PSLV

The Polar Satellite Launch Vehicle (PSLV) is the Indian Space Research Organisation's (ISRO) third-generation expendable launch system, developed at the Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram, and operated from the Satish Dhawan Space Centre (SDSC), Sriharikota. Conceived in the 1980s to give India indigenous capacity to launch Indian Remote Sensing (IRS) satellites into Sun-synchronous polar orbits—a capability earlier dependent on the Soviet Union—the PSLV made its maiden flight on 20 September 1993 (which failed) and its first fully successful flight on 15 October 1994, placing IRS-P2 into orbit. It superseded the earlier ASLV and SLV-3 programmes and remains, in 2026, ISRO's most reliable workhorse, frequently described as such because of its consistent success record.

Structurally, the PSLV is a four-stage vehicle alternating solid and liquid propulsion. The first stage is a solid-propellant (HTPB) motor, one of the largest in the world, augmented in the standard configuration by six strap-on boosters; the second stage uses the liquid-fuelled Vikas engine; the third stage reverts to solid propellant; and the fourth stage employs twin liquid engines for precise orbital injection. ISRO flies it in several variants—PSLV-G (generic, retired), the core-alone PSLV-CA (no strap-ons), the high-thrust PSLV-XL (six larger strap-ons, used for Chandrayaan-1 and Mangalyaan), the PSLV-DL (two strap-ons) and PSLV-QL (four strap-ons). Beyond polar Sun-synchronous orbits, the PSLV reaches Low Earth Orbit and sub-Geostationary Transfer Orbits, and its restartable fourth stage permits multi-orbit missions.

The PSLV's landmark missions define India's space programme. It launched Chandrayaan-1 (October 2008), India's first lunar probe; the Mars Orbiter Mission, Mangalyaan (PSLV-C25, November 2013), making India the first nation to reach Martian orbit on its maiden attempt; and the record-setting PSLV-C37 (15 February 2017), which deployed 104 satellites in a single flight. It is also the commercial mainstay through NewSpace India Limited (NSIL) and earlier Antrix, having launched hundreds of foreign satellites. The PSLV carried Astrosat (2015), India's first dedicated space observatory, and the Aditya-L1 solar mission (September 2023). Heavier geostationary communications satellites are instead launched by the GSLV and LVM3 (GSLV Mk III), which carry the indigenous cryogenic upper stage.

For UPSC, the PSLV is tested across the General Studies Paper III science-and-technology segment and the post-independence/awareness sections, and recurs in Prelims through factual matching of missions to launch vehicles. Examiners typically ask candidates to distinguish PSLV from GSLV (polar/LEO versus geostationary, and the cryogenic-engine question), to associate specific missions—Mangalyaan, Chandrayaan-1, the 104-satellite record—with the correct vehicle, and to identify the launch site (Sriharikota) and developing agency (ISRO/VSSC). A frequent mains angle concerns the strategic and commercial significance of indigenous launch capability for self-reliance (atmanirbharta), foreign-exchange earnings, and India's position in the global small-satellite launch market. Knowing the variants (CA, XL, DL, QL) and the four-stage solid–liquid configuration provides the precise detail competitive answers demand.