Faulty PSLV fails to deliver earth observation satellite in orbit

Sriharikota: ISRO on Sunday failed to put its earth observation satellite in orbit after its trusted PSLV rocket developed a fault minutes after launch from the spaceport here.

In ISRO's 101st mission from the spaceport here, the Polar Satellite Launch Vehicle (PSLV-C61) had a text-book lift off at 5:59 am, only to experience an anomaly in the 12th minute of the flight.

"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 afn observation and the mission could not be accomplished," Indian Space Research Organisation (ISRO) Chairman V Narayanan said.

He said 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," Narayanan said post the unsuccessful launch.

This was the third failure of the PSLV, ISRO’s trusted warhorse rocket that launched the Chandrayaan-1 and Mars Orbiter Mission. The PSLV has had 63 launches so far. The previous failures were in 1993, the inaugural flight of the PSLV, and in 2017 when it did not succeed in putting in orbit a navigation satellite.

In January, ISRO's navigation satellite NVS-02 encountered a failure after being put in orbit by a Geosynchronous Satellite Launch Vehicle (GSLV). The satellite, meant to be placed in a geostationary orbit, is operating from an elliptical orbit at present.

On Sunday, post lift-off, the PSLV C61 flight was tracked from the Mission Control Centre and other units of ISRO located in various parts of the country.

According to the data shared by ISRO, the PS1 (first stage) separation was scheduled for 111.64 seconds after lift-off, but it was achieved at 110 seconds.

Further, the second stage ignition of the rocket was targeted to be achieved at 111.84 seconds, but the process occurred at 110.2 seconds leaving a marginal difference.

Similarly, the PS2 (second stage) separation was targeted at 264.34 seconds but it took place at 261.8 seconds.

Although things were proceeding on expected lines, as understood by the regular announcements by the scientists over the progress of the mission, it was after reaching the third stage that a glitch surfaced.

Meanwhile, a retired ISRO official, when asked about the fate of the rocket after facing such an issue, said that it would have fallen into the sea as the issue cropped up at an altitude of about 450 km.

EOS-09 is a repeat satellite similar to EOS-04 launched in 2022 that has been designed with the mission objective to ensure remote sensing data for the user community engaged in operational applications and to improve the frequency of observation.

The mission's payload, a Synthetic Aperture Radar (SAR) which is inside the satellite, is capable of providing images for various earth observation applications under all-weather conditions, day and night.

This all-weather, round-the-clock imaging is vital for applications ranging from agriculture and forestry monitoring to disaster management, urban planning and national security.

The mission was aimed to be a debris-free one.

According to scientists, a sufficient amount of the fuel had been reserved for de-orbiting the satellite after its effective mission life by lowering it to an orbit that ensures its decay within two years, towards ensuring a debris-free mission.

Meanwhile, former ISRO Chairman S Somanath sad, "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, he said in a post on X.