Polar Satellite Launch Vehicle (PSLV)

• Context (ToI): ISRO’s 101^st launch, the PSLV-C61 mission failed to place the EOS-09 Earth observation satellite into a sun-synchronous polar orbit.
• The setback marks only the 3^rd unsuccessful PSLV mission out of a total of 63 launches over the past 32 years, excluding a partial failure in 1997. This was ISRO’s 2^nd consecutive mission failure in 2025.
• The 1^st PSLV’s failure occurred during the rocket’s maiden flight, PSLV-D1, in 1993, while the 2^nd failure was PSLV-C39 in 2017, which failed to deploy the IRNSS-1H satellite.

About Polar Satellite Launch Vehicle (PSLV)

• Polar Satellite Launch Vehicle (PSLV) is India’s 3^rd generation launch vehicle and 1^st Indian launch vehicle equipped with liquid stages.
• After its 1^st successful launch in October 1994, PSLV emerged as a reliable and versatile workhorse launch vehicle of India.

Stages of PSLV

• The PSLV has four stages, using solid and liquid propulsion systems alternately.
  • 1st Stage and 3rd Stage: Solid-fuelled stages
  • 2nd Stage and 4th Stage: Liquid-fuelled stages.
    • The 2^nd stage engine, Vikas, is a derivative of France’s Viking engine.
    • The PS4 is the uppermost stage of PSLV, comprising two Earth-storable liquid engines.

Orbits in which PSLV Places Satellites

• It can take up to 1,750 kg of payload to Sun-Synchronous Polar Orbits of 600 km altitude.
• PSLV can also launch small-sized satellites into Geostationary Transfer Orbit (GTO).

Notable Launches

• The PSLV has launched around 345 satellites for 34 countries and was also used in primary ISRO missions.
  1. Chandrayaan-1/PSLV-C11 (2008): India’s 1^st mission to the Moon.
  2. Mars Orbiter Mission/PSLV-25 (2013): India became the 1^st Asian nation to reach Mars orbit and the 1^st in the world to do so in its maiden attempt.
  3. Astrosat/PSLV-C30 (2015): India’s 1^st dedicated multi-wavelength space observatory.
  4. PSLV-C37 (2017): Set a world record by launching 104 satellites in a single mission.
  5. IRNSS (2013-18): PSLV launched all seven satellites of the Indian Regional Navigation Satellite System (IRNSS), later named NavIC.
  6. PSLV-C58 / XPoSat (2024): India’s 1^st dedicated polarimetry mission to study cosmic X-rays.