PS3 stage (L) being integrated with PSLV-C62 launch vehicle during pre-launch phase

The Indian Space Research Organisation's (ISRO) PSLV-C62 mission, launched on 12 January 2026 from Sriharikota, aimed to deploy the EOS-N1 satellite alongside 15 co-passenger satellites into orbit. 

Within minutes of lift-off, ISRO reported an anomaly towards the end of the rocket's third stage, designated PS3. Mission control observed performance as expected until that point, after which increased disturbances in the vehicle's roll rates caused a deviation from the planned flight path.

This uncontrolled spinning prevented the rocket from proceeding as intended, rendering satellite deployment impossible. As of 16 January, ISRO had initiated a detailed analysis but had not disclosed the root cause.

Thailand's space agency, GISTDA, whose THEOS-2A satellite was aboard, confirmed that a malfunction late in the PS3 stage led to attitude-control issues and trajectory deviation. GISTDA anticipated that the rocket and payloads would re-enter and burn up over the southern Indian Ocean.

The incident bears similarities to the PSLV-C61 mission on 18 May 2025, which carried the EOS-09 satellite. That flight failed after the first two stages, with the PS3 stage experiencing a drop in chamber pressure in the motor casing. ISRO described the mission as unaccomplished, noting non-nominal PS3 performance.

Both missions shared nominal early ascent followed by PS3 anomalies—roll rate disturbance in C62 and pressure drop in C61—preventing payload insertion into designated orbits, except possibly for the KID payload on C62.

Following PSLV-C61, ISRO Chairman V. Narayanan established a Failure Analysis Committee (FAC) to investigate. The FAC, convened ad hoc for major incidents, reconstructs events using telemetry, subsystem data, and expert consultations. It identifies causes and recommends corrective actions before certifying the vehicle for return to flight. Members typically include ISRO experts, academics, and sometimes former chairmen, with the final report submitted to the Prime Minister's Office (PMO) via the Department of Space.

The PSLV-C61 FAC report reached the PMO in mid-2025 but remains unreleased to the public. Independent experts have criticised this opacity, particularly after PSLV-C62's similar failure. ISRO has not confirmed an FAC for C62, though its website mentions ongoing analysis.

In November 2025, Vikram Sarabhai Space Centre Director A. Rajarajan attributed C61's loss to a "slight manufacturing error" during a lecture, yet no official detailed statement followed.

ISRO's communication contrasts with past practices. After the GSLV-F10 failure in 2021, the FAC detailed a liquid hydrogen tank pressure issue from a leaking vent valve, causing turbo pump malfunction and mission abort.

Similar transparency occurred post-GSLV-F02 in 2006. However, reports for PSLV-C39 (2017) and issues with NVS-02 underperformance were withheld or terse, marking PSLV-C61 as a departure from detailed public summaries.

The PSLV-C62 primary payload, EOS-N1, was a DRDO surveillance satellite. Co-passengers hailed from Thailand (THEOS-2A), the UK, Nepal, France, Spain, Brazil, and seven Indian private firms. Facilitated by NewSpace India Ltd (NSIL), this marked the PSLV's first failure with international and domestic commercial satellites aboard. Previous PSLV failures—four in total—did not involve such payloads.

GISTDA reported THEOS-2A as insured, mitigating their losses. Indian private payloads reportedly lacked insurance, leaving developers to absorb costs. India's expense falls on EOS-N1's loss. The KID payload, a Spain-based Orbital Paradigm re-entry demonstrator intended for Pacific splashdown, transmitted off-nominal data for three minutes post-anomaly.

These back-to-back PS3 failures raise concerns over PSLV reliability, a workhorse with over 50 successful missions historically. The PS3 stage, powered by a solid rocket motor, demands precise control for stable ascent. Unresolved manufacturing or design issues from C61 may have persisted, underscoring the need for swift FAC insights and public disclosure to rebuild confidence among commercial partners.

ISRO's shift towards terseness could impact NSIL's credibility in the competitive global launch market, where transparency fosters trust. As analysis continues, stakeholders await corrective measures to prevent recurrence, potentially delaying future PSLV flights until cleared.

IDN (With Agency Inputs)