ISRO’s PSLV-C61 EOS-09 launch aborted midway; ISRO Chief V. Narayanan explains why

India's 101st space mission from Sriharikota suffered a major setback early Sunday when the Indian Space Research Organisation (ISRO) failed to complete the launch of its Earth observation satellite EOS-09. The mission lifted off as scheduled at 5:59 AM from the Satish Dhawan Space Centre but encountered an anomaly in the third stage of the Polar Satellite Launch Vehicle (PSLV-C61).

“Today we targeted the 101st launch from Sriharikota, the PSLV-C61 EOS-09 mission. The PSLV is a four-stage vehicle and up to the second stage, the performance was normal. The third stage motor started perfectly but during the functioning of the third stage we are seeing an observation and the mission could not be accomplished,” ISRO Chairman V Narayanan said in a post-launch statement.

He added, “...and the motor pressure—there was a fall in the chamber pressure of the motor case and the mission could not be accomplished. We are studying the entire performance, we shall come back at the earliest.”

ISRO PSLV-C61 EOS-09: Third stage falters after smooth lift-off

Though the PSLV-C61 launched without delay and performed reliably through its first two stages, the solid-fuel third stage failed to maintain the required pressure. This disruption halted the progress of the 1,696.24 kg EOS-09 satellite, which was designed for all-weather, day-and-night Earth observation.

The rocket, towering at 44.5 metres and weighing 321 tonnes, was carrying the high-performance Synthetic Aperture Radar (SAR) payload, intended to support sectors like agriculture, disaster response, urban planning, forestry and national security.

The mission was also structured to be debris-free, with fuel reserved for de-orbiting the satellite after its operational life to prevent long-term space debris.

ISRO’s track record and the significance of EOS-09

This mission was the 63rd overall flight of the PSLV and the 27th using its heavier-lifting XL configuration. PSLV failures are rare. Since its first flight in 1993, ISRO has recorded just three setbacks, including Sunday’s mission.

The previous failures were PSLV-D1 in 1993 and PSLV-C39 in 2017, the latter due to a faulty heat shield that prevented satellite deployment. The current failure is expected to prompt an internal review as well as the formation of a Failure Analysis Committee.

The EOS-09 satellite, similar to the EOS-04 launched in 2022, was developed to enhance the frequency and reliability of remote sensing data. The SAR payload inside the satellite could have delivered high-resolution images even in cloudy or dark conditions—key for precision-based resource management.

Failure Analysis Committee to investigate

ISRO has confirmed that a detailed review will be undertaken to assess what went wrong. “Today 101st launch was attempted, PSLV-C61 performance was normal till 2nd stage. Due to an observation in 3rd stage, the mission could not be accomplished,” ISRO stated on its official X handle.

Sources told CNN-News18 that a Failure Analysis Committee (FAC) will be set up to probe the issue. The FAC will include ISRO experts and members from the academic sector, and is likely to be headed by a former ISRO Chief or a senior retired scientist. The committee will comb through flight data, launch preparations, and all associated systems.

While ISRO has not yet released its final technical report, Chairman Narayanan’s assurance suggests the agency will soon regroup for another attempt. “After analysis we shall come back,” he said.

Despite Sunday’s setback, ISRO maintains a strong reputation for dependable launch missions. The EOS-09 failure may delay upcoming plans temporarily, but it also offers the opportunity to reinforce technical rigour.

For now, the space agency turns inward to evaluate its systems and regain momentum. India’s ambitious space programme—marked by achievements like the Chandrayaan and Mars missions—remains undeterred. The mission may have failed, but the resolve remains intact.

(With inputs from ANI, PTI)