In a rare setback for India’s space ambitions, the Indian Space Research Organisation (ISRO) faced an unexpected anomaly during the launch of PSLV-C61 carrying the EOS-09 Earth observation satellite. The mission, launched early Sunday morning from the Satish Dhawan Space Centre in Sriharikota, marked ISRO’s 101st attempt — a moment that was expected to be yet another milestone in India’s growing space journey. However, despite a flawless liftoff and smooth execution of the first two stages, the mission could not be completed due to an issue during the third stage of the rocket’s flight.
A Routine Mission Turns Into a Learning Moment
Launched precisely at 5:59 AM IST on Sunday, May 18, PSLV-C61 soared into the skies as part of a routine Earth observation mission. Onboard was the EOS-09 satellite, a successor to the previously launched EOS-04, designed to deliver critical remote sensing data for operational users.
The goal was to place EOS-09 in a Sun Synchronous Polar Orbit (SSPO) — an orbit ideal for earth imaging and environmental monitoring. But just as the mission progressed into its third stage, an anomaly surfaced.
“The PSLV-C61 performance was normal till the second stage. Due to an observation in the third stage, the mission could not be accomplished,” ISRO posted on X (formerly Twitter), within half an hour of the launch.
What Went Wrong?
While ISRO has not released full technical details yet, initial statements suggest that the third stage motor, though it ignited successfully, encountered an abnormal behavior mid-flight. This deviation from expected performance ultimately prevented the satellite from being placed into its intended orbit.
ISRO Chairman V. Narayanan addressed the issue in a brief statement following the launch:
“The PSLV is a four-stage vehicle. The first two stages performed normally. The third stage motor started perfectly, but during its functioning, we observed an anomaly and hence the mission could not be accomplished. After detailed analysis, we will provide more information.”
The fourth and final stage, which would have involved Orbit Change Thrusters (OCT) and passivation of the PS4 stage to reduce orbital debris, never commenced, as the mission failed before satellite deployment.
The EOS-09 Satellite: What Was at Stake?
EOS-09 was meant to bolster India’s earth observation capabilities, delivering real-time, high-resolution images for applications including:
- Agriculture and forestry monitoring
- Water resources and flood mapping
- Urban planning
- Disaster management
- National security surveillance
As a repeat of EOS-04, it was built to provide continuity in remote sensing data, especially beneficial for agencies that rely on consistent observation intervals. Its failure to reach orbit delays these improvements for the user community that depends on accurate geospatial data.
A Rare Setback in an Impressive Track Record
ISRO’s Polar Satellite Launch Vehicle (PSLV) has long been regarded as the workhorse of Indian space missions, boasting a remarkably high success rate with over 90 successful launches. This recent setback with PSLV-C61 is a reminder that even the most reliable systems can face technical challenges.
Despite the failure, this launch underscores ISRO’s continued commitment to transparency and rapid diagnostics. The organization has previously turned launch failures into valuable learning experiences — as seen after the Chandrayaan-2 mission — which ultimately paved the way for the historic Chandrayaan-3 lunar landing.
What Happens Next?
Chairman V. Narayanan has assured that a detailed post-flight analysis will be conducted to pinpoint the exact cause of the anomaly. Such exercises are standard protocol and crucial to preventing similar issues in future missions.
Given ISRO’s busy calendar for 2025 — including Chandrayaan-4 preparations, Aditya-L2 solar mission advancements, and the ambitious Gaganyaan human spaceflight program — resolving the issue quickly and thoroughly is of national and strategic importance.
A Hiccup, Not a Halt
While the failure of PSLV-C61 to deploy EOS-09 is a disappointment, it is also a testament to the risks and complexities involved in space exploration. India’s space program has witnessed tremendous achievements in recent years, and one technical anomaly cannot overshadow the milestones already reached.
As ISRO investigates and learns from this setback, the nation watches with faith — knowing that each challenge brings the agency one step closer to future triumphs.
