review of the PS3 configuration, examining design margins, raw material acceptance criteria, assembly procedures and quality assurance practices.

As part of the review, the organisation introduced a series of engineering improvements aimed at enhancing reliability and operational robustness. The nozzle configuration was revised to provide greater design margins, while procedures governing raw material acceptance, stage assembly and quality inspections were updated and strengthened.

Engineers also reinforced the mechanical interfaces and incorporated redundancy into critical sealing systems. These modifications were accompanied by a detailed verification programme to confirm the adequacy of the revised design margins under operating conditions.

ISRO further implemented enhanced assembly procedures and additional Non-Destructive Testing (NDT) measures across various stages of integration and transportation. The upgraded PS3 solid motor stage was subsequently realised and subjected to the successful static firing test.

The latest test demonstrates progress in ISRO's efforts to address the issues identified during recent PSLV flights and restore confidence in one of India's most widely used launch vehicles.

The PSLV has historically served as the country's workhorse launcher, supporting Earth observation, scientific and commercial satellite missions.

ISRO stated that the "new version of the PS3 Solid motor stage is realised and tested successfully". The space agency added that, based on detailed analysis and reviews of the test data, further tests are planned before the upgraded configuration is cleared for future missions.

The successful qualification effort is expected to contribute to improved mission reliability as ISRO continues preparations for upcoming PSLV launches and expands its broader space transportation capabilities.

ISRO