In May 2025, shortly after the launch of PSLV-C61 (EOS-09) from Sriharikota, a fault was reported in its:

Correct option is C

The correct answer is (c) Third stage

Explanation:

• The PSLV-C61 mission was launched by the Indian Space Research Organisation (ISRO) on 18 May 2025 from Satish Dhawan Space Centre, Sriharikota.

• The mission aimed to place the Earth Observation Satellite-09 (EOS-09) into a Sun-synchronous polar orbit.

• The first and second stages of the PSLV performed normally during the launch sequence.

• During the third stage (PS3) operation, ISRO detected a sudden drop in chamber pressure in the solid rocket motor.

• This anomaly prevented the rocket from achieving the required velocity and altitude, resulting in mission failure before the fourth stage could place the satellite in orbit.

Information Booster:

• PSLV (Polar Satellite Launch Vehicle) is often called ISRO’s “workhorse launch vehicle.”

• PSLV has four stages: First and third stages use solid propellant, while second and fourth stages use liquid propellant.

Additional Knowledge:

First stage (Option a)

• The first stage (PS1) is the largest stage using solid propellant with strap-on boosters.

• In PSLV-C61 mission, this stage performed normally.

Second stage (Option b)

• The second stage (PS2) uses Vikas liquid engine with UDMH and N₂O₄ propellants.

• ISRO confirmed that this stage operated successfully in the mission.

Fourth stage (Option d)

• The fourth stage (PS4) uses two liquid engines for precise orbital insertion.

• Due to the third stage anomaly, the mission could not proceed to complete fourth stage operations.