UPSC Prelims 2018 Q61: Science & Technology – Space Technology & Astronomy
- (a) 1 only
- (b) 1 and 2 only
- (c) 2 and 3 only
- (d) None
Answer: (a) 1 only
Explanation
Indian Regional Navigation Satellite System (IRNSS / NavIC)
| Statement | Claim | Verdict | Detail |
|---|---|---|---|
| 1 | IRNSS has 3 satellites in geostationary and 4 in geosynchronous orbits | TRUE | IRNSS constellation = 7 operational satellites: 3 in GEO (equatorial, 32.5 E, 83 E, 131.5 E) + 4 in GSO/inclined GEO (2 at 55 E, 2 at 111.75 E, inclined at 29 degrees). |
| 2 | IRNSS covers entire India and about 5500 sq. km beyond borders | FALSE | IRNSS covers India + a region extending 1500 km beyond Indian borders (approximately 30 degrees to 130 degrees East, 30 degrees N to 50 degrees N). The '5500 sq km' figure is fictitious - it is 1500 km distance, not 5500 sq km area. |
| 3 | India will have full global coverage navigation by mid-2019 | FALSE | IRNSS/NavIC is designed as a regional system - NOT global. India has NO plans for a global system by 2019. GPS-like global coverage requires 24+ satellites; IRNSS has only 7 by design. |
Answer: (a) 1 only.
Why each option is right or wrong
- (a) CORRECT. Only Statement 1 is right - IRNSS's 3 GEO + 4 GSO constellation is well-established.
- (b) Incorrect. Statement 2 misstates the coverage as '5500 sq km' - actual is 1500 km beyond borders.
- (c) Incorrect. Statement 3 wrongly claims global coverage by 2019 - IRNSS is regional, not global.
- (d) Incorrect. Statement 1 is genuinely correct about the constellation design.
Key point
IRNSS / NavIC: 7 satellites (3 GEO + 4 GSO). Regional coverage: India + 1500 km beyond. Regional NOT global system. Renamed NavIC (Navigation with Indian Constellation) in 2016. Runs on L5 and S-band.
Remember
The Indian Regional Navigation Satellite System (IRNSS), also called NavIC, has 7 operational satellites - 3 in geostationary orbit and 4 in geosynchronous (inclined) orbits. It provides regional coverage over India and about 1500 km beyond its borders, and is NOT designed to become a global navigation system. India has no plans to make NavIC globally operational.
Common mistakes
- Confusing IRNSS/NavIC (Indian regional) with GPS (US global), Galileo (EU global), BeiDou (Chinese global) - only NavIC is regional-only.
- Assuming '5500 sq km' is coverage - the correct spec is 1500 km linear distance beyond borders.
- Believing India plans a global GNSS by 2019 - no such plan; NavIC remains regional by design and mandate.
Exam tip
Regional vs Global GNSS: GPS (24+ sats, USA), GLONASS (24 sats, Russia), Galileo (30 sats, EU), BeiDou (30+ sats, China) - all global. NavIC (7 sats, India), QZSS (7 sats, Japan) - regional.
Sources
- Indian Space Research Organisation — Indian Regional Navigation Satellite System (IRNSS) Signal in Space ICD for Standard Positioning Service
- Department of Space - Annual Report on Navigation Satellite Programme