PSLV-C61 rocket carrying Earth Observation Satellite (EOS-09) lifts off from the first launch pad, in Sriharikota, Sunday, May 18, 2025. After a precise liftoff, Chairman V. Narayanan said that the mission could not be accomplished as planned
| Photo Credit: PTI
The Indian Space Research Organisation said on Sunday (May 18, 2025) that it could not complete its 101st mission, the PSLV-C61/EOS-09, due to a technical glitch.
Minutes after the Polar Satellite Launch Vehicle (PSLV-C61), carrying the earth observation satellite EOS-09, lifted off from the Satish Dhawan Space Centre in Sriharikota at 5:59 a.m., the space agency said that the mission could not be “accomplished” due to a glitch in the third stage of the launch vehicle. The PSLV was expected to place the satellite into a Sun Synchronous Polar Orbit (SSPO) 17 minutes after lift-off.
“The PSLV is a four-stage vehicle and second-stage performance was quite normal. The third stage’s motor started perfectly but during the functioning of the stage, we are seeing an observation and the mission could not be accomplished. After analysis, we shall come back,” ISRO Chairman V. Narayanan said.
Mr. Narayanan later told reporters that during the third stage, there “was a fall in chamber pressure in the motor case”, due to which the “mission could not be accomplished”.
The third stage of the PSLV is a solid rocket motor that provides the upper stages high thrust after the atmospheric phase of the launch.
Former ISRO Chairman S. Somanath in a post on X stated, “I am aware of the formidable challenges we faced during the development of the third-stage solid motor — an endeavour marked by multiple failures. It is indeed unusual to witness such anomalies resurfacing at this stage. Nevertheless, I have complete confidence that the team will identify the root cause both swiftly and effectively.”
The C61 mission was also the 63rd flight of the PSLV and the 27th in the PSLV-XL configuration.
Before Sunday’s (May 18, 2025) launch, the PSLV had suffered only two failures since its first mission in 1993. The very first mission, PSLV-D1, could not place the IRS-1E satellite in orbit and in 2017, the 41st flight of the launch vehicle ended in failure. Since then, all PSLV launches had been successful with the previous one being the SpaDeX mission in December 2024.
The setback of the PSLV-C61/EOS-09 mission follows the ISRO’s failure to perform the intended orbit-raising operations for the NVS-02 satellite due to a valve malfunction. The NVS-02 was launched on January 29 in what was the landmark 100th launch from Sriharikota.
Similar to the EOS-04 satellite, EOS-09 was designed with the mission objective of ensuring remote sensing data for the user community engaged in operational applications and to improve the frequency of observation.
The space agency said that the spacecraft was configured using ISRO’s RISAT-1 heritage bus, with most of the functional requirements of the Synthetic Aperture Radar (SAR) payload and the bus platform systems derived from the earlier ISRO missions.
The satellite weighing 1,696.24 kg carries a SAR payload capable of providing images for various earth observation applications under all-weather conditions. The EOS-09 was designed to provide continuous and reliable remote sensing data for operational applications across various sectors and had a mission life of five years, the ISRO said.
Published – May 18, 2025 06:57 am IST
