The Indian Space Research Organisation (ISRO) has temporarily grounded its Polar Satellite Launch Vehicle (PSLV) fleet following the failure of the PSLV-C61 mission on May 18, 2025.

This mission, which was intended to deploy the advanced EOS-09 earth observation satellite, ended in failure when the rocket's third stage suffered a sudden drop in chamber pressure, resulting in a loss of thrust and the subsequent loss of both the rocket and the satellite over the Indian Ocean.

The first two stages of the launch vehicle performed as expected, but the malfunction in the third stage—suspected to be due to a rupture in the fibre casing of the solid-fuel motor—prevented the mission from reaching its intended orbit.

The EOS-09 satellite, equipped with a sophisticated Synthetic Aperture Radar (SAR) for all-weather, day-and-night imaging, was designed to support environmental monitoring, disaster response, and national security applications, making its loss a significant operational setback for ISRO.

In response, ISRO has convened a high-level committee, including experts from premier institutions, to investigate the anomaly. The committee is analysing telemetry and system diagnostics from the failed mission, with a detailed report expected by mid-June 2025. Several internal committees are also scrutinising each subsystem and operational aspect of the PSLV to ensure a thorough review and resolution.

Despite this setback and the temporary grounding of the PSLV fleet—a standard safety measure in such circumstances—ISRO's other launch vehicles remain unaffected. Preparations for major upcoming missions, such as the high-profile NASA-ISRO Synthetic Aperture Radar (NISAR) mission scheduled for June 2025 aboard a GSLV rocket, are continuing as planned.

The NISAR mission, a $1.5 billion collaboration with NASA, will deploy one of the world’s most advanced radar imaging satellites to monitor Earth’s changing systems and natural hazards. Other critical missions, including the Gaganyaan human spaceflight tests, are also proceeding on schedule.

ISRO officials emphasise their confidence in swiftly resolving the PSLV issue and stress that the grounding is a precautionary measure to ensure flawless operations for future launches, particularly with ambitious crewed and international missions on the horizon.

Agencies