Polar Satellite Launch Vehicle (PSLV)

Source: IE

Subject: Science and Technology

Context: ISRO’s PSLV-C62 mission suffered a failure due to an anomaly in its third stage (PS3), marking the second consecutive PSLV failure after PSLV-C61 in May 2025.

About Polar Satellite Launch Vehicle (PSLV):

What it is?

• PSLV is India’s third-generation orbital launch vehicle, designed primarily to place satellites into Polar and Sun-Synchronous Orbits, and known globally as ISRO’s workhorse rocket.

Developed by:

• It is developed and operated by the Indian Space Research Organisation (ISRO) through its various centres including Vikram Sarabhai Space Centre and Liquid Propulsion Systems Centre.

PSLV: Key Stages:

• PS1: First Stage (Powerful liftoff stage):

• Uses a large solid rocket motor (S139) and strap-on boosters Fuel: HTPB (solid fuel) Its job is to lift the heavy rocket off the ground and push it through the thickest part of the atmosphere Strap-on boosters give extra push, like turbo engines during takeoff

• Uses a large solid rocket motor (S139) and strap-on boosters

• Fuel: HTPB (solid fuel)

• Its job is to lift the heavy rocket off the ground and push it through the thickest part of the atmosphere

• Strap-on boosters give extra push, like turbo engines during takeoff

• PS2: Second Stage (Control and stability stage):

• Uses the Vikas liquid engine Fuel: UDMH + Nitrogen Tetroxide This stage gives smooth, controlled thrust after PS1 burns out It helps the rocket stay stable and on the right path while climbing higher

• Uses the Vikas liquid engine

• Fuel: UDMH + Nitrogen Tetroxide

• This stage gives smooth, controlled thrust after PS1 burns out

• It helps the rocket stay stable and on the right path while climbing higher

• PS3: Third Stage (High-speed booster):

• Uses a solid motor (S7) Fuel: HTPB This stage provides a big speed boost needed to reach near-orbital velocity Think of it as the final sprint before the satellite is placed in orbit

• Uses a solid motor (S7)

• Fuel: HTPB

• This stage provides a big speed boost needed to reach near-orbital velocity

• Think of it as the final sprint before the satellite is placed in orbit

• PS4: Fourth Stage (Precision stage):

• Uses two liquid engines (PS4) Fuel: MMH + MON This stage acts like a fine-tuning engine It precisely places satellites into the correct orbit and can make small adjustments

• Uses two liquid engines (PS4)

• Fuel: MMH + MON

• This stage acts like a fine-tuning engine

• It precisely places satellites into the correct orbit and can make small adjustments

Functions of PSLV:

• Launches Earth observation, navigation and communication satellites.

• Places satellites in Low Earth Orbit, Polar Orbit and GTO.

• Supports India’s strategic, commercial and scientific missions.

• Backbone of India’s space commercialisation through NSIL.