ISRO's PSLV-C61 Mission Fails As Third-Stage Anomaly Derails EOS-09 Satellite Launch

India's Polar Satellite Launch Vehicle (PSLV-C61) mission encountered a rare setback early on Sunday morning after an anomaly in its third-stage propulsion system led to the failure of the EOS-09 Earth observation satellite launch.

The rocket lifted off at 5:59 a.m. IST from the Satish Dhawan Space Centre in Sriharikota but deviated from its planned trajectory during the third stage's solid rocket motor phase, prompting ISRO to abort the mission.

Photo Credit: PTI

The 1,696 kg EOS-09 satellite - intended to deliver all-weather imaging via its C-band Synthetic Aperture Radar (SAR) - failed to achieve its target sun-synchronous polar orbit at an altitude of 524 km.

Preliminary telemetry suggests that the third-stage motor, which uses hydroxyl-terminated polybutadiene (HTPB) propellant, underperformed 203 seconds into flight. This marks only the third complete failure of the PSLV programme in 63 launches, and the first since 2017.

ISRO Chairman V Narayanan confirmed the issue during the live broadcast shortly after lift-off.

Engineers are now scrutinising the flight data to determine whether the issue arose from irregular propellant flow, nozzle malfunction, or structural deficiencies. A failure analysis committee has been constituted to examine the PS3 stage's manufacturing records and testing procedures.

The failure represents a setback for India's efforts to bolster border monitoring and disaster management through SAR imaging.

The PSLV-C61 mission held particular significance as ISRO's 101st launch, following a streak of 58 consecutive successes since 2017.

Although the rocket's fourth stage and the satellite were destroyed using flight termination protocols, all debris is expected to fall safely.

This incident temporarily halts India's ambitious plan to deploy a 52-satellite surveillance constellation. However, ISRO has assured that four further PSLV launches remain scheduled for 2025.

The space agency has a strong record of quick recoveries from such failures, historically managing turnaround times of less than six months.