The Indian Space Research Organisation (ISRO) faced an unexpected setback on Sunday, May 18, when its PSLV-C61 mission failed to deliver the EOS-09 Earth observation satellite into its intended sun-synchronous polar orbit. This marked the 63rd flight of the PSLV (Polar Satellite Launch Vehicle) and the 27th in the XL configuration, which uses six extended solid strap-on boosters.
According to ISRO Chairman V. Narayanan, the launch sequence began smoothly from Sriharikota’s Satish Dhawan Space Centre, and both the first and second stages functioned nominally. However, the mission encountered a critical failure during the third stage, which relies on a solid motor system designed to push the satellite into its targeted orbit. Narayanan noted a sudden fall in chamber pressure within this stage, causing the vehicle to underperform and ultimately miss the required orbit insertion.
He stated on the livestream:
“The third stage motor started perfectly but during its functioning, we saw an anomaly in the pressure profile. The mission could not be accomplished.”
This mission failure is notable because PSLV has built a reputation for reliability, with only a few failures since its 1993 debut. Past issues included:
-
1993: The maiden launch failed due to a programming error and retro-rocket malfunction during stage separation.
-
2017 (PSLV-C39): The payload fairing failed to separate, trapping the satellite inside the rocket.
In the current PSLV-C61 case, while details are still emerging, potential causes could include solid motor defects, faulty igniters, structural inconsistencies, or guidance/control anomalies. ISRO has set up a Failure Analysis Committee to thoroughly review telemetry data and onboard systems to pinpoint the exact cause and ensure corrective actions are taken.
Despite this incident, ISRO’s PSLV series remains a cornerstone of India's space ambitions, having successfully launched hundreds of satellites, including critical missions like Chandrayaan-1, Mangalyaan (Mars Orbiter), and numerous commercial payloads. This failure is a reminder of the technical complexity of space launches, but ISRO’s track record suggests it will bounce back with a refined and safer approach in its future missions.
