New Delhi: ISRO’s PSLV-C62 mission began to tumble uncontrollably just after the third stage entered into a planned coast stage. ISRO Chairman V Narayanan
has indicated that ISRO is investigating the problem, “Today we had attempted the PSLV-C62/EOS-N1 mission. The PSLV vehicle is a four stage vehicle with two solid stages and two liquid stages. The performance of the vehicle up to the end of the coast stage of the third stage was as expected. Close to the end of the third stage, we were seeing little more disturbance in the vehicle roll rates, and subsequently there is a deviation episode in the flight path. We are analysing the data and we shall come back at the earliest.” This is the first time that ISRO has failed on a mission to deploy a foreign satellite.
The previous PSLV launch, the PSLV-C61 mission also experienced a failure in the third stage on 18 May, 2025. There was an anomalous drop in chamber pressure of the third stage, after the first and second stages operated nominally. ISRO instituted a national level probe into the failure of the mission by leading scientists across India. However, the results of this probe were never publicly disclosed, and it is unclear if ISRO has identified the root cause, and taken any steps to permanently fix it. Transparency is the key here, with responsible spacefaring nations and even private spaceflight companies around the world providing detailed technical information on failures as well as redressal steps to the general public.
Flight Record of the PSLV
This was the 64th flight of the PSLV. The first demonstration flight took place on 20 September 1993. There was an unexpected disturbance during the separation of the second stage, that caused a loss of velocity and altitude, preventing the payload, the IRS-1E satellite from being deployed into polar orbit. After that, the rocket had a flawless operational record for 24 years till the heat shield failed to separate on the PSLV-C39 flight to deploy the IRNSS-1H satellite, leaving the payload trapped within the nose cone of the rocket. The subsequent PSLV-C61/EOS-09 Mission on 18 May, 2025 experienced an anomaly in the third stage, followed by a similar problem during the PSLV-C62/EOS-N1 flight today.
