Why ISRO’s Consecutive PSLV Failures Have Raised Questions on Transparency and Quality Control

The back-to-back failures of the Polar Satellite Launch Vehicle (PSLV) — long regarded as the most reliable rocket in India’s space programme — have unsettled both strategic planners and commercial clients. With the PSLV-C61 mission failing in May 2025 and PSLV-C62 meeting a similar fate in January, the spotlight is now firmly on ISRO’s internal processes, its handling of technical anomalies, and the broader implications for India’s space ambitions.

What exactly went wrong with the PSLV-C61 mission?

The PSLV-C61 mission, launched by the Indian Space Research Organisation, was meant to place the EOS-09 Earth observation satellite into orbit. While the rocket’s first and second stages performed nominally, telemetry data revealed a sudden drop in chamber pressure in the third stage (PS3) around 203 seconds into the flight.

The PS3 is a solid-fuel motor — a mature and extensively flown component. In such motors, a rapid pressure drop is usually symptomatic of a serious structural issue, such as a casing breach or nozzle failure. Without adequate pressure, the motor cannot generate the thrust needed to maintain trajectory, leading to mission failure. The EOS-09 satellite was consequently lost.

Why the third stage anomaly is especially worrying

The PS3 stage is considered one of the most dependable elements of the PSLV architecture. Unlike liquid stages, solid motors have fewer moving parts and are generally less prone to in-flight anomalies. This is precisely why the recurrence of a third-stage-related problem in two consecutive missions has raised alarm.

In the January PSLV-C62 mission, ISRO Chairman V. Narayanan attributed the failure to a “roll rate disturbance”, indicating that the rocket began spinning uncontrollably. Crucially, the PS3 does not have independent roll control; it relies on stabilisation from the fourth stage. Any asymmetric gas leak or side-venting from the third stage could generate a torque strong enough to overwhelm these controls.

The unanswered questions around the Failure Analysis Committee report

Following the C61 failure, ISRO constituted a Failure Analysis Committee (FAC), which submitted its findings to the Prime Minister’s Office. However, the report has not been made public. This lack of disclosure has drawn attention because ISRO has historically published detailed post-failure analyses, even for sensitive missions.

One explanation could be the protection of classified payload information. Yet, experts note that technical failure reports can be released with payload-specific details redacted. Another possibility lies in commercial considerations: PSLV is being aggressively marketed by NewSpace India Limited as a dependable launch vehicle. A public admission of manufacturing lapses or quality-control failures could affect insurance premiums and client confidence.

How commercial pressures may be shaping disclosure

The PSLV is no longer just a national launcher; it is a commercial product competing in a crowded global small-satellite launch market. Any perception that the failure stemmed from negligence, substandard materials, or inadequate testing could tarnish its reputation.

By keeping the FAC report classified, ISRO and the Department of Space have effectively shielded the organisation from external technical scrutiny. This becomes significant because the PSLV-C62 mission was cleared for launch barely eight months after the earlier failure — a relatively short “return-to-flight” window for a rocket with unresolved third-stage concerns.

Why transparency matters for ‘return to flight’ decisions

In global space programmes, independent review is often central to restoring confidence after a failure. External experts can validate corrective measures and challenge optimistic internal assessments. In this case, the absence of public or peer review meant that the adequacy of ISRO’s fixes remained unverifiable.

That the same stage appears implicated in both failures suggests a potential common root cause — possibly in materials, manufacturing batches, or quality assurance processes. Launching again without broader scrutiny has now resulted in a second failure, compounding reputational damage.

The larger implications for ISRO’s flagship launcher

The PSLV has earned its “workhorse” label by delivering hundreds of satellites with remarkable consistency. Two consecutive failures, especially linked to a core stage, threaten that legacy at a time when India is positioning itself as a reliable space partner for the Global South and private operators.

Beyond immediate commercial fallout, the episode raises institutional questions: how ISRO balances transparency with strategic and commercial interests, and whether internal accountability mechanisms are robust enough in an era of rapid launch cadence and market competition.

For a programme built on public trust and technical credibility, restoring confidence in the PSLV may now depend not just on engineering fixes, but on how openly ISRO explains what went wrong — and how convincingly it demonstrates that the lessons have truly been learned.