UPSC Prelims 2002 Q139: Science & Technology – Space Technology & Astronomy
With reference to Indian satellites and their launchers, consider the following statements:
1. All the INSAT - series of satellites were launched abroad
2. PSLVs were used to launch IRS - series of satellites
3. India used the indigenously built cryogenic engines for the first time for powering the third
stage of GSLV
4. GSAT, launched in the year 2001, has payloads to demonstrate digital broadcasts and internet
services
Which of these statements are correct?
- (a) 1, 2, 3 and 4
- (b) 2, 3 and 4
- (c) 1, 2 and 4
- (d) 1 and 3
Answer: (c) 1, 2 and 4
Explanation
Indian satellites and launchers
| Statement | Verdict (as of 2002) |
|---|---|
| 1. All INSAT satellites were launched abroad | True — Ariane, Delta or Space Shuttle launches |
| 2. PSLVs were used to launch IRS satellites | True |
| 3. Indigenous cryogenic engine used for GSLV's third stage | False — the first GSLV (2001) used a Russian cryogenic stage |
| 4. GSAT launched in 2001 has digital broadcast and internet payloads | True — GSAT-1 on GSLV-D1 |
By 2002 all INSAT satellites had been launched by foreign vehicles, IRS satellites flew on the PSLV, and GSAT-1 (2001) tested digital broadcast and internet services. The GSLV's cryogenic stage was bought from Russia, so statement 3 fails. The answer is 1, 2 and 4.
Answer: (c) 1, 2 and 4.
Why each option is right or wrong
- (a) Incorrect. It includes statement 3, which is false.
- (b) Incorrect. It includes statement 3, which is false and leaves out statement 1.
- (c) CORRECT. Statements 1, 2 and 4 are true.
- (d) Incorrect. It includes statement 3, which is false.
Key point
Launchers: SLV, ASLV, PSLV (IRS, polar), GSLV (GSAT, geostationary); indigenous cryogenic engine first flew in 2014 (GSLV-D5).
Remember
PSLV launches IRS; GSLV launches GSAT; early cryogenic stage was Russian.
Common mistakes
- Believing the GSLV-D1 cryogenic stage was Indian-made.
- Thinking INSAT satellites were launched from India.
- Mixing the roles of the PSLV and the GSLV.
Exam tip
The cryogenic claim is the trap: the first GSLV used a Russian stage.
Sources
- ISRO — launch vehicles and satellites
- Economic Survey 2001-02