With reference to India’s satellite launch vehicle, 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?

PSLV (Polar Satellite Launch Vehicle) is primarily designed to launch earth-observation or remote-sensing satellites into Sun-Synchronous circular polar orbits at altitudes of 600-900 km.

GSLV (Geosynchronous Satellite Launch Vehicle) is mainly designed to launch communication satellites into Geosynchronous Transfer Orbit (GTO), which is a highly elliptical orbit (typically 250 x 36,000 km).

Satellites in Geosynchronous Earth Orbit (GEO), at an altitude of approximately 36,000 km, appear to remain fixed in the sky due to their geosynchronous nature. This is not the case for satellites launched by PSLV.

GSLV Mk III is a three-stage heavy-lift launch vehicle. It consists of two solid strap-ons, a core liquid booster, and a cryogenic upper stage.

Statement 1 is correct. Statements 2 and 3 are not correct. Hence, only statement 1 is correct.

Sources:

• The Hindu - Difference between GSLV and PSLV
• ISRO - GSLV MK-3