Space & defence technology (ISRO, DRDO)
India's space and defence technology landscape—ISRO's launch vehicles and missions, DRDO's missile and weapons programmes—mapped for UPSC Prelims and GS-3.
ISRO: Mandate, Vehicles, and Landmark Missions
The Indian Space Research Organisation (ISRO) was established on 15 August 1969, superseding INCOSPAR (1962), and functions under the Department of Space, which reports directly to the Prime Minister. The Space Activities programme is steered by the Space Commission (1972). The 2023 Indian Space Policy formalised the roles of three new entities: IN-SPACe (the single-window promoter and authoriser for private players, set up 2020), NSIL (NewSpace India Limited, the commercial arm incorporated 2019), and ISRO itself as the R&D body.
Launch vehicles
Candidates must distinguish the workhorses by payload class and orbit. The PSLV (Polar Satellite Launch Vehicle) delivers to Sun-synchronous polar orbits; it placed Chandrayaan-1 (2008) and Mangalyaan/Mars Orbiter Mission (launched 5 November 2013, inserted 24 September 2014) and set the record of 104 satellites on a single flight (PSLV-C37, 15 February 2017). The GSLV Mk II uses an indigenous cryogenic upper stage (first success GSAT-14, 5 January 2014). The LVM3 (formerly GSLV Mk III), India's heaviest lifter, launched Chandrayaan-2 (2019), Chandrayaan-3, and the OneWeb constellation, and is the designated vehicle for Gaganyaan. The SSLV (Small Satellite Launch Vehicle) achieved its first full success on 16 February 2023.
Headline missions
Chandrayaan-3 achieved India's first soft landing near the lunar south pole on 23 August 2023, making India the fourth nation to soft-land on the Moon and the first at that latitude; the landing site is named Shiv Shakti Point. Aditya-L1, launched 2 September 2023, was inserted into a halo orbit around the Sun-Earth Lagrange point L1 on 6 January 2024 to study the solar corona. Gaganyaan is India's crewed mission targeting low Earth orbit, with uncrewed test flights preceding the human flight. NISAR (NASA-ISRO Synthetic Aperture Radar), a dual-frequency (L- and S-band) Earth-observation satellite, is the flagship bilateral mission. NavIC (IRNSS) is India's seven-satellite regional navigation constellation.
High-yield distinctions: GSAT series = communication (geostationary); IRS/Cartosat/RISAT = remote sensing and radar imaging; ASTROSAT (2015) = India's first dedicated multi-wavelength space observatory. The reusable-launch-vehicle technology demonstrator (RLV-TD 'Pushpak') landing experiments and the semi-cryogenic SCE-200 engine represent the next technology frontier.
The Mission DefSpace and Space Situational Awareness initiatives, plus the 2019 Mission Shakti anti-satellite (ASAT) test that destroyed a live satellite in low Earth orbit, mark the militarisation-of-space dimension that links ISRO capability to national security.
