भारत के उपग्रह प्रमोचित करने वाले वाहनों के सन्दर्भ में, निम्नलिखित कथनों पर विचार कीजिए :
- 1.PSLV से वे उपग्रह प्रमोचित किए जाते हैं जो पृथ्वी के संसाधनों के मानीटरन में उपयोगी हैं, जबकि GSLV को मुख्यतः संचार उपग्रहों को प्रमोचित करने के लिए अभिकल्पित किया गया है ।
- 2.PSLV द्वारा प्रमोचित उपग्रह आकाश में एक ही स्थिति में स्थायी रूप में स्थिर रहते प्रतीत होते हैं जैसा कि पृथ्वी के एक विशिष्ट स्थान से देखा जाता है ।
- 3.GSLV Mk III, एक चार-स्टेज वाला प्रमोचन वाहन है, जिसमें प्रथम और तृतीय चरणों में ठोस रॉकेट मोटरों का तथा द्वितीय और चतुर्थ चरणों में द्रव रॉकेट इंजनों का प्रयोग होता है ।
उपर्युक्त कथनों में से कौन-सा/से सही है/हैं ?
Read this question in English
With reference to India’s satellite launch vehicles, consider the following statements:
1. PSLVs launch the satellites useful for Earth resources monitoring whereas GSLVs are designed mainly to launch communication satellites.
2. Satellites launched by PSLV appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth.
3. GSLV Mk III is a four-staged launch vehicle with the first and third stages using solid rocket motors; and the second and fourth stages using liquid rocket engines.
Which of the statements given above is/are correct?
(a) 1 only · (b) 2 and 3 · (c) 1 and 2 · (d) 3 only
उत्तर और व्याख्या · explanation in English
Answer: (a) केवल 1
Only statement 1 is correct. PSLV is ISRO's workhorse for earth-observation (remote-sensing) satellites in low, sun-synchronous polar orbits, while GSLV's main job is communication satellites for geosynchronous transfer orbit. GSLV Mk III has three stages, not four.
- ✓ 1. Government of India's science portal says PSLV is designed mainly to deliver earth-observation or remote-sensing satellites, and VSSC says GSLV places INSAT and GSAT communication satellites into geosynchronous transfer orbit.
- ✗ 2. A satellite looks fixed in the sky only if it is in geostationary orbit, about 35,786 km up. PSLV mainly puts satellites in polar orbits at 600-900 km, which sweep across the sky.
- ✗ 3. GSLV Mk III (LVM3) is a three-stage vehicle: two solid strap-on motors (S200), a liquid core stage (L110) and a cryogenic upper stage (C25). It has no fourth stage.
- • Since then ISRO now names this rocket LVM3 (GSLV Mk III); the configuration described on ISRO's LVM3 page is the same three-stage design.
Remember · PSLV: earth-observation satellites into polar sun-synchronous orbits. GSLV: communication satellites into geostationary transfer orbit. GSLV Mk III (LVM3): three stages.
Sources
- Indigenous Launching Vehicles for Space Expedition, India Science and Technology portal (Government of India) ↗ “It is designed mainly to deliver the “earth-observation” or “remote-sensing” satellites with lift-off mass of up to about 1750 Kg to Sun-Synchronous circular polar orbits of 600-900 Km altitude.”
- GSLV, Vikram Sarabhai Space Centre (ISRO) ↗ “Geosynchronous Satellite Launch Vehicle (GSLV) is capable of placing 2.3 ton class of satellites like the INSAT & GSAT communication satellites and INRSS & IDRSS series of spacecrafts into Geosynchronous Transfer Orbit (GTO).”
- LVM3 (Geosynchronous Satellite Launch Vehicle Mk III), ISRO ↗ “LVM3 is configured as a three stage vehicle with two solid strap-on motors (S200), one liquid core stage (L110) and a high thrust cryogenic upper stage (C25).”
Question and answer: UPSC's official GS Paper I (2018, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·