Science & Technology
Space Technology
GS Paper III
Space Technology — Quick Revision
One-page UPSC revision of space technology: ISRO launch vehicles, orbit types, satellite systems, key missions with dates, Gaganyaan and space-sector reform.
SyllabusGS III · Awareness in the fields of IT, space, computers, robotics, nano-technology, bio-technology and IPR
A last-week revision sheet for space. Most Prelims questions here are matching questions — mission to vehicle, orbit to purpose, body to function.
Launch Vehicles at a Glance
| Vehicle | Stages | Cryogenic stage? | Known for |
|---|---|---|---|
| SLV-3 | 4 solid | No | Rohini RS-1, 18 July 1980 |
| ASLV | 5 solid | No | Experimental, early 1990s |
| PSLV | Solid–liquid–solid–liquid | No | Chandrayaan-1, Mangalyaan, Aditya-L1; 104 satellites (2017) |
| GSLV Mk II | 3 stages | Yes (indigenous since GSLV-D5, January 2014) | GSAT and NVS navigation satellites |
| LVM3 | S200 boosters, L110 core, C25 upper | Yes | Chandrayaan-2, Chandrayaan-3, OneWeb batches; Gaganyaan |
| SSLV | 3 solid + liquid trimming module | No | Small satellites; success in 2023 and 2024 |
Orbits
| Orbit | Key fact |
|---|---|
| LEO | Up to about 2,000 km; space stations, imaging |
| Sun-synchronous | Near-polar; same local solar time on every pass |
| MEO | Global navigation (GPS) |
| Geosynchronous | About 35,786 km; period of one sidereal day |
| Geostationary | Geosynchronous + equatorial + zero inclination; fixed in the sky |
| GTO | Elliptical transfer orbit to reach GEO |
| L1 | About 1.5 million km sunward; Aditya-L1 |
Missions and Dates
| Mission | Launch | Vehicle | Remember |
|---|---|---|---|
| Aryabhata | April 1975 | Soviet rocket | First Indian satellite |
| Chandrayaan-1 | October 2008 | PSLV-C11 | Moon Impact Probe; water molecules |
| Mars Orbiter Mission | November 2013 | PSLV-C25 | Mars orbit September 2014, first attempt |
| AstroSat | September 2015 | PSLV | First Indian space observatory |
| Chandrayaan-2 | July 2019 | GSLV Mk III | Orbiter working; lander lost |
| Chandrayaan-3 | July 2023 | LVM3 | Landed 23 August 2023 near south pole |
| Aditya-L1 | September 2023 | PSLV-C57 | Halo orbit at L1, January 2024 |
| XPoSat | January 2024 | PSLV-C58 | X-ray polarimetry |
| SpaDeX | December 2024 | PSLV-C60 | Docking achieved January 2025 |
| NISAR | July 2025 | GSLV-F16 | NASA–ISRO radar imaging satellite |
High-yield facts
- Chandrayaan-3 made India the fourth country to soft-land on the Moon and the first near the south pole.
- SpaDeX made India the fourth country to dock spacecraft in orbit.
- NavIC: seven satellites, regional (India + about 1,500 km); NVS series adds the L1 band.
- Gaganyaan crew-escape test: TV-D1, 21 October 2023.
- Targets announced: Bharatiya Antariksh Station by 2035, Indian on the Moon by 2040.
Institutions
| Body | Year | Role |
|---|---|---|
| INCOSPAR | 1962 | Precursor of ISRO, under Vikram Sarabhai |
| ISRO | 1969 | Research, development, missions |
| Department of Space / Space Commission | 1972 | Policy and administration |
| NSIL | 2019 | Commercial arm of the Department of Space |
| IN-SPACe | 2020 | Authorises and promotes non-government space activity |
| Indian Space Policy | 2023 | End-to-end private participation |
FDI (February 2024): 74% automatic (satellite manufacturing and operation) · 49% automatic (launch vehicles, spaceports) · 100% automatic (components and systems).
Traps
Watch these
- PSLV has no cryogenic stage.
- Geosynchronous is not always geostationary.
- India was the first Asian country to reach Mars orbit — not the first country.
- Aditya-L1 observes the Sun from L1; it does not orbit the Sun’s surface region.
Related Topics
- Indian Space Programme: Launch Vehicles, Orbits and Missions
- Space Technology — practice questions
- Space Technology — overview
- Defence Technology
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