ISRO missions overview

Applications and foundations

India’s space programme grew around communications, meteorology, remote sensing, navigation and disaster management while developing launch capability. Aryabhata, launched in 1975, was India’s first satellite. SLV-3 placed Rohini in orbit in 1980, demonstrating indigenous launch capability. INSAT supports communication and meteorology; Indian Remote Sensing satellites support mapping, agriculture, water and disaster planning.

Exploration missions

Chandrayaan-1 (2008) was India’s first lunar mission and its instruments contributed evidence of hydroxyl/water molecules on the Moon. Mars Orbiter Mission/Mangalyaan, launched in 2013, was India’s first interplanetary mission and entered Mars orbit in 2014, demonstrating technology as well as observations. Chandrayaan-2 (2019) combined orbiter, lander and rover; the lander did not soft-land successfully, while the orbiter continued useful lunar science. Chandrayaan-3 achieved a lunar soft landing on 23 August 2023 and demonstrated controlled descent and rover mobility near the south-polar region. Aditya-L1, India’s solar observatory, entered a halo orbit around the Sun–Earth L1 point in January 2024, enabling sustained study of the corona, solar wind and space weather. Gaganyaan is a human-spaceflight programme involving crew and service modules, escape systems and life support; a planned objective is not a completed flight.

Launchers and navigation

PSLV is versatile and strongly associated with polar and sun-synchronous missions. GSLV uses a cryogenic upper stage for heavier geostationary-transfer payloads. LVM3 is a heavier launcher associated with Gaganyaan development. NavIC provides regional positioning, navigation and timing for India and the surrounding region.

Exam tips

Distinguish orbiter, lander, rover, launch vehicle and telescope. L1 is a Sun–Earth Lagrange point, not a planet. Remote sensing needs no physical contact with the target. Match PSLV/GSLV with their broad roles, Chandrayaan with Moon, Aditya with Sun and NavIC with regional navigation. State mission achievements precisely rather than turning a planned goal into a completed result.

Prelims revision checklist

Identify the definition first, then connect it to the relevant institution, date, process and example. Do not treat a scientific mechanism as a policy instrument, an international label as automatic domestic legal status, or a rank as ownership. Watch absolute words such as “always” and “only”; they are rarely correct unless part of a formal definition. In current-affairs questions, apply the stable principle and verify changing figures or variants from an official source.

Additional recall

For elimination, ask what is being measured, who has authority, and whether the statement describes a mechanism, a legal category or an outcome. Similar terms often differ by scope and timing. A precise answer should preserve the distinction between a broad umbrella concept and its narrower operational example.

Analogy

ISRO missions overview — Analogy

An orbiter circles like a photographer, a lander reaches the doorstep, and a rover walks the grounds; the launcher is the transport that gets them there.