APPSC Group II · Bite-size lessons
Space Technology and Applications
About 7 min · General Studies and Mental Ability · English
Time worked out from the lesson's 533 words at 150 words a minute, plus a minute for each question.
Space technology forms a crucial component of India's scientific achievements and is listed under Science and Technology in APPSC Group II Mains Paper II. Questions typically focus on ISRO's missions, satellite applications, launch vehicles, and India's space policy developments. This topic bridges science with current affairs.
Key ideas
- ISRO Structure: Founded in 1969, headquartered in Bengaluru. Department of Space (DOS) oversees ISRO, reporting directly to the Prime Minister. Key centres include VSSC (Thiruvananthapuram), SAC (Ahmedabad), and SHAR (Sriharikota in AP).
- Satellite Classification by Orbit: Geostationary (GEO) at 35,786 km for communication; Low Earth Orbit (LEO) below 2,000 km for Earth observation; Medium Earth Orbit (MEO) for navigation satellites; Polar orbits for remote sensing.
- Launch Vehicle Evolution: SLV → ASLV → PSLV → GSLV → GSLV Mk III (LVM3). PSLV is the "workhorse" with highest reliability; GSLV uses cryogenic engines for heavier payloads.
- Remote Sensing Applications: Agriculture monitoring, urban planning, disaster management, forest cover assessment, water resource mapping. IRS series is among the world's largest civilian remote sensing satellite systems.
- Communication Satellites (INSAT/GSAT series): Enable television broadcasting, telecom, weather monitoring, and emergency communication. GSAT-30 and GSAT-31 are recent operational satellites.
Watch out for
- Confusing PSLV and GSLV capabilities → PSLV launches lighter satellites to polar/sun-synchronous orbits; GSLV launches heavier satellites to geostationary transfer orbit. Remember: PSLV = Polar, lighter; GSLV = Geo, heavier.
- Assuming Chandrayaan-3 was India's first Moon mission → Chandrayaan-1 (2008) was the first; Chandrayaan-2 (2019) had orbiter success but lander failure; Chandrayaan-3 (2023) achieved soft landing. Know the progression.
- Mixing up NavIC and GPS → GPS is American (global coverage, 24+ satellites); NavIC is Indian (regional coverage—India + 1,500 km, 7 satellites). NavIC provides better accuracy over Indian subcontinent.
Quick reference
- ISRO headquarters: Bengaluru; Spaceport: Sriharikota, AP
- PSLV: Most reliable launcher, 50+ missions, polar/sun-synchronous orbits
- GSLV Mk III (LVM3): Heavy-lift, cryogenic upper stage, used for Chandrayaan-3
- Chandrayaan-3 (2023): First successful landing near Moon's south pole globally
- NavIC: 7-satellite regional navigation, covers India + 1,500 km radius
Check yourself: 3 questions
1. Which of the following statements about India's space programme is/are correct? 1. PSLV (Polar Satellite Launch Vehicle) is primarily used for launching satellites into polar and sun-synchronous orbits. 2. GSLV Mk-III has the capability to launch 4-tonne class satellites into Geosynchronous Transfer Orbit. 3. Chandrayaan-3 successfully achieved soft landing on the Moon's south polar region. Select the correct answer using the code given below:
2. Satish Dhawan Space Centre (SDSC) at Sriharikota is used for launching various types of satellites. Which of the following launch vehicles are associated with this centre? 1. PSLV 2. GSLV 3. LVM3 4. Sounding rockets Select the correct answer:
3. Consider the following statements about ISRO's satellite launch capabilities: 1. PSLV (Polar Satellite Launch Vehicle) is primarily used for launching satellites into polar and sun-synchronous orbits. 2. GSLV (Geosynchronous Satellite Launch Vehicle) uses indigenous cryogenic engines for upper stages. 3. The Satish Dhawan Space Centre at Sriharikota is located in Andhra Pradesh. Which of the statements given above is/are correct?
This lesson is cut from the topic's note, not rewritten. Fact-checked on 17 Oct 2026: an AI-assisted check of this note against cited sources; the errors it found were corrected that day. Some errors may remain. The questions are from Shishya's validated question bank.
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